Emulsion type annulus protection fluid and preparation method thereof

Abstract

The present application relates to the technical field of oilfield chemistry, and is an emulsion type annulus protection fluid and a preparation method thereof, which comprises, in terms of mass percentage, 1-2% of anti-carbon dioxide corrosion inhibitor, 1-2% of sulfur removal agent, 1-2% of bactericide, 1-5% of surfactant, 40-60% of organic oil, 0.1-2% of emulsion polymer stabilizer and 5-50% of water, and is prepared by the following method: adding the required amounts of anti-carbon dioxide corrosion inhibitor, sulfur removal agent, bactericide, surfactant, emulsion polymer stabilizer and water into the required amount of organic oil, and then mixing and stirring to obtain the emulsion type annulus protection fluid. The present application has the advantages of simple preparation process, good corrosion protection effect, good protection effect on the wellbore string of a well containing carbon dioxide and hydrogen sulfide, and the use of organic oil as a continuous phase to form a water-in-oil stable emulsion, which can not only retain the characteristics of oil-based products, but also greatly reduce the cost.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of oil field chemistry, and is an emulsion type annulus protection fluid and a preparation method thereof. BACKGROUND

[0002] With the deepening of oil and gas field development, research and development and application of carbon dioxide flooding enhanced oil recovery (EOR) technology have been vigorously carried out at home and abroad in recent years. This technology can not only meet the needs of oil field development, but also solve the problem of carbon dioxide sequestration, protect the atmospheric environment and control the greenhouse effect. Carbon dioxide is often used in oil and gas fields to improve oil recovery. This technology can significantly improve the recovery of high-viscosity crude oil in low-permeability and ultra-low-permeability reservoirs. However, in the process of carbon dioxide flooding, on the one hand, according to production experience, carbon dioxide gas will inevitably flow into the annulus of the wellbore; on the other hand, during the completion operation, there will be a liquid phase medium remaining in the annulus, so the wellbore material will be damaged by carbon dioxide corrosion, and the presence of sulfur corrosion medium in the annulus may further induce environmental cracking of the pipe material.

[0003] In view of the above problems, carbon dioxide corrosion resistant alloy steel is generally used, but due to the high cost, it is not suitable for large-scale promotion. At the same time, water-based annulus protection fluid is used, which has low long-term performance and needs to be replaced regularly, and there is also a scaling problem. There have been cases of corrosion cracking in the use of water-based annulus protection fluid in China.

[0004] Chinese patent document with publication number CN104498010A discloses an oil casing annulus protection fluid for oil production, which comprises the following raw materials: base oil, bactericide, corrosion inhibitor, scale inhibitor, surfactant, preservative and pH adjuster; the total weight percentage of each component is 0.5-3% of bactericide, 1-5% of carbon dioxide corrosion inhibitor, 0.2-1% of scale inhibitor, 0.1-0.5% of surfactant, 2-5% of preservative and 2-10% of pH adjuster, and the balance is base oil.

[0005] However, the oil-based annulus protection fluid used in the prior art is expensive. Therefore, it is necessary to develop a new annulus protection fluid to solve the above problems. SUMMARY

[0006] The present application provides an emulsion type annulus protection fluid and a preparation method thereof, which overcomes the shortcomings of the prior art and effectively solves the problems of low corrosion resistance of existing water-based annulus protection fluid to carbon steel pipe material, unsuitability for high carbon dioxide gas environment, and high price of oil-based annulus protection fluid which can meet the corrosion resistance requirement.

[0007] One of the technical solutions of the present application is realized by the following measures: an emulsion type annulus protection fluid, comprising, in terms of mass percentage: 1-2% of anti-carbon dioxide corrosion inhibitor, 1-2% of sulfur removal agent, 1-2% of bactericide, 1-5% of surfactant, 40-60% of organic oil, 0.1-2% of emulsion polymer stabilizer, and 5-50% of water, wherein the emulsion type annulus protection fluid is prepared by the following method: adding the required amount of anti-carbon dioxide corrosion inhibitor, sulfur removal agent, bactericide, surfactant, emulsion polymer stabilizer and water into the required amount of organic oil, and then mixing and stirring to obtain the emulsion type annulus protection fluid.

[0008] The following is a further optimization or / and improvement of one of the above technical solutions of the application:

[0009] The above anti-carbon dioxide corrosion inhibitor is prepared by the following method:

[0010] S01, the required amount of macromolecular petroleum acid is mixed with polyamine uniformly, and then reacted to obtain intermediate one;

[0011] S02, intermediate one is mixed with the required amount of guanidine hydrochloride uniformly, and then reacted to obtain intermediate two;

[0012] S03, a solvent and a chain transfer agent are added to the required amount of monomer, and then a required amount of initiator is added to react to obtain intermediate three;

[0013] S04, intermediate two, intermediate three and the required amount of polyether amine are mixed uniformly, and then reacted to obtain the first polymer;

[0014] S05, the required amount of intermediate one obtained in step S01 is reacted with a polybasic carboxylic acid to obtain a first reaction product;

[0015] S06, the chlorinated compound is mixed with the first reaction product to carry out crosslinking reaction to obtain the second polymer;

[0016] S07, the first polymer, the second polymer and the modified imidazoline are mixed to obtain the anti-carbon dioxide corrosion inhibitor, wherein the required amount of intermediate one obtained in step S01, guanidine hydrochloride and primary amine are mixed and reacted to obtain the modified imidazoline.

