Preparation method of high-temperature-resistant salt-resistant filtrate reducer for drilling fluid

Abstract

The invention belongs to the field of petroleum development, and discloses a preparation method of a high-temperature-resistant salt-resistant filtrate reducer for a drilling fluid, which comprises the following steps: dissolving N-(3-acetylphenyl)-N-vinyl methacrylamide and p-acetamidobenzenesulfonyl chloride in a solvent tetrahydrofuran, adding catalysts copper bromide and sodium carbonate, introducing nitrogen, heating for reaction, and cooling to room temperature; extracting with trichloromethane, and concentrating to obtain a product A; adding purified water, acrylamide, acrylic acid, AMPS, hexadecyl dimethyl allyl ammonium chloride and the product A into a liquid preparation tank, adjusting pH with NaOH, cooling, blowing nitrogen, and adding a chain transfer agent, an oxidizing agent and a reducing agent to obtain a white elastic solid. After shearing, drying, grinding and sieving to obtain white powder, namely the high-temperature-resistant and salt-resistant filtrate reducer for the drilling fluid. The product can be used as a saturated salt water drilling fluid filtrate reducer at the high temperature of 220 DEG C.

Description

Technical Field

[0001] The invention belongs to the field of petroleum development, and more specifically, relates to a method for preparing a high temperature and salt resistant fluid loss reducer for drilling fluid. Background Art

[0002] Polyacrylamide is commonly used in drilling fluids. It is a synthetic product with excellent performance and low price. It has good thickening, drag reduction, filtration loss reduction, flocculation and other effects. But its disadvantages are also obvious: poor shear stability, poor salt resistance, and poor thermal stability. However, these can be improved by chemical modification methods. 2-Acrylamide-2-methylpropanesulfonic acid (AMPS) is the most commonly used modified monomer. AMPS can form a multi-polymer with acrylamide and other functional monomers, which can effectively improve the temperature and salt resistance and are used in oil fields. In these copolymers, the introduction of different monomers can make the copolymers have different properties. Among the commonly used groups, the sulfonic group and the pyrrolidone group have good salt and temperature resistance, the amide group has good adsorption performance, and the carboxyl group has good hydration function.

[0003] However, as oil and gas drilling goes deeper and deeper, the formation temperature becomes higher and higher, and more and more salt rock layers and salt gypsum layers are encountered, the requirements for the temperature resistance and salt resistance of drilling fluids are higher, and current products are difficult to meet these high demands. This requires us to find more suitable functional monomers to improve performance. Summary of the invention

[0004] The main purpose of the invention is to synthesize a new functional monomer and provide a method for preparing a high temperature and salt resistant fluid loss reducer for drilling fluid.

[0005] The technical solution adopted by the present invention is: a method for preparing a high temperature and salt resistant fluid loss reducer for drilling fluid, characterized in that the steps are: (1) Weigh 150 parts by mass of N-(3-acetylphenyl)-N-vinylmethacrylamide and 306 parts by mass of p-acetamidobenzenesulfonyl chloride; (2) Add 300 parts of tetrahydrofuran solvent into a three-necked flask, add the raw material of step 1), add 2 parts of copper bromide and 2 parts of sodium carbonate; (3) Continue to introduce nitrogen, raise the temperature to 90°C, and react for 12 hours; (4) Extract with chloroform for multiple times, combine the extracts, and concentrate to obtain the final product functional monomer A. The reaction formula is as follows: ; (5) Add 750-850 parts of purified water, 450-550 parts of acrylamide (AM), 60-80 parts of acrylic acid (AA), 80-100 parts of AMPS, 5-20 parts of hexadecyl dimethyl allyl ammonium chloride (C16DMAAC), and 10-40 parts of functional monomer A to the liquid preparation tank by weight, and stir thoroughly; (6) Adjust the pH to 6-7 with NaOH and cool to 0-2°C; (7) After blowing N2 for 15 minutes, add 0.01-0.3 parts of chain transfer agent, 0.02-0.1 parts of oxidant, 0.02-0.1 parts of reducing agent, and 0.02-0.1 parts of initiator. After the temperature of the reaction liquid rises and the wire is drawn, remove the nitrogen and seal the reactor. After the reaction is completed, a white elastic solid product is obtained; (8) The white elastic solid product is sent into a machine to be crushed, and then placed in an oven for drying to obtain white solid particles; (9) Grind the white solid particles and pass them through an 80-mesh sieve to obtain a white powder which is a high-temperature and salt-resistant fluid loss reducer for drilling fluid.

