Patent Application
20230064911
Corrosion is one of the most problematic challenges in the production of oil and gas. A common contributor to corrosion is acidic fluids. Acidic fluids are present in a multitude of operations in the oil and gas industry. In operations using acidic well fluids, metal surfaces of equipment such as piping, tubing, pumps, blending equipment, and umbilical lines may be exposed to the acidic fluid. The acidic fluids may include one or more of a variety of acids, such as hydrochloric acid, acetic acid, formic acid, hydrofluoric acid, or any combination of such acids. In addition, many fluids used in the oil and gas industry may include a water source that may incidentally contain certain amounts of acid, which, in turn, may cause the fluid to be at least slightly acidic. Even weakly acidic fluids may be problematic in that they may cause corrosion of metals. Corrosion may occur anywhere in a well production system or pipeline system.
Examples of common types of corrosion include, but are not limited to, the rusting of metal, the dissolution of metal in an acidic solution, and patina development on the surface of a metal. The expense of replacing corrosion damaged equipment is high. While the rate at which corrosion will occur depends on a number of factors such as metallurgy, chemical nature of the corrodent, salinity, pH, temperature, etc., some sort of corrosion almost inevitably occurs. One way to mitigate this problem includes using corrosion inhibitors in the hydrocarbon production system.
For a detailed description of the preferred embodiments of the invention, reference will now be made to the accompanying drawings in which:
The present disclosure relates to inhibiting the corrosion of metal surfaces and, more particularly, to the use of substituted carboxamides as a corrosion inhibitor that is effective in oil and gas production. The methods, compositions and systems disclosed herein comprise single compounds that may effectively function as corrosion inhibitors. The corrosion inhibitor compounds may coat metal surfaces in acidic environments, thereby protecting said surfaces from corroding. This may be advantageous as the minimum effective concentration of the substituted carboxamide present in the corrosion inhibitor compounds may be lower than those currently used in industry. Additionally, the substituted carboxamide may be stable at higher temperatures than those currently used.
For inhibition of corrosion, a corrosion inhibitor compound comprising a substituted carboxamide may come into contact with metal surfaces susceptible to corrosion, alone or in combination with other fluids, such as treatment fluids or produced fluids. For example, the corrosion inhibitor compound comprising a substituted carboxamide may be prepared and then introduced into a wellbore such that corrosion of metal surfaces (e.g., at surface, the wellhead, or downhole) that come into contact with the fluid may be reduced. Alternatively, the corrosion inhibitor compound comprising a substituted carboxamide may be added to produced fluids, either downhole or at the surface, such that corrosion of metal surfaces that come into contact with the produced fluids may be reduced. The metals that may be protected include, but are not limited to, steel grade N-80, J-55, P-110, QT800, HS80, and other common oilfield alloys, such as 13Cr, 25Cr, Incoloy 825, and 316L. The corrosion inhibitor compounds disclosed herein may comprise an aqueous component. The corrosion inhibitor compounds may also be used alone, or with other fluids, including, for example, with fluids that may further comprise an acid.
The corrosion inhibitor compounds may coat a metal surface in any suitable manner. In some embodiments, the metal surfaces that may be disposed downhole may be coated with the corrosion inhibitor before the metal surface is disposed downhole. The coating of the metal surface may be achieved because the substituted carboxamide is a surfactant and behaves accordingly. For example, the substituted carboxamide may form a monolayer at interfaces that may facilitate a lower energy state. Hydrophilic or more polar functional groups, such as amides and thiones, may be attracted to and may be adsorbed onto the surface of the metal. The adsorption of organic inhibitors on the metal surface may be include pi-bond orbital adsorption, electrostatic adsorption, chemisorption, or combinations thereof.
Suitable substituted carboxamides may be prepared by any of a variety of suitable techniques. In some embodiments, a substituted carboxamide may be synthesized by reacting equimolar amounts of a substituted or unsubstituted thiourea and a polyalkylene polyamine which may form a primary amine or a secondary amine. The formed primary amine or secondary amine may be any substituted amine in which at least one substituent is terminated by a five membered heterocyclic ring having at least one thione group. In some embodiments, the substituted carboxamide may be synthesized by reacting equimolar amount of substituted or unsubstituted urea and a polyalkylene polyamine. One of ordinary skill in the art, along with the present disclosure, may be able to select the appropriate reactants for a given application.
