Patent Application
20240294836
This patent application claims priority under 35 U.S.C. Section 119 to Mexican Patent Application No. MX/a/2023/002067, filed Feb. 17, 2023, the entire disclosure of which is incorporated herein by reference.
The present disclosure belongs to the field of chemical products for crude oil conditioning, particularly, to basic demulsifying compounds. The present disclosure concerns to the application of random bipolymers based on alkyl acrylic-aminoalkyl acrylic with amphoteric endings to destabilize water-in-crude oil (W/O) emulsions in order to remove the emulsified water and salts—dissolved in the later, on land and on platform separation units for crude oils with gravities from 10 to 40° API.
Currently, the production of crude oils with a low API gravity—heavy and extra-heavy—is increasing because of the depletion of light and medium crude oil reserves. During the crude oil extraction process, the dragging of water and salts-dissolved in the water and crystals dispersed in the organic phasic—is an inevitable process. The water present in the crude oil is in form as primary emulsion—water/crude oil, W/O—or as complex emulsions, O/W/O—secondary or tertiary, with irregular shapes, inverted, etc. These emulsions could be microemulsions—droplet size between 0.1 and 100 μm—or nano-emulsions—droplet size less to 0.1 μm, being the latter ones that have been observing more frequently in recently extracted crude oils. It is important to mention that the W/O or O/W/O emulsions present high colloidal stability because of the action of natural surfactants present in the crude oil, mainly, asphaltenes and resins agglomerates, which form a rigid and very stable film around the dispersed water droplets in the crude oil, preventing the coalescence of the water droplets. [1] Asphaltenes present a polyaromatic structure with polar groups, which induce a surfactant activity and, therefore, a great stabilization of emulsion.[2] In addition to this hindrance, the presence of paraffinic agglomerates, which tend to precipitate on the water/crude oil interface, cause the appearance of another barrier that prevents the coalescence of water droplets.
The presence of water and salts in crude oil is harmful, since both contaminates cause major problems such as: (1) corrosion and abrasion in employed equipment and pipes to transport this; (2) scale formation, which creates an obstruction to the flow of crude oil; and, finally, (3) they induce the poisoning of catalysts used during various stages of the chemical treatment of this resource.
About the above, it is essential to eliminate the emulsified water, or, at least, to reduce its volume to a maximum of 0.5 vol %, to fulfill the crude oil export specifications. The separation of the aqueous phase makes possible to eliminate the salts dissolved in it. Because of aforementioned, the crude-oil dehydration process becomes a technological challenge, which must be solved with efficient processes and at a low cost. In this sense, to induce the destabilization of emulsions present in crude oil, and thus, to remove the emulsified water, at industrial level has been applied various treatments—mechanical, thermal, electrical, between others—.[3] However, the treatment based on chemical products is the most employed, both at laboratory and at industrial level; this procedure consists of the addition of some chemical compounds capable of provoking the breakdown of the rigid film—formed by asphaltenes and resins—that surrounds the water droplet. Various chemical compounds have been reported in the literature as demulsifying agents for crude oils. [3]
In this regard, ionic liquids present a good performance for the removal of emulsified water, which is mainly due to the fact that these are amphoteric molecules. However, these have the drawback of a high production cost, which makes them unfeasible to be applied at industrial level; for this reason, their use is mainly restricted at laboratory level. [4-6] On the other hand, demulsifiers based on polyethers have shown good performance to induce the destabilization of the water/crude oil interface. Among the products based on polyethers are the ethoxylated phenolic resins and the ethoxylated nonylphenols, which have been widely used at industrial level. The efficiency of these products to remove the water depends on the length of the alkylic chain and the degree of ethoxylation. [7] It is important to mention that these are frequently dosed as a formulation of ethoxylated phenolic resin/ethoxylated nonylphenol.
Despite its good performance as dehydrating agents, both products present the problem of a low chemical stability in acid medium, because of the terminal hydroxyl groups, —OH, which suffer chemical degradation and lead to null efficiency in the dehydrating process. In addition to this, if the degree of ethoxylation is too high, the partition coefficient (Log P) decreases, therefore, the water solubility increases, which implies a diffusion problem in crude oil. Another factor against of both products is the synthesis process, since these are manufactured under high-temperature and high-pressure conditions. Finally, at worldwide exists an important decline in the production of ethylene oxide, which causes an increase in the cost of production.
Another type of demulsifiers based on polyethers, widely employed a laboratory and industrial level, are the triblock bipolymers of propylene polyoxide (PPO) and ethylene polyoxide (POE).[8-11] In order to have a good diffusion of these products in the organic phase, it is important that the propylene oxide (PO) should be in a higher weight proportion than the ethylene oxide (EO). On the other hand, it should be mentioned that these polymers are applied as a formulation or combination of at least three PPO/PEO basics of different molecular mass, with the main aim that the formulation possesses the three required properties of a good demulsifying agent-breaker, coalescer and clarifier. For this reason, it is necessary to carry out three synthesis processes of triblock bipolymers—each one of two synthesis steps at high temperature and pressure: the first one to form the PPO block and the second one to obtain the PEO block—to only get one formulation, evidently, it becomes an inconvenient for its usage. In addition to this, and as in the case of ethoxylated phenolic resin and ethoxylated nonylphenol, the PEO-PPO-PEO triblock bipolymers present the problem of chemical degradation in acid medium, because of the protonation of the ending hydroxyl groups; besides, in acid medium exists the formation of micelles, which strengthen the bond between the triblock bipolymer and the water molecules, complicating the dehydrating process.