[0017] In the above step S01, the molar ratio of the macromolecular petroleum acid to the polyamine is 0.9 to 1.1:0.9 to 1.1, the reaction temperature is 250 to 300°C, and the reaction time is 9 to 11 hours, wherein the polyamine is polyethylene polyamine, and the macromolecular petroleum acid is a byproduct in the petroleum refining process; in the step S02, the molar ratio of the intermediate I to the guanidine hydrochloride is 0.9 to 1.1:0.9 to 1.1, the reaction temperature is 140 to 150°C, and the reaction time is 2.5 to 3.5 hours; in the step S03, the monomer is one or more of acrylic acid, maleic anhydride, and methacrylic acid, the solvent is one of methanol, ethanol, n-butanol, propylene glycol, glycerol, ethylene glycol, dimethylbenzene, trimethylbenzene, dimethyl sulfoxide, and dimethyl formamide, the chain transfer agent is n-dodecanethiol, and the initiator is one of azobisisobutyronitrile and dibenzoyl peroxide, the reaction temperature is 60 to 120°C, and the reaction time is 3.5 to 4.5 hours; and in the step S04, the polyether amine is one of D350 and D600, the reaction temperature is 100 to 150°C, and the reaction time is 3.5 to 4.5 hours.

[0018] In the above step S05, the polycarboxylic acid is one of adipic acid and oxalic acid, the molar ratio of the polycarboxylic acid to the intermediate I is 1:1 to 2, the reaction temperature is 100 to 150°C, and the reaction time is 3.5 to 4.5 hours; in the step S06, the chlorine-containing compound is 1,4-p-dichlorobenzene, the molar ratio of the chlorine-containing compound to the first reaction product is 1:1 to 2, the reaction temperature is 70 to 100°C, and the reaction time is 3.5 to 4.5 hours; and in the step S07, the molar ratio of the intermediate I, the guanidine hydrochloride, and the primary amine is 1:1:1, the reaction temperature is 145 to 155°C, and the reaction time is 3.5 to 4.5 hours, wherein the primary amine is one of dodecyl primary amine, tetradecyl primary amine, hexadecyl primary amine, and octadecyl primary amine.

[0019] The above sulfur removal agent is prepared by the following method:

[0020] S11, a desired amount of an alcohol amine is mixed with an aldehyde to obtain a sulfur removal agent intermediate;

[0021] S12, the sulfur removal agent intermediate is vacuum dehydrated and purified, and then a desired amount of a polycarboxylic acid, a high-carbon acid, a catalyst, and dimethylbenzene are sequentially added and reacted to obtain the sulfur removal agent.

[0022] In step S11 above, the alkanolamine is monoethanolamine, the aldehyde is formaldehyde, and the molar ratio of alkanolamine to aldehyde is 0.9 to 1.1:0.9 to 1.1. The reaction temperature is 60°C to 80°C, and the reaction time is 2 to 4 hours. Or / and in step S12, the polycarboxylic acid is one of adipic acid, glutaric acid, oxalic acid, and malonic acid, the percarbonate is one or more of dodecanoic acid, tetradecanoic acid, hexadecanoic acid, and octadecanoic acid, and the catalyst is one of dodecylbenzenesulfonic acid, p-toluenesulfonic acid, and aminosulfonic acid. The molar ratio of polycarboxylic acid to desulfurizing agent intermediate is 1:1 to 2, the molar ratio of percarbonate to desulfurizing agent intermediate is 1:1 to 2, the mass of catalyst added is 0.5% to 2.5% of the mass of desulfurizing agent intermediate, the reaction temperature is 120°C to 150°C, and the reaction time is 2 to 10 hours.

[0023] The above-mentioned bactericide is an oil-soluble polymeric guanidine, which is prepared according to the following method:

[0024] S21, after mixing the required amount of petroleum acid with polyethylene polyamine, react to obtain intermediate one;

[0025] S22, after mixing intermediate one with the required amount of guanidine hydrochloride evenly, react to obtain intermediate two;

[0026] S23, the reactant monomer, solvent and chain transfer agent are mixed evenly, and then the required amount of initiator is added and reacted to obtain the reaction product;

[0027] S24, after adding intermediate II and the required amount of p-toluenesulfonic acid to the reaction product, the reaction is carried out to obtain oil-soluble polymeric guanidine.

[0028] In step S21 above, the molar ratio of petroleum acid to polyethylene polyamine is 0.9 to 1.1:0.9 to 1.1, the reaction temperature is 250°C to 300°C, and the reaction time is 10h to 12h; or / and in step S22, the molar ratio of intermediate one to guanidine hydrochloride is 0.9 to 1.1:0.9 to 1.1, the reaction temperature is 150°C to 180°C, and the reaction time is 2h to 4h; or / and in step S23, the reaction monomer is one or more of acrylic acid, methyl acrylate, ethyl acrylate, and maleic anhydride, the solvent is xylene, the chain transfer agent is n-dodecyl mercaptan, and the initiator is one of azobisisobutyronitrile and benzoyl peroxide.

[0029] The surfactants mentioned above are one or more of the following: sorbitan fatty acid ester surfactants, Tween-type emulsifiers, EO-50, PO-50, monostearate emulsifiers, and distearate emulsifiers; and / or the organic oil is one of vegetable oil, bio-oil, and biodiesel; and / or the emulsion polymer stabilizer is one of polyacrylic acid, polymethyl acrylate, polyethyl acrylate, acrylate-methyl acrylate copolymer, and ethylene-vinyl acetate.

[0030] The surfactant is Tween 80 or Tween 60.

[0031] The second technical solution of the present application is realized by the following method: a preparation method of the emulsion type annulus protection fluid, which is prepared by adding a required amount of carbon dioxide corrosion inhibitor, sulfur removal agent, bactericide, surfactant, emulsion polymer stabilizer and water into a required amount of organic oil, and then mixing and stirring to obtain the emulsion type annulus protection fluid.

