Multifunctional drilling fluid treatment agent and method of making same

Abstract

The application relates to the technical field of drilling fluids, and discloses a multifunctional drilling fluid treatment agent and a preparation method thereof. The preparation raw materials of the treatment agent include 40 parts by weight of water, 0.5-20 parts by weight of a water-soluble natural polymer material, 2-20 parts by weight of a pH regulator, 5-80 parts by weight of a water-soluble anionic monomer, 2-40 parts by weight of a crosslinking monomer, 1-50 parts by weight of an organic acid, 0.5-20 parts by weight of a water-soluble cationic monomer, 1-20 parts by weight of a special methyl methacrylate ester, 1-10 parts by weight of a cyclic polysaccharide, 0.5-10 parts by weight of silane coupling agent modified nanoparticles and 0.5-10 parts by weight of an initiator. The multifunctional drilling fluid treatment agent provided in the application can make the drilling fluid have good high-temperature filtration-reducing performance, inhibition performance, lubricating performance, viscosity-increasing performance, plugging performance and environmental protection performance, and the preparation method is simple and suitable for industrial popularization.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of drilling fluid, in particular to a multifunctional drilling fluid treatment agent and a preparation method thereof. BACKGROUND

[0002] In oil and gas exploration and development, drilling fluid, as the blood of drilling engineering, bears the functions of balancing formation pressure, stabilizing well wall, carrying cuttings, cooling and lubricating, and transmitting hydrodynamic force. With the gradual expansion of the exploration and development of conventional oil and gas resources to deep strata, in order to meet the performance requirements of temperature resistance, filtration loss control, plugging and anti-sloughing, and lubrication of drilling fluid, poly-sulfonated drilling fluid system is usually used in China.

[0003] The poly-sulfonated drilling fluid system has the characteristics of good temperature resistance and salt resistance, which promotes the progress of drilling technology in China. However, the disadvantages of this system are also obvious, mainly including two aspects: first, the formula is complex, and there are many types of treatment agents, which leads to complicated treatment and maintenance procedures. Second, it is highly toxic, and the core treatment agents such as sulfonated asphalt and SMP added in the system are moderately toxic / micro-toxic, with low biodegradation index, which does not meet the environmental protection requirements, has high environmental pollution risk, and it is difficult to harmlessly treat waste drilling fluid.

[0004] In order to overcome the above problems of poly-sulfonated drilling fluid system, since the 1990s, a small number of multifunctional products with multiple application effects have been formed by expanding other functions with filtration loss as the core function. For example, the ARJ type multifunctional treatment agent developed by Changjiang University has the functions of increasing viscosity, reducing filtration loss and lubrication. The poly-sulfonated treatment agent SPAMH developed by Southwest Petroleum College integrates SMP, SMC and polymer, and has the functions of reducing water loss and reducing viscosity. The YFF type multifunctional treatment agent reported by Petroleum University (East China) has the effects of inhibition, plugging and filtration loss reduction.

[0005] CN107722950A discloses a complex multifunctional drilling fluid additive, which is a mixture composed of bentonite, soda ash, caustic soda, sodium carboxymethyl cellulose and potassium chloride. CN201210438285 discloses a complex multifunctional drilling fluid treatment agent and a preparation method thereof, which is a mixture composed of cationic fluorocarbon surfactant, alcohol amine compound, ionic surfactant and defoaming agent, and has multiple functions such as lubrication, anti-sloughing, filtration loss reduction and surface tension reduction. CN1052349 discloses a hydrolyzed double polyammonium salt prepared by polyacrylonitrile and polyacrylamide hydrolysis reaction, and a mixture of polyacrylonitrile or polyacrylamide is further compounded to form a drilling fluid treatment agent with the functions of anti-sloughing, viscosity reduction or viscosity increase according to different requirements.

[0006] However, the above multifunctional drilling fluid treatment agents are difficult to simultaneously have good high-temperature filtration loss reduction performance, inhibition performance, lubrication performance, viscosity increase performance, plugging performance and environmental protection performance, and various modified additives need to be additionally added in the use process. SUMMARY

[0007] The present application aims to overcome the problem that the multifunctional drilling fluid treatment agent in the prior art is difficult to simultaneously have good high-temperature filtration-reducing performance, inhibition performance, lubrication performance, viscosity-increasing performance, plugging performance and environmental protection performance, and provides a multifunctional drilling fluid treatment agent and a preparation method thereof.

[0008] To achieve the above-mentioned purpose, the first aspect of the present application provides a multifunctional drilling fluid treatment agent, wherein the preparation raw material of the treatment agent comprises: 40 parts by weight of water, 0.5-20 parts by weight of a water-soluble natural polymer material, 2-20 parts by weight of a pH regulator, 5-80 parts by weight of a water-soluble anionic monomer, 2-40 parts by weight of a crosslinking monomer, 1-50 parts by weight of an organic acid, 0.5-20 parts by weight of a water-soluble cationic monomer, 1-20 parts by weight of a special ester of methacrylic acid, 1-10 parts by weight of a cyclic polysaccharide, 0.5-10 parts by weight of a silane coupling agent modified nanoparticle and 0.5-10 parts by weight of an initiator.