In order to avoid this protonation of the ending hydroxyl groups, the functionalization of these groups has been reported in the literature. The Mexican patent document MX 321203 B [12] and the US patent document U.S. Pat. No. 8,815,960 [13] describe the laboratory-level synthesis procedure for the functionalization of the POE-POP-POE triblock copolymers with aliphatic and/or cyclic secondary amines. The functionalized copolymers were evaluated in a crude oil of 15.9° API, which displayed a better performance in the removal of emulsified water that the FC-1 and FC-2 commercial formulations based on polyethers.
Cendejas et al. firstly assessed the water removal performance of the PEO-PPO-PEO non-functionalized triblock bipolymers, considering different molecular mass, in a heavy crude oil of 15.0° API; noting that, despite presenting a poor performance as demulsifier agents, there is a suitable molecular mass of bipolymer—for this case
The bifunctionalized triblock bipolymers were assessed in the same crude oil, determining that the functionalized bipolymer with N-butyl and N-ethanolamine displayed the highest water removal efficiency, removing 90 vol % at a dosage of 500 ppm.
On the other hand, Zamora et al. synthesized PEO-PPO-PEO triblock bipolymers with quaternary ammonium salt endings.[15] Unlike the obtained bipolymers by Cendejas et al., in which the ending fragments correspond to a neutral tertiary amine; about the latter case, there is an ending fragment with an ionic character, which, obviously, generates a different chemical environment in the molecule, mimicking these fragments to an ionic liquid. These triblock bipolymers with quaternary ammonium salts ending were evaluated in two Mexican crude oils—7.5 and 17.8° API—. In this sense, the bipolymers with ending fragment of trioctylammonium benzenesulfonate and quinolinium benzensulfonate showed the best performance in both crude oils; however, the bipolymers with quinolinium endings displayed a higher dehydrating efficiency in the extra-heavy crude oil, since these managed to remove 100 vol % of the emulsified water.
The obtention of the functionalized bipolymers with secondary and tertiary amines described above involves two synthesis stage at laboratory level, with various unit operations in each stage. In order to scale up these products, the Canadian patent document CA 2852863 C [16], the U.S. Pat. No. 10,125,226 B2 [17] and the Mexican patent document MX 368308 B [18] protect the synthesis procedure to functionalize the PEO-PPO-PEO triblock bipolymers with secondary and tertiary amines in reactors with a capacity from 1 to 100 L. The main advantage of this synthesis process is the reduction in the number of unit operations considered in each synthesis step-shorter total synthesis time.
On the other hand, the United State patent document U.S. Pat. No. 11,261,282 B2 protects the obtaining of PEO-PPO-PEO triblock bipolymers with amphoteric endings and their use as demulsifying agents.[19] N,N-Dialkyl amine triblock bipolymers are functionalized with acrylic derivatives by means of the Michael reaction. The amphoteric triblock bipolymers were evaluated in two crude oils of 7.5 and 11.2° API. The presence of amphoteric endings—ionic fragment—confers to the bipolymer a greater capacity to induce, in a more efficient manner, the destabilization of the water/crude oil interface and, therefore, to promote a greater coalescence of the water droplets, surpassing in efficiency to the non-functionalized triblock bipolymer and a commercial formulation based on polyethers.
These functionalizations in the triblock bipolymers avoid the chemical degradation and increase their performance to remove the emulsified water, even when several synthesis steps are required to obtain them. Following this line of research, Fuentes et al. carried out a quantitative structure activity relationship (QSAR) analysis using quantum parameters of amphoteric triblock bipolymers and physicochemical properties of crude oils.[20] Six equations were obtained in the study, V1-V6; however, only the V1 equation fulfilled with the stablished criteria about the external validation, rm2>0.5, being in this case rm2=0.72; thus, the V1 equation allows obtaining a calculated removal efficiency value for this type of chemical compounds.
In order to get demulsifying agents with a different chemistry to the polyethers, the use of acrylic-based polymers has been reported in the literature. In this sense, Yuan et al. described the assessment of an ionic polyacrylate, based on poly(N-[3-(dimethylamino) propyl] methacryamide) quaternized with 3-chloro-1-propanol to destabilize a crude oil-in-water (O/W) emulsion. It is important to mention that these products are dissolved in water to be applied to the treated system—continuous phase: water; therefore, these cannot be used to destabilize water—in crude oil (W/O) emulsions; where the demulsifying agent must be dissolved in an organic solvent to be applied—continuous phase: crude oil.[21] On the other hand, the CN 101,255,354 patent document describes the performance of bipolymers based on butyl acrylate and acrylic acid as dehydrants of petroleum, synthesized by means of solution polymerization.[22] The acrylic-based bipolymers displayed a good performance as emulsion breakers, as well as good clarification of the aqueous phase.