A substituted carboxamide may be formed by reacting the substituted amine with a fatty acid. The substituted amine may be a primary amine or a secondary amine wherein at least one substituent may be terminated by a five-membered heterocyclic ring and wherein at least one pendant group may comprise a ketone group or a thione group. In some embodiments, the heterocyclic atoms in the five-membered ring may include at least one nitrogen atom. Any suitable fatty acid may be used, including, but not limited to, carbonic acid, formic acid, acetic acid, propionic acid, butyric acid, valeric acid, caproic acid, enanthic acid, caprylic acid, pelargonic acid, capric acid, undecylic acid, lauric acid, tridecylic acid, myristic acid, pentadecylic acid, palmitic acid, margaric acid, stearic acid, nonadecylic acid, arachidic acid, tall oil fatty acid, the like, and/or any combination thereof. The amidization reaction may occur at a temperature of about 150° C. to about 200° C. and under atmospheric pressure.
The produced substituted carboxamide may be any suitable substituted carboxamide capable of providing corrosion inhibition properties fluids. In some embodiments, a substituted carboxamide wherein at least one substituent is terminated with a heterocyclic five-membered ring with at least one pendent group comprising a ketone group or a thione group may be used. Suitable substituted carboxamides may include, but are not limited to, a substituted carboxamide of Formula (1) as follows:
wherein R1 may be selected from the group consisting of a hydrogen, an alky group, an alkenyl group, a heteroatom substituted alkyl group, or a heteroatom atom substituted alkenyl group, wherein R2 may be a hydrogen, an alkyl group, an alkenyl group, a heteroatom substituted alkyl group, a heteroatom atom substituted alkenyl group, or an alkyl or alkenyl group terminated by a five-membered heterocyclic ring with at least one pendent group comprising a ketone group, a thione group, or any combination thereof, wherein R3 may be an alkyl or alkenyl group terminated by a five-membered heterocyclic ring with at least one pendent group comprising a ketone group, a thione group, or any combination thereof. Suitable heteroatoms that may be substituted in R1 and/or R2 may include, but are not limited to, nitrogen, oxygen, and sulfur, among others. The alkyl, alkenyl, or heteroatom substituted groups of R1, R2, and R3 may be the same or different and, in some embodiments, may include 1 carbon atom to 20 carbon atoms. Alternatively, the alkyl, alkenyl, or heteroatom substituted groups of R1, R2, and R3 may include from 1 to 20 carbon atoms, from 4-15 carbon atoms, or from 5-10 carbon atoms. In some embodiments, the alkyl, alkenyl, or heteroatom substituted groups of R1, R2, and R3 may include from 1 to 6 carbon atoms. For example, R3 may be a chain of 2 to 4 carbon atoms terminated by the five-member heterocyclic rings while R1 may be a chain of 6 to 20 carbon atoms.
Examples of suitable substituted carboxamides may depend on the reactants used to create said substituted carboxamide. An example of a suitable substituted carboxamide for use as a corrosion inhibitor compounds, shown in Structure (2) below may be formed from reaction of equimolar amounts of thiourea or urea and diethylenetriamine followed by reaction with a carboxylic acid, such as tall oil fatty acid.
wherein X1 may be selected from the group consisting of a thione or a ketone, wherein R1 may be selected from the group consisting of a hydrogen, an alky group, an alkenyl group, a heteroatom substituted alkyl group, or a heteroatom atom substituted alkenyl group.
Another example of a suitable substituted carboxamide for use as a corrosion inhibitor compound may be formed from reaction of thiourea or urea and tetraethylenepentamine in a 2:1 molar ratio followed by reaction with a carboxylic acid, such as tall oil fatty acid, as shown below in Structure (3):
wherein X1 may be individually selected from the group consisting of a thione or a ketone, wherein R1 is selected from the group consisting of a hydrogen, an alky group, an alkenyl group, a heteroatom substituted alkyl group, or a heteroatom atom substituted alkenyl group.