[0009] The second aspect of the present application provides a preparation method of the multifunctional drilling fluid treatment agent in the first aspect of the present application, wherein the method comprises the following steps: first, uniformly mixing water and a water-soluble natural polymer material, then sequentially adding a pH regulator, a water-soluble anionic monomer, a crosslinking monomer, an organic acid, a water-soluble cationic monomer, a special ester of methacrylic acid and a cyclic polysaccharide, uniformly stirring, then adding a silane coupling agent modified nanoparticle, again uniformly stirring, then adding an initiator, standing at room temperature, obtaining a rubber block, crushing the rubber block, and obtaining the multifunctional drilling fluid treatment agent.

[0010] Through the above technical solution, the present application has the following beneficial technical effects:

[0011] 1) The multifunctional drilling fluid treatment agent provided in the present application is polymerized from a water-soluble natural polymer material, a pH regulator, a water-soluble anionic monomer, a crosslinking monomer, an organic acid, a water-soluble cationic monomer, a special ester of methacrylic acid, a cyclic polysaccharide, an initiator and a silane coupling agent modified nanoparticle, so that the drilling fluid has good high-temperature filtration-reducing performance, inhibition performance, lubrication performance, viscosity-increasing performance, plugging performance and environmental protection performance;

[0012] 2) The preparation method of the multifunctional drilling fluid treatment agent provided in the present application is simple to operate and suitable for industrial popularization. DETAILED DESCRIPTION

[0013] The endpoints of the ranges and any values disclosed herein are not limited to the precise values recited as the exact dimensions are not considered critical for the purposes of the application. The endpoints of the ranges and any values are provided as approximations only and are understood to be open-ended. Thus, the endpoints can be combined with one another to form ranges that are not expressly delineated herein. The ranges and values are understood to be approximate, and thus, the values can be combined with other values to form new ranges that are not expressly delineated herein.

[0014] The first aspect of the present application provides a multifunctional drilling fluid treatment agent, wherein the preparation raw materials of the treatment agent include: 40 parts by weight of water, 0.5-20 parts by weight of water-soluble natural polymer material, 2-20 parts by weight of pH regulator, 5-80 parts by weight of water-soluble anionic monomer, 2-40 parts by weight of crosslinking monomer, 1-50 parts by weight of organic acid, 0.5-20 parts by weight of water-soluble cationic monomer, 1-20 parts by weight of special methyl acrylic ester, 1-10 parts by weight of cyclic polysaccharide, 0.5-10 parts by weight of silane coupling agent modified nanoparticles and 0.5-10 parts by weight of initiator.

[0015] In a preferred embodiment of the present application, the preparation raw materials of the treatment agent include: 40 parts by weight of water, 3-8 parts by weight of water-soluble natural polymer material, 6-8 parts by weight of pH regulator, 25-50 parts by weight of water-soluble anionic monomer, 5-15 parts by weight of crosslinking monomer, 3-20 parts by weight of organic acid, 1-8 parts by weight of water-soluble cationic monomer, 5-15 parts by weight of special methyl acrylic ester, 4-8 parts by weight of cyclic polysaccharide, 2-5 parts by weight of silane coupling agent modified nanoparticles and 1-4 parts by weight of initiator.

[0016] In the present application, when the preparation raw materials of the treatment agent are used in the above defined range, the multifunctional drilling fluid treatment agent has better comprehensive modification effect on the drilling fluid.

[0017] In a preferred embodiment of the present application, the water-soluble natural polymer material is selected from water-soluble sweet potato starch and / or water-soluble corn starch, preferably water-soluble sweet potato starch.

[0018] In the present application, the water-soluble sweet potato starch and the water-soluble corn starch are conventional commercially available products, and the present application does not make special limitations thereon. When the water-soluble sweet potato starch is used, the drilling fluid prepared by using the multifunctional drilling fluid treatment agent has lower high temperature and high pressure filtration loss and better lubricating performance.

[0019] In a preferred embodiment of the present application, the pH regulator is selected from sodium hydroxide and / or potassium hydroxide, preferably sodium hydroxide.

[0020] In a preferred embodiment of the present application, the water-soluble anionic monomer is selected from one or more of 2-acrylamido-2-methylpropanesulfonic acid (AMPS), sodium allylsulfonate, sodium 4-vinylbenzenesulfonate, preferably 2-acrylamido-2-methylpropanesulfonic acid.

[0021] In a preferred embodiment of the present application, the crosslinking monomer is selected from one or more of acrylamide, N-hydroxymethyl acrylamide, N,N-methylene acrylamide, preferably acrylamide and / or N,N-methylene acrylamide.

[0022] In a preferred embodiment of the present application, the organic acid is selected from acrylic acid and / or maleic acid, preferably acrylic acid.

[0023] In a preferred embodiment of the present application, the water-soluble cationic monomer is selected from methacryloyloxyethyl trimethyl ammonium chloride and / or dimethyldiallyl ammonium chloride, preferably methacryloyloxyethyl trimethyl ammonium chloride.

[0024] In a preferred embodiment of the present application, the special methacrylic ester is selected from hydroxyethyl methacrylate and / or dimethylaminoethyl methacrylate, preferably dimethylaminoethyl methacrylate.

[0025] In a preferred embodiment of the present application, the cyclic polysaccharide is selected from a-cyclodextrin and / or β-cyclodextrin, preferably β-cyclodextrin.