Cevada et al. described the assessment of two random acrylic bipolymers based on butyl acrylate (BuA) and ethylhexyl acrylate (2-EHA) as demulsifying agents in a heavy Mexican crude oil of 10.2° API.[23] The BuA/2-EHA acrylic bipolymers were synthesized by emulsion polymerization, varying the monomeric ratio at 70/30 and 30/70 wt %, as well as the molecular mass of the synthesized polymers. The bipolymer with 70 wt % of butyl acrylate—hydrophobic monomer—and with an average molecular mass of 11,000 g mol−1 displayed the higher removal efficiency of emulsified water.
On the other side, the Mexican patent application document Mx/a/2018/002971,[24] the U.S. Pat. No. 10,793,783 B2,[25] and the Canadian patent document CA 3013494 C [26] report the use of random bipolymers based on alkyl acrylic-carboxyalkyl acrylic, with different monomeric weight ratio, which were evaluated as dehydrating agents for different crude oils. The alkyl acrylic-carboxyalkyl acrylic monomeric ratio of 80/20 wt % exhibited the best performance in the removal of emulsified water in extra-heavy crude oils-6.1 and 7.5° API, being capable of removing 100 vol %, exceeding a commercial formulation based on polyethers.
The Mexican patent application document Mx/a/2020/011505 [27] and the United States patent application document US 2022/0135886 A1 [28] report the use of bipolymers based on ethylen alkanoate-acrylic (labeled as BV), of different molecular mass, as destabilizers of complex emulsions in crude oil blends. The performance of the BV random bipolymers to remove the emulsified water present in a crude oil blend with specific gravity of 20.1° API was compared with the COP-04 ethylen alkanoate-acrylic—bipolymer block—and the FC-01 commercial formulation based on polyethers. The BV random bipolymers showed a higher coalescence rate, reaching the total water removal at 90 min, whereas the COP-04 and FC-01 products managed to remove 93 and 82 vol %, respectively. Therefore, it is notorious that the randomness of the polymeric system gives to the bipolymers a better diffusion in the organic phase, as well as a better interaction in the destabilization of the water/crude oil interface, compared with a block system—based on acrylic or polyether.
On the other hand, the Mexican patent document MX 386485 B, [29] the United State patent document U.S. Pat. No. 10,975,185 B2,[30] and the Canadian patent document CA 2987447 C [31] describe the synthesis to obtain random bipolymers based on alky acrylic-aminoalkyl acrylics with different monomeric compositions; the general structure of these bipolymers is presented in the Formula (1); while the specific case of N-alkylmorpholine is shown in the Formula (2).
where, R1 and R3 radical=hydrogen or methyl; R2=alkyl group; R4 and R5=hydrogen, methyl and ethyl; the x and y values range from 2 to 900; whereas that the z value ranges from 1 to 3. Number average molecular masses are in the range from 1,000 to 180,000 g·mol−1. These random bipolymers were assessed as dehydrating agents in crude oils with specific gravities of 12.3, 18.7 and 38.7° API. The random bipolymers with alkyl acrylic-aminoalkyl acrylic weight monomeric ratio of 60/40, 70/30 and 80/20 wt % displayed a good performance to destabilize the water/crude oil interface, completely removing the emulsified water; whereas the FDH-1 commercial formulation—comprised four PEO-PPO-PEO basics of different molecular mass—, presented a lower removal efficiency and coalescence rate.
It is important to reiterate that the presence of water-in-crude oil emulsions is a huge problem for the oil industry, because of this does not only affect the quality of crude oil, but also, this causes a great damage to the facilities—pipes and equipment, as well as in subsequent processes—refining stage. These drawbacks cause a negative economic impact; therefore, it is extremely important for the oil industry to eliminate the water from the crude oil, or, at least, that the water amount could be less that the established for export.
On the basis of what has been described above, it is notorious that random acrylic bipolymers display excellent demulsifying properties for a wide variety of crude oils. Considering this, the present disclosure is related to obtaining a random acrylic bipolymer with amphoteric fragments, which is carried out by the functionalization of random bipolymers based on alkyl acrylic—aminoalkyl acrylic—Formulas (1) and (2); described in the Mexican patent document MX 386485 B,[29] the United State patent document U.S. Pat. No. 10,975,185 B2,[30] and the Canadian patent document CA 2987447 C; [31] with acrylic derivatives through the aza-Michael addition reaction.
The following references provide further background:
In one aspect, a first object of the present disclosure relates to a process for obtaining random acrylic bipolymers with amphoteric endings, which are synthesized by the aza-Michael addition reaction. Once the amphoteric random acrylic bipolymers have been obtained, a second object of the present disclosure is the assessment of these products as dehydrating agents of crude oils with gravities between 10 and 40° API, where the presence of the amphoteric fragment into the bipolymer creates a different environment chemical comparing with the non-functionalized random acrylic bipolymers, inducing in more efficient manner the destabilization of the asphaltenes' and resins' layers-which surround the emulsified water droplets, besides of mimic to an ionic liquid.
