UPGRADING OF HEAVY OIL OR HEAVY OIL-DERIVED PRODUCT WITH IONIC LIQUIDS

Abstract

Processes for upgrading a heavy oil or heavy oil-derived feedstock in presence of an ionic liquid are described, and can improve the heavy oil or heavy oil-derived properties such as viscosity and composition, and reduced contaminant content, such as a reduced Total Acid Number (TAN) and a reduced heavy metal content. Processes for upgrading heavy oil or heavy oil-derived in presence of an ionic liquid can include a catalytic cracking treatment carried out under catalytic cracking conditions, and/or a non-catalytic treatment, as well as various separation steps to separate the ionic liquid or a diluent if present in the feedstock. The ionic liquids that can be used in the context of the processes described herein include ionic liquids that are feed-miscible or feed-immiscible.

Description

RELATED PATENT APPLICATION

The present application claims priority from Canadian patent application no. 3.074.850 filed Mar. 5, 2020, the disclosure of which is hereby incorporated by reference in its entirety.

TECHNICAL FIELD

The technical field generally relates to the treatment of heavy oil or heavy oil-derived products, and more particularly to the upgrading of heavy oil, such as bitumen, or heavy-oil derived products using ionic liquids.

BACKGROUND

Heavy oil, including extra heavy oil such as bitumen, found in underground reservoirs or recovered therefrom by mining operations or by in situ recovery processes generally have a high viscosity. This high viscosity can make difficult the pipeline transportation of heavy oil and bitumen in particular. Various methods exist to decrease heavy oil viscosity and increase suitability for pipeline transportation, although such methods have various drawbacks. Furthermore, heavy oil generally also includes undesirable components, such as sulphur, naphthenic acids and heavy metals.

Heavy oil upgrader facilities of various designs can upgrade the heavy oil to produce less viscous products and to remove undesirable components. However, conventional upgrader facilities have high associated capital and operating costs. In addition, in some conventional upgrading methods such as severe thermal cracking, hydrogen originally present in the heavy oil is lost to the gas phase such that, in the absence of added hydrogen, significant yet undesirable olefin production can occur.

Another option to improve heavy oil viscosity, such as bitumen, is to dilute the bitumen, for example with naphtha or natural gas condensate as a diluent. Diluted bitumen is often referred to as “dilbit”. While bitumen dilution does not have the same capital cost penalty as a bitumen upgrader facility, it still has high associated operating costs. For example, since dilbit includes a significant volume of diluent (e.g., one third diluent and two thirds bitumen per barrel of diluted bitumen), significant pipeline capacity is therefore taken up by the diluent for pipelining of the dilbit as well as the return pipelining of separated diluent to be reused in bitumen dilution.

The less viscous products that are obtained from heavy oil upgrading are further treated to provide fractions of different boiling point, e.g., by distillation. These fractions, which can include atmospheric gas oil, naphtha, heavy vacuum gas oil or light vacuum gas oil for instance, can themselves be upgraded into lighter products for example using hydrocracking, which can be expensive and can present some challenges. Moreover, the material left over after distillation, commonly referred to as “residuum”, can itself be upgraded to recover additional lighter products.

Various challenges still exist with regard to heavy oil and heavy oil-derived upgrading processes and these processes can benefit from alternative technologies.

SUMMARY

In accordance with an aspect, there is provided a process for treating a heavy oil or heavy oil-derived feedstock. The process includes contacting an acidic ionic liquid catalyst with the feedstock to obtain an ionic liquid-feedstock mixture; subjecting the ionic liquid-feedstock mixture to a catalytic cracking treatment, the catalytic cracking treatment including heating the ionic liquid-feedstock mixture under catalytic cracking conditions to obtain an ionic liquid-cracked feedstock mixture; and separating the acidic ionic liquid catalyst from the ionic liquid-cracked feedstock mixture to obtain a cracked product and a recovered acidic ionic liquid catalyst.

In some implementations, the feedstock includes bitumen.

In some implementations, the feedstock includes a diluent-depleted bitumen stream from a distillation unit, a diluent stripping unit or a diluent recovery unit.

In some implementations, the feedstock includes a diluent-depleted bitumen stream that is obtained from a bitumen froth treatment operation.

In some implementations, the feedstock includes a diluent-depleted bitumen stream that has not been subjected to fractionation or distillation prior to being contacted with the acidic ionic liquid catalyst.

In some implementations, the feedstock includes a residuum stream from a distillation tower that has been operated to remove light hydrocarbon components.

In some implementations, the feedstock includes a bitumen stream that is obtained from an in situ recovery operation or from surface mining operations.

In some implementations, the feedstock includes an overhead distillate product from a distillation tower.

In some implementations, the feedstock includes naphtha, atmospheric gas oil, light vacuum gas oil, heavy vacuum gas oil or any combination thereof.

In some implementations, the process further includes subjecting the feedstock to a pre-treatment prior to the contacting of the feedstock with the acidic ionic liquid catalyst.

In some implementations, the pre-treatment includes heating the feedstock at a pre-treatment temperature.

In some implementations, the pre-treatment temperature is sufficient to reduce viscosity of the feedstock.

In some implementations, the pre-treatment includes adding a diluent to the feedstock.

In some implementations, the diluent includes at least one of a naphthenic solvent, an aromatic hydrocarbon, and a non-deasphalting organic solvent.

In some implementations, the diluent includes toluene.

In some implementations, the feedstock includes bitumen and a diluent.

In some implementations, the process further includes recovering the diluent to obtain a recovered diluent.

In some implementations, recovering the diluent is performed after the catalytic cracking treatment of the ionic liquid-feedstock mixture under catalytic cracking conditions and before separating the acidic ionic liquid catalyst from the ionic liquid-cracked feedstock mixture.

In some implementations, recovering the diluent is performed after separating the acidic ionic liquid catalyst from the ionic liquid-cracked feedstock mixture.

In some implementations, recovering the diluent includes evaporating the diluent from the ionic liquid-cracked feedstock mixture or the cracked product.

In some implementations, the process further includes contacting at least a portion of the recovered diluent with the feedstock.

In some implementations, the recovered acidic ionic liquid catalyst is reused as part of the acidic ionic liquid catalyst that contacts the feedstock.

In some implementations, separating the acidic ionic liquid catalyst from the ionic liquid-cracked feedstock mixture includes a liquid-liquid extraction of the ionic liquid-cracked feedstock mixture.

In some implementations, the liquid-liquid extraction of the ionic liquid-cracked feedstock mixture includes washing the ionic liquid-cracked feedstock mixture with water.

In some implementations, the acidic ionic liquid catalyst is a Lewis acidic ionic liquid catalyst including a Lewis acidic anion and a cation selected from the group consisting of 1,3-dialkylimidazolium cations, tetraalkylphosphonium cations, tetraalkylammonium cations, trialkylammonium cations and combinations thereof.

In some implementations, the Lewis acidic ionic liquid catalyst includes a Lewis acidic anion and a 1-alkyl-3-methylimidazolium cation.

In some implementations, the 1-alkyl-3-methylimidazolium cation is selected from the group consisting of 1-ethyl-3-methylimidazolium (EMIM) and 1-n-butyl-3-methylimidazolium (BMIM).

In some implementations, the Lewis acidic ionic liquid catalyst includes a Lewis acidic anion and a trialkylammonium cation.

In some implementations, the trialkylammonium cation includes triethylammonium.

In some implementations, the Lewis acidic anion is a chlorometallate anion.

In some implementations, the chlorometallate anion is selected from the group consisting of AlCl₄⁻, Al₂Cl₇⁻, FeCl₄⁻ and Fe₂Cl₇⁻.

In some implementations, the Lewis acidic ionic liquid is selected from the group consisting of [EMIM][AlCl₄], [BMIM][AlCl₄], [EMIM][FeCl₄], [BMIM][FeCl₄].

In some implementations, the Lewis acidic ionic liquid is [EMIM][AlCl₄].

In some implementations, the Lewis acidic ionic liquid includes a metal ion-modified ionic liquid.

In some implementations, the metal ion-modified ionic liquid is selected from the group consisting of [Et₃NH][AlCl₄]—Ni²⁺, [EMIM][AlCl₄]—Ni²⁺, [BMIM][AlCl₄]—Ni²⁺, [Et₃NH][AlCl₄]—Fe²⁺, [EMIM][AlCl₄]—Fe²⁺, [BMIM][AlCl₄]—Fe²⁺ and combinations thereof.

In some implementations, the acidic ionic liquid catalyst is a strong Lewis acidic ionic liquid.

In some implementations, the strong Lewis acidic ionic liquid includes a Group(III)halometallate with a mole fraction χ_MXn above 0.5.

In some implementations, the strong Lewis acidic ionic liquid includes a Group(III)halometallate with a Gutmman Acceptor Number (AN) above 90.

In some implementations, the strong Lewis acidic ionic liquid includes a haloaluminate or a halogallate ionic liquid, with a mole fraction χ_MXn above 0.5.

In some implementations, the mole fraction χ_MXn is from about 0.6 to about 0.75.

In some implementations, the strong Lewis acidic ionic liquid includes a chloroaluminate ionic liquid with a mole fraction χ_AlCl3 from about 0.6 to about 0.75 or a chlorogallate with a mole fraction χ_GaCl3 above 0.5 to about 0.75.

In some implementations, the strong Lewis acidic ionic liquid includes a chloroaluminate ionic liquid with a mole fraction χ_AlCl3 from about 0.6 to about 0.7.

In some implementations, the strong Lewis acidic ionic liquid includes a cation selected from the group consisting of 1,3-dialkylimidazolium cations, tetraalkylphosphonium cations, tetraalkylammonium cations, trialkylammonium cations, and combinations thereof.

In some implementations, the strong Lewis acidic ionic liquid includes a cation selected from the group consisting of 1-ethyl-3-methylimidazolium (EMIM), 1-n-butyl-3-methylimidazolium (BMIM), triethylammonium (HN₂₂₂) and combinations thereof.

In some implementations, the strong Lewis acidic ionic liquid includes [EMIM][Al₂Cl₇], [BMIM][Al₂Cl₇], [EMIM][Ga₂Cl₇], [BMIM][Ga₂Cl₇], [EMIM][Ga₃Cl₁₀], [BMIM][Ga₃Cl₁₀], [HN₂₂₂][Al₂Cl₇], [HN₂₂₂][Ga₂Cl₇], [HN₂₂₂][Ga₃Cl₁₀] or any combinations thereof.

In some implementations, the strong Lewis acidic ionic liquid includes [HN₂₂₂][Al₂Cl₇], [HN₂₂₂][Ga₂Cl₇], [HN₂₂₂][Ga₃Cl₁₀] or any combinations thereof.

In some implementations, the acidic ionic liquid catalyst is a Bronsted acidic ionic liquid catalyst.

In some implementations, the Bronsted acidic ionic liquid catalyst includes a protonated imidazolium cation, a protonated C_1-nalkyl-substituted imidazolium cation, a protonated tri(C_1-nalkyl)ammonium cation, a protonated pyridinium cation, a guanidinium cation, a protonated C_1-nalkyl-substituted guanidinium cation, a protonated pyrrolidinium cation, a protonated N—C_1-nalkyl-pyrrolidinium cation, a protonated ammonium cation, a protonated tri(C_1-nalkyl)ammonium cation, a COOH-bearing imidazolium cation or a SO₃H-bearing imidazolium cation, where in the C_1-nalkyl group, n is an integer from 2 to 20.

In some implementations, the Bronsted acidic ionic liquid catalyst includes a cation selected from the group consisting of

where R can represent a C_1-n alkyl group with n from 2 to 20.

In some implementations, the Bronsted acidic ionic liquid catalyst includes an anion selected from the group consisting of [(HSO₄)(H₂SO₄)_x]⁻ with x=0 or 1 and [H₂PO₄]⁻.

In some implementations, the Bronsted acidic ionic liquids includes Triethylammonium hydrogen sulfate [HN₂₂₂][(HSO₄)(H₂SO₄)_x] with x=0 or 1, N-methylpyrrolidinium hydrogen sulfate [Hmpyr][(HSO₄)(H₂SO₄)_x] with x=0 or 1, or any combination thereof.

In some implementations, the acidic ionic liquid catalyst includes a combination of a Lewis acidic ionic liquid and a Bronsted acidic ionic liquid catalyst. In some implementations, the Lewis acidic ionic liquid and the Bronsted acidic ionic liquid in the combination are as defined herein.

In some implementations, the acidic ionic liquid catalyst includes a combination of at least one strong Lewis acidic ionic liquid and a Bronsted acidic ionic liquid catalyst. In some implementations, the strong Lewis acidic ionic liquid and the Bronsted acidic ionic liquid in the combination are as defined herein.

In some implementations, the heating is performed at a temperature between about 50° C. and about 250° C.

In some implementations, the concentration of the acidic ionic liquid catalyst in the ionic liquid-bitumen mixture is between about 5 wt % and about 50 wt %.

In accordance with another aspect, there is provided a process for upgrading a heavy oil or heavy oil-derived feedstock. The process includes contacting the feedstock with a feed-miscible ionic liquid to obtain an ionic liquid-feedstock mixture; and subjecting the ionic liquid-feedstock mixture to a non-catalytic treatment, the non-catalytic treatment including mixing the ionic liquid-feedstock mixture at a mixing temperature below an asphaltene aggregation temperature of the ionic liquid-feedstock mixture to obtain a treated ionic liquid-feedstock mixture; wherein at least one of a Total Acid Number (TAN) of the treated ionic liquid-feedstock mixture, a viscosity of the treated ionic liquid-feedstock mixture and an asphaltene content of the treated ionic liquid-feedstock mixture is reduced compared to the feedstock.

In some implementations, the feedstock includes bitumen.

In some implementations, the feedstock includes diluent-depleted bitumen stream from a distillation unit, a diluent stripping unit or a diluent recovery unit.

In some implementations, the feedstock includes a diluent-depleted bitumen stream that is obtained from a bitumen froth treatment operation.

In some implementations, the feedstock includes a diluent-depleted bitumen stream that has not been subjected to fractionation or distillation prior to being contacted with the feed-miscible ionic liquid.

In some implementations, the feedstock includes a residuum stream from a distillation tower that has been operated to remove light hydrocarbon components.

In some implementations, the feedstock includes a bitumen stream that is obtained from an in situ recovery operation or from surface mining operations.

In some implementations, the process further includes subjecting the feedstock to a pre-treatment prior to the contacting of the feedstock with the feed-miscible ionic liquid.

In some implementations, the pre-treatment includes heating the feedstock at a pre-treatment temperature.

In some implementations, the pre-treatment temperature is sufficient to reduce viscosity of the feedstock.

In some implementations, the pre-treatment includes adding a diluent to the feedstock.

In some implementations, the diluent includes at least one of a naphthenic solvent, an aromatic hydrocarbon, and a non-deasphalting organic solvent.

In some implementations, the diluent includes toluene.

In some implementations, the feedstock includes bitumen and a diluent.

In some implementations, the process further includes recovering the diluent to obtain a recovered diluent.

In some implementations, the process further includes separating the feed-miscible ionic liquid from the treated ionic liquid-feedstock mixture to obtain a recovered feed-miscible ionic liquid and a treated product.

In some implementations, recovering the diluent is performed after the non-catalytic treatment of the ionic liquid-feedstock mixture and before separating the feed-miscible ionic liquid from the treated ionic liquid-feedstock mixture.

In some implementations, recovering the diluent is performed after separating the feed-miscible ionic liquid from the treated ionic liquid-feedstock mixture.

In some implementations, recovering the diluent includes evaporating the diluent from the treated ionic liquid-feedstock mixture or from the treated product.

In some implementations, the process further includes contacting at least a portion of the recovered diluent with the feedstock.

In some implementations, the recovered feed-miscible ionic liquid is reused as part of the feed-miscible ionic liquid that contacts the feedstock.

In some implementations, the feed-miscible ionic liquid includes a carbamate ionic liquid, a phosphonium ionic liquid, a fatty acid-based ionic liquid including a trialkylammonium cation and combinations thereof.

In some implementations, the carbamate ionic liquid includes N, N′-dipropylammonium, N, N′-dipropyl carbamate (DPCARB) or N, N′-dibenzylammonium, N, N′-dibenzyl carbamate (DBCARB), and combinations thereof.

In some implementations, the phosphonium ionic liquid includes trihexyl-tetradecylphosphonium dicyanamide.