[0032] The present application has the advantages of simple preparation process, good corrosion protection effect, good protection effect on the wellbore string of the well containing carbon dioxide and hydrogen sulfide, and the use of organic oil as the continuous phase to form a water-in-oil stable emulsion, which can not only retain the characteristics of oil-based products, but also greatly reduce the cost. DETAILED DESCRIPTION

[0033] The present application is not limited by the following examples, and the specific implementation can be determined according to the technical solutions of the present application and the actual situation. The various chemical reagents and chemical products mentioned in the present application are well-known and commonly used chemical reagents and chemical products in the prior art unless otherwise specified.

[0034] The present application will be further described below in combination with examples:

[0035] Example 1: The emulsion type annulus protection fluid comprises 1% to 2% of carbon dioxide corrosion inhibitor, 1% to 2% of sulfur removal agent, 1% to 2% of bactericide, 1% to 5% of surfactant, 40% to 60% of organic oil, 0.1% to 2% of emulsion polymer stabilizer, and 5% to 50% of water in terms of mass percentage, and the emulsion type annulus protection fluid is prepared by adding a required amount of carbon dioxide corrosion inhibitor, sulfur removal agent, bactericide, surfactant, emulsion polymer stabilizer and water into a required amount of organic oil, and then mixing and stirring to obtain the emulsion type annulus protection fluid.

[0036] The emulsion type annulus protection fluid of the present application has good protection effect on the wellbore string of the well containing carbon dioxide and hydrogen sulfide, and uses organic oil as the continuous phase to form a water-in-oil stable emulsion, which is relatively low in cost compared with the pure oil-based annulus protection fluid.

[0037] Example 2: As an optimization of the above example, the carbon dioxide corrosion inhibitor is prepared by the following method:

[0038] S01, a required amount of macromolecular petroleum acid is uniformly mixed with a polyamine, and then reacted to obtain intermediate one;

[0039] S02, intermediate one is uniformly mixed with a required amount of guanidine hydrochloride, and then reacted to obtain intermediate two;

[0040] S03, after adding solvent and chain transfer agent to the required amount of monomer, adding the required amount of initiator to react, obtaining intermediate three;

[0041] S04, mixing intermediate two, intermediate three and the required amount of polyether amine uniformly to react, obtaining the first polymer;

[0042] S05, reacting the required amount of intermediate one obtained in step S01 with polycarboxylic acid to obtain the first reaction product;

[0043] S06, mixing the chlorine-containing compound with the first reaction product to carry out crosslinking reaction, obtaining the second polymer;

[0044] S07, compounding the obtained first polymer, second polymer and modified imidazoline to obtain the anti-carbon dioxide corrosion inhibitor, wherein the required amount of intermediate one obtained in step S01, guanidine hydrochloride and primary amine are mixed to react, obtaining the modified imidazoline.

[0045] In the above embodiment, in step S01, the molar ratio of macromolecular petroleum acid to polyamine is 0.9 to 1.1:0.9 to 1.1, the reaction temperature is 250°C to 300°C, and the reaction time is 9h to 11h, wherein the polyamine is polyethylene polyamine, and the macromolecular petroleum acid is a byproduct in the petroleum refining process, in step S02, the molar ratio of intermediate one to guanidine hydrochloride is 0.9 to 1.1:0.9 to 1.1, the reaction temperature is 140°C to 150°C, and the reaction time is 2.5h to 3.5h, in step S03, the monomer is one or more of acrylic acid, maleic anhydride, and methacrylic acid, the solvent is one of methanol, ethanol, n-butanol, propylene glycol, glycerol, ethylene glycol, dimethylbenzene, trimethylbenzene, dimethyl sulfoxide, and dimethyl formamide, the chain transfer agent is n-dodecanethiol, and the initiator is one of azobisisobutyronitrile and dibenzoyl peroxide, the reaction temperature is 60°C to 120°C, and the reaction time is 3.5h to 4.5h, in step S04, the polyether amine is one of D350 and D600, the reaction temperature is 100°C to 150°C, and the reaction time is 3.5h to 4.5h.

[0046] In the embodiment 4, as the optimization of the above-mentioned embodiments, in the step S05, the polycarboxylic acid is one of adipic acid and oxalic acid, the molar ratio of the polycarboxylic acid to the intermediate one is 1:1 to 2, the reaction temperature is 100 DEG C to 150 DEG C, and the reaction time is 3.5 h to 4.5 h; in the step S06, the chlorine-containing compound is 1,4-p-dichlorobenzene, the molar ratio of the chlorine-containing compound to the first reaction product is 1:1 to 2, the reaction temperature is 70 DEG C to 100 DEG C, and the reaction time is 3.5 h to 4.5 h; in the step S07, the molar ratio of the intermediate one, guanidine hydrochloride and the primary amine is 1:1:1, the reaction temperature is 145 DEG C to 155 DEG C, and the reaction time is 3.5 h to 4.5 h, wherein the primary amine is one of dodecyl primary amine, tetradecyl primary amine, hexadecyl primary amine and octadecyl primary amine.

[0047] In the present application, the chemical reaction mechanism for obtaining the intermediate one in the preparation of the anti-carbon dioxide corrosion inhibitor is as follows:

[0048]

[0049] wherein k is 2 to 10.

[0050] The chemical reaction mechanism for obtaining the intermediate two is as follows:

[0051]

[0052] wherein k is 2 to 10.

[0053] The chemical reaction mechanism for obtaining the intermediate three is as follows:

[0054]

[0055] The chemical reaction mechanism for obtaining the first polymer is as follows:

[0056]

[0057] wherein a, b, c and k are 2 to 10.

[0058] The chemical reaction mechanism for obtaining the first reaction product is as follows:

[0059]

[0060] wherein k is 2 to 10.