[0026] In the present application, the inventors have found through research that the special methacrylic ester and the cyclic polysaccharide synergistically act to enable the multifunctional drilling fluid treatment agent prepared to simultaneously improve the inhibition performance and the fluid loss reduction performance of the drilling fluid.

[0027] In a preferred embodiment of the present application, the silane coupling agent modified nanoparticles are selected from one or more of silane coupling agent modified nanosilica, silane coupling agent modified nanoalumina, silane coupling agent modified nanozirconia, silane coupling agent modified nanosilicon nitride, silane coupling agent modified nanosilicon carbide, preferably silane coupling agent modified nanosilica.

[0028] In the present application, the inventors have found through research that the nanoparticles modified by the silane coupling agent can polymerize with the water-soluble natural high molecular material, the water-soluble anionic monomer, the organic acid, the water-soluble cationic monomer, the special methacrylic ester, and the cyclic polysaccharide under the action of the initiator, the crosslinking monomer, and the pH regulator, which can significantly improve the plugging performance and the lubricating performance of the drilling fluid.

[0029] In a preferred embodiment of the present application, the preparation method of the silane coupling agent modified nanoparticles is not particularly limited, and the known method can be used for preparation. For example, the dried nanoparticles are dispersed in toluene solvent by ultrasonic, then the silane coupling agent is added, and the stirring reaction is carried out at 60-90℃ under nitrogen protection at a stirring speed of 300-500r / min for 5-8h to obtain the silane coupling agent modified nanoparticles.

[0030] The drying temperature is 90-105℃, the drying time is 12-16h; the silane coupling agent is selected from one or more of KH560, KH570, KH520 and KH172; the nanoparticles are selected from one or more of nanosilica, nanoalumina, nanozirconia, nanosilicon nitride and nanosilicon carbide; the ultrasonic time is 30-50min; the amount of toluene solvent is 150-300g based on 100g of nanoparticles; the amount of silane coupling agent is 2-8g, preferably 2-4g. After the reaction is completed, the silane coupling agent modified nanoparticles are obtained by washing with anhydrous ethanol and centrifugal separation.

[0031] In a preferred embodiment of the present application, the initiator is selected from ammonium persulfate and / or potassium persulfate, preferably ammonium persulfate.

[0032] In a preferred embodiment of the present application, the average particle size of the multifunctional drilling fluid treatment agent is ≤0.9mm.

[0033] The second aspect of the present application provides a preparation method of a multifunctional drilling fluid treatment agent, wherein the preparation method comprises the following steps: firstly, uniformly mixing water and water-soluble natural polymer material, then sequentially adding pH regulator, water-soluble anionic monomer, crosslinking monomer, organic acid, water-soluble cationic monomer, special methyl acrylic acid ester and cyclic polysaccharide, uniformly stirring, then adding silane coupling agent modified nanoparticles, again uniformly stirring, then adding initiator, and standing at room temperature to obtain a rubber block. The rubber block is crushed to obtain the multifunctional drilling fluid treatment agent.

[0034] In a preferred embodiment of the present application, the mixing of water and water-soluble natural polymer material is carried out at room temperature, and the stirring speed is 200-400r / min, and the stirring time is 5-10min. In the present application, room temperature has the known meaning, and the present application does not make special limitation thereto.

[0035] In a preferred embodiment of the present application, after adding the pH regulator, water-soluble anionic monomer, crosslinking monomer, organic acid, water-soluble cationic monomer, special methyl acrylic acid ester and cyclic polysaccharide, stirring is carried out at 30-50℃, the stirring speed is 200-400r / min, and the stirring time is 30-60min.

[0036] In a preferred embodiment of the present application, after the addition of the silane coupling agent to modify the nanoparticles, stirring is carried out at 30-50°C, the stirring speed is 200-400 r / min, and the stirring time is 5-10 min.

[0037] In a preferred embodiment of the present application, after the addition of the initiator, stirring is carried out at 30-50°C, the stirring speed is 200-400 r / min, and the stirring time is 2-6 min.

[0038] The present application will be described in detail below through examples. The preparation method of the silane coupling agent modified nanoparticles is as follows:

[0039] The nanosilica is dried at 100°C for 12 h, 100 g of which is dispersed in 200 g of toluene, and after ultrasonic treatment for 30 min, the water bath is warmed to 70°C, 4 g of silane coupling agent KH560 is added, and the reaction is carried out at a stirring speed of 400 r / min for 6 h. Then the product is taken out, washed with anhydrous ethanol for three times, centrifuged, and the obtained solid product is dried under vacuum at room temperature. After grinding, the silane coupling agent modified nanosilica is obtained.

[0040] The nanosilica is dried at 100°C for 12 h, 100 g of which is dispersed in 200 g of toluene, and after ultrasonic treatment for 30 min, the water bath is warmed to 70°C, 4 g of silane coupling agent KH560 is added, and the reaction is carried out at a stirring speed of 400 r / min for 6 h. Then the product is taken out, washed with anhydrous ethanol for three times, centrifuged, and the obtained solid product is dried under vacuum at room temperature. After grinding, the silane coupling agent modified nanosilica is obtained.

[0041] The nanosilica is dried at 100°C for 12 h, 100 g of which is dispersed in 200 g of toluene, and after ultrasonic treatment for 30 min, the water bath is warmed to 70°C, 4 g of silane coupling agent KH560 is added, and the reaction is carried out at a stirring speed of 400 r / min for 6 h. Then the product is taken out, washed with anhydrous ethanol for three times, centrifuged, and the obtained solid product is dried under vacuum at room temperature. After grinding, the silane coupling agent modified nanosilica is obtained.