In some implementations, the fatty acid-based ionic liquid includes Trioctylammonium hexanoate [HN₈₈₈][Hexanoate], Trioctylammonium oleate [HN₈₈₈][Oleate] or a combination thereof.

In some implementations, the non-catalytic treatment further includes heating the ionic liquid-feedstock mixture at a heating temperature below the mixing temperature.

In some implementations, the heating temperature is between about 20° C. and about 120° C.

In some implementations, the heating is performed near atmospheric pressure.

In some implementations, the concentration of the feed-miscible ionic liquid in the ionic liquid-feedstock mixture is between about 5 wt % and about 50 wt %.

In accordance with another aspect, there is provided a process for upgrading a feedstock including a heavy oil or heavy oil-derived product and a diluent. The process includes contacting the feedstock with a feed-immiscible ionic liquid to obtain an ionic liquid-feedstock mixture; and subjecting the ionic liquid-feedstock mixture to a non-catalytic treatment, the non-catalytic treatment including mixing the ionic liquid-feedstock mixture to obtain a treated ionic liquid-feedstock mixture; wherein at least one of a Total Acid Number (TAN) of the treated ionic liquid-feedstock mixture and a heavy metal content of the treated ionic liquid-feedstock mixture is reduced compared to the feedstock.

In some implementations, the feedstock includes bitumen.

In some implementations, the feedstock includes a bitumen stream that is obtained from an in situ recovery operation or from surface mining operations.

In some implementations, the feedstock includes bitumen and the proportion of the bitumen relative to the feed-immiscible ionic liquid is between about 1:2 w/w and about 1:1 w/w.

In some implementations, the feedstock includes a residuum stream from a distillation tower that has been operated to remove light hydrocarbon components.

In some implementations, the diluent is selected from the group consisting of a naphthenic diluent, toluene and a mixture thereof.

In some implementations, the process further includes subjecting the treated ionic liquid-feedstock mixture to a liquid-liquid separation to obtain a first phase including a treated feedstock and the diluent and a second phase including a recovered feed-immiscible ionic liquid.

In some implementations, the process further includes separating the first phase to recover the diluent as a recovered diluent, and to obtain a treated product.

In some implementations, recovering the diluent includes evaporating the diluent to obtain the treated product.

In some implementations, the process further includes contacting at least a portion of the recovered diluent with the feedstock.

In some implementations, the recovered feed-immiscible ionic liquid is reused as part of the feed-immiscible ionic liquid that contacts the feedstock.

In some implementations, the feed-immiscible ionic liquid includes an amino acid based ionic liquid, an imidazolium ionic liquid, a phosphonium ionic liquid, a carbamate ionic liquid, and combinations thereof.

In some implementations, the amino acid ionic liquid includes tetraethylammonium β-alaninate, 1-ethyl-3-methylimidazolium glycinate, and combinations thereof.

In some implementations, the imidazolium ionic liquid includes 1-ethyl-3-methylimidazolium ethyl sulphate, 1-butyl-3-methylimidazolium tetrafluoroborate, 1-ethyl-3-methylimidazolium tetrafluoroborate, and combinations thereof.

In some implementations, the phosphonium ionic liquid includes tributyl-methylphosphonium methyl sulphate.

In some implementations, the carbamate ionic liquid includes N, N′-dimethylammonium, N, N′-dimethylcarbamate (DMCARB).

In some implementations, the non-catalytic treatment further includes heating the ionic liquid-feedstock mixture at a heating temperature.

In some implementations, the heating temperature is between about 40° C. and about 70° C.

In some implementations, the concentration of the feed-immiscible ionic liquid in the ionic liquid-feedstock mixture is between about 5 wt % and about 50 wt %.

In some implementations, the heavy metal content includes at least one of a nickel content, an iron content and a vanadium content.

In accordance with another aspect, there is provided a process for upgrading a feedstock including a heavy oil or heavy oil-derived product and a diluent. The process includes contacting the feedstock with an ionic liquid to obtain an ionic liquid-feedstock mixture; mixing the ionic liquid-feedstock mixture at a mixing temperature; and separating the ionic liquid-feedstock mixture to obtain a first phase including a treated feedstock and the diluent and a second phase including a recovered ionic liquid; wherein the treated feedstock has a reduced heavy metal content compared to the feedstock.

In some implementations, the feedstock includes bitumen.

In some implementations, the feedstock includes a bitumen stream that is obtained from an in situ recovery operation or from surface mining operations.

In some implementations, the feedstock includes bitumen and the proportion of the bitumen relative to the ionic liquid is between about 1:2 w/w and about 1:1 w/w.

In some implementations, the feedstock includes a residuum stream from a distillation tower that has been operated to remove light hydrocarbon components.

In some implementations, the diluent is selected from the group consisting of a naphthenic diluent, toluene and a mixture thereof.

In some implementations, the ionic liquid is a feed-immiscible ionic liquid, and the first phase and the second phase are obtained by subjecting the ionic liquid-feedstock mixture to a liquid-liquid separation.

In some implementations, the process further includes separating the first phase to recover the diluent as a recovered diluent, and to obtain a treated product.

In some implementations, recovering the diluent includes evaporating the diluent to obtain the treated product.

In some implementations, the process further includes contacting at least a portion of the recovered diluent with the feedstock.

In some implementations, the recovered ionic liquid is reused as part of the ionic liquid that contacts the feedstock.

In some implementations, the ionic liquid includes an amino acid based ionic liquid, an imidazolium ionic liquid, a phosphonium ionic liquid, a carbamate ionic liquid, and combinations thereof.

In some implementations, the amino acid ionic liquid includes tetraethylammonium β-alaninate, 1-ethyl-3-methylimidazolium glycinate, and combinations thereof.

In some implementations, the imidazolium ionic liquid includes 1-ethyl-3-methylimidazolium ethyl sulphate, 1-butyl-3-methylimidazolium tetrafluoroborate, 1-ethyl-3-methylimidazolium tetrafluoroborate, and combinations thereof.

In some implementations, the phosphonium ionic liquid includes tributyl-methylphosphonium methyl sulphate.

In some implementations, the carbamate ionic liquid includes N, N′-dimethylammonium, N, N′-dimethylcarbamate (DMCARB).

In some implementations, the process further includes heating the ionic liquid-feedstock mixture at a heating temperature.

In some implementations, the heating temperature is between about 40° C. and about 70° C.

In some implementations, the concentration of the ionic liquid in the ionic liquid-feedstock mixture is between about 5 wt % and about 50 wt %.

In some implementations, the heavy metal content includes at least one of a nickel content, an iron content, and a vanadium content.

In accordance with another aspect, there is provided a process for upgrading a feedstock including heavy oil or heavy oil-derived product and a diluent. The process includes contacting the feedstock with an amino acid ionic liquid to obtain an ionic liquid-feedstock mixture; mixing the ionic liquid-feedstock mixture at a mixing temperature; and separating the ionic liquid-feedstock mixture to obtain a first phase including a treated feedstock and the diluent and a second phase including a recovered amino acid ionic liquid; wherein the Total Acid Number (TAN) of the treated feedstock is reduced compared to the TAN of the feedstock.

In some implementations, the feedstock includes bitumen.

In some implementations, the feedstock includes a bitumen stream that is obtained from an in situ recovery operation or from surface mining operations.

In some implementations, the feedstock includes bitumen and the proportion of the bitumen relative to the amino acid ionic liquid is between about 1:2 w/w and about 1:1 w/w.

In some implementations, the feedstock includes a residuum stream from a distillation tower that has been operated to remove light hydrocarbon components.

In some implementations, the diluent is selected from the group consisting of a naphthenic diluent, toluene and a mixture thereof.

In some implementations, the first phase and the second phase are obtained by subjecting the ionic liquid-feedstock mixture to a liquid-liquid separation.

In some implementations, the process further includes separating the first phase to recover the diluent as a recovered diluent, and to obtain a treated product.

In some implementations, recovering the diluent includes evaporating the diluent to obtain the treated product.

In some implementations, the process further includes contacting at least a portion of the recovered diluent with the feedstock.

In some implementations, the recovered amino acid ionic liquid is reused as part of the amino acid ionic liquid that contacts the feedstock.

In some implementations, the amino acid ionic liquid includes tetraethylammonium β-alaninate, 1-ethyl-3-methylimidazolium glycinate, and combinations thereof.

In some implementations, the process further includes heating the ionic liquid-feedstock mixture at a heating temperature.

In some implementations, the heating temperature is between about 40° C. and about 70° C.

In some implementations, the concentration of the amino acid ionic liquid in the ionic liquid-bitumen mixture is between about 5 wt % and about 50 wt %.

In accordance with another aspect, there is provided a process for upgrading a heavy oil or heavy oil-derived feedstock. The process includes contacting a first ionic liquid catalyst with the feedstock to obtain a first ionic liquid-feedstock mixture; subjecting the first ionic liquid-feedstock mixture to a catalytic cracking treatment, the catalytic cracking treatment including heating the first ionic liquid-feedstock mixture under catalytic cracking conditions to obtain an ionic liquid-cracked feedstock mixture; contacting the ionic liquid-cracked feedstock mixture with a second ionic liquid to obtain a second ionic liquid-feedstock mixture; and subjecting the second ionic liquid-feedstock mixture to a non-catalytic treatment, the non-catalytic treatment including mixing the second ionic liquid-feedstock mixture to obtain a treated ionic liquid-feedstock mixture.

In some implementations, the process further includes separating the first ionic liquid catalyst from the ionic liquid-cracked feedstock mixture to obtain a recovered first ionic liquid catalyst.

In some implementations, the recovered first ionic liquid is reused as part of the first ionic liquid that contacts the feedstock.

In some implementations, the process further includes separating the second ionic liquid from the treated ionic liquid-feedstock mixture to obtain a recovered second ionic liquid.

In some implementations, the recovered second ionic liquid is reused as part of the second ionic liquid that contacts the ionic liquid-cracked feedstock mixture.

In some implementations, the feedstock includes bitumen.

In some implementations, the feedstock includes a diluent-depleted bitumen stream from a bitumen froth treatment operation or from a distillation unit, a diluent stripping unit or a diluent recovery unit.

In some implementations, the feedstock includes a diluent-depleted bitumen stream that has not been subjected to fractionation or distillation prior to being contacted with the acidic ionic liquid catalyst.

In some implementations, the feedstock includes a residuum stream from a distillation tower that has been operated to remove light hydrocarbon components.

In some implementations, the feedstock includes a bitumen stream that is obtained from an in situ recovery operation or from surface mining operations.

In some implementations, the feedstock includes naphtha, atmospheric gas oil, light vacuum gas oil, heavy vacuum gas oil or any combination thereof.

In some implementations, the process further includes adding a diluent to the feedstock or to the second ionic liquid-feedstock mixture.

In some implementations, the process further includes subjecting the feedstock to a pre-treatment prior to the contacting of the feedstock with the first ionic liquid catalyst.

In some implementations, the pre-treatment includes heating the feedstock at a pre-treatment temperature.

In some implementations, the pre-treatment temperature is sufficient to reduce viscosity of the feedstock.

In some implementations, the pre-treatment includes adding a diluent to the feedstock.

In some implementations, the diluent includes at least one of a naphthenic solvent, an aromatic hydrocarbon, and a non-deasphalting organic solvent.

In some implementations, the diluent includes toluene.

In some implementations, the feedstock includes bitumen and a diluent.

In some implementations, the process further includes recovering the diluent following the non-catalytic treatment to obtain a recovered diluent.

In some implementations, the process further includes contacting at least a portion of the recovered diluent with the feedstock or the second ionic liquid-feedstock mixture.

In some implementations, the first ionic liquid catalyst includes an acidic ionic liquid catalyst.

In some implementations, the acidic ionic liquid catalyst is a Lewis acidic ionic liquid including a Lewis acidic anion and a cation selected from the group consisting of 1,3-dialkylimidazolium cations, tetraalkylphosphonium cations, tetraalkylammonium cations, trialkylammonium cations and combinations thereof.

In some implementations, the Lewis acidic ionic liquid catalyst includes a Lewis acidic anion and a 1-alkyl-3-methylimidazolium cation.

In some implementations, the 1-alkyl-3-methylimidazolium cation is selected from the group consisting of 1-ethyl-3-methylimidazolium (EMIM) and 1-n-butyl-3-methylimidazolium (BMIM).

In some implementations, the Lewis acidic ionic liquid catalyst includes a Lewis acidic anion and a trialkylammonium cation.

In some implementations, the trialkylammonium cation includes triethylammonium.

In some implementations, the Lewis acidic anion is a chlorometallate anion.

In some implementations, the chlorometallate anion is selected from the group consisting of AlCl₄⁻, Al₂Cl₇⁻, FeCl₄⁻ and Fe₂Cl₇⁻.

In some implementations, the Lewis acidic ionic liquid is selected from the group consisting of [EMIM][AlCl₄], [BMIM][AlCl₄], [EMIM][FeCl₄], [BMIM][FeCl₄].

In some implementations, the Lewis acidic ionic liquid is [EMIM][AlCl₄].

In some implementations, the Lewis acidic ionic liquid includes a metal ion-modified ionic liquid.

In some implementations, the metal ion-modified ionic liquid is selected from the group consisting of [Et₃NH][AlCl₄]—Ni²⁺, [EMIM][AlCl₄]—Ni²⁺, [BMIM][AlCl₄]—Ni²⁺, [Et₃NH][AlCl₄]—Fe²⁺, [EMIM][AlCl₄]—Fe²⁺, [BMIM][AlCl₄]—Fe²⁺ and combinations thereof.

In some implementations, the acidic ionic liquid catalyst is a strong Lewis acidic ionic liquid.

In some implementations, the strong Lewis acidic ionic liquid is as defined herein.

In some implementations, the second ionic liquid is a feed-miscible ionic liquid.

In some implementations, the feed-miscible ionic liquid includes a carbamate ionic liquid, a phosphonium ionic liquid, a fatty acid-based ionic liquid including a trialkylammonium cation or any combination thereof.

In some implementations, the carbamate ionic liquid includes N, N′-dipropylammonium, N, N′-dipropyl carbamate (DPCARB) or N, N′-dibenzylammonium, N, N′-dibenzyl carbamate (DBCARB), and combinations thereof.

In some implementations, the phosphonium ionic liquid includes trihexyl-tetradecylphosphonium dicyanamide.

In some implementations, the fatty acid-based ionic liquid includes Trioctylammonium hexanoate [HN₈₈₈][Hexanoate], Trioctylammonium oleate [HN₈₈₈][Oleate] or a combination thereof.

In some implementations, the second ionic liquid is a feed-immiscible ionic liquid.

In some implementations, the feed-immiscible ionic liquid includes an amino acid based ionic liquid, an imidazolium ionic liquid, a phosphonium ionic liquid, a carbamate ionic liquid, and combinations thereof.

In some implementations, the amino acid ionic liquid includes tetraethylammonium β-alaninate, 1-ethyl-3-methylimidazolium glycinate, and combinations thereof.

In some implementations, the imidazolium ionic liquid includes 1-ethyl-3-methylimidazolium ethyl sulphate, 1-butyl-3-methylimidazolium tetrafluoroborate, 1-ethyl-3-methylimidazolium tetrafluoroborate, and combinations thereof.

In some implementations, the phosphonium ionic liquid includes tributyl-methylphosphonium methyl sulphate.

In some implementations, the carbamate ionic liquid includes N, N′-dimethylammonium, N, N′-dimethylcarbamate (DMCARB).

In some implementations, at least one of a Total Acid Number (TAN), a viscosity, a heavy metal content, and an asphaltene content of the treated ionic liquid-feedstock mixture is reduced compared to the feedstock.

In some implementations, the heavy metal content includes at least one of a nickel content, an iron content, and a vanadium content.

In accordance with another aspect, there is provided a process for upgrading a heavy oil or a heavy oil-derived feedstock. The process includes providing a mixture of the feedstock and a catalyst including at least one strong Lewis acidic ionic liquid, and subjecting the mixture to a catalytic cracking treatment, wherein the catalytic cracking treatment is performed at a temperature that is lower compared to a temperature at which is conducted a conventional cracking process.

In some implementations, the temperature of the catalytic cracking treatment is from about 50° C. to about 250° C.

In some implementations, the temperature of the catalytic cracking treatment is from about 100° C. to about 200° C.