In another aspect, the present disclosure relates to random acrylic bipolymers based on alkyl acrylic-aminoalkyl acrylic with amphoteric endings, as dehydrating agents to remove emulsified water in crude oil with gravities from 10 to 40° API, having structural formulas (3) and (4), with molecular masses from 1,900 to 600,000 g·mol−1 as follows:
In another aspect, the present disclosure relates to a process of synthesizing amphoteric random acrylic bipolymers for use as dehydrating agents for crude oils according to the present disclosure, where the process involves carrying out an aza-Michael addition reaction by dissolving the alkyl acrylic-aminoalkyl acrylic in an organic solvent, where the organic solvent has a boiling point ranging from about 40° C. to about 130° C., and where the organic solvent can include, without limitation, methanol, ethanol, isopropanol, chloroform, benezene and its derivatives, toluene, xylene, and the like.
In one embodiment of the process of the present disclosure, the acrylic derivatives used for functionalization can include, without limitation, acrylic acid, methacrylic acid, 2-methoxyethyl acrylate, 2-phenoxyethyl acrylate, di(ethylene glycol) ethyl ether acrylate, 2-methoxyethyl methacrylate, 2-phenoxyethyl methacrylate, di(ethylene glycol) ethyl ether methacrylate, 2-ethoxyethyl, 2-ethoxyethyl methacrylate, 2-butoxyethyl acrylate, 2-butoxyethyl methacrylate, 2-ethoxymethyl acrylate, 2-ethoxymethyl methacrylate, hydroxymethyl acrylate, 2-hydroxyethyl acrylate, 3-hydroxypropyl acrylate, 4-hydroxybutyl acrylate, 5-hydroxypentyl acrylate, 6-hydroxyhexyl acrylate, 7-hydroxyheptyl acrylate, 8-hydroxyoctyl acrylate, 9-hydroxynonyl acrylate, 10-hydroxydecyl acrylate, 11-undecyl acrylate, 12-dodecyl, hydroxymethyl methacrylate, 2-hydroxyethyl methacrylate, 3-hydroxypropyl methacrylate, 4-hydroxybutyl methacrylate, 5-hydroxypentyl methacrylate, 6-hydroxyhexyl methacrylate, 7-hydroxyheptyl methacrylate, 8-hydroxyoctyl methacrylate, 9-hydroxynonyl methacrylate, 10-hydroxydecyl methacrylate, 11-undecyl methacrylate or 12-dodecyl methacrylate, 2-carboxyethyl acrylate, 3-carboxypropyl acrylate, 4-carboxybutyl acrylate, 2-carboxyethyl methacrylate, 3-carboxypropyl, 4-carboxybutyl methacrylate, 2-ethylamino acrylate, 2-(dimethylamino)ethyl acrylate, 3-propylamino acrylate, 3-(dimethylamino)propyl acrylate, 2-(diethylamino)ethyl acrylate, 2-ethylamino methacrylate, 2-(dimethylamino)ethyl methacrylate, 3-propylamino methacrylate, 3-(dimethylamino)propyl methacrylate, 2-(diethylamino)ethyl methacrylate, 3-sulfonatopropyl acrylate potassium salt, and the like.
In one embodiment of the process of the present disclosure, the functionalization involves the aza-Michael addition reaction, where a molar ratio of random bipolymer based on alkyl acrylic aminoalkyl acrylic/acrylic derivative is in a range from about 1.0/1.0 to 1.0/8.0 the weight percentage of the aminoalkyl acrylate monomer.
In one embodiment of the process of the present disclosure, the acrylic derivative is added under reagent deficiency conditions at a mass flow ranging from between about 1 and about 50 g L−1 min−1.
In one embodiment of the process of the present disclosure, the aza-Michael addition reaction is carried out at a reaction temperature ranging from between about 45° C. and about 120° C. for a period ranging from about 2 h to about 12 h.
In another aspect, the present disclosure relates to a method of using the amphoteric random acrylic bipolymers according to the present disclosure, where the method involves dissolving the dry amphoteric random acrylic bipolymer in a suitable organic solvent, where the organic solvent can include, without limitation, dichloromethane, methanol, ethanol, isopropanol, chloroform, acetone, dimethyl sulfoxide, tetrahydrofuran, dioxane, 2-butoxyethanol, 2-butoxyethanol acetate, benzene and its derivatives, toluene, xylene, jet fuel, naphtha, and the like, for its final application as a dehydrating agent in crude oils with gravities ranging from about 10 to about 40° API.
In one embodiment of the method of the present disclosure, the concentration of a solution of the amphoteric random acrylic bipolymer ranges from about 1.0 to about 50.0 wt %.
In one embodiment of the method of the present disclosure, the solution is dosed in the crude oil with a concentration in a range from about 10 to about 2,000 ppm.