[0042] Water-soluble sweet potato starch: water-soluble starch type II, purchased from Shijiazhuang Tangtian Starch Co., Ltd.

[0043] Water-soluble corn starch: water-soluble starch type III, purchased from Shijiazhuang Tangtian Starch Co., Ltd.

[0044] Corn starch: non-water-soluble, purchased from Binzhou Jinhui Corn Development Co., Ltd.

[0045] Commercially available tackifying polymer-based fluid loss additive: carboxyl sulfonic acid-based copolymer HS-2 (type I), purchased from Baoding Santuo Chemical Product Co., Ltd.

[0046] Commercially available resin fluid loss additive: lignite resin SPNH, purchased from Shandong Juxinda Chemical Co., Ltd.

[0047] Commercially available plugging agent: sulfonated asphalt FT-1, purchased from Shandong Zhengyang New Material Technology Co., Ltd.

[0048] Commercially available inhibitor: polyamine inhibitor SJA-1, purchased from Dongying Mingde Petroleum Technology Co., Ltd.

[0049] Commercially available lubricant: water-based drilling fluid lubricant LLT-018B, purchased from Xinxiang Longli Drilling Fluids Co., Ltd.

[0050] Example 1

[0051] (1) In a four-necked flask equipped with a stirrer, a dropping funnel and a thermometer, 40 g of water and 3 g of water-soluble sweet potato starch were added, and stirred at room temperature at a stirring speed of 300 r / min for 5 min;

[0052] (2) While maintaining the stirring speed of 300 r / min, 6 g of sodium hydroxide, 25 g of AMPS, 5 g of acrylamide, 3 g of acrylic acid, 1 g of methacryloyloxyethyl trimethylammonium chloride, 10 g of dimethylaminoethyl methacrylate and 6 g of β-cyclodextrin were sequentially added to the four-necked flask, and the temperature was raised to 40℃, and stirred for 30 min;

[0053] (3) While maintaining the stirring speed of 300 r / min and the temperature of 40℃, 2 g of silane coupling agent modified nano-silica was continuously added to the four-necked flask, and after stirring for 5 min, 1 g of ammonium persulfate was added, and after stirring for 2 min, the solution in the four-necked flask was poured into a tray, and was left to stand at room temperature for 24 h to obtain a gel block. The gel block was cut, dried at 105℃ for 24 h, crushed with a crusher, and sieved with a standard sieve having a mesh size of 0.9 mm to obtain a multifunctional drilling fluid treatment agent.

[0054] Example 2

[0055] (1) In a four-necked flask equipped with a stirrer, a dropping funnel and a thermometer, 40 g of water and 8 g of water-soluble sweet potato starch were added, and stirred at room temperature at a stirring speed of 300 r / min for 5 min;

[0056] (2) While maintaining the stirring speed of 300 r / min, 8 g of sodium hydroxide, 50 g of AMPS, 15 g of N,N-methylene acrylamide, 20 g of acrylic acid, 8 g of methacryloyloxyethyl trimethylammonium chloride, 10 g of dimethylaminoethyl methacrylate and 4 g of β-cyclodextrin were sequentially added to the four-necked flask, and the temperature was raised to 40℃, and stirred for 60 min;

[0057] (3) keep the stirring speed of 300 r / min and the temperature of 40℃, continue to add 5 g of silane coupling agent modified nano-silica into the four-necked flask, after stirring for 5 min, add 4 g of ammonium persulfate, after stirring for 2 min, pour the solution in the four-necked flask into a tray, stand for 24 h at room temperature, obtain a glue block, cut the glue block, dry at 105℃ for 24 h, crush by using a crusher, sieve by using a standard sieve with a mesh size of 0.9 mm, and obtain the multifunctional drilling fluid treating agent.

[0058] Example 3

[0059] (1) in a four-necked flask equipped with a stirrer, a dropping funnel and a thermometer, add 40 g of water and 5 g of water-soluble sweet potato starch, stir at a stirring speed of 300 r / min for 5 min at room temperature;

[0060] (2) keep the stirring speed of 300 r / min, add 7 g of sodium hydroxide, 35 g of AMPS, 10 g of acrylamide, 12 g of acrylic acid, 5 g of methacryloyloxyethyl trimethyl ammonium chloride, 15 g of dimethylaminoethyl methacrylate and 8 g of β-cyclodextrin into the four-necked flask in sequence, heat to 40℃, and stir for 40 min;

[0061] (3) keep the stirring speed of 300 r / min and the temperature of 40℃, continue to add 3 g of silane coupling agent modified nano-silica into the four-necked flask, after stirring for 5 min, add 2.5 g of ammonium persulfate, after stirring for 6 min, pour the solution in the four-necked flask into a tray, stand for 24 h at room temperature, obtain a glue block, cut the glue block, dry at 105℃ for 24 h, crush by using a crusher, sieve by using a standard sieve with a mesh size of 0.9 mm, and obtain the multifunctional drilling fluid treating agent.