In some implementations, the temperature of the catalytic cracking treatment is from about 100° C. to about 150° C.

In some implementations, the feedstock includes bitumen.

In some implementations, the feedstock includes a diluent-depleted bitumen stream from a distillation unit, a diluent stripping unit or a diluent recovery unit.

In some implementations, the feedstock includes a diluent-depleted bitumen stream that is obtained from a bitumen froth treatment operation.

In some implementations, the feedstock includes a diluent-depleted bitumen stream that has not been subjected to fractionation or distillation prior to being contacted with the catalyst.

In some implementations, the feedstock includes a residuum stream from a distillation tower that has been operated to remove light hydrocarbon components.

In some implementations, the feedstock includes a bitumen stream that is obtained from an in situ recovery operation or from surface mining operations.

In some implementations, the feedstock includes an overhead distillate product from a distillation tower.

In some implementations, the feedstock includes naphtha, atmospheric gas oil, light vacuum gas oil, heavy vacuum gas oil or any combination thereof.

In some implementations, the process further includes subjecting the feedstock to a pre-treatment prior to the catalytic treatment.

In some implementations, the pre-treatment includes heating the feedstock at a pre-treatment temperature.

In some implementations, the pre-treatment includes adding a diluent to the feedstock.

In some implementations, the diluent includes at least one of a naphthenic solvent, an aromatic hydrocarbon, and a non-deasphalting organic solvent.

In some implementations, the diluent includes toluene.

In some implementations, the strong Lewis acidic ionic liquid is as defined herein.

In some implementations, the catalyst further includes a Bronsted acidic ionic liquid catalyst.

In some implementations, the Bronsted acidic ionic liquid catalyst is as defined herein.

In some implementations, the catalyst is present in the mixture at a concentration between about 5 wt % and about 50 wt %.

In accordance with another aspect, there is provided a process for recovering a partially upgraded heavy oil from a subsurface reservoir provided with at least one well. The includes injecting an upgrading fluid including at least one ionic liquid through the well into the reservoir; and producing the partially upgraded heavy oil from the reservoir.

In some implementations, the subsurface reservoir is provided with at least one well pair, the at least one well forming an injection well and the well pair further including a production well positioned below and substantially parallel to the injection well, and wherein the partially upgraded heavy oil is produced from the production well.

In some implementations, the upgrading fluid further includes a carrier fluid.

In some implementations, the upgrading fluid includes steam and the upgrading fluid is injected at a temperature from about 150° C. to about 300° C.

In some implementations, injecting the upgrading fluid includes co-injecting steam and the ionic liquid into the reservoir.

In some implementations, injecting the upgrading fluid includes injecting slugs of the ionic liquid at regular or irregular time intervals while continuously injecting steam into the reservoir.

In some implementations, the process includes a SAGD, CSS or LASER recovery operation.

In some implementations, the process includes a late-life steamflood operation.

In some implementations, the late-life steamflood operation is performed after a SAGD or CSS operation.

In some implementations, the upgrading fluid includes steam and a solvent and the process includes an ES-SAGD operation.

In some implementations, the upgrading fluid includes at least one solvent and the process includes a solvent assisted recovery operation.

In some implementations, the upgrading fluid is injected continuously.

In some implementations, injecting the upgrading fluid includes injecting slugs of the upgrading fluid.

In some implementations, injecting the upgrading fluid includes injecting slugs of the ionic liquid at regular or irregular time intervals while continuously injecting the solvent.

In some implementations, injecting the upgrading fluid includes injecting a heated upgrading fluid into the reservoir.

In some implementations, the heated upgrading fluid is obtained by co-injecting steam with the upgrading fluid or by heating the upgrading fluid with an electric resistive heater.

In some implementations, injecting the upgrading fluid includes injecting a superheated upgrading fluid into the reservoir.

In some implementations, the solvent includes at least one C3-C7 alkane.

In some implementations, the upgrading fluid further includes at least one hydrogen donor compound.

In some implementations, the hydrogen donor compound is selected from the group consisting of low-carbon number alkanes, alcohols, glycerol, formic acid, decalin, tetralin and mixtures thereof.

In some implementations, the upgrading fluid includes water, steam, a solvent or any mixture thereof and the upgrading fluid is heated using electromagnetic radiations in the reservoir.

In some implementations, the electromagnetic radiations include radio frequency waves.

In some implementations, the upgrading fluid includes water and the ionic liquid is present in the upgrading fluid at a concentration of about 50 wt % or less.

In some implementations, the upgrading fluid includes a polar solvent.

In some implementations, the upgrading fluid includes more than 50 wt % of solvent.

In some implementations, the upgrading fluid includes hot water and the process includes a late-life hot waterflood operation.

In some implementations, the upgrading fluid includes cold water.

In some implementations, injecting the upgrading fluid is performed in a hot reservoir.

In some implementations, the process includes a heat recovery operation and injecting the upgrading fluid is performed at an early stage of the heat recovery operation.

In some implementations, injecting the upgrading fluid is performed during a startup phase of a recovery operation and at a pressure of up to about 11 MPa.

In some implementations, injecting the upgrading fluid is performed during a production phase of a recovery operation and at a pressure of about 2 MPa or less. In some implementations, the pressure is about 1.5 MPa or less.

In some implementations, the ionic liquid includes a heavy oil-miscible ionic liquid.

In some implementations, the ionic liquid includes an acidic ionic liquid.

In some implementations, the acidic ionic liquid is as defined herein. In some implementations, the acidic ionic liquid and can include a Lewis acidic ionic liquid as defined herein, a Bronsted acid ionic liquid as defined herein, a strong Lewis acidic ionic liquid as defined herein or any combination thereof.

In some implementations, the heavy oil includes bitumen.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a flowchart of a general flow diagram for treating a bitumen feedstock including a catalytic cracking treatment followed by an ionic liquid separation, wherein various bitumen recovery processes are shown.

FIG. 2 is a flowchart of a general flow diagram for treating a bitumen feedstock including a non-catalytic treatment followed by an ionic liquid separation, wherein various bitumen recovery processes are shown.

FIG. 3 is a flowchart of a process for treating a bitumen feedstock, including a catalytic cracking treatment, in accordance with an implementation.

FIG. 4 is a flowchart of a process for treating a bitumen feedstock, including a blending/mixing step, a catalytic cracking treatment, and a separation step to separate a diluent and an ionic liquid from an ionic liquid-cracked bitumen mixture, in accordance with an implementation.

FIG. 5 is a flowchart of a process for treating a bitumen feedstock, including a blending/mixing step, a catalytic cracking treatment, and a separation step to separate a diluent and an ionic liquid from an ionic liquid-cracked bitumen mixture, in accordance with another implementation.

FIG. 6 is a flowchart of a process for treating a bitumen feedstock, including a blending/mixing step, a catalytic cracking treatment, and a separation step to separate a diluent and an ionic liquid from an ionic liquid-cracked bitumen mixture, in accordance with yet another implementation.

FIG. 7 is a flowchart of a process for treating a bitumen feedstock, including a catalytic cracking treatment, and a separation step to separate a diluent and an ionic liquid from an ionic liquid-cracked bitumen mixture, in accordance with an implementation.

FIG. 8 is a flowchart of a process for treating a bitumen feedstock, including a non-catalytic treatment, and a separation step to separate an ionic liquid from a treated ionic liquid-bitumen mixture, in accordance with an implementation.

FIG. 9 is a flowchart of a process for treating a bitumen feedstock, including a non-catalytic treatment, and a separation step to separate a diluent and an ionic liquid from a treated ionic liquid-bitumen mixture, in accordance with an implementation.

FIG. 10 is a flowchart of a process for treating a bitumen feedstock, including a catalytic treatment followed by a non-catalytic treatment, in accordance with an implementation.

FIG. 11 is a schematic representation of a well pair during an in situ bitumen recovery process, the well pair including an injection well and a production well located in a bitumen-bearing reservoir, wherein an upgrading fluid is injected into the reservoir via the injection well, including a representation of a zone including mobilized bitumen.

FIG. 12 is a graph showing the effect of a Lewis acidic ionic liquid (ILLA1) on the catalytic cracking of a bitumen sample at different temperatures. The graph shows the percentage of the different oil fractions (calculated using TGA) of the sample treated using 20 wt % ILLA1 at 100° C. (ILLA1-100) or 150° C. (ILLA1-150) for 3 h. Controls: bitumen sample heated at 100° C. (Cont100) or 150° C. (Cont150), no catalyst, for 3 h.

FIG. 13 is a graph showing the effect of a Lewis acidic ionic liquid (ILLA1) on the catalytic cracking of a bitumen sample at different concentrations. The graph shows the percentage of the different oil fractions (calculated using TGA) of the sample treated using 10 and 20 wt % ILLA1 at 150° C. for 1 h (10% ILLA1 and 20% ILLA2, respectively). Control: bitumen sample heated at 150° C., no catalyst, for 1 h (Cont150).

FIG. 14 is a graph showing the effect of various Bronsted acidic ionic liquids (ILBA2₀, ILBA2₁, ILBA3₀ and ILBA3₁) on the catalytic cracking of a bitumen sample. The graph shows the percentage of the different oil fractions (calculated using TGA) of the sample treated using 20 wt % of the ILBA as catalyst at 150° C. for 3 h. Control: bitumen sample heated at 150° C., no catalyst, for 3 h (Cont150).

FIG. 15 is a graph showing the effect of combinations of a Lewis acidic ionic liquid (ILLA1) and a Bronsted acidic ionic liquid (ILBA2₀, ILBA2₁, ILBA3₀ or ILBA3₁) on the catalytic cracking of a bitumen sample. The graph shows the percentage of the different oil fractions (calculated using TGA) of the sample treated using about 10 wt %/10 wt % of combinations ILLA1/ILBA2₀, ILLA1/ILBA2₁, ILLA1/ILBA3₀, and ILLA1/ILBA3₁ as catalysts at 150° C. for 1 h. Controls: bitumen sample heated at 150° C., no catalyst, for 1 h (Cont150) and bitumen sample treated with 10 wt % ILLA1 at 150° C., for 1 h.

DETAILED DESCRIPTION

Techniques described herein relate to the treatment of heavy oil or a heavy oil-derived product in the presence of ionic liquids and can also be referred to as “upgrading” or “partial upgrading”. In some implementations, the heavy oil or heavy oil-derived product that is upgraded or partially upgraded can include a heavy oil feedstock recovered from a subsurface extraction operation or from a surface mining process or can be a feedstock derived from the recovered heavy oil. The feedstock derived from the recovered heavy oil can include any product that is obtained downstream extraction that requires upgrading or partial upgrading. The feedstock derived from the recovered heavy oil can thus include a product that has already been subjected to an upgrading operation. In some implementations, the heavy oil can include an extra heavy oil such as bitumen (e.g., from oil sands). In other implementations, the heavy oil product that is upgraded or partially upgraded, which can include bitumen, is present in an underground reservoir. In other words, the upgrading or partial upgrading can take place in situ in an underground formation.

In some implementations, the upgrading or partial upgrading of the heavy oil or a heavy oil-derived feedstock can include subjecting the feedstock to a catalytic cracking treatment in the presence of an ionic liquid or subjecting the feedstock to a non-catalytic treatment in the presence of an ionic liquid at a given temperature, each performed as a standalone step. The upgrading, or partial upgrading, of the feedstock can also include a combination of the catalytic cracking treatment in presence of a first ionic liquid and the non-catalytic treatment in presence of a second ionic liquid performed according to a given sequence. The upgrading techniques described herein can facilitate viscosity and/or density reduction of the heavy oil or heavy oil-derived feedstock, and improve its chemical composition for instance by reducing asphaltene content and/or removing impurities such as sulphur and heavy metals. The viscosity and/or density reduction can, in turn, help reduce or eliminate diluent requirements for the treated product to be pipelinable. The upgrading techniques can also facilitate avoiding the need for the addition of an external source of hydrogen (i.e., hydroprocessing steps) in order to produce a higher quality product, having, for instance, a reduced sulphur content, a reduced metal content, a reduced total acid number, and/or a reduced viscosity compared to an untreated feedstock. It should be understood that as used herein, the expression “a method/process/system for upgrading a heavy oil or heavy oil-derived feedstock” may refer to an upgrading of the heavy oil or heavy oil-derived feedstock (e.g., a treatment that makes the feedstock pipelinable) or to a partial upgrading of the heavy oil or heavy oil-derived feedstock (e.g., a treatment that takes the feedstock closer to being pipelinable). In some implementations, the heavy oil or heavy oil-derived feedstock can be subjected to a pre-treatment step prior to the addition of the ionic liquid for the subsequent catalytic cracking treatment or non-catalytic treatment. For instance, the pre-treatment can include the addition of a diluent and/or a heating step. The pre-treatment can contribute to achieve desired properties of the heavy oil or heavy oil-derived feedstock, for instance with regard to its viscosity, to facilitate the subsequent interaction with the ionic liquid.

In some implementations, the upgrading or partial upgrading of the heavy oil can take place in situ and can include subjecting the heavy oil to a treatment in the presence of an ionic liquid in an underground reservoir. The in situ upgrading techniques described herein can facilitate viscosity and/or density reduction of the heavy oil and improve its chemical composition for instance by reducing asphaltene content. The viscosity and/or density reduction can, in turn, help reduce diluent requirements for the product that is produced at the surface to be pipelinable.

Feedstock and Viscosity Characteristics and Overview of General Process

As mentioned above, techniques are described herein to facilitate the reduction in viscosity of heavy oil or heavy oil-derived feedstocks and/or improve the chemical composition of the feedstocks. In some implementations, the heavy oil can include bitumen. The term “bitumen” as used herein refers to hydrocarbon material extracted from bituminous formations, such as oil sands formations, the density of which is typically around 1000 kg/m³, and the viscosity of which is typically between about 1 million cP to about 100 million cP when measured at 20° C. The heavy oil or heavy oil-derived feedstock can include bitumen that was extracted from oil sands ore using a surface mining process, or using an in situ recovery process (e.g., a thermal energy-based recovery method such as steam assisted gravity drainage (SAGD) or cyclic steam stimulation (CSS), a solvent-based recovery method such as in situ solvent or solvent-steam extraction, an in situ combustion recovery method, a cold production process, an electromagnetic energy assisted process, or a concurrent or sequential combination thereof). The bitumen included in the feedstock can also come from any other suitable source, such as bitumen obtained from a non-aqueous extraction process or bitumen obtained from a paraffinic froth treatment.

In the following description, solely to facilitate the reading and unless otherwise specified, reference will be made to “bitumen feedstock” as the product that is treated with the ionic liquids according to the present technology. However, as mentioned above, the techniques described herein can be implemented to treat any type of heavy oils or any type of products derived therefrom requiring upgrading or partial upgrading. For instance, the techniques described herein can be employed to treat a residuum stream from a distillation tower (e.g., vacuum distillation tower) that has been operated to remove light hydrocarbon components (e.g., gas oils and other hydrocarbons that boil below about 525° C.). Alternatively, the techniques described herein can be used to upgrade intermediate fractions obtained by distillation that have boiling points below about 525° C. and can include naphtha, atmospheric gas oil, heavy vacuum gas oil or light vacuum gas oil for instance.

The bitumen feedstock refers to the bitumen material that can be subjected to the upgrading techniques in presence of an ionic liquid. In some implementations, the bitumen feedstock includes both heavy and light hydrocarbon fractions and has very low or substantially zero water content and mineral solids content (e.g., below 2.5% water, or below 0.5% water and below 1.0% solids). The bitumen feedstock can include various non-hydrocarbon compounds (e.g., sulfur, heavy metals, etc.) that are often found in bitumen and may be associated with certain fractions or solubility classes of bitumen, such as asphaltenes.

It should also be noted that the bitumen feedstock can in some cases be a blend of different hydrocarbon streams, e.g., one or more heavy hydrocarbon streams can be blended with one or more light hydrocarbon streams to form a blended bitumen feedstock that has desired properties to be subjected to upgrading techniques in the presence of an ionic liquid as described herein.