[0006] The chain transfer agent is a mixture of one or more of aliphatic mercaptans, xanthogenic acid disulfides, polyphenols, sulfur, halides and nitroso compounds.

[0007] The oxidant is one or more of tert-butyl hydroperoxide, potassium persulfate, sodium persulfate, and ammonium persulfate.

[0008] The initiator is one or more of azobisisobutylimidazoline hydrochloride, azobisisobutyronitrile, azobisisovaleronitrile and azobisisobutylamidine hydrochloride.

[0009] The reducing agent is one or more of potassium pyrosulfite, sodium pyrosulfite, ferrous sulfate, ammonium ferrous sulfate, and sodium methanesulfinate.

[0010] The beneficial effects of the present invention are as follows: N-(3-acetylphenyl)-N-vinylmethacrylamide contains a functional group -CO and a benzene ring, and the -CO carbonyl reacts with water to generate two -OHs, which easily form hydrogen bonds with water, adsorbing water while also improving salt resistance. As a rigid group, the benzene ring is not easily destroyed at high temperatures and is resistant to shearing, and has good high temperature resistance, which is of great help to the high temperature and high pressure filtration and wall building of stable drilling fluids and the resistance to salt and calcium corrosion. Para-acetamidobenzenesulfonyl chloride contains functional groups -CONH and -SO2, and -CONH will slowly hydrolyze at high temperatures to generate -COOH, which is easy to form hydrogen bonds with water, adsorbing water while also having high salt resistance. -SO2 sulfonyl has unique physical and chemical properties, and the sulfonyl group can slightly improve the solubility of the product, and the sulfonyl group can also provide two hydrogen bond receptors, and the sulfonyl group structure is relatively stable and not easily destroyed. The introduction of the sulfonyl group improves the high temperature and salt resistance of the product. Product A combines the advantageous functional groups of the two raw materials, and the reaction also generates a pyrrolidone group. This functional group has a stable structure and is not easily destroyed at high temperatures, further improving the high temperature resistance. DETAILED DESCRIPTION

[0011] Example 1: 1) Weigh 150 parts of N-(3-acetylphenyl)-N-vinylmethacrylamide and 306 parts of p-acetamidobenzenesulfonyl chloride by mass; 2) Add 300 parts of tetrahydrofuran solvent into a three-necked flask, add the raw material of step 1), add 2 parts of copper bromide and 2 parts of sodium carbonate; 3) Continue to introduce nitrogen, raise the temperature to 90°C, and react for 12 hours; 4) Extracting with chloroform for multiple times, combining the extracts, and concentrating to obtain the final product functional monomer A; 5) Add 796 parts of purified water, 520 parts of acrylamide (AM), 70 parts of acrylic acid (AA), 88 parts of AMPS, 10 parts of hexadecyl dimethyl allyl ammonium chloride (C16DMAAC), and 15 parts of the final product functional monomer A into the liquid preparation tank and stir well; 6) Adjust the pH to 6.5 with NaOH and cool to 1.6°C; 7) After N2 was introduced for 15 minutes, 0.1 parts of sodium hypophosphite, 0.03 parts of tert-butyl hydroperoxide, 0.04 parts of ammonium ferrous sulfate, and 0.03 parts of azobisisobutyronitrile were added. After the temperature of the reaction solution increased and the wire was drawn, the nitrogen was removed and the reactor was sealed. After the reaction was completed, a white elastic solid product was obtained; 8) The white elastic solid product is sent into a machine to be crushed, and then placed in an oven for drying to obtain white solid particles; 9) Grind the white solid particles and pass them through an 80-mesh sieve. The resulting white powder is the high-temperature and salt-resistant fluid loss reducer for drilling fluid.

