A lubricating fluid loss reducer for drilling fluid and its preparation method

Abstract

The present invention discloses a lubricating filtrate reducer for drilling fluid, which comprises the following components in parts by weight: 32 to 33 parts of water, 9.5 to 10.5 parts of PSC-I, 9.5 to 10.5 parts of SMP-I aqueous solution, 10 to 11 parts of FA367 solution, 12.5 to 13.5 parts of waste engine oil, 14.5 to 15.5 parts of emulsified asphalt, and 8.5 to 9.5 parts of diesel emulsion. The preparation method is also disclosed, which includes adding the formulated amounts of PSC-I, SMP-I aqueous solution, FA367 solution, waste engine oil, and emulsified asphalt into water and mixing and stirring; dropping the prepared diesel emulsion into the mixed system obtained in step 1) and stirring for an emulsification reaction to obtain the lubricating filtrate reducer for drilling fluid. The present invention makes good compatibility of each component, and the obtained lubricating filtrate reducer for drilling fluid has remarkable lubricating, plugging and anti-collapse, and filtrate reduction effects. At the same time, the preparation method of the present invention is simple, the conditions are mild, and the cost is low.

Description

Technical Field

[0001] The present invention relates to the technical field of oil and gas drilling, and particularly relates to a lubricating fluid loss reducer for drilling fluid and a preparation method thereof. Background Art

[0002] With the increase in the number of deep wells, ultra-deep wells, highly deviated wells, horizontal wells, high-density and high-temperature wells drilled, the lubricity, anti-collapse property, and fluid loss wall-building property of drilling fluid are important conditions for ensuring successful well completion. To ensure successful drilling, a large amount of lubricant for drilling fluid needs to be used to reduce the frictional resistance during drilling, reduce the torque and resistance of the drill string during drilling, increase the drilling speed, and reduce downhole accidents. Researchers at home and abroad have evaluated the lubricating performance of drilling fluid and concluded that air and oil are at two extreme positions in terms of lubricity, while the lubricity of water-based drilling fluid lies between them. Good lubricity of drilling fluid can reduce the wear of drill bits, drill tools, and other accessories, extend their service life, prevent sticking and jamming of the drill string, reduce bit balling, and facilitate the handling of downhole accidents. During drilling, due to the fixed power of the power equipment, the tensile and torsional resistance of the drill string and the stability of the wellbore wall have limits. If the lubricating performance of the drilling fluid is poor, it will cause an increase in the rotary resistance of the drill string, difficulty in tripping, and even sticking and jamming accidents; when the rotary resistance of the drill string is too large, it will cause the drill string to vibrate, which may lead to drill string fracture and wellbore instability. Therefore, it is necessary to add lubricants and high-temperature resistant fluid loss reducers to ensure downhole safety. Therefore, it is of great significance to develop a drilling fluid treatment agent with multifunctional properties of lubrication and fluid loss reduction. Summary of the Invention

[0003] The purpose of the present invention is to provide a lubricating fluid loss reducer for drilling fluid and a preparation method thereof, so as to provide a drilling fluid treatment agent with multifunctional properties of lubrication and fluid loss reduction.

[0004] The present invention is achieved through the following technical solutions:

[0005] The first purpose of the present invention is to provide a lubricating fluid loss reducer for drilling fluid, which comprises the following components in parts by weight: 32 to 33 parts of water, 9.5 to 10.5 parts of PSC-I, 9.5 to 10.5 parts of SMP-I aqueous solution, 10 to 11 parts of FA367 solution, 12.5 to 13.5 parts of waste engine oil, 14.5 to 15.5 parts of emulsified asphalt, and 8.5 to 9.5 parts of diesel emulsion.

[0006] Optionally, the diesel emulsion is prepared from diesel and S-80, and the weight ratio of diesel to S-80 is 2:1.

[0007] The second purpose of the present invention is to provide a preparation method of the above-mentioned lubricating fluid loss reducer for drilling fluid, which includes:

[0008] 1) Add the formulated amounts of PSC-I, SMP-I aqueous solution, FA367 solution, waste oil, and emulsified asphalt to water, and mix and stir.

[0009] 2) Drop the prepared diesel emulsion into the mixed system obtained in step 1) above, stir and emulsify to obtain the lubricating fluid loss reducer for drilling fluid.

[0010] Optionally, in step 1), add the formulated amounts of PSC-I, SMP-I aqueous solution, FA367 solution, waste oil, and emulsified asphalt to water in sequence, and the temperature of the water is 30°C to 40°C.