The patent or application file contains at least one drawing executed in color. Copies of this patent or patent application publication with color drawing(s) will be provided by the Office upon request and payment of the necessary fee.
In order to get a better understanding of the random bipolymers based on acrylics with amphoteric fragments for the removal of aqueous dispersions in crude oils and their synthesis procedure in the present disclosure, the content of the drawings is briefly described below:
In order to respond to the technological challenge that represents the development of demulsifying agents capable of efficiently eliminating the emulsified water present in crude oil, and besides, that will be also chemically resistant to well acid stimulation conditions, the present disclosure consists of novel demulsifying agents obtained for the functionalization of random bipolymers based on alkyl acrylate and aminoalkyl acrylate—protected for the Mexican patent document 386485 B, the U.S. Pat. No. 10,975,185 B2,[30] and the Canadian patent document CA 2987447 C [31], with different acrylic derivatives, by means of the aza-Michael addition reaction. Amphoteric random acrylic bipolymers were assessed as demulsifying agents in crude oils with specific gravities between 10 and 40° API, showing superior performance as breakers, coalescers, and clarifiers than the non-functionalized acrylic bipolymer and a commercial formulation based on polyethers.
Despite the fact the functionalization implying on more reaction stage in the process for obtaining the demulsifying agents object of the present disclosure, it is important to highlight that a single amphoteric random acrylic bipolymer presents the required properties to dehydrate a crude oil: (1) to destabilize the asphaltenes' and resins' barriers—breaker—, (2) to induce more efficiently the coalescence of dispersed water droplets—coalescer—and (3) an excellent clarification of the removed water—clarifier—. This implies clear advantages in terms of the cost-benefit ratio, in contrast to the commercial formulations based on polyethers, in where at least three PEO-PPO-PEO triblock bipolymers of different molecular masses are required to provide the functions as braker, coalescer and clarifying. Likewise, it is important to mention that there are currently periodic deficiencies in the production of ethylene oxide, as well as restrictions on its use.
In addition to the above, the results about the described evaluations as demonstrative examples in the present disclosure show that amphoteric random acrylic bipolymers represent a viable alternative as demulsifying agents capable of removing all the emulsified water present in crude oil, complying with the export specifications, and furthermore, ensuring the integrity of employed equipment for the transport and treatment.
For obtaining the amphoteric random acrylic bipolymers, firstly, it is necessary to synthesize the random bipolymer based on alkyl acrylic-aminoalkyl acrylic of controlled molecular mass by means of emulsion polymerization in a semi-continuous process, following the procedure described in the Mexican patent document MX 386485 B, the U.S. Pat. No. 10,975,185 B2,[30] and the Canadian patent document CA 2987447 C.[31] Formula (1) exhibits the base structure of random bipolymer based on alkyl acrylic-aminoalkyl acrylic protected in the aforementioned documents. Once the bipolymer based on alkyl acrylic-aminoalkyl acrylic (non-functionalized random bipolymer) has been synthesized, the functionalization is carried out by means of the aza-Michael addition reaction, where, firstly, the dried random bipolymer based on alkyl acrylic-aminoalkyl acrylic is dissolved in an organic solvent, whose boiling point is in the range from 40 to 130° C., such as methanol, ethanol, isopropanol, chloroform, benzene and its derivatives, toluene or xylene, individually or in a mixture of them. On the basis of the weight percent of the aminoalkyl acrylic monomer in the random bipolymer, the molar ration of the non-functionalized/acrylic derivative is from 1.0/1.0 to 1.0/8.0. The acrylic derivative must be added slowly under monomer starving conditions, at mass flow between 1 and 50 g·L−1 min−1, in order to avoid the Trommsdorff effect. The system is kept at reflux and the reaction temperature is selected in the range from 45 to 120° C., whereas the reaction time is established from 2 to 12 h. After the reaction is complete, the solvent is evaporated at a temperature from 40 to 130° C., to obtain a viscous liquid. Once the amphoteric random acrylic bipolymer is dried, it is dissolved in a suitable organic solvent: dichloromethane, methanol, ethanol, isopropanol, chloroform, acetone, dimethyl sulfoxide, tetrahydrofuran, dioxane, 2-butoxyethanol, 2-butoxyethanol acetate, benzene and its derivatives, toluene, xylene, jet fuel, and naphtha, for its final application as a dehydrating agent in crude oils with gravities from 10 to 40° API. The effective concentration of the amphoteric random acrylic bipolymer in solution can vary between 1.0 and 50.0 wt %; whereas the formulation of the amphoteric random acrylic bipolymer is dosed at a concentration between 10 and 2,000 ppm in crude oils with gravities from 10 to 40° API, in order to destabilize the water-in-crude oil emulsions present in crude oils and thus, to remove the emulsified water.
Formulas (3) and (4) display the model structures of the amphoteric random acrylic bipolymers comprised in the present disclosure.
Number molecular masses of the bipolymers are considered in the range from 1,900 to 600,000 g·mol−1.