Referring to FIGS. 1 and 2, the bitumen feedstock can include bitumen 32 extracted using surface mining operations. In such operations, the oil sands ore 34 is extracted through mining, followed by breaking down and crushing of the ore 36, which produces a looser material that can be mixed with warm or hot water to obtain a slurry preparation suitable for hydrotransport 38. At this stage, the slurry can also be subjected to various forms of conditioning to improve its properties. The hydrotransport 38 provides a pipeline connection between mining operations 36 and primary extraction operations 40. The primary extraction 40 is performed to separate the hydrotransported slurry into bitumen froth 42 and tailings 44. The bitumen froth 42 is then subjected to secondary extraction 46, or froth treatment, to separate the bitumen 32 from froth treatment tailings 48 using a solvent or diluent 50, thereby producing a bitumen feedstock 70. Optionally, the bitumen feedstock 32 can be further processed in a diluent recovery unit that has received the diluted bitumen feedstock from the secondary extraction 46 to recover the solvent or diluent 50. The bitumen feedstock 70 can thus also be a diluent-depleted bitumen produced by a diluent recovery unit that recovers paraffinic solvent from a solvent diluted bitumen overflow stream that is part of a paraffinic froth treatment operation.

Still referring to FIGS. 1 and 2, the bitumen feedstock can also include bitumen 52 extracted using in situ recovery operations. In situ recovery operations include injecting a pre-heated mobilizing fluid 54 via an injection well 56 overlying a production well 58. A produced fluid 60 is extracted from the production well 58 and subjected to at-surface processing 62 to separate a stream of recycled mobilizing fluid 64 from a bitumen feedstock 70 suitable for the upgrading techniques described herein. In implementations where the mobilizing fluid 64 includes a solvent or a diluent, the bitumen feedstock 70 can optionally be further processed in a diluent recovery unit that has received the bitumen feedstock from an in situ recovery facility to recover the solvent or diluent.

It is to be understood that as used herein, the expression “bitumen feedstock” can thus refer to either one of a diluted bitumen feedstock, i.e., a bitumen feedstock that still includes a solvent or a diluent, or to a bitumen feedstock from which solvent or diluent has been removed therefrom, in both cases when the bitumen feedstock has been obtained from surface mining operations or when the bitumen feedstock is obtained from in situ recovery operations.

In some implementations, the bitumen feedstock is a diluent-depleted bitumen stream that has not been subjected to certain conventional separation steps, such as fractionation or distillation, prior to the upgrading, and therefore still has many if not substantially all of the heavy and light hydrocarbon components of the native bitumen. In other implementations, the bitumen feedstock can be a residuum stream from a distillation tower (e.g., vacuum distillation tower) that has been operated to remove light hydrocarbon components (e.g., gas oils and other hydrocarbons that boil below about 525° C.).

In some implementations, the bitumen feedstock subjected to upgrading in the presence of an ionic liquid can include bitumen extracted from various sources, and can be combined in a blending step 66 prior to being subjected to the upgrading. A hydrocarbon co-feed 68 can also be added to the blending step 66.

Referring to FIG. 1, an ionic liquid is then added 72 to the bitumen feedstock 70 to obtain an ionic liquid-bitumen mixture 74, which is then subjected to a catalytic cracking treatment 76 under conditions to produce an ionic liquid-cracked bitumen mixture 78. Further details regarding the expression “catalytic cracking treatment” as used herein and the conditions at which the catalytic cracking treatment is performed are provided below. The ionic liquid-cracked bitumen mixture 78 can optionally be separated 80 to recover at least a portion of the ionic liquid as a recovered ionic liquid 96. A cracked bitumen product 82 is then obtained. In some implementations, the cracked bitumen product 82 can be a partially upgraded product that can be subjected to further upgrading treatment(s) if deemed necessary. In other implementations, the cracked bitumen product 82 can be sufficiently upgraded such that pipeline specifications are met, or further processed if needed.

Referring to FIG. 2, an ionic liquid is added 72 to the bitumen feedstock 70 to obtain an ionic liquid-bitumen mixture 74, which is then subjected to a non-catalytic treatment 84 to produce a treated ionic liquid-bitumen mixture 86. The treated ionic liquid-bitumen mixture 86 can optionally be separated 88 to recover at least a portion of the ionic liquid as a recovered ionic liquid. A bitumen product 90 is then obtained. Similarly to what is mentioned above regarding the cracked bitumen product 82, the bitumen product 90 can be a partially upgraded product that can be subjected to further upgrading treatment(s) if deemed necessary, or the bitumen product 90 can be sufficiently upgraded such that pipeline specifications are met, for instance.

In some implementations, the bitumen feedstock 70 can be subjected to a pre-treatment prior to the addition of the ionic liquid to the bitumen feedstock 70 for the subsequent catalytic cracking treatment 76 or non-catalytic treatment 84. The pre-treatment can include various steps depending on the results that are desired to be achieved, and depending on the characteristics of the bitumen feedstock 70. The pre-treatment can include adding a diluent, or additive agent, to the bitumen feedstock. The addition of the diluent to the bitumen feedstock 70 can contribute to dilute the bitumen feedstock 70 and reduce its viscosity. In some scenarios, the reduced viscosity of the bitumen feedstock 70 can facilitate the blending of the mixture of bitumen feedstock/diluent with the ionic liquid. Examples of suitable diluents can include for instance aromatic hydrocarbons, non-deasphalting organic solvents, and the like. In some scenarios, the diluent can be for instance toluene or xylene. Furthermore, in some implementations, the pre-treatment can include a heating step, whether or not a diluent has been added to the bitumen feedstock 70 during the pre-treatment step, and if a diluent has been added, prior to or after the addition of the diluent. The heating step can be performed prior to or during the addition of the ionic liquid to the bitumen feedstock 70. In some implementations, the heating step can be performed at a temperature sufficient to decrease the viscosity of the bitumen feedstock 70, which can facilitate the subsequent blending of the bitumen feedstock 70 with the ionic liquid. In some implementations and as will be discussed in further detail below, the addition of the diluent, or additive agent, can also be performed simultaneously with the addition of the ionic liquid, in a blending/mixing step. It is to be noted that while FIGS. 4-6 and 9 illustrate a mixing/blending step where the bitumen feedstock 70 is blended/mixed with the ionic liquid and optionally a diluent, the addition of the diluent can be done prior to the addition of the ionic liquid, i.e., not necessarily simultaneously.

The upgrading techniques in presence of an ionic liquid, including the catalytic cracking treatment 76 and the non-catalytic treatment 84, will now be described in further detail.

Catalytic Cracking Using Ionic Liquids

Conventional upgrading techniques can include cracking treatments such as thermal cracking and catalytic cracking to convert heavy hydrocarbon fractions, such as bitumen, to lighter fractions that are considered more valuable, such as gasoline and distillate, by breaking the chemical bonds of long-chain hydrocarbons into smaller-chain hydrocarbons. These conventional upgrading techniques generally involve treating heavy hydrocarbons at high temperature and/or high pressure, and can lead to the formation of coke as an undesirable by-product. In the case of catalytic cracking, coke can in turn deactivate the catalyst when depositing thereon, and so can heavy metals, nitrogen and sulfur. In the context of the present description and in contrast with conventional cracking techniques, the expression “catalytic cracking treatment” in the presence of an ionic liquid and the conditions at which the catalytic cracking treatment is performed (which can also be referred to as “catalytic cracking conditions” in the context of the present description) refer to a treatment operated at a temperature and/or a pressure that is lower compared to the temperature and pressure conditions at which are conducted conventional cracking processes, as will be described in more detail below.

With reference to FIG. 3, an implementation of a bitumen feedstock 70 that is subjected to a catalytic cracking treatment 76 in presence of an ionic liquid used as a catalyst is shown. In some implementations, the conditions at which the catalytic cracking treatment is performed can include operating the catalytic cracking treatment 76 at temperatures between about 50° C. and about 250° C. In some scenarios and without being limiting, the conditions at which the catalytic cracking treatment is performed can include operating the catalytic cracking treatment 76 near atmospheric pressure.

In some implementations, the ionic liquid catalyst is an acidic ionic liquid catalyst. In the present disclosure and unless otherwise specified, the term “acidic ionic liquid catalyst” is meant to refer to a Bronsted acidic ionic liquid catalyst, a Lewis acidic ionic liquid catalyst (e.g., strong Lewis acidic ionic liquid catalyst), or a combination thereof.

In some implementations, the acidic ionic liquid catalyst is a Bronsted acidic ionic liquid catalyst. Bronsted acidic ionic liquids can catalyse reactions due to a labile proton which is present in their structure (in the cation or in the anion). For example, Bronsted acidic ionic liquids can include acidic functional groups such as SO₃H or COOH, attached to the cation, or can include an acidic hydrogen on a nitrogen or oxygen atom in the cation. Bronsted acidic ionic liquids can be prepared by proton transfer between a Bronsted acid and a Bronsted base. The most common Bronsted acidic ionic liquids include a protonated imidazolium cation, a protonated C_1-nalkyl-substituted imidazolium cation, a protonated pyridinium cation, a guanidinium cation, a protonated C_1-nalkyl-substituted guanidinium cation, a protonated pyrrolidinium cation, a protonated N—C_1-nalkyl-pyrrolidinium cation (e.g., a protonated N-methylpyrrolidinium cation), a protonated ammonium cation, a protonated tri(C_1-nalkyl)ammonium cation, a COOH-bearing imidazolium cation or a SO₃H-bearing imidazolium cation, where in the C_1-nalkyl group n is from 2 to 20, i.e., n can be 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19 or 20. In some implementations, n is from 1 to 8, for example n is 1 or 2. The acidity of the Bronsted acidic ionic liquids can be modulated to provide the opportunity to design materials that are tailor made for certain applications, their ability to dissolve a wide range of materials can eliminate the need to add solvent, and they can act as both catalyst and solvent at the same time.

Examples of Bronsted acidic ionic liquid cations:

where R can represent a C_1-n alkyl group with n being from 2 to 20.

In some implementations, the anion of the Bronsted acidic ionic liquids can include halides, nitrates, nitrites, sulfates, hydrogen sulfates, alkyl sulfates, aryl sulfates, carbonates, bicarbonates, carboxylates, phosphates, hydrogen phosphates, dihydrogen phosphates, or hypochlorites. In some implementations, the anion of the Bronsted acidic ionic liquids can include [(HSO₄)(H₂SO₄)_x]⁻ with x=0 or 1 or [H₂PO₄]⁻.

In some implementations, the Bronsted acidic ionic liquids can include the compounds Triethylammonium dihydrogen phosphate [HN₂₂₂][H₂PO₄], Triethylammonium hydrogen sulfate [HN₂₂₂][(HSO₄)(H₂SO₄)_x] with x=0 or 1, N-methylpyrrolidinium hydrogen sulfate [Hmpyr][(HSO₄)(H₂SO₄)_x] with x=0 or 1, or any combination thereof.

In some implementations, the acidic ionic liquid catalyst is a Lewis acidic ionic liquid catalyst and includes a complex anion (e.g., AlCl₄⁻ formed from complexation between Lewis acid AlCl₃ and anion Cl⁻) and a cation (e.g., an imidazolium cation or an ammonium cation). In some implementations, the acidic ionic liquid catalyst can be a strong Lewis acidic ionic liquid. Lewis acids have the ability to act as an electron pair acceptor. Lewis acids are formed by reacting a metal halide with an organic halide salt, at various molar ratios. Several factors can contribute to make Lewis acidic ionic liquids advantageous for catalytic application.

In some implementations, the cation of the Lewis acidic ionic liquid catalyst can include for instance 1,3-dialkylimidazolium cations, tetraalkylphosphonium cations, tetraalkylammonium cations, trialkylammonium cations, and combinations thereof. In some implementations, the acidic ionic liquid catalyst can be a Lewis acidic ionic liquid catalyst including a complex anion formed from complexation between a Lewis acid and Lewis base anion, and a 1-alkyl-3-methylimidazolium cation. In some scenarios, the 1-alkyl-3-methylimidazolium cation can be for instance 1-ethyl-3-methylimidazolium (EMIM) or 1-n-butyl-3-methylimidazolium (BMIM). When the Lewis acidic ionic liquid catalyst includes a complex anion and a trialkylammonium cation, the trialkylammonium cation can be for instance triethylammonium. In some implementations, the complex anion is a chlorometallate anion, and can be for instance AlCl₄⁻, Al₂Cl₇⁻, FeCl₄⁻ and Fe₂Cl₇⁻. In some implementations, the Lewis acidic ionic liquid catalyst can be for instance [EMIM][AlCl₄], [BMIM][AlCl₄], [EMIM][FeCl₄], [BMIM][FeCl₄]. In yet other implementations, Lewis acidic ionic liquid catalyst can include a metal ion-modified ionic liquid, which can be for instance [Et₃NH][AlCl₄]—Ni²⁺, [EMIM][AlCl₄]—Ni²⁺, [BMIM][AlCl₄]—Ni²⁺, [Et₃NH][AlCl₄]—Fe²⁺, [EMIM][AlCl₄]—Fe²⁺, [BMIM][AlCl₄]—Fe²⁺, and combinations thereof. It should be understood that as used herein, the term “complex anion” can be referred to as a “Lewis acidic anion”.

In some implementations, the Lewis acidic ionic liquid catalyst can include a strong Lewis acidic ionic liquid, namely a strong halometallate ionic liquid or halometallate-containing ionic liquid. A “strong” Lewis acidic ionic liquid can thus refer to a halometallate ionic liquid or halometallate-containing ionic liquid presenting a high degree of acidity. In some implementations, the strong Lewis acidic ionic liquid can be a Lewis superacidic ionic liquid. The acidity or strength of a Lewis acidic ionic liquid can be expressed by the value of the mole fraction (χ_MXn) of the metal halide MX_n used to prepare the ionic liquid. In some implementations, the strong Lewis acidic ionic liquid can include a Group(III)halometallate, such as a haloaluminate or a halogallate ionic liquid, with a mole fraction χ_MXn above 0.5, more preferably from about 0.6 to about 0.75. For instance, the strong Lewis acidic ionic liquid can include a chloroaluminate ionic liquid with a mole fraction χ_AlCl3 from about 0.6 to about 0.75, preferably from about 0.6 to about 0.7, or a chlorogallate with a mole fraction χ_GaCl3 above 0.5 to about 0.75, preferably from about 0.6 to about 0.75. In some implementations, the strong Lewis acidic ionic liquid can be a Group(III)halometallate having a Gutmann acceptor number (AN) of at least 90. In some embodiments, the strong Lewis acidic ionic liquid can be a Group(III)halometallate with an AN of above 90. In some implementations, the AN can above 100 and the strong Lewis acidic ionic liquid can be qualified as a Lewis superacidic ionic liquid.

In some implementations, the cation of the strong Lewis acidic ionic liquid can include 1,3-dialkylimidazolium cations, tetraalkylphosphonium cations, tetraalkylammonium cations, trialkylammonium cations, and combinations thereof. In some implementations, the cation of the strong Lewis acidic ionic liquid can include a 1-alkyl-3-methylimidazolium cation, such as 1-ethyl-3-methylimidazolium (EMIM) or 1-n-butyl-3-methylimidazolium (BMIM). When the cation of the strong Lewis acidic ionic liquid includes a trialkylammonium cation, the trialkylammonium cation can be for instance triethylammonium ([HN₂₂₂]). In some implementations, the strong Lewis acidic ionic liquid includes a chlorometallate anion such as Al₂Cl₇⁻, Fe₂Cl₇⁻, Ga₂Cl₇⁻ or Ga₃Cl₁₀⁻ or any combination thereof. In some implementations, the strong Lewis acidic ionic liquid can be for instance [EMIM][Al₂Cl₇], [BMIM][Al₂Cl₇], [EMIM][Ga₂Cl₇⁻], [BMIM][Ga₂Cl₇⁻], [EMIM][Ga₃Cl₁₀], [BMIM][Ga₃Cl₁₀]. In yet other implementations, the strong Lewis acidic ionic liquid can be [HN₂₂₂][Al₂Cl₇], [HN₂₂₂][Ga₂Cl₇] or [HN₂₂₂][Ga₃Cl_10].

In further implementations, the strong Lewis acidic ionic liquid can include an adduct-based halometallate ionic liquid prepared by addition of an excess of anhydrous metal halide to donor compounds under solventless conditions. For instance, such adduct-based halometallate ionic liquid can include AlCl₃ or GaCl₃ (χ_MC3˜0.60) with substoichiometric amounts of simple donors including O-donors such as urea, N,N-dimethylurea, acetamide (AcA), dimethylacetamide, P₈₈₈O, S-donors such as thiourea, or P-donors such as trioctylphosphine (P₈₈₈).