[0062] Example 4

[0063] (1) in a four-necked flask equipped with a stirrer, a dropping funnel and a thermometer, add 40 g of water and 1.5 g of water-soluble sweet potato starch, stir at a stirring speed of 300 r / min for 5 min at room temperature;

[0064] (2) keep the stirring speed of 300 r / min, add 2 g of sodium hydroxide, 15 g of sodium allyl sulfonate, 25 g of acrylamide, 2 g of maleic acid, 18 g of methacryloyloxyethyl trimethyl ammonium chloride, 2 g of hydroxyethyl methacrylate and 8 g of α-cyclodextrin into the four-necked flask in sequence, heat to 40℃, and stir for 30 min;

[0065] (3) keeping the stirring speed of 300 r / min and the temperature of 40 °C, continue to add 0.5 g of silane coupling agent modified nano silicon nitride into the four-necked flask, after stirring for 5 min, add 0.5 g of potassium persulfate, after stirring for 10 min, pour the solution in the four-necked flask into the tray, stand at room temperature for 24 h, obtain the glue block, cut the glue block, dry at 105 °C for 24 h, crush by using the crusher, and sieve by using the standard sieve with a mesh size of 0.9 mm, obtain the multifunctional drilling fluid treating agent.

[0066] Example 5

[0067] (1) in a four-necked flask equipped with a stirrer, a dropping funnel and a thermometer, add 40 g of water and 5.5 g of water-soluble corn starch, stir at a stirring speed of 300 r / min at room temperature for 5 min;

[0068] (2) keep the stirring speed of 300 r / min, add 15 g of sodium hydroxide, 35 g of 4-vinylbenzenesulfonic acid sodium, 35 g of N-hydroxymethyl acrylamide, 30 g of maleic acid, 12 g of dimethyldiallylammonium chloride, 2 g of hydroxyethyl methacrylate and 2 g of α-cyclodextrin into the four-necked flask in sequence, heat to 40 °C, and stir for 40 min;

[0069] (3) keep the stirring speed of 300 r / min and the temperature of 40 °C, continue to add 8 g of silane coupling agent modified nano alumina into the four-necked flask, after stirring for 5 min, add 6 g of ammonium persulfate, after stirring for 2 min, pour the solution in the four-necked flask into the tray, stand at room temperature for 24 h, obtain the glue block, cut the glue block, dry at 105 °C for 24 h, crush by using the crusher, and sieve by using the standard sieve with a mesh size of 0.9 mm, obtain the multifunctional drilling fluid treating agent.

[0070] Example 6

[0071] The same as example 1, except that the water-soluble corn starch is replaced by water-soluble sweet potato starch in equal amount.

[0072] Comparative example 1

[0073] The same as example 5, except that the silane coupling agent modified nano silicon dioxide is replaced by nano silicon dioxide without silane coupling agent modification treatment in equal amount.

[0074] Comparative example 2

[0075] The same as example 5, except that the water-soluble corn starch is replaced by corn starch in equal amount.

[0076] Comparative example 3

[0077] The same as Example 5, except that the amount of sodium hydroxide is 1 g, the amount of sodium allyl sulfonate is 2 g, and the amount of methacryloyloxyethyl trimethyl ammonium chloride is 28 g.

[0078] Comparative Example 4

[0079] The same as Example 2, except that no dimethylaminoethyl methacrylate and β-cyclodextrin are added.

[0080] Test Example 1

[0081] The multifunctional drilling fluid treatment agent prepared in the examples and comparative examples and commercially available tackifying polymer-based fluid loss additive, resin-based fluid loss additive, plugging agent, inhibitor, and lubricant are added to Base Slurry I, respectively, to configure a drilling fluid, and the high-temperature treated drilling fluid is tested for fluid loss performance, lubrication performance, and plugging performance, and the test results are shown in Table 1. In Example 1, for example, the drilling fluid is configured, and the testing method for fluid loss performance, lubrication performance, and plugging performance is as follows:

[0082] 400 mL of distilled water is measured into a cup, 0.56 g of anhydrous sodium carbonate and 16.0 g of bentonite are added, a high-speed blender is used, the speed is set to 11000 r / min, and stirring is performed for 20 min, with at least two stops in between to scrape off the bentonite adhering to the wall of the container. After being maintained at 25°C for 24 h, 16 g of sodium chloride is added to the high-speed blender at a speed of 11000 r / min, and stirring is performed for 20 min to obtain Base Slurry I. The speed of the high-speed blender is set to 11000 r / min, 12 g of the multifunctional drilling fluid treatment agent prepared in Example 1 is added to 400 mL of Base Slurry I, and stirring is performed for 20 min to obtain a drilling fluid.

[0083] High-temperature high-pressure fluid loss performance evaluation: The drilling fluid is placed in a 150°C roller furnace, aged for 16 h, and then cooled to room temperature. The speed of the high-speed blender is set to 11000 r / min, and stirring is continued for 5 min. A high-temperature high-pressure fluid loss instrument is used to evaluate the high-temperature high-pressure fluid loss of the drilling fluid at 150°C and a pressure difference of 3.5 MPa according to the provisions of Section 7.3 of GB / T 16783.1.

[0084] Lubrication performance evaluation: Base Slurry I is placed in a 150°C roller furnace and aged for 16 h, then removed and cooled to room temperature, and stirring is continued at a speed of 11000 r / min for 5 min. An API fluid loss instrument is used to test the API fluid loss, and a mud cake is obtained. A mud cake adhesion coefficient instrument is used to test the viscosity coefficient of the mud cake. The same test is performed on the drilling fluid under the same conditions, and the viscosity coefficient reduction rate of the drilling fluid mud cake is calculated according to Formula (1).