In some embodiments, Structure (2) may be further reacted with a saturated diacid, an unsaturated diacid, a saturated anhydride, or an unsaturated anhydride to form a substituted carboxamide for use as the corrosion inhibitor compound of Structure (4) as follows:
wherein X1 may be individually selected from the group consisting of a thione or a ketone, wherein R1 is selected from the group consisting of an alky group, an alkenyl group, a heteroatom substituted alkyl group, or a heteroatom atom substituted alkenyl group. In some embodiments, Structure (4) may function as a corrosion inhibitor, wherein the distance between the two five-membered rings may be controlled by varying R1. In some embodiments as R1 gets longer or shorter some properties may be affected, such as solubility, viscosity, and melting point. In another embodiment, Structure (2) or Structure (3) may be further reacted with acids that include, but are not limited to, acrylic acid, acetic acid, thioglycolic acid, glycolic acid, methane sulfonic acid, phosphonic acid, or combinations thereof, to form corrosion inhibitor compounds comprising at least one acrylated five-membered heterocyclic ring wherein at least one pendent group may comprise a ketone group or a thione group, of Structure (5) and Structure (6), respectively, as follows:
wherein X1 and X2 may be individually selected from the group consisting of a thione or a ketone, wherein R1 is selected from the group consisting of a hydrogen, an alky group, an alkenyl group, a heteroatom substituted alkyl group, or a heteroatom atom substituted alkenyl group, wherein Y is the radical derived from the acid listed above. It may be advantageous to use the above acrylated formulas disclosed herein as they may affect the solubility of the product. For example, depending upon the application, greater or less water or brine solubility may be desired.
In some embodiments, the corrosion inhibitor compounds disclosed herein may be provided in a solvent. Suitable solvents include, for example, methyl alcohol, ethyl alcohol, isopropyl alcohol, methanol, glycol, ethylene glycol, propylene glycol, dimethyl formamide, N-methyl pyrrolidone, propylene glycol methyl ether, toluene, xylene, monobutyl ether, hexane, cyclohexane, 2-Butoxyethanol, any organic solvent, aromatic solvents and any combination thereof. In some embodiments, the solvent may be present in an amount in a range of from about 50 wt. % to about 99.5 wt. %, or about 65 wt. % to about 98 wt. %, or about 80 wt. % to about 90 wt. % based on a total weight of the solvent and the corrosion inhibitor.
Methods are provided herein for adding one or more corrosion inhibitor compounds to a fluid, wherein the fluid may comprise any one or more of water, a gas, a liquid hydrocarbon, and any combination thereof. In certain embodiments, the method may comprise adding to the fluid an effective amount of an embodiment of the corrosion inhibitor compounds to inhibit, retard, reduce, control, delay, and/or the like the formation of corrosion on metal parts and materials.
It should be noted that the corrosion inhibitor compounds, and methods of use thereof, as disclosed herein, may be introduced into a fluid comprising one or more of water, a gas, a liquid hydrocarbon, or any combination thereof. Although listed separately from liquid hydrocarbon, the gas may in some embodiments include gaseous hydrocarbon, though the gas need not necessarily include hydrocarbon. In certain embodiments, the corrosion inhibitor compound may be introduced into the fluid through a conduit or an injection point. In certain embodiments, one or more corrosion inhibitor compounds may be introduced into a wellhead, a wellbore, a subterranean formation, a conduit, a vessel, and the like and may contact and/or be introduced into a fluid residing therein. In at least one embodiment, the wellhead, wellbore, subterranean formation, conduit, vessel, or the like may be in a deepwater environment. In at least one embodiment, the corrosion inhibitor compounds may be introduced into the deepwater environment by way of an umbilical. In certain embodiments, the fluid may be flowing, or it may be substantially stationary. In some instances, the fluid may contact metal surfaces. By introduction of the corrosion inhibitor compound into the fluid, corrosion of the metal surface may be inhibited.
In certain embodiments, the fluid may be within a vessel, or within a conduit (e.g., a conduit that may transport the fluid), or within a subterranean formation, or within a wellbore penetrating a portion of the subterranean formation, and/or within a wellhead of a wellbore. Examples of conduits include, but are not limited to, pipelines, production piping, subsea tubulars, process equipment, and the like as used in industrial settings and/or as used in the production of oil and/or gas from a subterranean formation, and the like. The conduit may in certain embodiments penetrate at least a portion of a subterranean formation, as in the case of an oil and/or gas well. In some embodiments, the wellhead may be in a deepwater environment. In particular embodiments, the conduit may be a wellhead, a wellbore, or may be located within a wellbore penetrating at least a portion of a subterranean formation. The oil and/or gas well may be a subsea well (e.g., with the subterranean formation being located below the sea floor), or it may be a surface well (e.g., with the subterranean formation being located belowground). In some embodiments, the subsea well may be in a deepwater environment.