In further implementations, the Lewis acidic ionic liquids can include an ionic liquid of a general formula L-BCl₃-nAlCl₃ or L-BCl₃-nGaCl₃ where L is an N-donor such as a phosphine or an aromatic amine and n is from 1 to 3. The N-donor can for instance include pyridine (py), 3-picoline (3pic), 4-picoline (4pic), 1-methylimidazol (mim), trioctylphosphine (P₈₈₈) and trioctylphosphine oxide (P₈₈₈O). Such Lewis acidic ionic liquids can present an AN above 100 and can be qualified as Lewis superacidic ionic liquid.

In some implementations, one can adjust the strength (i.e., the acidity) of the Lewis acidic ionic liquids depending on the level of upgrading and/or viscosity reduction that is desired. For instance, the Lewis acidic ionic liquids acidity can be tuned by replacing one cation to another or using an ionic liquid with more than one cation and/or more than one anion. These types of Lewis acidic ionic liquids are called “Double salt ionic liquids” (DSILs). Examples of DSILs that can be used as the ionic liquid can include salts with a cation such as [HN₂₂₂] and mixtures of chlorometallate anions in different molar fractions, such as [HN₂₂₂][0.20AlCl₄+0.80FeCl₄], [HN₂₂₂][0.25AlCl₄+0.75FeCl₄], [HN₂₂₂][0.33AlCl₄+0.67FeCl₄], [HN₂₂₂][0.40AlCl₄+0.60FeCl₄], [HN₂₂₂][0.50AlCl₄+0.50FeCl₄], [HN₂₂₂][0.60AlCl₄+0.40FeCl₄], [HN₂₂₂][0.67AlCl₄+0.33FeCl₄], [HN₂₂₂][0.80AlCl₄+0.20FeCl₄], [HN₂₂₂][0.50Al₂Cl₇+0.50FeCl₄], [HN₂₂₂][0.33Al₂Cl₇+0.67ZnCl₃], [HN₂₂₂][0.5AlCl₃+0.5ZnCl₄], [HN₂₂₂]_1.5[0.50ZnCl₄+0.50FeCl₄], [HN₂₂₂]_0.5[0.50AlCl₄+0.50FeCl₃], [HN₂₂₂]_0.8[0.6AlCl₃+0.4ZnCl₄], [HN₂₂₂]_0.88[0.67AlCl₃+0.33ZnCl₄], [HN₂₂₂]_1.50[0.50Al₂Cl₇+0.50ZnCl₄], [HN₂₂₂]_1.50[0.50Al₂Cl₇+0.50ZnCl₄], [HN₂₂₂]_1.40[0.60Al₂Cl₇+0.40ZnCl₄], [HN₂₂₂]_1.33[0.67Al₂Cl₇+0.33ZnCl₄], [HN₂₂₂]_1.30[0.70Al₂Cl₇+0.30ZnCl₄] or [HN₂₂₂]_1.10[0.90Al₂Cl₇+0.10ZnCl₄]. Other suitable DSILs can include the cation [HN₂₂₂] and an anion including a mixture of a chlorometallate and HSO₄, such as [HN_222][0.8Al₂Cl₇+0.2HSO₄], [HN₂₂₂][0.67Al₂Cl₇+0.33HSO₄], [HN₂₂₂][0.5Al₂Cl₇+0.5HSO₄] or [HN₂₂₂][0.33Al₂Cl₇+0.67HSO₄]. Such DSILs can be prepared as disclosed in U.S. Pat. No. 10,357,762.

In some implementations, the selection of the Lewis acidic ionic liquid can be carried out based on its ability to mix with the bitumen, i.e., based on its miscibility in the bitumen or stream to be upgraded. Since the miscibility is mainly dependent on the type of cation used in the ionic liquid, one can select a suitable cation for allowing proper miscibility with the bitumen or stream to be treated.

In some implementations, the acidic ionic liquid catalyst can include a combination of any of the above described Bronsted and Lewis acidic ionic liquids. For instance, the acidic ionic liquid catalyst can include at least one of the above described Bronsted acidic ionic liquid in combination with at least one of the strong Lewis acidic ionic liquids as defined above. In some implementations, the acidic ionic liquid catalyst can be a combination of two or more of the following acidic ionic liquids: Triethylammonium heptachlorodialuminate [HN₂₂₂][Al₂Cl₇], Triethylammonium hydrogen sulfate [HN₂₂₂][(HSO₄)(H₂SO₄)_x] with x=0 or 1 and N-methylpyrrolidinium hydrogen sulfate [Hmpyr][(HSO₄)(H₂SO₄)_x] with x=0 or 1.

In some implementations, the acidic ionic liquid catalyst can include both Lewis acids combined with Bronsted acids to yield Bronsted-Lewis acidic ionic liquids. Examples of Bronsted-Lewis acidic ionic liquid can include 1-(3-sulfonic acid)-propyl-3-methylimidazole chlorozincinates ([HO_BS—(CH₂)₃-MIM]Cl—ZnCl₂), [HO_BS—(CH₂)₃—NEt₃]Cl—FeCl₃, [HSO₃-PMIM]⁺(½Zn²⁺)SO₄²⁻ with PMIM=1-methyl-3-propyl-imidazolium, 1-carboxyethylene-3-(4-zinc acetate sulfobutyl) imidazolium chloride ([CH₃COO—Zn—O₃S-BIM-CH₂CH₂COOH]Cl), 1-(1,2-dicarboxy)ethylene-3-(4-zinc acetate sulfobutyl) imidazolium chloride ([CH₃COO—Zn—O₃S-BOM-C₄H₅O₄]Cl) to name a few. In some implementations, cooperation of Bronsted and Lewis acid sites can enhance catalytic performance. In some implementations, this can be attributed to a synergy of Bronsted and Lewis acidities manifested by the catalyst. In certain implementations, one can use so-called “dual Bronsted-Lewis acidic ionic liquids” that include a combination of one proton and sp² aryl substituents at the nitrogen atoms of an imidazolium core. Examples of such dual Bronsted-Lewis acidic ionic liquids can include complexes of the formula [HPhImX][FeCl₄] (Im=1,3-imidazole and X═H, CHs, OCH₃, and NO₂).

In some implementations, the concentration of the acidic ionic liquid catalyst in the ionic liquid-bitumen mixture can be between about 5 wt % and about 50 wt %. In other implementations, the concentration of the acidic ionic liquid catalyst in the bitumen/diluent mixture 210 can be below 5 wt %, or above 50 wt %. The concentration of the acidic ionic liquid catalyst in the ionic liquid-bitumen mixture can depend for instance of the characteristics of the bitumen feedstock, and/or the characteristics of the acidic ionic liquid catalyst.

The catalytic cracking treatment 76 can be performed in any suitable vessel, or reactor, that can be operated at conditions as described herein and that enables the obtention of an ionic liquid-cracked bitumen mixture 78. In some implementations, the vessel can be a vessel designed such that the ionic liquid-cracked bitumen mixture 78 can be retrieved as an overflow stream and an undesirable products stream such as coke can be retrieved as an underflow stream. In other implementations, the ionic liquid-cracked bitumen mixture 78 can be retrieved from the vessel as a single stream that includes all of the hydrocarbon components but that has improved physical and/or chemical properties. As mentioned above, the conditions enabling the catalytic cracking of the ionic liquid-bitumen mixture 74 generally include a temperature and a pressure at which the catalytic cracking treatment 76 is conducted, for a given duration. The conditions at which the catalytic cracking treatment is performed can vary depending on the characteristics of the bitumen feedstock 70. For instance, for a bitumen feedstock 70 having a high proportion of heavy hydrocarbon, the severity of the catalytic cracking can be increased, while for a bitumen feedstock having a low proportion of heavy hydrocarbon, the severity of the catalytic cracking can be decreased. “Severity” as used herein refers to the severity of the conditions of temperature and residence time at which the bitumen feedstock is treated. The severity can be expressed in terms of an equivalent reaction time (ERT) in seconds of residence time when a reactor is operating at 427° C. (800° F.). The ERT corresponds to the residence time that would achieve the same conversion of heavy material at a given temperature as if the reaction was conducted at 427° C. (800° F.).

Still referring to FIG. 3, optionally, the ionic liquid-cracked bitumen mixture 78 can be subjected to a separation step 92 to separate the acidic ionic liquid catalyst 98 and/or to separate diluent 94 that was initially part of the bitumen feedstock, if applicable, from the ionic liquid-cracked bitumen mixture 78. A cracked bitumen product 90 is then obtained. The cracked bitumen product 90 can be subjected to separation to be separated into various streams according to their boiling points, for instance in a fractionator or distillation column.

Referring to FIGS. 4 to 6, a bitumen feedstock 70 and an acidic ionic liquid catalyst are blended or mixed 100 together to obtain an ionic liquid-bitumen mixture 74. Optionally, a diluent 102 can also be added to the ionic liquid-bitumen mixture 74 during the mixing step 100, for instance to improve characteristic(s) of the ionic liquid-bitumen mixture 74 or to facilitate the obtention of an at least partially homogenized ionic liquid-bitumen mixture 74 by further reducing its viscosity. As mentioned above, in some scenarios, the bitumen feedstock 70 can already include a diluent, such that it may not be advantageous to add additional diluent during the mixing step 100. In other scenarios, even if bitumen feedstock 70 already includes a diluent, there may still advantages to add additional diluent during the mixing step 100, for instance to obtain given characteristics of the ionic liquid-bitumen mixture 74. Examples of suitable diluents that can be used include natural gas condensates, hexane or cyclohexane, naphthenic diluent, or any other suitable diluent.

Still with reference to FIGS. 4 to 6, the ionic liquid-bitumen mixture 74 is then subjected to the catalytic cracking treatment 76 to produce the ionic liquid-cracked bitumen mixture 78. The ionic liquid-cracked bitumen mixture 78 is then subjected to one or two separation steps, to recover at least a portion of diluent 102 if present, and at least a portion of the acidic ionic liquid catalyst 72. The ionic liquid-cracked bitumen mixture 78 can be subjected to a single separation step 104 configured to separate the diluent 102 and the acidic ionic liquid catalyst 72 from the ionic liquid-cracked bitumen mixture 78 in a single step, as shown in FIG. 4. In some implementations, the acidic ionic liquid catalyst 72 and the diluent 102 can be separated from the cracked bitumen product 90 as a single stream, and optionally separated from each other thereafter. When the ionic liquid-cracked bitumen mixture 78 is subjected to two separation steps 106,108, the two separation steps 106,108 can be performed in one sequence or the other. In some implementations, the separation step 104, 106, 108 can be performed for instance in a gravity settler, a diluent recovery unit, or a solvent recovery unit. FIG. 5 illustrates an implementation where the ionic liquid-cracked bitumen mixture 78 is subjected to a first separation step 106 to recover a recovered diluent 94 and produce a diluent-depleted cracked bitumen mixture 110, which is then subjected to a second separation step 108 to recover a recovered acidic ionic liquid catalyst 98 and produce the cracked bitumen product 90. FIG. 6 illustrates another implementation where the ionic liquid-cracked bitumen mixture 78 is subjected to a first separation step 108 to recover a recovered acidic ionic liquid catalyst 98 and produce an ionic liquid-depleted cracked bitumen mixture 112 which is then subjected to a second separation step 106 to recover a recovered diluent 94 and produce the cracked bitumen product 90.

The separation step 106 is configured to recover the diluent 102 from the ionic liquid-cracked bitumen mixture 78 or from the ionic liquid-depleted cracked bitumen mixture 112. In some implementations, the separation step 106 can include evaporating the diluent 102 from the liquid-cracked bitumen mixture 78 or from the ionic liquid-depleted cracked bitumen mixture 112 to obtain the recovered diluent 94. At least a portion of the recovered diluent 94 can be recycled to be used as the diluent 102 that can be optionally added to the bitumen feedstock 70 and the acidic ionic liquid catalyst 72 for the mixing step 100.

The separation step 108 is configured to recover the acidic ionic liquid catalyst 98 from the ionic liquid-cracked bitumen mixture 78 or the diluent-depleted cracked bitumen mixture 110. In some implementations, the separation step 108 includes a liquid-liquid extraction of the ionic liquid-cracked bitumen mixture 78 or the diluent-depleted cracked bitumen mixture 110. In implementations where the acidic ionic liquid catalyst is water soluble, the liquid-liquid extraction of the ionic liquid-cracked bitumen mixture 78 or the diluent-depleted cracked bitumen mixture 110 can include washing the ionic liquid-cracked bitumen mixture 78 or the diluent-depleted cracked bitumen mixture 110 with water. At least a portion of the recovered acidic ionic liquid catalyst 98 can be recycled to be reused as the acidic ionic liquid catalyst 72 to be combined with the bitumen feedstock 70.

Referring now to FIG. 7, an embodiment of the implementations described above is presented. In the embodiment shown, a bitumen feedstock 200 is blended/mixed 208 with a diluent 206 to obtain a bitumen/diluent mixture 210. The diluent 206 can be chosen for instance to arrive at certain characteristics of the bitumen/diluent mixture 210, for example in terms of viscosity. The diluent 206 can include for instance natural gas condensates, hexane or cyclohexane, naphthenic diluent, or any other suitable diluent. In some implementations, the blending/mixing step 208 can include heating the bitumen feedstock 200 for a given period of time. The bitumen/diluent mixture 210 is then subjected to catalytic cracking 212 in presence of an acidic ionic liquid catalyst 214, the bitumen/diluent mixture 210 and the acidic ionic liquid catalyst 214 forming an ionic liquid-bitumen mixture. In some implementations, the concentration of the acidic ionic liquid catalyst in the ionic liquid-bitumen mixture can be between about 5 wt % and about 50 wt %. In other implementations, the concentration of the acidic ionic liquid catalyst in the ionic liquid-bitumen mixture can be below 5 wt %, or above 50 wt %. The catalytic cracking 212 is performed under conditions that can include for instance heating the ionic liquid-bitumen mixture at temperatures between 50° C. and 250° C. In some scenarios and without being limitative, the catalytic cracking can be performed at pressures near normal atmospheric pressure. It is to be understood that other conditions can be implemented for the catalytic cracking treatment, and can be determined or adjusted depending on the bitumen/diluent mixture 210 physical and chemical properties, among other factors. Following the catalytic cracking 212, a cracked reaction mixture 216 is subjected to diluent removal 218 to recover at least a portion of the diluent as recovered diluent 220 and obtain a diluent-depleted cracked bitumen mixture 222. The diluent removal 218 step can be done by evaporation of the diluent 206. In some implementations, a system including a diluent recovery unit, a solvent recovery unit or a flash drum can be used to recover the diluent 206. Optionally, the recovered diluent 220 can be recycled to be reused to blend/mix with the bitumen feedstock 200. The diluent-depleted cracked bitumen mixture 222 is then subjected to another separation step 224 to separate at least a portion of the acidic ionic liquid catalyst 214 from the diluent-depleted cracked bitumen mixture 222 as a recovered acidic ionic liquid catalyst 226 and to produce a cracked bitumen product 228. In some scenarios, when the acidic ionic liquid catalyst 214 is water soluble, the second separation step 224 can be performed as a water washing step. Although FIG. 7 shows the diluent separation step 218 performed prior to the acidic ionic liquid catalyst separation step 224, it is to be understood that the order of these steps can be interchanged such that the acidic ionic liquid catalyst separation step 224 can be performed prior to the diluent separation step 218. In some implementations and as mentioned above, the sequence of the separation steps 218, 224 can be determined according to the characteristics of the diluent 206 and the acidic ionic liquid catalyst 214 and the corresponding separation techniques that have to be put in place to recover each of them.

Non-Catalytic Treatment Using Ionic Liquids

As mentioned above, reducing the viscosity of a bitumen feedstock can be advantageous to improve its pipelinability. There can also be advantages in reducing the total acid number (TAN) of the bitumen feedstock, which can in turn contribute to reduce corrosive properties of the bitumen feedstock. It can be also advantageous to remove certain contaminants such as sulphur and heavy metals, and/or to decrease the asphaltene content of the bitumen feedstock. The techniques described below are aimed at improving such characteristics of the bitumen feedstock by subjecting the bitumen feedstock to a non-catalytic treatment in presence of an ionic liquid.