[0012] Example 2: 1) Weigh 150 parts of N-(3-acetylphenyl)-N-vinylmethacrylamide and 306 parts of p-acetamidobenzenesulfonyl chloride by mass; 2) Add 300 parts of tetrahydrofuran solvent into a three-necked flask, add the raw material from 1), 2 parts of copper bromide and 2 parts of sodium carbonate; 3) Continue to introduce nitrogen, raise the temperature to 90°C, and react for 12 hours; 4) Extracting with chloroform for multiple times, combining the extracts, and concentrating to obtain the final product functional monomer A; 5) Add 786 parts of purified water, 520 parts of acrylamide (AM), 70 parts of acrylic acid (AA), 88 parts of AMPS, 10 parts of hexadecyl dimethyl allyl ammonium chloride (C16DMAAC), and 25 parts of the final product functional monomer A into the liquid preparation tank and stir well; 6) Adjust the pH to 6.5 with NaOH and cool to 1.5°C; 7) After N2 was introduced for 15 minutes, 0.1 parts of sodium hypophosphite, 0.03 parts of tert-butyl hydroperoxide, 0.04 parts of ammonium ferrous sulfate, and 0.03 parts of azobisisobutyronitrile were added. After the temperature of the reaction solution increased and the wire was drawn, the nitrogen was removed and the reactor was sealed. After the reaction was completed, a white elastic solid product was obtained; 8) The white elastic solid product is sent into a machine to be crushed, and then placed in an oven for drying to obtain white solid particles; 9) Grind the white solid particles and pass them through an 80-mesh sieve. The resulting white powder is the high-temperature and salt-resistant fluid loss reducer for drilling fluid.

[0013] Example 3: 1) Weigh 150 parts of N-(3-acetylphenyl)-N-vinylmethacrylamide and 306 parts of p-acetamidobenzenesulfonyl chloride by mass; 2) Add 300 parts of tetrahydrofuran solvent into a three-necked flask, add the raw material from 1), 2 parts of copper bromide and 2 parts of sodium carbonate; 3) Continue to introduce nitrogen, raise the temperature to 90°C, and react for 12 hours; 4) Extracting with chloroform for multiple times, combining the extracts, and concentrating to obtain the final product functional monomer A; 5) Add 776 parts of purified water, 520 parts of acrylamide (AM), 70 parts of acrylic acid (AA), 88 parts of AMPS, 10 parts of hexadecyl dimethyl allyl ammonium chloride (C16DMAAC), and 35 parts of the final product functional monomer A into the liquid preparation tank and stir well; 6) Adjust the pH to 6.5 with NaOH and cool to 1.4°C; 7) After N2 was introduced for 15 minutes, 0.1 parts of sodium hypophosphite, 0.03 parts of tert-butyl hydroperoxide, 0.04 parts of ammonium ferrous sulfate, and 0.03 parts of azobisisobutyronitrile were added. After the temperature of the reaction solution increased and the wire was drawn, the nitrogen was removed and the reactor was sealed. After the reaction was completed, a white elastic solid product was obtained; 8) The white elastic solid product is sent into a machine to be crushed, and then placed in an oven for drying to obtain white solid particles; 9) Grind the white solid particles and pass them through an 80-mesh sieve to obtain a white powder which is a high temperature and salt resistant fluid loss reducer for drilling fluid.

[0014] Comparative Example 1: 1) Add 776 parts of purified water, 520 parts of acrylamide (AM), 70 parts of acrylic acid (AA), 88 parts of AMPS, and 10 parts of hexadecyl dimethyl allyl ammonium chloride (C16DMAAC) into a liquid preparation tank and stir well; 2) Adjust the pH to 6.5 with NaOH and cool to 1.4°C; 3) After N2 was introduced for 15 minutes, 0.1 parts of sodium hypophosphite, 0.03 parts of tert-butyl hydroperoxide, 0.04 parts of ammonium ferrous sulfate, and 0.03 parts of azobisisobutyronitrile were added. After the temperature of the reaction solution increased and the wire was drawn, the nitrogen was removed and the reactor was sealed. After the reaction was completed, a white elastic solid product was obtained; 4) The white elastic solid product is sent into a machine to be crushed, and then placed in an oven for drying to obtain white solid particles; 5) Grind the white solid particles and pass them through an 80-mesh sieve to obtain white powder.