[0061] The chemical reaction mechanism for obtaining the second polymer is as follows:

[0062]

[0063] wherein k and d are 2 to 10.

[0064] The chemical reaction mechanism of the modified imidazoline is as follows:

[0065]

[0066] The value range of k and d is 2 to 10.

[0067] Example 5: As an optimization of the above examples, the sulfur removal agent is prepared according to the following method:

[0068] S11, a desired amount of alcohol amine is mixed with aldehyde to obtain a sulfur removal agent intermediate;

[0069] S12, the sulfur removal agent intermediate is vacuum dehydrated and purified, and then a desired amount of polycarboxylic acid, high carbonic acid, catalyst and dimethylbenzene are sequentially added and reacted to obtain the sulfur removal agent.

[0070] Example 6: As an optimization of the above examples, in step S11, the alcohol amine is monoethanolamine and the aldehyde is formaldehyde, wherein the molar ratio of alcohol amine to aldehyde is 0.9 to 1.1:0.9 to 1.1, the reaction temperature is 60 to 80°C, and the reaction time is 2 to 4 hours.

[0071] Example 7: As an optimization of the above examples, in step S12, the polycarboxylic acid is one of adipic acid, glutaric acid, oxalic acid, and malonic acid, the high carbonic acid is one or more of dodecanoic acid, tetradecanoic acid, hexadecanoic acid, and octadecanoic acid, and the catalyst is one of dodecylbenzenesulfonic acid, p-toluenesulfonic acid, and sulfamic acid, wherein the molar ratio of polycarboxylic acid to sulfur removal agent intermediate is 1:1 to 2, the molar ratio of high carbonic acid to sulfur removal agent intermediate is 1:1 to 2, the mass of the catalyst added is 0.5% to 2.5% of the mass of the sulfur removal agent intermediate, the reaction temperature is 120 to 150°C, and the reaction time is 2 to 10 hours.

[0072] Example 8: As an optimization of the above examples, the bactericide is oil-soluble polymeric guanidine, which is prepared according to the following method:

[0073] S21, a desired amount of petroleum acid is mixed with polyethylene polyamine to obtain intermediate one;

[0074] S22, intermediate one is uniformly mixed with a desired amount of guanidine hydrochloride to obtain intermediate two;

[0075] S23, the reaction monomer, solvent and chain transfer agent are uniformly mixed, and then a desired amount of initiator is added and reacted to obtain a reaction product;

[0076] S24, intermediate two and a desired amount of p-toluenesulfonic acid are added to the reaction product to obtain oil-soluble polymeric guanidine.

[0077] Example 9: As an optimization of the above-mentioned examples, in step S21, the molar ratio of petroleum acid to polyethylene polyamine is 0.9 to 1.1:0.9 to 1.1, the reaction temperature is 250°C to 300°C, and the reaction time is 10h to 12h, in step S22, the molar ratio of intermediate one to guanidine hydrochloride is 0.9 to 1.1:0.9 to 1.1, the reaction temperature is 150°C to 180°C, and the reaction time is 2h to 4h.

[0078] Example 10: As an optimization of the above-mentioned examples, in step S23, the reaction monomer is one or more of acrylic acid, methyl acrylate, ethyl acrylate, and maleic anhydride, the solvent is xylene, the chain transfer agent is n-dodecanethiol, and the initiator is one of azobisisobutyronitrile and dibenzoyl peroxide.

[0079] Example 11: As an optimization of the above-mentioned examples, the surfactant is one or more of sorbitan fatty acid ester surfactant, Tween-type emulsifier, EO-50, PO-50, monostearate-type emulsifier, and distearate-type emulsifier.

[0080] Example 12: As an optimization of the above-mentioned examples, the surfactant is Tween 80 and Tween 60.

[0081] Example 13: As an optimization of the above-mentioned examples, the organic oil is one of vegetable oil, bio-oil, and biomass diesel.

[0082] Example 14: As an optimization of the above-mentioned examples, the emulsion polymer stabilizer is one of polyacrylic acid, polyacrylate, polyacrylate, acrylic acid-methyl acrylate copolymer, and ethylene-vinyl acetate.

[0083] Example 15: The preparation method of the emulsion-type annulus protection fluid is carried out according to the following method: a desired amount of organic oil is added with a desired amount of anti-carbon dioxide corrosion inhibitor, sulfur removal agent, bactericide, surfactant, emulsion polymer stabilizer, and water, and after mixing and stirring, an emulsion-type annulus protection fluid is obtained.

[0084] Example 16: In the emulsion-type annulus protection fluid,

[0085] The anti-carbon dioxide corrosion inhibitor is prepared according to the following method:

[0086] First step, in the reaction kettle, add 350kg (1kmol) of macromolecular petroleum acid (molecular weight 350), add 439kg (1kmol) of polyethylene polyamine (molecular weight 439), mix uniformly, slowly heat to 280°C, reflux for 10h, get intermediate one;

[0087] Second step, mix intermediate one with 95.5kg (1kmol) of guanidine hydrochloride uniformly, control temperature at 150°C for 3h, get intermediate two;

[0088] Third step, take solvent (ethanol) 200 kg, add monomer (acrylic acid) 100 kg, chain transfer agent (n-dodecanethiol) 2 kg, control temperature 80℃, add initiator (azo diisobutyronitrile) 0.4 kg (add 4 times, 0.1 kg / h), react for 4 h, then remove the solvent by vacuum dehydration, to obtain intermediate three;

[0089] Fourth step, mix 884.5 kg of intermediate two and 302 kg of intermediate three uniformly, add polyetheramine (D350) 50 kg, control temperature 150℃, react for 4 h, to obtain the first polymer (comb-shaped structure imidazoline);