With reference to FIG. 8, in an implementation of a non-catalytic treatment, a bitumen feedstock 300 is combined with an ionic liquid 304 in a blending/mixing step 306 to form an ionic liquid-bitumen mixture 308. The bitumen feedstock 300 can be of various sources and have various characteristics as previously described above. The bitumen feedstock 300 can optionally include a diluent. If the bitumen feedstock 300 incudes a diluent, the diluent can be separated from the bitumen feedstock 300 prior to the non-catalytic treatment, or the bitumen feedstock 300 can remain as a mixture of bitumen and diluent. In some implementations, the ionic liquid 304 can be added to the bitumen feedstock 300 to reach a concentration of the ionic liquid 304 ranging from about 5 wt % to about 50 wt %. In other implementations, the concentration of the acidic ionic liquid catalyst in the ionic liquid-bitumen mixture can be below 5 wt %, or above 50 wt %.

The ionic liquid-bitumen mixture 308 is then subjected to a non-catalytic treatment 310 in a suitable vessel. In the context of the present description, the non-catalytic treatment 310 is performed under non-catalytic cracking conditions, and could thus be considered as a mild thermal treatment that is performed at low severity conditions. In some implementations, the non-catalytic cracking conditions include performing the non-catalytic treatment 310 at a temperature at which asphaltene aggregation within the ionic liquid-bitumen mixture 308 is avoided. For instance, in some embodiments, the temperature at which is conducted the non-catalytic treatment 310 can be between about 20° C. and about 120° C. In some implementations, the temperature at which is conducted the non-catalytic treatment 310 can be a temperature that enables proper mixing of the bitumen feedstock 300 with the ionic liquid 304 during the blending/mixing step 306, i.e., a temperature at which the respective viscosity of the bitumen feedstock 300 and the ionic liquid 304 is low enough to allow sufficient contact between the bitumen feedstock 300 and the ionic liquid 304. In some implementations, the non-catalytic treatment 310 can be performed at room temperature. The temperature at which the non-catalytic treatment 310 is conducted and the duration of the non-catalytic treatment 310 can depend on the endpoint that is desired to be achieved, on the initial viscosity of the bitumen feedstock 300 or of the ionic liquid 304, and/or on the properties of the ionic liquid used, for example.

In the implementation shown in FIG. 8, the ionic liquid 304 that is combined with the bitumen feedstock 300 for the non-catalytic treatment 310 includes ionic liquids that are miscible in bitumen or a mixture of bitumen and diluent, i.e., that are feed-miscible. Examples of ionic liquids that are miscible in a mixture of bitumen and toluene can include for instance some carbamate ionic liquids such as N,N′-dipropylammonium N,N′-dipropyl carbamate (DPCARB) and N,N′-dibenzylammonium N,N′-dibenzyl carbamate (DBCARB), phosphonium ionic liquids such as Trihexyl-tetradecylphosphonium dicyanamide (Cyphos IL 105), fatty acid-based ionic liquids including trialkylammonium cations such as Trioctylammonium hexanoate [HN₈₈₈][Hexanoate] or Trioctylammonium oleate [HN₈₈₈][Oleate], among others. In some implementations, the ionic liquid 304 used for the non-catalytic treatment 310 can be chosen according to its likelihood to not have cracking functionality, although the solvent properties of anionic liquid used for catalytic cracking may still favor its use under non-catalytic conditions.

Following the non-catalytic treatment 310, a treated ionic liquid-bitumen mixture 312 is obtained, which then may optionally be subjected to a separation step 314 to separate the ionic liquid 304 from the treated ionic liquid-bitumen mixture 312 and produce a recovered ionic liquid 316 and a treated bitumen product 318. When no separation step is performed, the treated ionic liquid-bitumen mixture 312 can be considered to correspond to the treated bitumen product 318. In some implementations, such a non-catalytic treatment 310 of the ionic liquid-bitumen mixture 306 can contribute to improve physical properties of the bitumen feedstock 300 such as viscosity reduction and asphaltene content reduction, as well as TAN reduction. In some implementations, the alkalinity of the ionic liquid 304 can be correlated with the TAN reduction that is achieved: the stronger the alkalinity of the ionic liquid 304, the greater the TAN reduction in the treated ionic liquid-bitumen mixture 312 or the treated bitumen product 90. In some implementations, subjecting the ionic liquid-bitumen mixture 308 to the non-catalytic treatment 310 as described herein can facilitate achieving viscosity reduction ranging from 40% to 90% and/or TAN reduction ranging from 15% to 55%, when ionic liquids such as DPCARB, DBCARB, [HN₈₈₈][Hexanoate], [HN₈₈₈][Oleate] or Cyphos IL 105 are used.

Referring now to FIG. 9, in another implementation of a non-catalytic treatment, a bitumen feedstock 300, a diluent 302 and an ionic liquid 304 are combined in a blending/mixing step 306 to produce an ionic liquid-bitumen mixture 308. The diluent 302 can be for instance a naphthenic diluent. In implementations where the bitumen feedstock 300 already includes a diluent, the diluent 302 addition can be omitted.

In the implementation shown in FIG. 9, the ionic liquid 304 that is combined with the bitumen feedstock 300 for the non-catalytic treatment 311 include ionic liquids that are immiscible in a mixture of bitumen and toluene, i.e., that are feed-immiscible. Ionic liquids that are immiscible in a bitumen and toluene mixture can include for instance amino acid based ionic liquids such as tetraethylammonium β-alaninate and 1-ethyl-3-methylimidazolium glycinate, imidazolium ionic liquids such as 1-ethyl-3-methylimidazolium ethyl sulphate and 1-butyl-3-methylimidazolium tetrafluoroborate, phosphonium ionic liquids such as Tributyl-methylphosphonium methyl sulphate, and carbamate ionic liquids such as N,N′-dimethylammonium N,N′-dimethylcarbamate (DMCARB).

In some implementations, the ionic liquid 304 can be added to the bitumen feedstock 300 to reach a concentration of the ionic liquid 304 ranging from about 5 wt % to about 50 wt %. In some implementations, the proportion of the bitumen relative to the feed-immiscible ionic liquid is between about 1:2 w/w and about 1:1 w/w.

The ionic liquid-bitumen mixture 309 is then subjected to the non-catalytic treatment 311 to produce a treated ionic liquid-bitumen mixture 312. The non-catalytic treatment 311 shown in FIG. 9 can include heating the ionic liquid-bitumen mixture 309, for instance at temperatures ranging from about 40° C. to 70° C., which can facilitate efficient mixing of the three components of the ionic liquid-bitumen mixture 309. The non-catalytic treatment 311 can also include mixing, which can facilitate the transfer of at least a portion of contaminants contained in the bitumen feedstock 300 from the bitumen feedstock 300 to the mixture of diluent 302 and ionic liquid 304. In some implementations, the non-catalytic treatment 311 can include heating the ionic liquid-bitumen mixture 308 at a first temperature for a first duration as part of a first thermal treatment, and then heating the ionic liquid-bitumen mixture 309 at a second temperature for a second duration as part of a second thermal treatment and so on, to ensure that proper mixing and contact between the bitumen feedstock 300 and the ionic liquid 304 can be achieved.

The treated ionic liquid-bitumen mixture 312 is then subjected to a liquid-liquid extraction 320, during which a first phase 324 that includes the bitumen feedstock 300 and the diluent 302 (or the bitumen feedstock 300 if the bitumen feedstock 300 already includes a diluent) is separated from a second phase that includes the ionic liquid 304. The liquid-liquid extraction 320 can facilitate at least partial removal of undesirable components from the bitumen feedstock 300, such as sulphur, naphthenic acids and heavy metals, by enabling transfer of the undesirable components to the ionic liquid 304. The liquid-liquid extraction 320 can be performed in any suitable vessel, which can be for instance a liquid-liquid separation unit or a decanter. The first phase that includes the bitumen and the diluent can be withdrawn as a bitumen-diluent mixture stream 324. In some implementations, the bitumen-diluent mixture stream 324 can be subjected to additional separation step(s) 326 to separate the diluent from the bitumen and obtain a recovered diluent 330, which can optionally be recycled for reuse in the blending/mixing step 306, and a treated bitumen product 328. In other implementations, it can also be advantageous to keep the diluent and the bitumen combined together, for instance such that the viscosity of the diluent-bitumen mixture is within a given range. The second phase that includes the ionic liquid 304 can be withdrawn as a recovered ionic liquid stream 322, which can optionally be recycled for reuse in the blending/mixing step 306. The non-catalytic treatment 311 thus produces the bitumen-diluent mixture stream 324, or the treated bitumen product 328, if diluent has been separated therefrom.

As mentioned above, different ionic liquids that are immiscible in a mixture of bitumen and toluene can be used, or ionic liquids that are feed-immiscible, the choice of which can depend for instance of the characteristic(s) of the bitumen feedstock that is desired to be improved. For instance, subjecting the ionic liquid-bitumen mixture 309 to the non-catalytic treatment 311 as described herein in the presence of amino acid based ionic liquids can facilitate TAN reduction, which in some implementations, can be up to 100%. Similarly to the non-catalytic treatment 310 in presence of an ionic liquid that is miscible in a mixture of bitumen and toluene, the alkalinity of the ionic liquid 304 that is immiscible in a mixture of bitumen and toluene can be correlated with the TAN reduction achieved when the non-catalytic treatment 311 is performed. In some implementations, the concentration of metals such as nickel and vanadium can also be reduced when the ionic liquid-bitumen mixture 309 is subjected to the non-catalytic treatment 311. For instance, the reduction of nickel can be up to about 60%, and the reduction in vanadium can be up to 30%, depending on the ionic liquid used.

Catalytic Cracking Treatment and Non-Catalytic Treatment in Sequence

The techniques described herein to upgrade a bitumen feedstock in presence of an ionic liquid can also include a combination of a catalytic cracking treatment and a non-catalytic treatment performed sequentially to take advantage of the respective improvements on the bitumen properties that can be achieved by performing each of these two treatments. The choice of the ionic liquid used for the catalytic cracking treatment and the non-catalytic treatment and the sequence of the treatments, i.e., which ones of the catalytic cracking treatment and a non-catalytic treatment is performed first, can depend for instance on the characteristics of the bitumen feedstock, on the desired characteristics of the resulting partially upgraded bitumen product and/or on the overall process configuration and design.

Referring to FIG. 10, an implementation of an upgrading technique that includes a catalytic cracking treatment of a mixture of bitumen and an ionic liquid followed by a non-catalytic treatment of the resulting cracked mixture of bitumen and an ionic liquid is shown. In this implementation, a bitumen feedstock 400 and a first ionic liquid 402 are combined in a first blending/mixing step 406 to produce a first ionic liquid-bitumen mixture 408. In certain embodiments, the first ionic liquid 402 includes an acidic ionic liquid catalyst as described above. The first ionic liquid-bitumen mixture 408 is then subjected to a catalytic cracking treatment 410 under conditions as detailed above, to convert heavy hydrocarbons to lighter hydrocarbons. The catalytic cracking treatment 410 produces an ionic liquid-cracked bitumen mixture 412. In some implementations, the ionic liquid-cracked bitumen mixture 412 can be separated to remove the diluent, if present in the bitumen feedstock 400, and/or the ionic liquid 402, to obtain a cracked bitumen product 416. The separation step 414 can thus be configured to separate a recovered ionic liquid 418 and optionally a recovered diluent 420. Various separation methods can be implemented to separate the first ionic liquid 402 from the ionic liquid-cracked bitumen mixture 412, depending on the properties of the first ionic liquid 402. For instance, in some implementations, the first ionic liquid 402 can be miscible in water and thus can be removed by a water washing step. Each one of the recovered ionic liquid 418 and the recovered diluent 420 can be recycled to be reused in other parts of the process.

Following the separation step 414, the cracked bitumen product 416 is then combined with a second ionic liquid 422 in a second blending/mixing step 424. The blending/mixing step 424 can also include the addition of a diluent, for instance if the bitumen feedstock 400 does not initially include such diluent and depending on the choice of the second ionic liquid 422 and the choice of non-catalytic treatment that follows. For instance, when the second ionic liquid 422 is an ionic liquid that is miscible in a mixture of bitumen and toluene as described above, the presence of a diluent can be optional. When the second ionic liquid 422 is an ionic liquid that is immiscible in a mixture of bitumen and toluene as described above, it can be advantageous to add a diluent if the bitumen feedstock 400 does not initially include such diluent.

Following the second blending/mixing step 424, a second ionic liquid-bitumen mixture 426 is obtained. The second ionic liquid-bitumen mixture 426 is subjected to a non-catalytic treatment 428 to obtain a treated ionic liquid-bitumen mixture 430. The configuration of the non-catalytic treatment 428 can be chosen according to the endpoint(s) that are desired to be achieved, which in turn can contribute to determine the type of ionic liquid that is used as the second ionic liquid 422.

In some implementations, when a reduction in viscosity or a reduction of TAN in the cracked bitumen product 416 is desired, the second ionic liquid 422 can be chosen to be an ionic liquid that is miscible in a mixture of bitumen and diluent, and the non-catalytic treatment 428 generally includes mixing the second ionic liquid-bitumen mixture 426 at a given temperature for a given duration. Examples of suitable second ionic liquids 422 in such implementations include carbamate ionic liquids such as DPCARB, DBCARB, phosphonium ionic liquids such as Cyphos IL 105, or fatty acid-based ionic liquids including trialkylammonium cations such as Trioctylammonium hexanoate [HN₈₈₈][Hexanoate] or Trioctylammonium oleate [HN₈₈₈][Oleate]. In some implementations, the temperature at which is performed the non-catalytic treatment 428 can range for instance from room temperature to about 100° C. In some implementations, the duration of the non-catalytic treatment 428 can be for instance from 24 hours to 96 hours. It is to be understood that the temperature and the duration of the non-catalytic treatment 428 can vary according to numerous factors including the characteristics of the cracked bitumen product 416 and the second ionic liquid 422 chosen. Optionally, the second ionic liquid 422 can be separated 432 from the treated ionic liquid-bitumen mixture 430 to obtain a treated bitumen product 434.

In other implementations, when a reduction in contaminants such as sulphur and heavy metals, a TAN reduction, and/or a decrease the asphaltene content of the cracked bitumen product 416 is desired, the second ionic liquid 422 can be chosen to be an ionic liquid that is immiscible in a mixture of bitumen and diluent. Examples of suitable second ionic liquids 422 in such implementations include amino acid based ionic liquids, phosphonium ionic liquids and carbamate ionic liquids such as DMCARB. In these implementations, the non-catalytic treatment 428 can include mixing the second ionic liquid-bitumen mixture 426 at a given temperature for a given duration, and can be followed by a separation 432 that can be a liquid-liquid separation. As mentioned above, the mixing of the second ionic liquid-bitumen mixture 426 can facilitate the transfer of at least a portion of contaminants from the bitumen to the mixture of diluent and the second ionic liquid 422. The liquid-liquid extraction can then be performed to separate a first phase that includes bitumen and diluent of the second ionic liquid-bitumen mixture 426 from a second phase that includes the second ionic liquid 422. The first phase can be considered to correspond to the treated bitumen product 434, or if the diluent can then be separated from the first phase, the resulting bitumen can correspond to the treated bitumen product 434.

It should to be understood that although FIG. 10 illustrates an implementation that includes a catalytic cracking treatment followed by a non-catalytic treatment, in other implementations, the process for upgrading a bitumen feedstock can be in the reverse sequence and include the non-catalytic treatment followed by the catalytic cracking treatment.

In Situ Upgrading Using Ionic Liquids

In some implementations, the techniques described herein for upgrading heavy oil, such as bitumen, in the presence of ionic liquids, can be deployed in situ, i.e., directly in a bitumen-containing reservoir in an underground formation. Implementing such upgrading techniques in situ can provide various enhancements, such as reducing the viscosity and/or density of the bitumen and improving its chemical composition for instance by reducing asphaltene content in situ. The viscosity and/or density reduction can, in turn, help reduce diluent requirements for the product that is produced to the surface to be pipelinable. A production emulsion that includes upgraded hydrocarbons with reduced viscosity can facilitate reduced diluent added to the emulsion for transport and separation of the water from the oil in a surface facility, for example.