[0085]

[0086] P1 = reduction of mud cake stickiness coefficient, %;

[0087] F v 0 P1 = reduction of mud cake stickiness coefficient, %;

[0088] F v P1 = reduction of mud cake stickiness coefficient, %;

[0089] Evaluation of plugging performance: after aging of base mud I in a roller oven at 150°C for 16h, it was taken out and cooled to room temperature, and then tested by using a high temperature and high pressure permeability plugging instrument, with FANN ceramic sand (average pore size 10 μm) as the filter medium, a differential pressure of 3450 kPa, a test temperature of 150°C, and collection of the leakage liquid within 30 min. The same test was conducted on the drilling fluid under the same conditions, and the leakage liquid was collected, and the relative plugging rate of the drilling fluid was calculated according to formula (2).

[0090]

[0091] P2 = relative plugging rate, %;

[0092] Fl1 = volume of leakage liquid collected when the drilling fluid prepared by using base mud I is tested by using a high temperature and high pressure permeability plugging instrument after aging at 150°C for 16h;

[0093] Fl2 = volume of leakage liquid collected when base mud I is tested by using a high temperature and high pressure permeability plugging instrument after aging at 150°C for 16h.

[0094] Table 1

[0095]

[0096]

[0097] Note: Filtration reducer A*, refers to the drilling fluid prepared by using a commercially available tackifying polymer type filtration reducer and base mud I. Filtration reducer B*, refers to the drilling fluid prepared by using a commercially available resin type filtration reducer and base mud I. Plugging agent C*, refers to the drilling fluid prepared by using a commercially available sulfonated asphalt and base mud I. Inhibitor D*, refers to the drilling fluid prepared by using a commercially available polyamine inhibitor and base mud I. Lubricant E*, refers to the drilling fluid prepared by using a commercially available water-based lubricant and base mud I.

[0098] Test Example 2

[0099] The multifunctional drilling fluid treatment agent prepared in the examples and comparative examples and commercially available tackifying polymer type fluid loss additive, resin type fluid loss additive, plugging agent, inhibitor and lubricant were added into base slurry II respectively to configure drilling fluids, and then the inhibition performance of the drilling fluids was tested, and the test results are shown in Table 2. Taking Example 1 as an example, the drilling fluid was prepared and the inhibition performance was tested as follows:

[0100] 400 mL of distilled water was measured into a cup, 0.98 g of anhydrous sodium carbonate and 28.0 g of bentonite were added, a high-speed stirrer was used, the rotating speed was set to 11000 r / min, and stirring was performed for 20 min, during which the stirring was stopped at least twice to scrape off the bentonite adhered to the wall of the container. Base slurry II was obtained. The base slurry II was rolled at 120℃ for 16 h, and after cooling, stirring was continued at a speed of 11000 r / min for 5 min, and then the reading value of the six-speed rotational viscometer at 100 r / min for 100 s was measured.

[0101] 400 mL of distilled water was measured into a cup, 0.98 g of anhydrous sodium carbonate and 28.0 g of bentonite were added, a high-speed stirrer was used, the rotating speed was set to 11000 r / min, and stirring was performed for 20 min, during which the stirring was stopped at least twice to scrape off the bentonite adhered to the wall of the container. Base slurry II was obtained. The base slurry II was rolled at 120℃ for 16 h, and after cooling, stirring was continued at a speed of 11000 r / min for 5 min, and then the reading value of the six-speed rotational viscometer at 100 r / min for 100 s was measured.

[0102]

[0103] In the formula:

[0104] P3 - relative inhibition rate, %;

[0105] - the reading value of the six-speed rotational viscometer at 100 r / min for 100 s of base slurry II;

[0106] R 100 - the reading value of the six-speed rotational viscometer at 100 r / min for 100 s of the drilling fluid prepared by using base slurry II.

[0107] The higher the relative inhibition rate, the better the inhibition performance, which can better inhibit the dispersion of clay on the well wall, protect the well wall, and reduce the complex situation and accidents in the well caused by well wall instability.

[0108] Test Example 3

[0109] The multifunctional drilling fluid treatment agent prepared in the examples and comparative examples and the commercially available tackifying polymer type fluid loss additive, resin type fluid loss additive, plugging agent, inhibitor and lubricant were added into distilled water respectively, and the apparent viscosity of the product was tested by a six-speed rotational viscometer, and the test results are shown in Table 2. Taking Example 1 as an example, the apparent viscosity test method is as follows:

[0110] Using a low-speed blender, 4 g of the multifunctional drilling fluid treatment agent prepared in Example 1 was added into 400 mL of distilled water at a speed of 300 r / min, and after stirring for 20 min, the reading at a speed of 600 r / min was measured by a six-speed rotational viscometer, and the apparent viscosity of the solution was calculated according to formula (4).

[0111]

[0112] In the formula, AV is the apparent viscosity, mPa·s.

[0113] R 600 The reading of the six-speed rotational viscometer at a speed of 600 r / min.