[0015] Comparative Example 2: 1) Add 741 parts of purified water, 520 parts of acrylamide (AM), 70 parts of acrylic acid (AA), 88 parts of AMPS, 10 parts of hexadecyldimethylallyl ammonium chloride (C16DMAAC), 35 parts of N-(3-acetylphenyl)-N-vinylmethacrylamide, and 35 parts of p-acetamidobenzenesulfonyl chloride into a liquid preparation tank and stir well; 2) Adjust the pH to 6.5 with NaOH and cool to 1.8°C; 3) After N2 was introduced for 15 minutes, 0.1 parts of sodium hypophosphite, 0.03 parts of tert-butyl hydroperoxide, 0.04 parts of ammonium ferrous sulfate, and 0.03 parts of azobisisobutyronitrile were added. After the temperature of the reaction solution increased and the wire was drawn, the nitrogen was removed and the reactor was sealed. After the reaction was completed, a white elastic solid product was obtained; 4) The white elastic solid product is sent into a machine to be crushed, and then placed in an oven for drying to obtain white solid particles; 5) Grind the white solid particles and pass them through an 80-mesh sieve to obtain white powder.

[0016] Comparative Example 3: 1) Add 741 parts of purified water, 520 parts of acrylamide (AM), 70 parts of acrylic acid (AA), 88 parts of AMPS, 10 parts of hexadecyl dimethyl allyl ammonium chloride (C16DMAAC), 35 parts of N-(3-acetylphenyl)-N-vinyl methacrylamide, and 35 parts of N-((4-sulfonyl chloride)phenyl)acrylamide into a liquid preparation tank and stir well; 2) Adjust the pH to 6.5 with NaOH and cool to 1.7°C; 3) After N2 was introduced for 15 minutes, 0.1 parts of sodium hypophosphite, 0.03 parts of tert-butyl hydroperoxide, 0.04 parts of ammonium ferrous sulfate, and 0.03 parts of azobisisobutyronitrile were added. After the temperature of the reaction solution increased and the wire was drawn, the nitrogen was removed and the reactor was sealed. After the reaction was completed, a white elastic solid product was obtained; 4) The white elastic solid product is sent into a machine to be crushed, and then placed in an oven for drying to obtain white solid particles; 5) Grind the white solid particles and pass them through an 80-mesh sieve to obtain white powder.

[0017] Performance test: The base slurry is configured according to the method provided in the Petroleum and Natural Gas Industry Standard SY / T 7626-2021 of the People's Republic of China: 1. Preparation of fresh water base slurry: Add 400 ml of distilled water and 0.64 g of anhydrous sodium carbonate into a high-stirring cup, slowly add 16 g of bentonite for drilling fluid test slurry under high-speed stirring, and stir at high speed for 20 minutes; 2. Prepare 6 parts of fresh water base slurry according to step 1, add the white powder products of Examples 1-3 and Comparative Examples 1-3 respectively under high-speed stirring, stir for 20 minutes, then add 120g of sodium chloride respectively, stir at high speed for 20 minutes, cure at room temperature for 16 hours, and measure the API filtration loss according to GB / T16783.1; 3. Prepare 6 parts of fresh water base slurry according to step 1, add the white powder products of Examples 1-3 and Comparative Examples 1-3 respectively under high-speed stirring, stir for 20 minutes, then add 120g of sodium chloride respectively, stir at high speed for 20 minutes, put into a high-temperature tank and heat at 220°C for 16 hours, and measure the API filtration loss according to GB / T16783.1.

[0018] The results are as follows:

[0019] In the above table, comparative example 1 does not add the new functional monomer, and the fluid loss reduction effect is poor. From the experimental results of Examples 1-3, it can be seen that as the amount of the new monomer A increases, the high temperature and salt resistance of the fluid loss reducer is better.