FIG. 11 shows an implementation of an in situ recovery process that is carried out via a horizontal well pair 10 provided in a subsurface formation. The horizontal well pair 10 includes an injection well 12 overlying a production well 14. The injection well 12 and the production well 14 shown in FIG. 11 are generally parallel and separated by an interwell region 16. The injection well 10 includes a vertical portion 18 and a horizontal portion 20 extending from the vertical portion 14, and the production well 14 includes a vertical portion 22 and a horizontal portion 24 extending from the vertical portion 22. Multiple well pairs can extend from a single well pad so as to be laterally spaced apart from each other and form an array of well pairs. The well pairs of an array can be parallel to each other, but various other configurations are possible. In addition, one or more infill wells can be placed in between adjacent well pairs at approximately the same depth, and can in some cases be operated later in the life of the well pairs to recover bypassed hydrocarbons in between the well pairs. Step-out wells can also be provided adjacent to a well pair that is located at one end of the array. The infill and step-out wells can also be operated in conjunction with the ionic liquid enhanced processes described herein.

Still referring to FIG. 1, the process includes injecting an upgrading fluid 26 into the subsurface formation. In the illustrated implementation, the upgrading fluid 26 is injected into the subsurface formation via a tubing string 28 inserted into the injection well 12. The injection well 12 generally includes a casing in its vertical portion 18, and a liner in its horizontal portion 20. The liner extends within the wellbore and can include injection ports such that, when the upgrading fluid 26 exits the tubing string 28, the upgrading fluid 26 can fill the horizontal portion 20 of the injection well 12 and penetrate into the subsurface formation through the injection ports. Alternatively, the liner can also include a slotted portion or a screen portion that allows the upgrading fluid 26 to exit the injection well 12 and penetrate into the subsurface formation. The upgrading fluid 26 can also be injected via the production well 14. In some implementations, when the upgrading fluid 26 is injected via the production well 14, it can be done for instance prior to or at the beginning of a startup process when fluid communication must be established between the wells of the well pair. In yet other implementations, the upgrading fluid can be injected into the subsurface formation via a single well configuration that is operated in a cyclic mode. The upgrading fluid can be injected via the injection well, the production well, an infill well, a step-out well, a well dedicated for cyclical operation or any other type of suitable well. In some implementations, the upgrading fluid can be circulated within the given well, e.g., the injection well and/or production well of a well pair, which may be performed during a startup process for example. Various combinations of injection and circulation can also be used in the wells depending on the well arrangement in the reservoir.

In some implementations, a heater string 30 (e.g., electric resistive heaters) can be inserted in the injection well 12 to provide heat to the upgrading fluid 26 as it is being carried through the injection well 12 via the tubing string 28, to heat the upgrading fluid 26 prior to exiting from the tubing string 28. In some implementations, heating the upgrading fluid as it travels along the injection well can also be performed via other means, such as electromagnetic heating (e.g., radio-frequency (RF) heating), closed-loop circulation of a hot fluid that is fluidly isolated from the upgrading fluid, or a combination thereof. It is also noted that such techniques can also be used in the production well during a startup process and prior to ramping up to normal production mode.

In addition to heating the upgrading fluid 26 while travelling along the injection well 12, the heater string 30 can also provide heat to the interwell region 16, for instance to pre-heat the bitumen prior to the injection of the upgrading fluid 26 into the subsurface formation. In some implementations, a heater (e.g., electric resistive heaters, RF heaters or other heating means) can also be provided in the production well 14 to provide additional heat to the interwell region 16. Thus, the reservoir can be preheated prior to circulation and/or injection of the upgrading fluid. The heating can also continue or be stopped when circulation and/or injection begin.

The upgrading fluid 26 includes at least one ionic liquid, which can contact the bitumen in situ and thereby facilitate partially upgrading the bitumen before being produced at the surface. The ionic liquid can perform the upgrading within the reservoir itself when it penetrates into the reservoir and/or within the wellbore when the bitumen is entrained into the upgrading fluid during circulation. In some implementations, the ionic liquid present in the upgrading fluid can act as a catalyst of the upgrading treatment resulting in an effective bitumen viscosity reduction. Hence, the ionic liquid can have both solvent and catalyst properties. In addition, in some implementations, the use of ionic liquids during an in situ bitumen extraction operation can facilitate wettability alteration, i.e., making the reservoir solids more water-wet. This wettability alteration can, in turn, enhance bitumen recovery, particularly in bitumen-wet and weakly water-wet reservoirs. In some implementations, the upgrading fluid could only contain the ionic liquid (i.e., 100% ionic liquid), but injection of the ionic liquid can also be performed using a carrier fluid (e.g., solvent, water and/or steam) as will be detailed below. For instance, one can inject an upgrading fluid containing 50 wt % or less of the ionic liquid, the rest being a carrier fluid and optional other additives. In some implementations, the ionic liquid in the upgrading fluid can be an ionic liquid that is miscible with the bitumen. Using miscible ionic liquids can enhance upgrading effectiveness and facilitate recovering a production fluid that is more pipelineable. Examples of ionic liquids that are miscible with the bitumen can include some carbamate ionic liquids such as N,N′-dipropylammonium N,N′-dipropyl carbamate (DPCARB) and N,N′-dibenzylammonium N,N′-dibenzyl carbamate (DBCARB), phosphonium ionic liquids such as Trihexyl-tetradecylphosphonium dicyanamide (Cyphos IL 105), fatty acid-based ionic liquids including trialkylammonium cations such as Trioctylammonium hexanoate [HN₈₈₈][Hexanoate] or Trioctylammonium oleate [HN₈₈₈][Oleate], and some acidic ionic liquids, among others. In some implementations, the ionic liquid can also be a water miscible ionic liquid. Using a water miscible ionic liquid can further enhance the in situ extraction operation, especially in reservoirs with initial water mobility. Therefore, in some implementations, the ionic liquid can be selected to be miscible both in bitumen and water. In some implementations, using upgrading fluid containing ionic liquids that are acidic can improve the catalytic efficiency of the upgrading treatment. Examples of acidic ionic liquids that can be used in the upgrading fluid can include Lewis acidic ionic liquids, such as strong Lewis acidic ionic liquids, Bronsted acidic ionic liquids or combinations thereof. Specific acidic ionic liquids belonging to these categories have been exemplified above and could be used as ionic liquids in the upgrading fluid.

In some implementations, the in situ upgrading treatment can be performed at a temperature and pressure in the underground reservoir at which the upgrading fluid can effectively contact the bitumen components. The temperature and pressure can be adjusted to facilitate mixing of the upgrading fluid and the ionic liquid therein with the bitumen, which, in turn, can allow obtaining the desired upgrading effects including viscosity and/or density reduction. In some implementations, the temperature for the in situ upgrading can be between about 50° C. and about 300° C. In some implementations, the temperature can be between about 50° C. and about 250° C., or from about 100° C. to about 250° C. or between 125° C. and 175° C. In some implementations, the temperature can be at least about 150° C. or around 150° C. The pressure for the in situ upgrading in the presence of ionic liquids can be relatively low. In some implementations, where the ionic liquid is injected during a dilation start up phase of the recovery operation, the pressure can go up to about 10-11 MPa. In some implementations, for long-term operations, such as during the bitumen production phase, the pressure can be about 2 MPa or lower, or even below 1.5 MPa. In some implementations, the temperature and pressure are provided so that the ionic liquid and/or the other components of the upgrading fluid are in liquid phase when reaching the reservoir and/or contacting the bitumen. The upgrading fluid can be injected either as a gas or in liquid phase as long as the ionic liquid is in liquid state when contacting the bitumen in the reservoir. If injected as a gas, the ionic liquid can condense into liquid phase in the reservoir and mix with bitumen. The quantity of ionic liquid to be injected and residence time in the reservoir can be adjusted depending on the level of desired upgrading and/or the bitumen components. In some implementations, the ionic liquid can be contacted with the bitumen in the reservoir for several days. The concentration of ionic liquid in the upgrading fluid injected can be up to 100 wt %. In some implementations, the ionic liquid can be in a concentration of about 50 wt % or less.

In some implementations, the upgrading fluid that is injected into the reservoir for the partial upgrading of the bitumen therein, can include a carrier fluid in addition to the ionic liquid, which can allow conveying the ionic liquid to the reservoir. A variety of different carrier fluid can be used. In some implementations, the carrier fluid can be a mobilizing fluid. The carrier fluid can thus include steam, water, hydrocarbon solvents or combinations thereof. In other words, the upgrading fluid can contain a mobilizing fluid and the ionic liquid as an additive. The composition of the fluids that are circulated and/or injected over the course of the in situ operation can vary. For example, the fluids used during startup can be different in terms of the fluid type or the concentration compared to the fluids used during normal recovery. In addition, for a given recovery operation, ionic liquids can be included in the fluids introduced down a well during one or more of the stages of the process with no ionic liquids being introduced during certain times or stages.

In some implementations, the upgrading fluid can be injected into the reservoir in the context of a steam assisted recovery process, including for instance steam-assisted gravity drainage (SAGD), cyclic steam stimulation (CSS), Expanding Solvent SAGD (ES-SAGD), or Liquid Addition to Steam for Enhancing Recovery (LASER) operations. Such processes can utilize pure steam or can be steam dominated with other additives, such as hydrocarbon solvents like naphtha, aromatics, or the like in minor quantities. An upgrading fluid containing at least one ionic liquid and steam as the carrier fluid, optionally with small amounts of solvent or other additives, can thus be injected into the reservoir at the production stage of the bitumen recovery process. In other implementations, an upgrading fluid containing an ionic liquid and steam as the carrier fluid, can be used at a later stage of the recovery operation, for instance during winddown or blowdown. For instance, the steam-containing upgrading fluid can be used in a late-life steamflood operation, such as post-SAGD or post-CSS. Injection of ionic liquids during such steam assisted recovery processes can facilitate reducing energy demands thanks to the partial upgrading that occurs in situ. When ionic liquids are injected with steam, the ionic liquids injection pattern can be continuous or discontinuous. Hence, in some implementations, the ionic liquids can be continuously co-injected with steam, and optionally a solvent. However, in other implementations, slugs of the ionic liquid can be injected at regular or irregular time intervals into the reservoir while steam, optionally with solvent, is continuously injected. In the context of a steam-assisted recovery operation, the temperature at which the upgrading fluid is injected is generally between about 150° C. and about 200° C. However, in some implementations, the temperature can be up to about 250° C. such as for a SAGD operation and even up to about 300° C. for a CSS operation. The temperature can be adjusted depending on the pressure in the reservoir. In some implementations, the temperature can be adjusted depending on the injection pressure. The steam can be superheated steam or saturated steam.

In some implementations, the upgrading fluid can include at least one solvent as the main carrier fluid to carry the ionic liquid into the reservoir to enable contacting the bitumen therein. In some implementations, the upgrading fluid can thus be injected in the reservoir in the context of a solvent assisted recovery process or a solvent dominated recovery process. The solvent can be any solvent commonly used in such bitumen recovery operations capable of mobilizing the bitumen in the formation in which the ionic liquid can be mixed as an additive. Example of solvents can include C3-C7 alkanes, such as propane, butane, pentane, hexane, heptane or any mixture thereof. Injecting the ionic liquid together with the solvent in the reservoir, can enhance the solvent effectiveness and accelerate the viscosity reduction and partial upgrading of the bitumen. For instance, the overall upgrading effects can be enhanced when a deasphalting solvent is used together with an ionic liquid, as the solvent causes some deasphalting in situ while the ionic liquid has upgrading effects on the partially deasphalted hydrocarbons that are recovered to surface. The bitumen in the production fluid can thus have a reduced asphaltene content as well as upgraded hydrocarbons from the ionic liquid. The solvent can be injected in liquid or vapour phase into the reservoir and can be heated at surface and/or below surface. In some implementations, the upgrading fluid including the ionic liquid and a solvent as the main carrier can further be injected at high temperatures into reservoir.

Heating the upgrading fluid that includes solvent and ionic liquid prior to entering the reservoir can be achieved in various ways including at surface and within the well. For example, a small amount of steam (e.g., about 10 wt % or less) can be co-injected with the upgrading fluid. Therefore, the recovery operation can include co-injection of an upgrading fluid including ionic liquid and solvent, with minimum steam required for heating the upgrading fluid. An alternative way of heating the solvent-containing upgrading fluid to be injected into the reservoir, can involve using an electric resistive heater (ERH), which can be included in the injection well, as explained above. The upgrading fluid is thus heated as is flows through the injection well, more specifically in the horizontal section thereof, and delivered at higher temperature into the reservoir. In other implementations, the solvent-containing upgrading fluid can be injected as a superheated fluid. In this case, the upgrading fluid can be heated at the surface through heating of the solvent beyond its vaporization temperature and then the superheated upgrading fluid is injected through the injection well into the reservoir. In certain implementations, the solvent-containing upgrading fluid can further include additional agents which can assist the bitumen upgrading in situ. Examples of such agents can include hydrogen donor compounds, which can hydrogenate some of the bitumen compounds to further promote the bitumen upgrading. In some implementations, hydrogen donor compounds can include partially hydrogenated refinery or upgrader intermediate product streams that could donate hydrogen. In some implementations, hydrogen donor compounds can include low carbon number alkanes (e.g., C3 and/or C4 alkanes), alcohols, glycerol, formic acid, decalin, tetralin, to name a few, and combinations thereof.

In some implementations, the upgrading fluid, which can include water, steam, and/or solvent as the one or more carrier fluids, can be heated using electromagnetic (EM) radiation, such as radio frequency (RF) waves, before being injected into the reservoir. By using such external energy, an efficient heating of the upgrading fluid and/or reservoir fluids can be achieved. A heated upgrading fluid can then contact the bitumen in the reservoir to enable the viscosity reduction of the bitumen by combination of the solvent dilution effect and the catalytic upgrading effect of the ionic liquid. EM heating can be particularly useful to heat upgrading fluids including polar fluids including liquid water and polar solvents (e.g., alcohols, dimethyl ether). If the ionic liquid in the upgrading fluid is polar, the ionic liquid can also be heated by EM radiation. The ionic liquid can also be heated by conduction from the EM heated carrier fluid. Steam heating by EM would be minimal due to the low density of steam. However, in some implementations, EM heating can still be used to heat steam. In some implementations, the upgrading fluid that can be heated by EM radiation can include water or steam as the carrier fluid and the ionic liquid can be present in the upgrading fluid at a concentration of about 50 wt % or less. In other implementations, the upgrading fluid that can be heated by EM radiation mainly includes a polar solvent as the carrier fluid (i.e., more than 50 wt % solvent) and the recovery operation can be related to a solvent-dominated recovery process (SDRP). In some implementations, solvent-containing upgrading fluid that is heated by EM radiation can be injected in the context of a process related to a cyclic solvent-dominated recovery process (CSDRP).

In some implementations, the upgrading fluid can include hot water as the carrier fluid and the process can be implemented in the context of a late-life hot waterflood operation. For instance, the upgrading fluid can include the ionic liquid and hot water at a temperature of about 150° C., and injection can be performed in a mature reservoir to contact residual bitumen therein and produce upgraded residual bitumen from the reservoir. In general, the late-life flooding operation can involve injecting a flooding fluid, such as water, into the hydrocarbon depleted chambers formed by the in situ process so that the fluid flows through the chambers to be recovered at another well operated as a late-life production well, thereby recovering additional hydrocarbons, utilizing residual heat in the chambers, and conducting in situ upgrading for recovery of upgraded hydrocarbons.

In other implementations, the upgrading fluid can include cold water as the carrier fluid and the process can be implemented by injecting a late-life upgrading fluid into the reservoir. For instance, such cold water-containing upgrading fluid can be injected in a hot reservoir, such as at an early stage of a heat recovery operation, to recover partially upgraded bitumen and heat from the reservoir. In this manner, ionic liquids can be used for injection into a reservoir along with a heat recovery liquid, such as water, so that the water can be heated in situ for heat recovery while the ionic liquid enables some in situ upgrading of residual hydrocarbons. When the heated fluid is recovered to surface, it can be used to recover and reuse the heat in various ways and when it contains upgraded hydrocarbons it can also be subjected to separation to recover the hydrocarbons.