[0090] Fifth step, take 789 kg of intermediate one and 73 kg of adipic acid (0.5 kmol), control temperature 150℃, react for 4 h, then add 1,4-p-dichlorobenzene 87.5 kg (0.5 kmol), react for 4 h at 80℃, to obtain the second polymer (linear structure imidazoline);

[0091] Sixth step, take 789 kg of intermediate one, 95.5 kg of guanidine hydrochloride, 214.5 kg of hexadecyl primary amine, control temperature 150℃, react for 4 h, to prepare modified imidazoline by reaction;

[0092] Seventh step, mix the first polymer, the second polymer and the modified imidazoline according to the mass ratio of 9:0.5:0.5, stir uniformly, to obtain the anti-carbon dioxide corrosion inhibitor;

[0093] The sulfur removal agent is prepared according to the following method:

[0094] Put 1830 kg of ethanolamine into the kettle, start stirring and control temperature 60℃, slowly add 2500 kg (mass percentage 36%) of formaldehyde aqueous solution, after the addition is completed, continue to react at 60℃ for 3 h, to obtain the sulfur removal agent intermediate (i.e. triazine sulfur removal agent), vacuum dehydrate the sulfur removal agent intermediate for 2 h, add adipic acid 181 kg, sulfamic acid 11.5 kg, octadecanoic acid 4510 kg, add dimethylbenzene 2710 kg, control temperature 140℃, react for 6 h, to obtain the cross-linked and oil-soluble sulfur removal agent;

[0095] The bactericide is prepared according to the following method:

[0096] In the reaction kettle, add 200 kg of macromolecular petroleum acid, add 200 kg of polyethylene polyamine, stir uniformly, slowly warm up to 280℃, reflux reaction for 10 h, to prepare intermediate one, then add 7 kg of guanidine hydrochloride, control temperature 150℃ reaction for 3 h, to prepare intermediate two, take 50 kg of xylene, add 5 kg of methyl acrylate, 0.1 kg of dodecanethiol, control temperature 80℃, add azobisisobutyronitrile (AIBN) 0.1 g, reaction for 4 h, to obtain reaction product, then add intermediate two and p-toluenesulfonic acid 2 kg to the reaction product, control temperature 150℃ reaction for 4 h, to obtain bactericide (i.e. oil-soluble polymeric guanidine);

[0097] Take 1000 kg of biomass diesel, add 40 kg of the above-mentioned anti-carbon dioxide corrosion inhibitor, 40 kg of sulfur removal agent, 40 kg of bactericide, 100 kg of span 80, 10 kg of tween 80, 20 kg of polyacrylic acid, 1000 kg of tap water, mix and stir for 3 h, to obtain emulsion type annulus protection fluid.

[0098] In the emulsion type annulus protection fluid of example 17,

[0099] The preparation method of the anti-carbon dioxide corrosion inhibitor is different from that of example 16 in that in the third step, the monomer is methyl acrylate;

[0100] The sulfur removal agent is prepared according to the following method:

[0101] Put 1830 kg of ethanolamine into the kettle, start stirring and control temperature 60℃, slowly drop 2500 kg (mass percentage 36%) of formaldehyde aqueous solution, after dropping, continue to react at 60℃ for 3 h, to obtain sulfur removal agent intermediate (i.e. triazine type sulfur removal agent), vacuum dehydration of sulfur removal agent intermediate for 2 h, add 181 kg of glutaric acid, 11.5 kg of p-toluenesulfonic acid, 4510 kg of hexadecanoic acid, add 2710 kg of xylene, control temperature 140℃ reaction for 6 h, to obtain cross-linked and oil-soluble sulfur removal agent;

[0102] The bactericide is prepared according to the following method:

[0103] In the reaction kettle, add 200 kg of macromolecular petroleum acid, add 200 kg of polyethylene polyamine, stir uniformly, slowly warm up to 280℃, reflux reaction for 10 h, to prepare intermediate one, then add 7 kg of guanidine hydrochloride, control temperature 150℃ reaction for 3 h, to prepare intermediate two, take 50 kg of xylene, add 5 kg of methyl acrylate, 0.1 kg of dodecanethiol, control temperature 80℃, add azobisisobutyronitrile (AIBN) 0.1 g, reaction for 4 h, to obtain reaction product, then add intermediate two and p-toluenesulfonic acid 2 kg to the reaction product, control temperature 150℃ reaction for 4 h, to obtain bactericide (i.e. oil-soluble polymeric guanidine);

[0104] Take 1000 kg of biomass diesel, add the above obtained anti-carbon dioxide corrosion inhibitor 40 kg, sulfur removal agent 40 kg, bactericide 40 kg, span 85 100 kg, Tween 60 10 kg, acrylic acid-methyl acrylate copolymer 20 kg, tap water 1000 kg, mix and stir for 3 h to obtain an emulsion type annulus protection fluid.

[0105] In the emulsion type annulus protection fluid of Example 18,

[0106] The preparation method of the anti-carbon dioxide corrosion inhibitor is different from that of Example 16 in that in the sixth step, 214.5 kg of hexadecyl primary amine is replaced by 185.3 kg of dodecyl primary amine.

[0107] The sulfur removal agent is prepared by the following method:

[0108] Add 1830 kg of ethanolamine to the kettle, start stirring and control the temperature at 60°C, slowly add 2500 kg (36% by mass) of formaldehyde aqueous solution, after the addition is completed, continue to react at 60°C for 3 h to obtain a sulfur removal agent intermediate (i.e. a triazine type sulfur removal agent), vacuum dehydrate the sulfur removal agent intermediate for 2 h, add glutaric acid 181 kg, p-toluenesulfonic acid 11.5 kg, hexadecanoic acid 4510 kg, add dimethylbenzene 2710 kg, control the temperature at 140°C and react for 6 h to obtain a cross-linked and oil-soluble sulfur removal agent.