[0011] Optionally, in step 1), after adding each component in the formulated amount to water each time, stir for 20 min, and then add the subsequent components.

[0012] Optionally, during the mixing and stirring process in step 1), control the temperature at 30°C to 40°C.

[0013] Optionally, in step 2), after the diesel emulsion is dropped into the mixed system over a time greater than 40 min, continue to stir for 20 min.

[0014] Optionally, during the process of dropping the diesel emulsion in step 2), control the system temperature at 40°C to 50°C.

[0015] Optionally, the temperature of the stirring and emulsifying reaction is 55°C to 65°C, and the time is 30 min to 40 min.

[0016] Compared with the prior art, the present invention has the following advantages and beneficial effects:

[0017] The lubricating fluid loss reducer for drilling fluid provided by the present invention is a mixed emulsion - lubricating fluid loss reducer obtained by emulsifying asphalt products (i.e., emulsified asphalt), mineral oils, resin products (i.e., SMP-I aqueous solution), and emulsifiers (i.e., diesel emulsion) under certain conditions. It has good lubricating and high-temperature and high-pressure fluid loss reduction performance, can withstand a temperature of 150°C, can be used in various water-based drilling fluids, has good water solubility and compatibility, can effectively reduce the lubrication coefficient of the drilling fluid, the adhesion coefficient of the mud cake, and the high-temperature and high-pressure fluid loss volume, has a low viscosity effect, especially in heavy mud (such as polymer-weighted drilling fluid, polysulfonate-weighted drilling fluid), it does not increase viscosity, reduces water loss, and significantly reduces the adhesion coefficient of the mud cake. It is an excellent lubricating fluid loss reducer for formulating high-density drilling fluid. Specific Embodiments

[0018] To make the purpose, technical solutions, and advantages of the present invention clearer and more understandable, the present invention will be further described in detail below in conjunction with embodiments. The illustrative embodiments of the present invention and their descriptions are only used to explain the present invention and are not intended to limit the present invention.

[0019] An embodiment of the present invention provides a lubricating and filtrate loss reducing agent for drilling fluid and a preparation method thereof, so as to provide a drilling fluid treatment agent with multifunctional properties of lubrication and filtrate loss reduction. The raw materials for preparing the lubricating and filtrate loss reducing agent for drilling fluid include the following components: clear water, PSC-I, SMP-I, FA367, waste engine oil, emulsified asphalt, diesel, and emulsifier S-80.

[0020] The technical requirements for the clear water are as follows: meeting the national standard GB 5749-2006 "Hygienic Standard for Drinking Water".

[0021] The technical requirements for the PSC-I are as follows: meeting the enterprise standard Q / SY TZ 0114-2004 "Technical Requirements and Test Methods for Sulfonated Phenolic Humic Acid Chromium for Drilling Fluid".

[0022] The technical requirements for the SMP-1 aqueous solution are as follows: meeting the industry standard SY / T 5094-2017 "Filtrate Loss Reducing Agent Sulfomethylated Phenol Formaldehyde Resin SMP for Drilling Fluid".

[0023] The technical requirements for the FA367 are as follows: meeting the industry standard SY / T 5696-2017 "Encapsulating Agent Amphoteric Ion Polymer for Drilling Fluid".

[0024] The technical requirements for the waste engine oil are as follows: meeting the national standard GB / T 17145-1997 "Technical Guidelines for Recycling and Reusing Waste Lubricating Oil" - waste gear oil.

[0025] The technical requirements for the emulsified asphalt are as follows: meeting the enterprise standard Q / SHCG 3-2011 "Technical Requirements for Asphalt-based Treatment Agents for Drilling Fluid".

[0026] The technical requirements for the diesel are as follows: meeting the national standard GB २५२-२०१५ "Ordinary Diesel".

[0027] The technical requirements for the S-80 are as follows: meeting the industry standard HG / T 3508-2010 "Emulsifier S-80".

[0028] In order to obtain a drilling fluid treatment agent with good multifunctional properties of lubrication and filtrate loss reduction at the same time, the embodiment of the present invention adopts the following method for preparation:

[0029] (1) Add the measured clear water into the reaction kettle and heat it to 30°C - 40°C by introducing steam.

[0030] (2) Under stirring conditions, slowly add the measured PSC-I into the reaction kettle, control the system temperature at 30°C - 40°C, and stir for 20 minutes.