Amphoteric random acrylic bipolymers object of the present disclosure are added in effective amounts that vary between 10 and 2,000 ppm to crude oils with gravities of 10 to 40° API.
The present disclosure will be described with reference to a specific number of examples, which will be only considered as illustrative and not restrictive. Amphoteric random acrylic bipolymers were characterized using the following instrumental methods:
The KAm-1 y KAm-4 random bipolymers based on alkyl acrylic-aminoalkyl acrylic were synthesized considering an alkyl acrylic/aminoalkyl acrylic monomeric weigh ratio of 60/40 wt %, where the alkyl acrylic monomer corresponds to butyl acrylate (R1=hydrogen; R2=n-butyl) and the aminoalkyl acrylic monomer corresponds to 2-(dimethylamino) ethyl acrylate (R3=hydrogen; R4 and R5=methyl; z=2). For the KAm-1 random bipolymer (
n
Table 2 depicts the values of number average molecular mass and the polydispersity index of the amphoteric random acrylic bipolymers: KAm-4-AA—functionalization with acrylic acid (AA)—, Kam4-AMA—functionalization with methacrylic acid (AMA)—, KAm-4-2DMAE—functionalization with 2-(dimethylamino)ethyl acrylate (2DMAE)—, KAm-4-2CEA—functionalization with 2-carboxyethyl acrylate (2CEA)—, KAm-4-2HEA—functionalization with 2-hidroxyethyl acrylate (2HEA)—, KAm-4-2MEA—functionalization with 2-metoxyethyl acrylate (2MEA)—and KAm-4-3SPA—functionalization with 3-sulfopropyl acrylate salt potassium (3SPA).
n
The following examples are presented to illustrate the spectroscopic characteristic of amphoteric rando acrylic bipolymers applied as dehydrating agents in crude oils with gravities from 10 to 40° API. These examples should not be considered as limiting to what is claimed here.
Synthesis of amphoteric random acrylic bipolymer: aza-Michael addition reaction. 0.230 a 0.732 mmol of the KAm-1 or KAm-4 random bipolymer and 150 mL of organic dissolvent are added in a flat-bottom flask. Subsequently, from 0.230 to 2.928 mmol of acrylic derivative—acrylic acid (AA), methacrylic acid (AMA), 2-carboxyethyl acrylate (2CEA), 2-hydroxyethyl acrylate (2HEA), 2-methoxyethyl acrylate (2MEA), (2-dimethylamino) ethyl acrylate (2DMAE), or 3-sulfopropyl acrylate potassium salt (3SPA)—is added into the flat-bottom flask. Afterwards, the temperature is increased between 45 and 120° C., depending on the boiling point of the employed solvent. The reaction mixture is kept at constant reflux for a period from 2 to 12 h. Once the reaction is completed, the solvent is evaporated at a temperature from 40 to 130° C., in order to obtain a viscous liquid.
KAm-1-AA bipolymer. I.R. ν cm−1: 3,355; 3,033; 2,963; 2,942; 2,872; 2,746; 2,507; 1,947; 1,730; 1,596; 1,463; 1,372; 1,253; 1,176; 1,098; 1,028; 1,007; 939; 841; 812; and 741.
1H NMR (CDCl3) δ ppm: 0.94, 1.36, 1.60, 1.91, 2.28, 2.69, 2.87, 3.10, 3.40, 3.45, 3.60, 4.02.
13C NMR (CDCl3) δ ppm: 13.75, 14.15, 19.12, 30.53, 30.62, 34.49-36.74, 41.44, 43.60, 51.48, 55.55, 62.07, 62.14, 64.41, 64.49, 65.41, and 174.50.
KAm-1-AMA bipolymer. I.R. ν cm−1: 3,307; 3,034; 2,958; 2,935; 2,874; 2,744; 2,546; 1,954; 1,734; 1,633: 1,589; 1,456; 1,377; 1,255; 1,169; 1,119; 1,066; 1,022; 941; 839; 806; and 742.
1H NMR (CDCl3) δ ppm: 0.94, 1.37, 1.59, 1.92, 1.93, 2.29, 2.34, 2.86, 3.15, 3.16, 3.45, 3.60, 3.92, and 4.02.
13C NMR (, CDCl3) δ ppm: 13.70, 14.14, 18.49, 19.07, 30.56, 34.59-36.72, 41.43, 41.46, 43.56, 51.44, 56.52, 60.41, 60.88, 61.13, 64.42, 66.79, and 174.55.
KAm-1-2CEA bipolymer. I.R. ν cm−1: 3,348; 3,037; 2,962; 2,935; 2,875; 2,744; 2,557; 1,948; 1,736; 1,635; 1,589; 1,466; 1,402; 1,261; 1,176; 1,066; 995; 945; 820; and 742.
1H NMR (CDCl3) δ ppm: 0.93, 1.37, 1.59, 1.63, 1.90, 2.26, 2.57, 2.67, 2.86, 3.12, 3.16, 3.88, 3.93, 3.96, 4.03, and 4.41.