[0020] It can be seen from Comparative Example 2 and Example 3 that the raw materials are directly involved in the polymerization reaction without reacting, and the obtained product has a poor filtration reduction effect, which is far inferior to the product with the addition of the new functional monomer A. The reason is that 4-acetamidobenzenesulfonyl chloride has no double bond and cannot participate in the polymerization, and the heat and salt resistance effect cannot play a role.

[0021] Comparative Example 3: Raw materials used: N-((4-sulfonyl chloride)phenyl)acrylamide The structure is similar to that of p-acetamidobenzenesulfonyl chloride, but it contains a double bond and can participate in polymerization; the raw materials N-((4-sulfonyl chloride)phenyl)acrylamide and N-(3-acetylphenyl)-N-vinylmethacrylamide have more byproducts in the reaction, resulting in less product A, and the raw materials are mixed at one time, which is easy to produce more impurities. The purity of comparative example 3 is more than 30% lower than that of examples 1-3, and the dosage when used as a filter loss agent will be greatly increased.

Claims

1. A method for preparing a high temperature and salt resistant fluid loss reducer for drilling fluid, characterized in that: The steps are: (1) Weigh 150 parts by mass of N-(3-acetylphenyl)-N-vinylmethacrylamide and 306 parts by mass of p-acetamidobenzenesulfonyl chloride; (2) Add 300 parts of tetrahydrofuran solvent into a three-necked flask, add the raw materials of step 1), and then add 2 parts of copper bromide and 2 parts of sodium carbonate as catalyst; (3) Continue to introduce nitrogen, raise the temperature to 90°C, and react for 12 hours; (4) Extract with chloroform for multiple times, combine the extracts, and concentrate to obtain the final product functional monomer A. The reaction formula is as follows: ； (5) Add 750-850 parts of purified water, 450-550 parts of acrylamide (AM), 60-80 parts of acrylic acid (AA), 80-100 parts of AMPS, 5-20 parts of hexadecyl dimethyl allyl ammonium chloride (C16DMAAC), and 10-40 parts of functional monomer A to the liquid preparation tank by weight, and stir thoroughly; (6) Adjust the pH to 6-7 with NaOH and cool to 0-2°C; (7) After blowing N2 for 15 minutes, add 0.01-0.3 parts of chain transfer agent, 0.02-0.1 parts of oxidant, 0.02-0.1 parts of reducing agent, and 0.02-0.1 parts of initiator. After the temperature of the reaction liquid rises and the wire is drawn, remove the nitrogen and seal the reactor. After the reaction is completed, a white elastic solid product is obtained; (8) The white elastic solid product is sent into a machine to be crushed, and then placed in an oven for drying to obtain white solid particles; (9) Grind the white solid particles and pass them through an 80-mesh sieve to obtain a white powder which is a high-temperature and salt-resistant fluid loss reducer for drilling fluid.

2. The method for preparing a high temperature and salt resistant fluid loss reducer for drilling fluid according to claim 1, characterized in that: The chain transfer agent is a mixture of one or more of aliphatic mercaptans, xanthogenic acid disulfides, polyphenols, sulfur, halides and nitroso compounds.

3. The method for preparing a high temperature and salt resistant fluid loss reducer for drilling fluid according to claim 1, characterized in that: The oxidant is one or more of tert-butyl hydroperoxide, potassium persulfate, sodium persulfate, and ammonium persulfate.

4. The method for preparing a high temperature and salt resistant fluid loss reducer for drilling fluid according to claim 1, characterized in that: The initiator is one or more of azobisisobutylimidazoline hydrochloride, azobisisobutyronitrile, azobisisovaleronitrile and azobisisobutylamidine hydrochloride.

5. The method for preparing a high temperature and salt resistant fluid loss reducer for drilling fluid according to claim 1, characterized in that: The reducing agent is one or more of potassium pyrosulfite, sodium pyrosulfite, ferrous sulfate, ammonium ferrous sulfate, and sodium methanesulfinate.

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