In some embodiments, the corrosion inhibitor compounds of the present disclosure initially may be incorporated into a composition prior to being introduced into the fluid. The composition may be any suitable composition in which the corrosion inhibitor compound may be included. For example, the composition may include a solvent for the corrosion inhibitor compound. Suitable solvents include, for example, methyl alcohol, ethyl alcohol, isopropyl alcohol, methanol, glycol, ethylene glycol, propylene glycol, dimethyl formamide, N-methyl pyrrolidone, propylene glycol methyl ether, toluene, xylene, monobutyl ether, hexane, cyclohexane, 2-Butoxyethanol, any organic solvent, aromatic solvents and any combination thereof.
In some embodiments, the corrosion inhibitor compounds may be introduced into a fluid in any suitable amount for corrosion inhibition. In various embodiments, the corrosion inhibitor compounds of the present disclosure may be used as low dosage corrosion inhibitors such that an effective concentration of actives in one or more corrosion inhibitor compounds for inhibiting, retarding, mitigating, reducing, controlling, and/or delaying corrosion may from about 2 ppm to about 1,000 ppm by volume. Alternatively, the concentrations of actives may be from about 2 ppm to about 1,000 ppm, about 2.25 ppm to about 900 ppm, about 2.5 ppm to about 800 ppm, about 2.75 ppm to about 700 ppm, about 3 ppm to about 600 ppm, about 3.25 ppm to about 500 ppm, about 3.5 ppm to about 400 ppm, about 3.75 ppm to about 300 ppm, about 4 ppm to about 200 ppm, about 4.5 ppm to about 100 ppm, or about 5 ppm to about 50 ppm by volume. In some embodiments, the corrosion inhibitor compounds may be suitable in applications with temperatures up to 350° F. (177° C.) under pressures of about 1 atm to about 300 atms.
In certain embodiments, the corrosion inhibitor compounds may be introduced into a wellhead of a wellbore penetrating at least a portion of the subterranean formation, a wellbore, a subterranean formation, a vessel, and/or a conduit (and/or into a fluid within any of the foregoing) using any method or equipment known in the art. In other embodiments, a corrosion inhibitor compound of the present disclosure may be injected into a portion of a subterranean formation using an annular space or capillary injection system to continuously introduce the corrosion inhibitor compound into the formation. In some embodiments, the capillary injection may include an umbilical with the wellhead in a deepwater environment. In certain embodiments, a composition comprising a corrosion inhibitor compound of the present disclosure may be circulated in the wellbore using the same types of pumping systems and equipment at the surface that may be used to introduce fluids or additives into a wellbore penetrating at least a portion of the subterranean formation.
Accordingly, this disclosure describes methods, systems, and compositions that may use a substituted carboxamide as corrosion inhibitor compounds. The methods, systems, and compositions may include any of the following statements:
Statement 1. A method of inhibiting corrosion of a metal surface may comprise contacting the metal surface with a corrosion inhibitor compound comprising a substituted carboxamide.
Statement 2. The method of statement 1, further comprising coating the metal surface with the corrosion inhibitor compound.
Statement 3. The method of statement 1 or 2, further comprising introducing the corrosion inhibitor compound into a wellbore, wherein the metal surface is disposed in the wellbore.
Statement 4. The method of any of the preceding statements, wherein the substituted carboxamide comprises the molecular formula: R1C(O)NR2R3, wherein R1 is selected from the group consisting of a hydrogen, an alkyl group, an alkenyl group, a heteroatom substituted alkyl group, or a heteroatom atom substituted alkenyl group; wherein R2 is a hydrogen, an alky group, an alkenyl group, a heteroatom substituted alkyl group, a heteroatom atom substituted alkenyl group, or an alkyl or alkenyl group terminated by a five-membered heterocyclic ring with at least one pendent group comprising a ketone group, a thione group, or any combination thereof; and wherein R3 is an alkyl or alkenyl group terminated by a five-membered heterocyclic ring with at least one pendent group comprising a ketone group, a thione group, or any combination thereof.