It is noted that the selection of the ionic liquids and implementation at certain stages of in situ recovery processes can be performed based on operation parameters of the given process. For example, the stage for introduction of the ionic liquid can be performed based on the temperature and pressure of the reservoir and the upgrading ability of the ionic liquid at such temperatures. Thus, for ionic liquids that facilitate upgrading at lower temperatures compared to the temperatures of the production phase of the in situ process, it may be desirable to use the ionic liquids prior to and/or after the production phase when the temperatures are at a more ideal level. In another example, for a solvent dominated process that operates at lower temperatures, e.g., 40-80° C., during the production phase, it may be desirable to co-inject the solvent with an ionic liquid in slugs or continuously during the production phase. In a further example, for ionic liquids that can benefit from longer residence times in contact with the bitumen, it may be desirable to introduce the ionic liquid as early as possible, e.g., during startup or as a pre-treatment before startup, and optionally allowing the injected fluid to have a soaking time to further upgrade the hydrocarbons.

It is noted that in the context of the gravity dominated processes mentioned here, the ionic liquid can be selected or tailored to the operating parameters including the temperature and the carrier fluid (steam, water and/or solvent). Although ionic liquids tend to be stable, even at high temperatures, the ionic liquid can however be selected, in some implementations, to achieve the upgrading and/or dilution effect at low temperatures. In this context, longer residence time may be required.

It is noted here that gravity dominated processes, such as SAGD and variants thereof, can be used and include well arrangements that enable injection of a mobilizing fluid and drainage of fluids down to a lower production well. The gravity dominated processes can include horizontal well pair arrangements, but can also include various other well arrangements with one or more injection well per production well; one or more production well per injection well; horizontal, slanted or vertical wells; and the like. It is noted that other in situ processes can also be implemented, such as cyclical process like CSS and variants thereof. In such cyclical processes, each well is used for both injection and production cycles and there can be various arrangements of cyclically operated wells that are horizontal, slanted and/or vertical. It is also possible to operate a well arrangement in cyclic mode and then convert the wells for gravity dominated recovery, and vice versa. The ionic liquid based techniques described herein can be used in any of these in situ processes.

It should also be noted that once the ionic liquid has been injected into the reservoir, it can then be recovered at the surface with the production fluid containing some upgraded bitumen or a portion of the ionic liquid can purposefully remain in the reservoir. Where the ionic liquid is recovered with the production fluid, it can be separated at the surface and reused in the upgrading fluid for reinjection into the reservoir.

EXPERIMENTATION

Laboratory testing was performed to demonstrate the catalytic effect of various ionic liquids and/or their ability to reduce the viscosity of a bitumen sample as detailed in the following examples.

The bitumen sample used in the testing was composed of 1.5 wt % solids, 17 wt % asphaltenes, 14 wt % saturates, 35 wt % aromatics, and 30 wt % resin. The ionic liquids that were tested are reported in Table 1.

TABLE 1
Name and structure of the tested ionic liquids
Compound name and structure      Abbreviation
[HN222][Al2Cl7]  Triethylammonium heptachlorodialuminate ILLA1
[HN222][(HSO4)(H2SO4)x] (x = 0 or 1)  Triethylammonium hydrogen sulfate ILBA2 x = 0: ILBA20 x = 1: ILBA21
x = 0
x = 1
[Hmpyr][(HSO4)(H2SO4)x] (x = 0 or 1)  N-methylpyrrolidinium hydrogen sulfate ILBA3 x = 0: ILBA30 x = 1: ILBA31
x = 0
x = 1
[HN888][Oleate]                  ILS1
Trioctylammonium oleate
[HN888][Hexanoate]               ILS2
Trioctylammonium hexanoate

The compound ILLA1 is a strong Lewis acidic ionic liquid, compounds ILBA2 and ILBA3 are Bronsted acidic ionic liquids and compounds ILS1 and ILS2 are fatty acid-based ionic liquids. The compounds ILLA1, ILBA2 and ILBA3 were tested alone or in combinations to assess their ability for catalytically cracking the bitumen sample. ILS1 and ILS2 were tested to ass their ability to reduce the bitumen sample viscosity.

The viscosity was determined using a Brookfield DV2T™ (Brookfield, Middleboro, Mass., USA) viscometer with a small sample adapter and spindle SC4-27 or LV-4.

The thermal behaviour of the original bitumen sample and the samples after reaction with ionic liquids was determined by thermogravimetric analysis (TGA) performed using a TA Discovery 550™ TGA system (TA Instruments, New Castle, Del., USA). Samples of 15-20 mg were analyzed in 100 μL high-temperature platinum pans under a nitrogen atmosphere. All samples were heated from room temperature to 75° C. at 10° C. min⁻¹ with a 15 min isotherm at 75° C. to remove any excess volatiles or residual solvents. After the isotherm, samples were heated to 600° C. at 10° C. min⁻¹ and from 600 to 800 at 20° C. min⁻¹.

For the quantification, the fractions were separated as:

• • from 100 to 370° C.: light oil fraction (boiling points corresponding to gasoline, kerosene, and gas oil);
  • from 370 to 600° C.: heavy oil fraction;
  • from 600 to 800° C.: coke.

The weight loss was calculated for each fraction. The weight lost corresponding to the fractions of each sample was calculated and compared with those observed in the original sample.

Certain samples were characterized for their sulfur content using a Mitsubishi Model TS-100™ Trace Sulfur Analyzer with a liquid introduction, calibrated using elemental sulfur dissolved in xylene. The samples were dissolved in xylene and 10 μL of the resulting solutions were injected into the instrument.

Example 1: Bitumen Treatment ILLA1

In an N₂-filled glove bag, 20 mL glass vials equipped with Teflon™-coated magnetic stir bars were loaded with 5 g bitumen sample, followed by the addition of 0, 10, or 20 wt % of ILLA1. After the addition of the reactants, the vials were capped with vacuum grease and rubber septum and sealed with Parafilm™. The vials were removed from the glove bag and the reaction mixtures heated in a temperature-controlled oil bath with magnetic stirring at 100 or 150° C. for 1 or 3 h. After heating, the vials were removed from the oil bath and left to cool down on the benchtop.

Overall, the results indicate an increase in light products for the treatments at temperatures below thermal cracking (e.g., at 100 or 150° C.) using 10 wt % or 20 wt % ILLA1 in comparison to the control sample (no ionic liquid).

Effect of Temperature

ILLA1 (20 wt %) was used to treat the bitumen sample at 100 and 150° C. for 3 h, under constant stirring. As shown in FIG. 12, an increase in the light fraction was observed after treatment at both temperatures (1.9 and 4.3% at 100 and 150° C., respectively). At the same time, a decrease in the heavy fraction (5.8 and 7.4% at 100 and 150° C., respectively) and the coke fraction (3.9 and 3.1% at 100 and 150° C., respectively) were observed.

Effect of Catalyst Concentration

ILLA1 was added to the bitumen sample at different concentrations (10 or 20 wt %) and the reaction was performed for 1 h at 150° C., under constant stirring. As shown in FIG. 13, an increase in the light fraction was observed using both 10 and 20 wt % of the IL catalyst (˜4.5% increase) in comparison to the control sample (Cont150-1 h), together with a similar decrease (˜4.5%) in the heavy oil fraction.

Sulfur Content Determination

Sulfur was determined in the control sample (Cont150) and the sample treated with ILLA1 catalyst for 1 h (ILLA1-1 h). A reduction of 5.7% S was observed after treatment for 1 h (5.41 vs. 5.1 wt % S for Cont150 and ILLA1-1 h, respectively).

Example 2: Bitumen Treatment with ILBA2₀, ILBA2₁, ILBA3₀ and ILBA3₁

20 mL glass vials equipped with Teflon™-coated magnetic stir bars were loaded with 5 g bitumen sample followed by the addition of 20 wt % of ILBA2₀, ILBA2₁, ILBA3₀ or ILBA3₁ (collectively referred to as “ILBAs” below). After the addition of the reactants, the vials were capped with vacuum grease and rubber septum and sealed with Parafilm. The vials were heated in a temperature-controlled oil bath with magnetic stirring (200 rpm) at 150° C. for 3 h. After 3 h, the vials were removed from the oil bath and left to cool down on the benchtop.

The four tested Bronsted acidic ionic liquids were effective to upgrade the bitumen sample to some extent compared to the control (see FIG. 14). An increase in the acidity of the ILBA (i.e., from ILBA2₀ to ILBA2₁ or from ILBA3₀ to ILBA3₁) resulted in an increase of the light fraction and a decrease in the heavy fraction.

Example 3: Bitumen Treatment with a Combination of ILLA1 with One of ILBA2₀, ILBA2₁, ILBA3₀ and ILBA3₁

20 mL glass vials equipped with Teflon™-coated magnetic stir bars were loaded with 5 g bitumen sample followed by the addition of ˜0.6 g the ILBA. The vials were then transferred into an N₂-filled glove bag and ˜0.6 g ILLA1 was added. After the addition of the reactants, the vials were capped with vacuum grease and rubber septum and sealed with Parafilm™. The vials were removed from the glove bag and the reaction mixtures were heated in a temperature-controlled oil bath with magnetic stirring at 150° C. for 1 h. After reaction time, the vials were removed from the oil bath and left to cool down on the benchtop.

The results showed that the bitumen sample was upgraded to some extent using a combination of ILLA1 with one of ILBA2₀, ILBA2₁, ILBA3₀ and ILBA3₁ compared to the control. As more particularly seen in FIG. 15, an increase in the light fraction and a decrease in the heavy fraction were observed for the four combinations compared to the control. ILBA2₀ or ILBA2₁ in combination with ILLA1 shows an increase in the light fraction of the sample of 3.5 and 3.6% increase, respectively, a decrease in the heavy fraction of 7.8 and 7.6% decrease, respectively, and an increase in the coke fraction of 4.3 and 3.9% increase, respectively. A slight increase in the light fraction was also observed using the combination with ILBA2₀, ILBA2₁ or ILBA3₀ in comparison to when only ILLA1 was used.

Example 4: Bitumen Treatment with ILS1 and ILS2

3 g of warm bitumen sample (80° C.) was poured to 20 mL vials containing a magnetic stir bar and 1.5 g of ILS1 or ILS2 was added. The mixtures were stirred at 100° C. for 1 h and left on the bench to let them cool down to room temperature. ILS1 and ILS2 were able to fully mix with the bitumen. The viscosity of the samples was measured, and a reduction of the viscosity was observed as shown in Table 2.

TABLE 2
viscosity reduction of bitumen sample mixed with ILS1 and ILS2
Sample	Viscosity at 50° C.	Viscosity at 100° C.
Bitumen (original sample)	>13700 cP	~400 cP
Bitumen:ILS1 (2:1)	335 cP	~40 cP
Bitumen:ILS1 (2:1)	1470 cP	—

Claims

1. A process for treating a heavy oil or heavy oil-derived feedstock, the process comprising: contacting an acidic ionic liquid catalyst with the feedstock to obtain an ionic liquid-feedstock mixture;subjecting the ionic liquid-feedstock mixture to a catalytic cracking treatment, the catalytic cracking treatment comprising heating the ionic liquid-feedstock mixture under catalytic cracking conditions to obtain an ionic liquid-cracked feedstock mixture; andseparating the acidic ionic liquid catalyst from the ionic liquid-cracked feedstock mixture to obtain a cracked product and a recovered acidic ionic liquid catalyst.

2. The process of claim 1, wherein the feedstock comprises bitumen.

3. The process of claim 1, wherein the feedstock comprises a diluent-depleted bitumen stream from a distillation unit, a diluent stripping unit or a diluent recovery unit.

4. The process of claim 1, wherein the feedstock comprises a diluent-depleted bitumen stream that is obtained from a bitumen froth treatment operation.

5. The process of claim 1, wherein the feedstock comprises a diluent-depleted bitumen stream that has not been subjected to fractionation or distillation prior to being contacted with the acidic ionic liquid catalyst.

6. The process of claim 1, wherein the feedstock comprises a residuum stream from a distillation tower that has been operated to remove light hydrocarbon components.

7. (canceled)

8. The process of claim 1, wherein the feedstock comprises an overhead distillate product from a distillation tower.

9. (canceled)

10. The process of claim 1, further comprising subjecting the feedstock to a pre-treatment prior to the contacting of the feedstock with the acidic ionic liquid catalyst, wherein the pre-treatment comprises heating the feedstock at a pre-treatment temperature to reduce viscosity of the feedstock.

11. (canceled)

12. (canceled)

13. The process of claim 1, further comprising subjecting the feedstock to a pre-treatment prior to the contacting of the feedstock with the acidic ionic liquid catalyst, wherein the pre-treatment comprises adding a diluent comprising at least one of the naphthenic solvent, an aromatic hydrocarbon, and a non-deasphalting organic solvent, to the feedstock.

14. (canceled)

15. (canceled)

16. (canceled)

17. (canceled)

18. The process of claim 13, further comprising recovering the diluent to obtain a recovered diluent, wherein recovering the diluent is performed after the catalytic cracking treatment of the ionic liquid-feedstock mixture under catalytic cracking conditions and before separating the acidic ionic liquid catalyst from the ionic liquid-cracked feedstock mixture.

19. The process of claim 13, further comprising recovering the diluent to obtain a recovered diluent, wherein recovering the diluent is performed after separating the acidic ionic liquid catalyst from the ionic liquid-cracked feedstock mixture.

20. (canceled)

21. (canceled)

22. The process of claim 1, wherein the recovered acidic ionic liquid catalyst is reused as part of the acidic ionic liquid catalyst that contacts the feedstock.

23. The process of claim 1, wherein separating the acidic ionic liquid catalyst from the ionic liquid-cracked feedstock mixture comprises a liquid-liquid extraction of the ionic liquid-cracked feedstock mixture.

24. (canceled)

25. The process of claim 1, wherein the acidic ionic liquid catalyst is a Lewis acidic ionic liquid catalyst comprising a Lewis acidic anion and a cation selected from the group consisting of 1,3-dialkylimidazolium cations, tetraalkylphosphonium cations, tetraalkylammonium cations, trialkylammonium cations and combinations thereof.

26. (canceled)

27. (canceled)

28. (canceled)

29. (canceled)

30. The process of claim 25, wherein the Lewis acidic anion is a chlorometallate anion.

31. (canceled)

32. (canceled)

33. (canceled)

34. (canceled)

35. (canceled)

36. The process of claim 1, wherein the acidic ionic liquid catalyst is a strong Lewis acidic ionic liquid.

37. The process of claim 36, wherein the strong Lewis acidic ionic liquid comprises a Group(III)halometallate with a mole fraction XMXn above 0.5.

38. The process of claim 36, wherein the strong Lewis acidic ionic liquid comprises a Group(III)halometallate with a Gutmman Acceptor Number (AN) above 90.

39. The process of claim 36, wherein the strong Lewis acidic ionic liquid comprises a haloaluminate or a halogallate ionic liquid, with a mole fraction XMXn above 0.5.

40. (canceled)

41. (canceled)

42. (canceled)

43. The process of claim 39, wherein the strong Lewis acidic ionic liquid comprises a cation selected from the group consisting of 1,3-dialkylimidazolium cations, tetraalkylphosphonium cations, tetraalkylammonium cations, trialkylammonium cations, and combinations thereof.

44. (canceled)

45. (canceled)

46. (canceled)

47. The process of claim 1, wherein the acidic ionic liquid catalyst is a Bronsted acidic ionic liquid catalyst.

48. The process of claim 47, wherein the Bronsted acidic ionic liquid catalyst comprises a protonated imidazolium cation, a protonated C1-nalkyl-substituted imidazolium cation, a protonated tri(C1-nalkyl)ammonium cation, a protonated pyridinium cation, a guanidinium cation, a protonated C1-nalkyl-substituted guanidinium cation, a protonated pyrrolidinium cation, a protonated N—C1-nalkyl-pyrrolidinium cation, a protonated ammonium cation, a protonated tri(C1-nalkyl)ammonium cation, a COOH-bearing imidazolium cation or a SO3H-bearing imidazolium cation, where in the C1-nalkyl group, n is an integer from 2 to 20.

49. The process of claim 47, wherein the Bronsted acidic ionic liquid catalyst comprises a cation selected from the group consisting of

50. (canceled)

51. (canceled)

52. The process of claim 1, wherein the acidic ionic liquid catalyst comprises a combination of a Lewis acidic ionic liquid and a Bronsted acidic ionic liquid catalyst.

53. (canceled)

54. (canceled)

55. (canceled)

56. (canceled)

57. The process of claim 1, wherein the heating is performed at a temperature between about 50° C. and about 250° C.

58. The process of claim 1, wherein the concentration of the acidic ionic liquid catalyst in the ionic liquid-feedstock mixture is between about 5 wt % and about 50 wt %.

59-247. (canceled)