[0031] (3) Under stirring conditions, continue to slowly add the metered SMP-I aqueous solution into the reaction kettle, control the system temperature at 30°C to 40°C, and stir for 20 minutes;

[0032] (4) Under stirring conditions, continue to slowly add the metered FA367 solution into the reaction kettle, control the system temperature at 30°C to 40°C, and stir for 20 minutes;

[0033] (5) Under stirring conditions, continue to slowly add the metered waste engine oil into the reaction kettle, control the system temperature at 30°C to 40°C, and stir for 20 minutes;

[0034] (6) Under stirring conditions, continue to slowly add the metered emulsified asphalt into the reaction kettle, control the system temperature at 30°C to 40°C, and stir for 20 minutes;

[0035] (7) Under stirring conditions, continue to add the metered diesel emulsion dropwise into the reaction kettle over a time greater than 40 min. During the dropping process, control the system temperature at 40°C to 50°C. After the dropping is completed, stir for another 20 minutes;

[0036] (8) Pass steam to raise the temperature to 55°C to 65°C, keep stirring and conduct the emulsification reaction at a constant temperature for 30 min to 40 min, then cool to obtain the lubricating fluid loss reducer for drilling fluid. Then, the lubricating fluid loss reducer for drilling fluid is milled by a colloid mill, sampled and tested, and packaged.

[0037] In the embodiment of the present invention, waste engine oil is used to improve the lubricity of the product; emulsified asphalt is used to improve the lubricity and anti-collapse property of the product and play a role in reducing fluid loss; PSC-I and SMP-I aqueous solutions are used to improve the high-temperature resistance of the product and play a role in reducing fluid loss; diesel emulsion is used to fully emulsify the oil and water in the components and ensure the stability of the product mixture; FA367 solution is used to increase the viscosity of the product and the stability of the product mixture. At the same time, in the embodiment of the present invention, the lubricating fluid loss reducer for drilling fluid meets the index requirements of the standard Q / SY 17088-2016 "Technical Specification for Liquid Lubricants for Drilling Fluids". The reduction rate of the adhesion coefficient of the treated mud cake reaches 54.7%, and the reduction rate of the lubrication coefficient reaches 84.0%; the reduction rate of the high-temperature high-pressure fluid loss volume at 150°C reaches 62.1%, showing significant lubrication and fluid loss reduction effects. At the same time, the preparation method of the embodiment of the present invention has a simple production process, mild conditions, and low cost. The lubricating fluid loss reducer for drilling fluid obtained in the embodiment of the present invention is applied to the drilling fluid system, has good compatibility with other treatment agents in the system, has no adverse effect on the rheology, and can control the high-temperature high-pressure water loss of the drilling fluid at a lower dosage, improving the lubrication effect of the drilling fluid. At the same time, the preparation method of the present invention is simple, the conditions are mild, and the cost is low.

[0038] The following is illustrated by specific examples.

[0039] Example 1:

[0040] A lubricating fluid loss reducer for drilling fluid, which is made of the following components by weight: 32.7 parts of water, 10 parts of PSC-I, 10 parts of SMP-I aqueous solution, 10.3 parts of FA367 solution, 13 parts of waste engine oil, 15 parts of emulsified asphalt, and 9 parts of diesel emulsion.

[0041] The preparation method of the lubricating fluid loss reducer for drilling fluid includes the following steps:

[0042] (1) Add 327 kg of clear water into the reaction kettle, and heat it to 30°C - 40°C by introducing steam;

[0043] (2) Under stirring conditions, slowly add 100 kg of PSC-I into the reaction kettle, control the system temperature at 30°C - 40°C, and stir for 20 minutes;

[0044] (3) Under stirring conditions, continue to slowly add 100 kg of SMP-I aqueous solution into the reaction kettle, control the system temperature at 30°C - 40°C, and stir for 20 minutes;

[0045] (4) Under stirring conditions, continue to slowly add 103 kg of FA367 solution into the reaction kettle, control the system temperature at 30°C - 40°C, and stir for 20 minutes;

[0046] (5) Under stirring conditions, continue to slowly add 130 kg of waste engine oil into the reaction kettle, control the system temperature at 30°C - 40°C, and stir for 20 minutes;

[0047] (6) Under stirring conditions, continue to slowly add 150 kg of emulsified asphalt into the reaction kettle, control the system temperature at 30°C - 40°C, and stir for 20 minutes;

[0048] (7) Under stirring conditions, continue to add 90 kg of diesel emulsion dropwise into the reaction kettle over a time greater than 40 minutes. During the dropping process, control the system temperature at 40°C - 50°C, and stir for another 20 minutes after the dropping is completed;

[0049] (8) Heat by introducing steam to 55°C - 65°C, and carry out constant-temperature stirring emulsification reaction for 30 min - 40 min, then cool to obtain the lubricating fluid loss reducer for drilling fluid. Then, the lubricating fluid loss reducer for drilling fluid is milled by a colloid mill, sampled and tested, and packaged.