Statement 5. The method of any of the preceding statements, wherein the substituted carboxamide comprises the molecular formula:
wherein X1 is selected from the group consisting of a thione or a ketone, and wherein R1 is selected from the group consisting of a hydrogen, an alky group, an alkenyl group, a heteroatom substituted alkyl group, or a heteroatom atom substituted alkenyl group.
Statement 6. The method of any of the preceding statements, wherein the substituted carboxamide comprises the molecular formula:
wherein X1 is individually selected from the group consisting of a thione or a ketone; and wherein R1 is selected from the group consisting of a hydrogen, an alky group, an alkenyl group, a heteroatom substituted alkyl group, or a heteroatom atom substituted alkenyl group.
Statement 7. The method of any of the preceding statements, wherein the substituted carboxamide comprises the molecular formula:
wherein X1 is individually selected from the group consisting of a thione or a ketone, and wherein R1 is selected from the group consisting of an alky group, an alkenyl group, a heteroatom substituted alkyl group, or a heteroatom atom substituted alkenyl group.
Statement 8. The method of any of the preceding statements, wherein the substituted carboxamide is present in the fluid in an amount of from about 10 ppm to about 500 ppm.
Statement 9. The method of any of the preceding statements, wherein the corrosion inhibitor compound is provided in a solvent selected from the group consisting of methyl alcohol, ethyl alcohol, isopropyl alcohol, methanol, glycol, ethylene glycol, propylene glycol, dimethyl formamide, N-methyl pyrrolidone, propylene glycol methyl ether, toluene, xylene, monobutyl ether, hexane, cyclohexane, 2-Butoxyethanol, any organic solvent, aromatic solvents and any combination thereof.
Statement 10. The method of statement 3, wherein the introducing the corrosion inhibitor compound into the wellbore comprises pumping the corrosion inhibitor compound from a fluid supply, through a production tubing, and into the wellbore, and mixing the corrosion inhibitor compound with a produced fluid.
Statement 11. The method of statement 10, further comprising transporting the corrosion inhibitor compound mixed with the produced fluid to a surface of the wellbore, and coating at least one metal surface in which the corrosion inhibitor compound mixed with the produced fluid contacts.
Statement 12. The method of statement 4, wherein R2 is a heteroatom substituted five-membered heterocyclic ring with at least one pendent group comprising a ketone group or a thione group.
Statement 13. The method of statement 12, wherein the heteroatom substituted five-membered heterocyclic ring comprises nitrogen.
Statement 14. The method of statement 5, wherein the substituted carboxamide is alkylated.
Statement 15. The method of statement 6, wherein the substituted carboxamide is alkylated.
Statement 16. The method of statement 9 wherein the solvent is present in an amount of about 50 wt % to about 99.5 wt % based on the total weight of the solvent and the corrosion inhibitor.
Statement 17. A corrosion inhibitor may comprise: a solvent package; and a corrosion inhibitor compound comprising a substituted carboxamide having the formula: R1C(O)NR2R3, wherein R1 is selected from the group consisting of a hydrogen, an alky group, an alkenyl group, a heteroatom substituted alkyl group, or a heteroatom atom substituted alkenyl group, wherein R2 is a hydrogen, an alky group, an alkenyl group, a heteroatom substituted alkyl group, a heteroatom atom substituted alkenyl group, or an alkyl or alkenyl group terminated by a five-membered heterocyclic ring with at least one pendent group comprising a ketone group, a thione group, or any combination thereof, and wherein R3 is an alkyl or alkenyl group terminated by a five-membered heterocyclic ring with at least one pendent group comprising a ketone group, a thione group, or any combination thereof.
Statement 18. The method of statement 17 wherein the solvent package comprises solvent selected from the group consisting of methyl alcohol, ethyl alcohol, isopropyl alcohol, ethylene glycol, propylene glycol, dimethyl formamide, N-methyl pyrrolidone, propylene glycol methyl ether, butyl cellulose, aromatic solvents, and combinations thereof.