13C NMR (CDCl3) δ ppm: 13.76, 14.15, 19.13, 30.66, 33.80, 34.12-36.66, 37.50, 41.44, 43.60, 51.53, 55.66, 56.34, 59.90, 60.25, 60.34, 64.47, 65.61, and 174.53.
KAm-1-2HEA bipolymer. I.R. ν cm−1: 3,342; 3,037; 2,960; 2,935; 2,874; 2,538; 1,961; 1,736; 1,597; 1,462; 1,379; 1,257; 1,171; 1,096; 1,063; 941; 887; 839; 810; and 741.
1H NMR (CDCl3) δ ppm: 0.94, 1.37, 1.60, 1.62, 1.91, 2.27, 2.69, 2.70, 2.88, 3.12, 3.45, 3.59, 3.83, 3.96, 3.97, 4.04, 4.17, and 4.31.
13C NMR (CDCl3) δ ppm: 13.75, 14.14, 19.12, 30.44, 30.64, 34.22-36.68, 41.46, 43.38-43.64, 51.47, 55.57, 61.11, 63.04, 63.46, 64.42, 65.48, 67.24, 69.72, and 174.54.
KAm-1-2MEA bipolymer. I.R. ν cm−1: 3,363; 3,036; 2,958; 2,933; 2,874; 2,511; 1,973; 1,736; 1,595; 1,466; 1,379; 1,254; 1,163; 1,101; 941; 843; 810; and 739.
1H NMR (CDCl3) δ ppm: 0.95, 1.37, 1.60, 1.61, 1.92, 2.28, 2.37, 2.64, 2.66, 2.83, 3.12, 3.13, 3.48, 3.61, 3.65, 3.86, 3.88, 4.04, 4.05, and 4.16.
13C NMR (CDCl3) δ ppm: 13.71, 14.10, 19.06, 30.57, 30.94, 34.32-36.75, 41.40, 43.59, 45.17, 51.39, 56.21, 57.10, 58.67, 59.59, 61.79, 62.31, 64.40, 64.64, 65.28, 69.82, 70.28, and 174.51.
KAm-1-2DMAE bipolymer. I.R. ν cm−1: 3,369; 3,037; 2,960; 2,933; 2,874; 2,524; 1,994; 1,738; 1,589; 1,460; 1,381; 1,255; 1,167; 1,119; 1,066; 939; 839; 808; 739; 687; and 635.
1H NMR (CDCl3) δ ppm: 0.94, 1.38, 1.21, 1.60, 1.64, 1.91, 2.28, 2.31, 2.32, 2.42, 2.53, 2.67, 3.13, 3.15, 3.60, 3.89, 3.99, 4.05, 4.14, 4.19, and 4.20.
13C NMR (CDCl3) δ ppm: 13.70, 14.15, 19.07, 30.56, 33.27, 34.21-36.69, 41.46, 43.05, 44.07, 45.55, 51.48, 55.56, 55.87, 57.35, 57.64, 61.55, 62.22, 62.31, 64.42, 65.45, 67.32, and 174.52.
KAm-1-3SPA bipolymer. I.R. ν cm−1: 3,417; 3,037; 2,962; 2,933; 2,875; 2,538; 1,732; 1,595; 1,464; 1,392; 1,381; 1,190; 1,117; 1,041; 810; 739; 687; and 609.
1H NMR (CDCl3) δ ppm: 0.94, 1.37, 1.56, 1.59, 1.60, 1.89, 2.28, 2.43, 2.79, 3.13, 3.70, 3.87, 3.91, 4.03, 4.04, 4.12, and 4.18.
13C NMR (CDCl3) δ ppm: 13.72, 14.13, 19.08, 27.06, 30.60, 32.12, 34.15-36.68, 41.33, 43.66, 44.49, 51.42, 55.56, 56.61, 60.35, 62.06, 62.36, 64.40, 64.84, 65.31, and 174.47.
Assessment of amphoteric random acrylic bipolymers as dehydrating agents in crude oils with gravities from 10 to 40° API. Different concentrated solutions of each of the amphoteric random acrylic bipolymer were prepared from 1.0 to 50.0 wt %, employing solvents whose boiling point is considered in the range between 30 and 250° C., such as: dichloromethane, methanol, ethanol, isopropanol, chloroform, acetone, dimethyl sulfoxide, tetrahydrofuran, dioxane, 2-butoxyethanol, 2-butoxyethanol acetate, benzene and its derivatives, toluene, xylene, jet fuel, and naphtha. Small volumes of solution were added to prevent any influence of solvent in the removal of emulsified water from the evaluated crude oil. Amphoteric random acrylic bipolymers were evaluated at concentrations in the range from 10 to 2,000 ppm. In order to make a comparison of the emulsified water removal efficiency of the amphoteric random acrylic bipolymers, the non-functionalized random acrylic bipolymer—KAm-1 or KAm-4—and the FC-01 dehydrating commercial formulation—based on polyethers, which is widely used in the oil industry—were evaluated simultaneously.