[0050] Among them, the preparation method of the FA367 solution is: add 2500 Kg of clear water into the polymer preparation kettle, heat it to about 50°C, slowly add 50 Kg of FA367, stir evenly, and after fully dissolving, set aside.

[0051] Preparation method of diesel emulsion: Add 1120 Kg of diesel and 560 Kg of emulsifier S-80 into the emulsion preparation kettle, stir evenly and set aside.

[0052] Example 2:

[0053] A lubricating fluid loss reducer for drilling fluid, which is made of the following components by weight: 32.5 parts of water, 9.5 parts of PSC-I, 10.5 parts of SMP-I aqueous agent, 10.5 parts of FA367 solution, 12.8 parts of waste engine oil, 15.1 parts of emulsified asphalt, and 9.1 parts of diesel emulsion.

[0054] The preparation method is the same as that of Example 1.

[0055] Among them, the preparation method of the FA367 solution is: Add 2500 Kg of clear water into the polymer preparation kettle, heat up to about 50 °C, slowly add 50 Kg of FA367, stir evenly, and set aside after fully dissolving.

[0056] Preparation method of diesel emulsion: Add 1120 Kg of diesel and 560 Kg of emulsifier S-80 into the emulsion preparation kettle, stir evenly and set aside.

[0057] Example 3:

[0058] A lubricating fluid loss reducer for drilling fluid, which is made of the following components by weight: 32.5 parts of water, 9.8 parts of PSC-I, 10.2 parts of SMP-I aqueous agent, 10.5 parts of FA367 solution, 12.5 parts of waste engine oil, 15.5 parts of emulsified asphalt, and 9.0 parts of diesel emulsion.

[0059] The preparation method is the same as that of Example 1.

[0060] Among them, the preparation method of the FA367 solution is: Add 2500 Kg of clear water into the polymer preparation kettle, heat up to about 50 °C, slowly add 50 Kg of FA367, stir evenly, and set aside after fully dissolving.

[0061] Preparation method of diesel emulsion: Add 1120 Kg of diesel and 560 Kg of emulsifier S-80 into the emulsion preparation kettle, stir evenly and set aside.

[0062] Example 4:

[0063] A lubricating fluid loss reducer for drilling fluid, which is made of the following components by weight: 33.0 parts of water, 10.5 parts of PSC-I, 9.5 parts of SMP-I aqueous agent, 10.0 parts of FA367 solution, 13.5 parts of waste engine oil, 14.5 parts of emulsified asphalt, and 9.0 parts of diesel emulsion.

[0064] The preparation method is the same as that of Example 1.

[0065] Among them, the preparation method of the FA367 solution is as follows: Add 2500 Kg of clear water into the polymer preparation kettle, heat up to about 50 °C, slowly add 50 Kg of FA367, stir evenly, and after fully dissolving, set aside for use.

[0066] The preparation method of the diesel emulsion: Add 1120 Kg of diesel and 560 Kg of emulsifier S-80 into the emulsion preparation kettle, stir evenly, and set aside for use.

[0067] Example 5:

[0068] A lubricating fluid loss reducer for drilling fluid, which is made of the following components by weight: 32.0 parts of water, 10.3 parts of PSC-I, 9.7 parts of SMP-I aqueous solution, 10.8 parts of FA367 solution, 13.2 parts of waste engine oil, 14.8 parts of emulsified asphalt, and 9.2 parts of diesel emulsion.

[0069] The preparation method is the same as that of Example 1.

[0070] Among them, the preparation method of the FA367 solution is as follows: Add 2500 Kg of clear water into the polymer preparation kettle, heat up to about 50 °C, slowly add 50 Kg of FA367, stir evenly, and after fully dissolving, set aside for use.

[0071] The preparation method of the diesel emulsion: Add 1120 Kg of diesel and 560 Kg of emulsifier S-80 into the emulsion preparation kettle, stir evenly, and set aside for use.