[0114] Table 2

[0115] Relative inhibition rate / % Apparent viscosity / mPa-s Example 1 80.6 32.0 Example 2 83.3 33.5 Example 3 81.1 32.5 Example 4 61.7 26.5 Example 5 58.9 28.5 Example 6 80.6 29.0 Comparative Example 1 69.4 28.5 Comparative Example 2 58.9 26.5 Comparative Example 3 68.1 13.5 Comparative Example 4 27.8 26.5 Fluid loss additive A 25.5 29.0 Fluid loss additive B 3.2 3.0 Plugging agent C 19.6 1.5 Inhibitor D 86.9 0 Lubricant E 0 0

[0116] Note: Fluid loss additive A*, refers to the test results of the commercially available tackifying polymer type fluid loss additive. Fluid loss additive B*, refers to the test results of the commercially available resin type fluid loss additive. Plugging agent C*, refers to the test results of the commercially available sulfonated asphalt. Inhibitor D*, refers to the test results of the commercially available polyamine inhibitor. Lubricant E*, refers to the test results of the commercially available water-based lubricant.

[0117] As can be seen from Table 1 and Table 2, among the five conventional drilling fluid treatment agents in the polysulfonated drilling fluid system, the commercially available tackifying polymer type fluid loss additive has good fluid loss reduction, lubrication, plugging and tackifying functions, but has poor inhibition performance. The commercially available resin type fluid loss additive only has fluid loss reduction performance. The commercially available plugging agent has certain fluid loss reduction and plugging performance, but has poor inhibition and tackifying performance. The commercially available inhibitor only has inhibition performance. The commercially available lubricant fails to exhibit the above-mentioned performances when used alone.

[0118] As can be seen from Examples 1-6, the multifunctional drilling fluid treatment agent prepared in the present application can have excellent fluid loss reduction performance, lubrication performance, plugging performance, inhibition performance, tackifying performance and environmental protection performance, and the comprehensive performance is obviously better than that of the five commercially available products.

[0119] The high-temperature and high-pressure filtration loss of the drilling fluid in the present application is less than 17 mL after 150℃ rolling aging for 16h, which can meet the requirements of most domestic oilfields on the filtration loss reduction performance, and can replace sulfonated lignite, sulfomethyl phenolic aldehyde resin and lignite resin in the conventional poly-sulfur drilling fluid system, greatly reducing the types and amount of the treatment agent in the system, and reducing the construction difficulty and operation intensity.

[0120] From the comparative example 1 and the example 6, it can be seen that the multifunctional drilling fluid treatment agent prepared from the water-soluble sweet potato starch is more conducive to improving the high-temperature and high-pressure filtration loss reduction and lubrication performance of the drilling fluid.

[0121] From the comparative example 5 and the comparative example 1, it can be seen that, compared with the nano-silicon dioxide, the nano-silicon dioxide modified by the silane coupling agent can reduce the high-temperature and high-pressure filtration loss of the drilling fluid, increase the mud cake viscosity coefficient reduction rate and the relative plugging rate. This may be because the nano-silicon dioxide without modification cannot be polymerized with other components, and is prone to agglomeration, resulting in the performance of the drilling fluid being reduced.

[0122] From the comparative example 5 and the comparative example 2, it can be seen that the drilling fluid prepared from the multifunctional drilling fluid treatment agent prepared from the non-water-soluble corn starch has a slight decrease in the apparent viscosity of the 1wt% aqueous solution after high-temperature and high-pressure treatment, but the filtration loss is obviously increased, and the mud cake viscosity coefficient reduction rate and the relative plugging rate are greatly reduced. The drilling fluid prepared from the multifunctional drilling fluid treatment agent prepared from the water-soluble corn starch has good high-temperature filtration loss reduction performance, inhibition performance, lubrication performance, viscosity increasing performance and plugging performance after high-temperature and high-pressure treatment.

[0123] From the comparative example 5 and the comparative example 3, it can be seen that when the amount of sodium hydroxide, sodium allyl sulfonate and methacryloyloxyethyl trimethyl ammonium chloride is not within the range defined in the present application, the prepared drilling fluid does not have excellent filtration loss reduction performance, lubrication performance, plugging performance, inhibition performance and viscosity increasing performance after 150℃ rolling aging for 16h.

[0124] From the comparative example 2 and the comparative example 4, it can be seen that the addition of dimethylaminoethyl methacrylate and β-cyclodextrin is helpful to simultaneously improving the inhibition performance and filtration loss reduction performance of the drilling fluid. The commercially available inhibitor often increases the filtration loss of the drilling fluid while improving the inhibition performance of the drilling fluid.

[0125] Test Example 3

[0126] The multifunctional drilling fluid treatment agent prepared in the examples and the comparative examples and the commercially available viscosity-increasing polymer type filtration loss reducer, resin type filtration loss reducer, plugging agent, inhibitor and lubricant were subjected to toxicity detection according to the industry standard SY / T 6787-2010, and the EC 50 The results are shown in Table 3.

[0127] Table 3

[0128]

[0129]

[0130] Note: Filtration reducer A* refers to the test result of using a commercially available tacky polymer type filtration reducer. Filtration reducer B* refers to the test result of using a commercially available resin type filtration reducer. Plugging agent C* refers to the test result of using a commercially available sulfonated asphalt. Inhibitor D* refers to the test result of using a commercially available polyamine inhibitor. Lubricant E* refers to the test result of using a commercially available water-based lubricant.