[0109] The bactericide is prepared by the following method:

[0110] In the reaction kettle, add 200 kg of macromolecular petroleum acid (weight average molecular weight 350 g / mol), add polyethylene polyamine 251 kg, stir uniformly, slowly heat to 280°C, reflux for 10 h to prepare intermediate one, then add 7 kg of guanidine hydrochloride, control the temperature at 150°C and react for 3 h to prepare intermediate two, take 50 kg of dimethylbenzene, add 6 kg of ethyl acrylate, 0.1 kg of dodecanethiol, control the temperature at 80°C, add 0.1 g of benzoyl peroxide (BPO) and react for 4 h to obtain a reaction product, then add intermediate two and 2 kg of p-toluenesulfonic acid to the reaction product, control the temperature at 150°C and react for 4 h to obtain the bactericide (i.e. oil-soluble polymeric guanidine).

[0111] Take 1000 kg of biomass diesel, add the above obtained anti-carbon dioxide corrosion inhibitor 40 kg, sulfur removal agent 40 kg, bactericide 40 kg, span 85 100 kg, Tween 60 10 kg, ethylene-vinyl acetate 20 kg, tap water 1000 kg, mix and stir for 3 h to obtain an emulsion type annulus protection fluid.

[0112] In the emulsion type annulus protection fluid of Example 19,

[0113] The preparation method of the anti-carbon dioxide corrosion inhibitor is different from that of example 16 in that 73 kg of adipic acid is replaced by 87 kg of octanedioic acid.

[0114] The sulfur removal agent is prepared by the following method:

[0115] Add 1830 kg of ethanolamine into the kettle, start stirring and control the temperature at 60°C, slowly add 2500 kg (36% by mass) of formaldehyde aqueous solution, after the addition is completed, continue to react at 60°C for 3 h to obtain a sulfur removal agent intermediate (i.e. a triazine type sulfur removal agent), vacuum dehydrate the sulfur removal agent intermediate for 2 h, add adipic acid 181 kg, sulfamic acid 11.5 kg, octadecanoic acid 4510 kg, add dimethylbenzene 2710 kg, control the temperature at 140°C and react for 6 h to obtain a cross-linked and oil-soluble sulfur removal agent.

[0116] The bactericide is prepared by the following method:

[0117] In the reaction kettle, add 200 kg of macromolecular petroleum acid (weight average molecular weight 350 g / mol), add polyethylene polyamine 251 kg, stir uniformly, slowly heat to 280°C, reflux for 10 h to prepare intermediate one, then add 7 kg of guanidine hydrochloride, control the temperature at 150°C and react for 3 h to prepare intermediate two, take 50 kg of dimethylbenzene, add 5 kg of methyl acrylate and 0.1 kg of dodecanethiol, control the temperature at 80°C, add 0.1 g of azobisisobutyronitrile (AIBN) and react for 4 h to obtain a reaction product, then add 2 kg of intermediate two and p-toluenesulfonic acid to the reaction product, control the temperature at 150°C and react for 4 h to obtain a bactericide (i.e. an oil-soluble polymeric guanidine).

[0118] Take 1000 kg of biomass diesel, add 40 kg of the anti-carbon dioxide corrosion inhibitor, 40 kg of the sulfur removal agent, 40 kg of the bactericide, 100 kg of span 85, 10 kg of Tween 60, 20 kg of ethylene-vinyl acetate and 1000 kg of tap water, mix and stir for 3 h to obtain an emulsion type annulus protection fluid.

[0119] In the emulsion type annulus protection fluid of example 20,

[0120] The preparation method of the anti-carbon dioxide corrosion inhibitor is different from that of example 16 in that in the third step, the initiator is dibenzoyl peroxide.

[0121] The sulfur removal agent is prepared by the following method:

[0122] Put 1830 kg of ethanolamine into the kettle, start stirring and control the temperature at 60 DEG C, slowly add 2500 kg (mass percentage 36%) of formaldehyde aqueous solution, after the addition is completed, continue to react at 60 DEG C for 3 h, to obtain the intermediate of the sulfur removal agent (i.e. the triazine type sulfur removal agent), vacuum dehydration of the intermediate of the sulfur removal agent for 2 h, add 181 kg of glutaric acid, 11.5 kg of p-toluenesulfonic acid, 4510 kg of hexadecanoic acid, add 2710 kg of dimethylbenzene, control the temperature at 140 DEG C and react for 6 h to obtain the crosslinked and oil-soluble sulfur removal agent;

[0123] The bactericide is prepared according to the following method:

[0124] In the reaction kettle, add 200 kg of macromolecular petroleum acid (weight average molecular weight 350 g / mol), add 251 kg of polyethylene polyamine, stir uniformly, slowly warm up to 280 DEG C, reflux for 10 h to prepare intermediate one, then add 7 kg of guanidine hydrochloride, control the temperature at 150 DEG C and react for 3 h to prepare intermediate two, take 50 kg of dimethylbenzene, add 5 kg of methyl acrylate, 0.1 kg of dodecanethiol, control the temperature at 80 DEG C, add 0.1 g of azobisisobutyronitrile (AIBN) and react for 4 h to obtain the reaction product, then add intermediate two and 2 kg of p-toluenesulfonic acid to the reaction product, control the temperature at 150 DEG C and react for 4 h to obtain the bactericide (i.e. the oil-soluble polymeric guanidine);

[0125] Take 1000 kg of biomass diesel, add 40 kg of the above-obtained anti-carbon dioxide corrosion inhibitor, 40 kg of the sulfur removal agent, 40 kg of the bactericide, 100 kg of span 85, 10 kg of Tween 60, 20 kg of ethylene-vinyl acetate and 1000 kg of tap water, mix and stir for 3 h to obtain the emulsion type annulus protection fluid.