Statement 19. A system for introducing a corrosion inhibitor into a wellbore may comprise: a fluid supply containing the corrosion inhibitor, wherein the corrosion inhibitor comprises a corrosion inhibitor compound and a solvent package, wherein the corrosion inhibitor compound comprises a substituted carboxamide; and a tubular in a wellbore in a subterranean formation, wherein the tubular is in fluid communication with the corrosion inhibitor supply.
Statement 20. A system according to statement 19, wherein the substituted carboxamide has the formula: R1C(O)NR2R3, wherein R1 is selected from the group consisting of a hydrogen, an alky group, an alkenyl group, a heteroatom substituted alkyl group, or a heteroatom atom substituted alkenyl group, wherein R2 is a hydrogen, an alky group, an alkenyl group, a heteroatom substituted alkyl group, a heteroatom atom substituted alkenyl group, or an alkyl or alkenyl group terminated by a five-membered heterocyclic ring with at least one pendent group comprising a ketone group, a thione group, or any combination thereof, and wherein R3 is an alkyl or alkenyl group terminated by a five-membered heterocyclic ring with at least one pendent group comprising a ketone group, a thione group, or any combination thereof.
The wellbore 118 may be cased with one or more casings 114. Casing 114 may support and maintain the structure of wellbore 118 and prevent wellbore 118 from collapsing. In some embodiments, a portion of the well may not be cased and may be referred to as “open hole.” The space between production tubing 124 and casing 126 or wellbore wall 118 may be an annulus 134. Production fluid 138 may enter annulus 134 from formation 114 and then may enter production tubing 124 from annulus 134. Production tubing 124 may carry production fluid 138 uphole to production tree 106. Production fluid 138 may then be delivered to various surface facilities for processing via a surface pipeline 120.
As illustrated, corrosion inhibitor compounds 150 may be introduced into annulus 134 between production tubing 124 and casing 136. As previously described, corrosion inhibitor compounds 150 may be used alone, or they may be added to produced fluids, treatment fluids, and other additives. Corrosion inhibitor compounds 150 may be introduced into wellbore 118 in any suitable manner. In some embodiments, corrosion inhibitor compounds 150 may be injected into wellbore 118 at wellhead 112. In an embodiment, corrosion inhibitor compounds 150 may be continuously provided to wellbore 118. Suitable techniques for introduction of corrosion inhibitor compounds 150 may include, but are not limited to, neat annulus drip, slip stream, capillary string, or batch processes. As illustrated, corrosion inhibitor compounds 150 may be introduced to wellbore at wellhead 112 by way of neat annulus drip. Corrosion inhibitor compounds may flow through wellhead 112 and into annulus 134 formed between production tubing 124 and casing 136. Corrosion inhibitor compounds 150 may fall and/or drip to the bottom of wellbore 118. At the bottom of wellbore 132, corrosion inhibitor compounds 150 may mix with the produced fluids 138. The mixture 142 of corrosion inhibitor compounds 150 and produced fluids 138 may then be pumped through downhole tools 140 and up production tubing 124. As the mixture 142 of corrosion inhibitor compounds 150 and the produced fluids 138 flow through production tree 106, the corrosion inhibitor compounds 150 and the produced fluids 138 may continuously be in contact with production tubing 124, slickline 122, and downhole tools 140, in turn which may provide production tubing 124, slickline 122, and downhole tools 140 with corrosion resistance. This provided corrosion resistance may reduce the corrosion on said metal components of well system 100 and in turn extend the production life of said metal components.