[0131] As can be seen from Table 3, the environmental friendliness of commercially available tacky polymer filtration reducers, inhibitors and lubricants is slightly poor, the resin type filtration reducer is slightly toxic (1000-10000 mg / L), and the plugging agent is moderately toxic (<1000 mg / L).

[0132] The multifunctional drilling fluid treatment agent provided in the present application has the optimal toxicity detection result, far exceeding the highest industry standard: the first marine discharge standard (>30000 mg / L), indicating that the product has no biological toxicity and can greatly improve the environmental performance of the drilling fluid, and has a broad application prospect.

[0133] The preferred embodiments of the present application are described in detail above, but the present application is not limited thereto. Within the technical concept of the present application, various simple modifications can be made to the technical solutions of the present application, including combining various technical features in any other suitable manner, and these simple modifications and combinations should also be considered as disclosed by the present application and fall within the protection scope of the present application.

Claims

1. A multifunctional drilling fluid treatment agent, characterized in that, The raw materials for preparing the treatment agent include: 40 parts by weight of water, 0.5-20 parts by weight of water-soluble natural polymer material, 2-20 parts by weight of pH adjuster, 5-80 parts by weight of water-soluble anionic monomer, 2-40 parts by weight of crosslinking monomer, 1-50 parts by weight of organic acid, 0.5-20 parts by weight of water-soluble cationic monomer, 1-20 parts by weight of special methacrylate esters, 1-10 parts by weight of cyclic polysaccharide, 0.5-10 parts by weight of silane coupling agent modified nanoparticles, and 0.5-10 parts by weight of initiator; The water-soluble natural polymer material is selected from water-soluble sweet potato starch and / or water-soluble corn starch; The water-soluble anionic monomer is selected from one or more of 2-acrylamido-2-methylpropanesulfonic acid, sodium allyl sulfonate, and sodium 4-vinylbenzene sulfonate; The crosslinking monomer is selected from one or more of acrylamide, N-hydroxymethylacrylamide, and N,N-methyleneacrylamide; The organic acid is selected from acrylic acid and / or maleic acid; The water-soluble cationic monomer is selected from methacryloyloxyethyltrimethylammonium chloride and / or dimethyldiallylammonium chloride; The special methacrylates are selected from hydroxyethyl methacrylate and / or dimethylaminoethyl methacrylate; The cyclic polysaccharide is selected from α-cyclodextrin and / or β-cyclodextrin.

2. The treatment agent according to claim 1, wherein, The raw materials for preparing the treatment agent include: 40 parts by weight of water, 3-8 parts by weight of water-soluble natural polymer material, 6-8 parts by weight of pH adjuster, 25-50 parts by weight of water-soluble anionic monomer, 5-15 parts by weight of crosslinking monomer, 3-20 parts by weight of organic acid, 1-8 parts by weight of water-soluble cationic monomer, 5-15 parts by weight of special methacrylate esters, 4-8 parts by weight of cyclic polysaccharide, 2-5 parts by weight of silane coupling agent modified nanoparticles, and 1-4 parts by weight of initiator.

3. The treatment agent according to claim 1 or 2, wherein, The water-soluble natural polymer material is water-soluble sweet potato starch.

4. The treatment agent according to claim 1 or 2, wherein, The pH adjuster is selected from sodium hydroxide and / or potassium hydroxide.

5. The treatment agent according to claim 4, wherein, The pH adjuster is sodium hydroxide.

6. The treatment agent according to claim 1, wherein, The water-soluble anionic monomer is 2-acrylamide-2-methylpropanesulfonic acid.

7. The treatment agent according to claim 1, wherein, The crosslinking monomer is acrylamide and / or N,N-methyleneacrylamide.

8. The treatment agent according to claim 1, wherein, The organic acid is acrylic acid.

9. The treatment agent according to claim 1, wherein, The water-soluble cationic monomer is methacryloyloxyethyltrimethylammonium chloride.

10. The treatment agent according to claim 1, wherein, The special methacrylate ester is dimethylaminoethyl methacrylate.

11. The treatment agent according to claim 1, wherein, The cyclic polysaccharide is β-cyclodextrin.

12. The treatment agent according to claim 1, wherein, The silane coupling agent modified nanoparticles are selected from one or more of the following: silane coupling agent modified nano-silica, silane coupling agent modified nano-alumina, silane coupling agent modified nano-zirconia, silane coupling agent modified nano-silicon nitride, and silane coupling agent modified nano-silicon carbide.

13. The treatment agent according to claim 12, wherein, The silane coupling agent modified nanoparticles are silane coupling agent modified nano-silica.

14. The treatment agent according to claim 1, wherein, The initiator is selected from ammonium persulfate and / or potassium persulfate.

15. The treatment agent according to claim 14, wherein, The initiator is ammonium persulfate.

16. A method for preparing a multifunctional drilling fluid treatment agent according to any one of claims 1-15, characterized in that, The method includes the following steps: first, water and water-soluble natural polymer materials are mixed evenly, then pH adjuster, water-soluble anionic monomer, crosslinking monomer, organic acid, water-soluble cationic monomer, special methacrylate esters and cyclic polysaccharides are added in sequence, and after stirring evenly, silane coupling agent modified nanoparticles are added, and after stirring evenly again, initiator is added, and the mixture is allowed to stand at room temperature to obtain a gel block. The gel block is then crushed to obtain a multifunctional drilling fluid treatment agent.

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