[0126] The emulsion type annulus protection fluid obtained in examples 16 to 20 of the present application is subjected to performance test evaluation

[0127] The specific evaluation method is as follows: corrosion test is carried out by using a 1.5 L stainless steel corrosion evaluation kettle. The kettle is injected with an appropriate amount of the emulsion type annulus protection fluid sample obtained in examples 16 to 20 of the present application, sealed, nitrogen is introduced for 5 hours, the total pressure is 7.0 MPa, the system is warmed up to 80 DEG C, H2S and CO2 gas is introduced, the partial pressure of H2S is 1.0 MPa, the partial pressure of CO2 is 1.0 MPa, corrosion test is carried out on A3 steel sheet and N80 steel sheet, the time is 72 h, and the experimental results are shown in Table 1.

[0128] Table 1

[0129] .

[0130] As shown in Table 1, the emulsion type annular protection fluid has good thermal stability. The corrosion rate of A3 steel sheet is less than or equal to 0.0011 mm / a, and the corrosion rate of N80 steel sheet is less than or equal to 0.0037 mm / a under the condition of total pressure 7.0 MPa, H2S partial pressure 1.0 MPa, CO2 partial pressure 1.0 MPa, and 80 DEG C for 72 hours; the sterilization effect is good, and the sterilization effect is less than or equal to 3 pieces / mL, which can meet the corrosion protection requirements of ordinary carbon steel pipe annular space in high carbon acid environment.

[0131] The beneficial effects of the present application are as follows:

[0132] The anti-carbon dioxide corrosion inhibitor used in the present application has strong hydrophobicity, and the corrosion inhibition performance is significantly improved compared with ordinary oleic acid imidazoline;

[0133] The sulfur removal agent used in the present application is condensed by binary or ternary carboxylic acid and triazine sulfur removal agent, realizes polycyclic azide, and the polycyclic azide sulfur removal agent has obvious polycyclic coupling structure. The special coupling group can realize high-efficiency chain type decomposition when acting with sulfur, and the sulfur removal performance is higher than that of traditional monocyclic structure.

[0134] The sterilizing agent used in the present application is prepared by imidazoline, and has double functions of corrosion inhibition and sterilization. In addition, after further crosslinking, the sterilization and corrosion inhibition capacity can be further improved.

[0135] In the present application, the water in the emulsion part of the emulsion type annular protection fluid is introduced into the system to form a stable water-in-oil emulsion, which can retain the characteristics of oil-based products while greatly reducing the cost.

[0136] Therefore, the emulsion type annular protection fluid provided by the present application has good thermal stability and strong high-temperature resistance. The corrosion rate of A3 steel sheet is less than or equal to 0.0011 mm / a, and the corrosion rate of N80 steel sheet is less than or equal to 0.0037 mm / a under the condition of total pressure 7.0 MPa, H2S partial pressure 1.0 MPa, CO2 partial pressure 1.0 MPa, and 80 DEG C for 72 hours. The sterilization effect of saprophytic bacteria, iron bacteria and sulfate-reducing bacteria (SRB) is less than or equal to 3 pieces / mL, which can effectively prevent the corrosion and damage of wellbore environment to oil casing, provide sustained protection ability, greatly prolong the service life of wellbore annular pipe column, reduce the cost of oil and gas exploitation, and meet the needs of high-carbon acid oil and gas well annular protection. At the same time, the oil phase adopts biomass oil, which has no aromatic hydrocarbon, reduces the harm to human body and environment, and the biomass oil is renewable.

[0137] In summary, the emulsion type annular protection fluid has simple preparation process, good corrosion protection effect, and good protection effect on wellbore pipe column of well containing carbon dioxide and hydrogen sulfide. At the same time, organic oil is used as continuous phase to form water-in-oil stable emulsion, which can not only retain the characteristics of oil-based products, but also greatly reduce the cost.

[0138] The above technical features constitute embodiments of the present application, which have strong adaptability and implementation effects. Unnecessary technical features can be added or reduced according to actual needs to meet the needs of different situations.