In some embodiments, with continued reference to the
The disclosed corrosion inhibitor compounds may also directly or indirectly affect the various downhole equipment and tools that may come into contact with the corrosion inhibitor compounds during operation. Such equipment and tools may include, but are not limited to, wellbore casing, wellbore liner, completion string, insert strings, drill string, coiled tubing, slickline, wireline, drill pipe, drill collars, mud motors, downhole motors and/or pumps, surface-mounted motors and/or pumps, centralizers, turbolizers, scratchers, floats (e.g., shoes, collars, valves, etc.), logging tools and related telemetry equipment, actuators (e.g., electromechanical devices, hydromechanical devices, etc.), sliding sleeves, production sleeves, plugs, screens, filters, flow control devices (e.g., inflow control devices, autonomous inflow control devices, outflow control devices, etc.), couplings (e.g., electro-hydraulic wet connect, dry connect, inductive coupler, etc.), control lines (e.g., electrical, fiber optic, hydraulic, etc.), surveillance lines, drill bits and reamers, sensors or distributed sensors, downhole heat exchangers, valves and corresponding actuation devices, tool seals, packers, cement plugs, bridge plugs, and other wellbore isolation devices, or components, and the like. Any of these components may be included in the systems generally described above and depicted in
A Kettle test using a first composition comprising Structure (2) included a mixture of 38.05 g (0.5 mole) of thiourea and 51.6 g (0.5 mole) of diethylenetriamine (DETA). The mixture was charged to a 250-mL glass kettle equipped with a condenser, a stirrer, and a gas inlet tube. A slow nitrogen sparge was started. Using an electric heating mantle, the mixture was slowly heated to 170° C. while stirring. The reaction temperature was kept at 170° C. for 4 hours. The mixture was cooled down to 100° C. and lauric acid (100.16 g, 0.5 mole) was added. The mixture was heated back to 170° C. and kept at this temperature for 4 hours with nitrogen purging.
A Kettle test using a second composition comprising Structure (2) included a mixture of 38.05 g (0.5 mole) of thiourea and 51.6 g (0.5 mole) of diethylenetriamine (DETA) was charged to a 250-mL glass kettle equipped with a condenser, a stirrer and a gas inlet tube. A slow nitrogen sparge was started. Using an electric heating mantle, the mixture was slowly heated to 170° C. while stirring. The reaction temperature was kept at 170° C. for 4 hours. The mixture was cooled down to 100° C. and myristic acid (114.2 g, 0.5 mole) was added. The mixture was heated back to 170° C. and kept at this temperature for 4 hours with nitrogen purging.
A Kettle test using a composition comprising Structure (3) included a mixture of 76.1 g (1.0 mole) of thiourea and 94.7 g (0.5 mole) of tetraethylenepentamine (TEPA) was charged to a 250-mL glass kettle equipped with a condenser, a stirrer and a gas inlet tube. A slow nitrogen sparge was started. Using an electric heating mantle, the mixture was slowly heated to 170° C. while stirring. The reaction temperature was kept at 170° C. for 4 hours. The mixture was cooled down to 100° C. and myristic acid (114.2 g, 0.5 mole) was added. The mixture was heated back to 170° C. and kept at this temperature for 4 hours with nitrogen purging.
The baseline or uninhibited corrosion rate was monitored for 0.85 hours before the corrosion inhibitors were injected at 100 ppm (5 ppm actives). At a treatment rate of 100 ppm (5 ppm actives), the average baseline corrosion rate was reduced from 174 mils per year (“MPY”) to 35, 77 and 4 MPY for the DETA/Thiourea/Lauric, DETA/Thiourea/Myristic and TEPA/Thiourea/Myristic reaction product, as depicted in
It should be noted that the efficiency of a corrosion inhibitor may be calculated by the following formula: Inhibitor Efficiency(%)=100×(CRuninhibited−CRinhibited)/CRuninhibited, where CRuninhibited=the corrosion rate of the uninhibited system, and CRinhibited=the corrosion rate of the inhibited system. In general, the efficiency of a corrosion inhibitor increases with an increase in inhibitor concentration.
These tests were repeated with the addition of acetic acid (3.2% w/w) to the diluted products. As shown in
The foregoing has broadly outlined the features and technical advantages of the embodiments disclosed herein so that the detailed description of the invention that follows may be better understood. Additional features and advantages of the invention may be described hereinafter that form the subject of the claims of the invention. It should be appreciated by those skilled in the art that the conception and the specific embodiments disclosed may be readily utilized as a basis for modifying or designing other embodiments for carrying out the same purposes of the present invention. It should also be realized by those skilled in the art that such equivalent embodiments do not depart from the spirit and scope of the invention as set forth in the appended claims.
Although the present invention and its advantages have been described in detail, it should be understood that various changes, substitutions and alterations may be made herein without departing from the spirit and scope of the invention as defined by the appended claims.
| Filing Document | Filing Date | Country | Kind |
|---|---|---|---|
| PCT/US2020/034681 | 5/27/2020 | WO |