The assessment procedure of amphoteric random acrylic bipolymers as demulsifying agents is described below. Firstly, an aliquot of the solution of one of the amphoteric random acrylic bipolymers, non-functionalized random acrylic bipolymer or the commercial formulation is added into an oblong bottle; subsequently, the crude oil is poured out up to the 100 mL mark. It is important to mention that the homogenization of the crude oil sample—mechanical or manual agitation—should be avoided, since it can strongly alter the droplet size in the emulsion. Additionally, to one bottle is added the amount of the aliquot of xylene, which is labeled as blank—sample without demulsifying agent—. The bottles are placed into a thermal controlled bath between 40 and 90° C., counting this time as the starting point of the evaluation. The measurement of the removed water from the crude oil is carried out every 5 minutes during the first hour; afterwards, every hour during the evaluation time (5 h). Table 3 lists the physicochemical characterization and properties of crude oils that were used in the evaluation of the performance of amphoteric random acrylic bipolymers as dehydrating agents.
c
aApparent gravity.
bThe sample was diluted.
c Results are out of the method.
As an illustrative and non-limiting manner,
The KAm-1-2MEA bipolymer removed 69 vol % of emulsified water at 90 min of assessment, performance that was maintained throughout the assessment. The KAm-1-2HEA bipolymer and the non-functionalized bipolymer exhibited similar behavior in terms of their removal rate, both of them removed 58 vol % l of emulsified water; however, the KAm-1-2HEA bipolymer reached this efficiency after 120 min of testing, while the KAm-1 bipolymer achieved this efficiency 60 min after.
Finally, the FC-01 commercial formulation barely removed 42 vol % of emulsified water, as well as the KAm-1-3SPA and KAm-1-2DMAE bipolymers, although these bipolymers presented a lower coaelscence rate than the FC-01 formulation up to 240 min of the evaluation. It is important to mention that the functionalization with acrylic acid (AA), methacrylic acid (AMA) and 2-carboxiyethyl acrylic (2CEA) provide to the bipolymer a demulsifying performance in comparison with the KAm-1 non-functionalized bipolymer, therefore, the amphoteric fragment present in the KAm-1-AA, KAm-1-AMA and KAm-1-2CEA bipolymers induces, firstly, a greater diffusion capacity through the organic phase, and secondly, a more efficient destabilization of the asphaltenes' and resins' layers that surround the emulsified water droplets, and hence, a greater coalescence of these water droplets. The higher efficiency of the KAm-1AA bipolymer, compared with the KAm-1-AMA and KAm-1-2CEA bipolymers, is due to the fact that the acrylic acid (AA) monomer presents less molecular volume—VM=278.85 Å3—comparing with the methacrylic acid (AMA) monomer—VM=329.35 Å3—and the 2-carboxyethyl acrylate (2CEA) monomer—VM=475.11 Å3—. Therefore, the molecular volume of Kam-1AA will be less than the other two, which generates less steric hindrance with the asphaltenes' and resins' layers to induce more efficiently their destabilization.
The lower efficiency of the KAm-1-2MEA, KAm-1-2HEA, KAm-1-2DMAE, and KAm-1-3SPA bipolymers is also due to the effect of the higher molecular volume of the 2-methoxyethyl acrylate (2MEA) monomer—VM=479.65 Å3—, 2-hidroxyethyl acrylate (2HEA) monomer—VM=420.21 Å3—, 2-(dimethyl) aminoethyl acrylate (2DMAE) monomer—VM=539.96 Å3—, and 3-sulfopropyl acrylate potassium salt (3SPA) monomer—VM=4598.78 Å3—. The KAm-1-2MEA bipolymer presents a better performance to remove the emulsified water than the KAm-1-2HEA bipolymer, even though the molecular volume of the 2MEA monomer—VM=479.65 Å3—is slightly higher than that of the 2HEA monomer—VM=420.21 Å3—. Although the steric hindrance is an important factor during the destabilization of the asphaltnes' and resins' layers, the 2MEA monomer exhibits a higher partition coefficient— Log P=0.45—than the 2HEA monomer— Log P=0.17—, which confers to the KAm-1-2MEA bipolymer a greater diffusion through the organic phase, and hence, a higher capacity to reach more quickly and efficiently the water/crude oil interface.
By decreasing the dosage to 250 ppm in the NA light crude oil—35.3° API—(
On the other hand, the KAm-1-AMA and KAm-1-3SPA bipolymers barely removed 20 vol % of the emulsified water; however, both surpassed to the FC-01 formulation—17 vol %—. Finally, the KAm-1-2MEA and KAm-1-2DMAE bipolymers once again show the lowest demulsifying performance, removing scarcely 7 vol % of the emulsified water.
By decreasing the dosage to 500 ppm of the demulsifying agents evaluated in the CA light crude oil (36.3°API) a 60° C., a noticeable decrease in the efficiency to remove the emulsified water was observed (
The efficiency in the clarification of the removed water with the KAm-4-AMA and KAm-4-3SPA bipolymers is excellent as can be observed in
| Number | Date | Country | Kind |
|---|---|---|---|
| MX/A/2023/002067 | Feb 2023 | MX | national |