Claims

1. An emulsion type annulus protection fluid, characterized by According to the mass percentage, it comprises: 1% to 2% of the anti-carbon dioxide corrosion inhibitor, 1% to 2% of the sulfur removal agent, 1% to 2% of the bactericide, 1% to 5% of the surfactant, 40% to 60% of the organic oil, 0.1% to 2% of the emulsion polymer stabilizer, and 5% to 50% of the water, wherein the emulsion type annulus protection fluid is prepared by adding the anti-carbon dioxide corrosion inhibitor, the sulfur removal agent, the bactericide, the surfactant, the emulsion polymer stabilizer and the water into the required amount of the organic oil, and then stirring and mixing to obtain the emulsion type annulus protection fluid, The anti-carbon dioxide corrosion inhibitor is prepared by the following method: S01, a required amount of macromolecular petroleum acid is uniformly mixed with a polyamine, and then reacted to obtain an intermediate one, wherein the molar ratio of the macromolecular petroleum acid to the polyamine is 0.9 to 1.1:0.9 to 1.1, the reaction temperature is 250°C to 300°C, and the reaction time is 9h to 11h, wherein the polyamine is a polyethylene polyamine, and the macromolecular petroleum acid is a by-product in the petroleum refining process; S02, the intermediate one is uniformly mixed with a required amount of guanidine hydrochloride, and then reacted to obtain an intermediate two, wherein the molar ratio of the intermediate one to the guanidine hydrochloride is 0.9 to 1.1:0.9 to 1.1, the reaction temperature is 140°C to 150°C, and the reaction time is 2.5h to 3.5h; S03, a solvent and a chain transfer agent are added to a required amount of monomer, and then a required amount of an initiator is added to react to obtain an intermediate three, wherein the monomer is one or more of acrylic acid, maleic anhydride and methacrylic acid, the solvent is one of methanol, ethanol, n-butanol, propylene glycol, glycerol, ethylene glycol, dimethylbenzene, trimethylbenzene, dimethyl sulfoxide and dimethylformamide, the chain transfer agent is n-dodecanethiol, and the initiator is one of azobisisobutyronitrile and dibenzoyl peroxide, the reaction temperature is 60°C to 120°C, and the reaction time is 3.5h to 4.5h; S04, the intermediate two, the intermediate three and a required amount of polyether amine are uniformly mixed and then reacted to obtain a first polymer, wherein the polyether amine is one of D350 and D600, the reaction temperature is 100°C to 150°C, and the reaction time is 3.5h to 4.5h; S05, a required amount of the intermediate one obtained in step S01 is reacted with a polybasic acid to obtain a first reaction product, wherein the polybasic acid is one of adipic acid and oxalic acid, the molar ratio of the polybasic acid to the intermediate one is 1:1 to 2, the reaction temperature is 100°C to 150°C, and the reaction time is 3.5h to 4.5h; S06, a chlorine-containing compound is mixed with the first reaction product to perform a cross-linking reaction to obtain a second polymer, wherein the chlorine-containing compound is 1,4-p-dichlorobenzene, the molar ratio of the chlorine-containing compound to the first reaction product is 1:1 to 2, the reaction temperature is 70°C to 100°C, and the reaction time is 3.5h to 4.5h; S07, the obtained first polymer, second polymer and modified imidazoline are mixed to obtain the anti-carbon dioxide corrosion inhibitor, wherein the intermediate I, guanidine hydrochloride and primary amine obtained in step S01 are mixed and reacted to obtain the modified imidazoline, wherein the molar ratio of the intermediate I, guanidine hydrochloride and primary amine is 1:1:1, the reaction temperature is 145-155℃, the reaction time is 3.5-4.5h, and the primary amine is one of dodecyl primary amine, tetradecyl primary amine, hexadecyl primary amine and octadecyl primary amine, The sulfur removal agent is prepared by the following method: S11, a desired amount of alcohol amine is mixed with aldehyde to obtain a sulfur removal agent intermediate, wherein the alcohol amine is monoethanolamine, the aldehyde is formaldehyde, the molar ratio of the alcohol amine to the aldehyde is 0.9-1.1:0.9-1.1, the reaction temperature is 60-80℃, and the reaction time is 2-4h; S12, the sulfur removal agent intermediate is vacuum dehydrated and purified, and then a desired amount of polycarboxylic acid, high carbon acid, catalyst and dimethylbenzene are added in sequence to obtain the sulfur removal agent, wherein the polycarboxylic acid is one of adipic acid, glutaric acid, oxalic acid and malonic acid, the high carbon acid is one or more of dodecanoic acid, tetradecanoic acid, hexadecanoic acid and octadecanoic acid, the catalyst is one of dodecylbenzenesulfonic acid, p-toluenesulfonic acid and sulfamic acid, the molar ratio of the polycarboxylic acid to the sulfur removal agent intermediate is 1:1-2, the molar ratio of the high carbon acid to the sulfur removal agent intermediate is 1:1-2, the mass of the catalyst added is 0.5%-2.5% of the mass of the sulfur removal agent intermediate, the reaction temperature is 120-150℃, and the reaction time is 2-10h, The bactericide is an oil-soluble polymeric guanidine, which is prepared by the following method: S21, a desired amount of petroleum acid is mixed with polyethylene polyamine to obtain intermediate I, wherein the molar ratio of the petroleum acid to the polyethylene polyamine is 0.9-1.1:0.9-1.1, the reaction temperature is 250-300℃, and the reaction time is 10-12h; S22, intermediate I is uniformly mixed with a desired amount of guanidine hydrochloride to obtain intermediate II, wherein the molar ratio of intermediate I to guanidine hydrochloride is 0.9-1.1:0.9-1.1, the reaction temperature is 150-180℃, and the reaction time is 2-4h; S23, the reaction monomer, solvent and chain transfer agent are uniformly mixed, and then a desired amount of initiator is added to obtain a reaction product, wherein the reaction monomer is one or more of methyl acrylate and ethyl acrylate, the solvent is dimethylbenzene, the chain transfer agent is n-dodecanethiol, and the initiator is one of azobisisobutyronitrile and dibenzoyl peroxide; S24, intermediate II and a desired amount of p-toluenesulfonic acid are added to the reaction product to obtain the oil-soluble polymeric guanidine.

2. The emulsion type annulus protection fluid according to claim 1, characterized in that The surface active agent is one or more of sorbitan fatty acid ester surface active agent, Tween type emulsifier, EO-50, PO-50, monostearate type emulsifier, and distearate type emulsifier; or / and the organic oil is one of plant oil, bio-oil, and biomass diesel; or / and the emulsion polymer stabilizer is one of polyacrylic acid, polyacrylate, polyacrylate, acrylic acid-methyl acrylate copolymer, and ethylene-vinyl acetate.

3. The emulsion type annulus protection fluid according to claim 2, characterized in that The surface active agent is Tween 80 or Tween 60.

4. A method for producing the emulsion-type annulus protection fluid according to any one of claims 1 to 3, characterized by The emulsion type annulus protection fluid is prepared by adding a required amount of anti-carbon dioxide corrosion inhibitor, sulfur removal agent, bactericide, surface active agent, emulsion polymer stabilizer, and water into a required amount of organic oil, and mixing and stirring.

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