[0072] The lubricating fluid loss reducer for drilling fluid in the embodiment of the present invention is a mixed emulsion - lubricating fluid loss reducer obtained by emulsification reaction of asphalt products (i.e., emulsified asphalt), mineral oils, resin products (i.e., SMP-I aqueous solution), and emulsifiers (i.e., diesel emulsion) under certain conditions. It has good lubricating and high-temperature high-pressure fluid loss reduction performance, can resist temperatures up to 150 °C, can be used in various water-based drilling fluids, has good water solubility and compatibility, can effectively reduce the lubrication coefficient, mud cake adhesion coefficient, and high-temperature high-pressure fluid loss volume of the drilling fluid, has a low viscosity effect, especially in heavy mud (such as polymer-weighted drilling fluid, polysulfonate-weighted drilling fluid), it does not increase viscosity, reduces water loss, and significantly reduces the mud cake adhesion coefficient, and is an excellent lubricating fluid loss reducer for formulating high-density drilling fluid.

[0073] The specific tests are as follows:

[0074] In Test Example 1, according to the standard Q / SY 17088-2016 "Technical Specification for Liquid Lubricants for Drilling Fluids", the fluid loss reducers obtained in Examples 1 to 5 were evaluated. Taking Example 1 as an example, the evaluation was carried out according to the following method:

[0075] (1) Lubricity evaluation: According to the standard requirements, the reduction rate of the mud cake adhesion coefficient obtained from the lubricating fluid loss reducer for drilling fluid in Example 1 was measured to be 54.7% (meeting the standard requirement of ≥50.0%), and the reduction rate of the lubrication coefficient was 84.0% (meeting the standard requirement of ≥80.0%). This shows that the lubricating fluid loss reducer for drilling fluid in Example 1 can significantly improve the comprehensive lubrication performance of the drilling fluid, thereby reducing the friction resistance and torque of the drill string, and playing a role in increasing the drilling speed and reducing downhole accidents.

[0076] (2) Fluid loss reduction evaluation: Add 28.0 g (7.0% dosage) of the sample of the lubricating fluid loss reducer for drilling fluid in Example 1 to the standard base mud, stir at high speed for 20 min, heat roll the prepared base mud and the sample mud at 150 °C for 16 h, and the reduction rate of the high-temperature high-pressure fluid loss volume at 150 °C was measured to be 62.1%. This shows that the lubricating fluid loss reducer for drilling fluid in Example 1 has good high-temperature fluid loss reduction effect, can improve the mud cake quality, and enhance the plugging performance.

[0077] (3) Viscosity effect evaluation: According to the standard requirements, the increase value of the apparent viscosity of the drilling fluid obtained from the lubricating fluid loss reducer for drilling fluid in Example 1 was measured to be 1.5 mPa·s (meeting the standard requirement of ≤5.0 mPa·s), and the viscosity effect is low.

[0078] (4) Foaming evaluation: Take 300 ml of the standard base mud, add 3.0 g (1.0% dosage) of the sample of the lubricating fluid loss reducer for drilling fluid in Example 1, stir at high speed for 5 min, then immediately pour the stirred mixture into a 500 ml graduated cylinder, and read the volume after standing for 10 s. The foaming rate was calculated to be 3.33%. This shows that the lubricating fluid loss reducer for drilling fluid in Example 1 has low foaming property.

[0079] Examples 2 to 5 were evaluated according to the same method, and the specific results are shown in Table 1 below.

[0080] Table 1 Performance evaluation results of fluid loss reducers in Examples 1 to 5

[0081] Project Standard Index Example 1 Example 2 Example 3 Example 4 Example 5 Increase value of apparent viscosity, mPa.s ≤5.0 1.5 2.0 2.0 1.0 1.5 Reduction rate of mud cake adhesion coefficient, % ≥50.0 54.7 53.5 52.8 55.0 55.2 Reduction rate of lubrication coefficient, % ≥80.0 84.0 83.2 83.0 83.6 84.3 Reduction rate of high temperature and high pressure filtration loss, % / 62.1 62.5 63.0 61.5 61.0 Foaming rate, % / 3.33 5.00 3.33 1.67 1.67

[0082] Test Example 2 Compatibility evaluation in drilling fluid systems

[0083] The lubricating fluid loss reducer for drilling fluid obtained in Example 1 was used in polymer weighted drilling fluid systems, polysulfonate weighted drilling fluid systems, high-density polysulfonate drilling fluid systems, and KCL polysulfonate drilling fluid systems, and then the performance of each drilling fluid system was tested. The results are as follows.

[0084] (1) Performance evaluation in polymer weighted drilling fluid

[0085] Base slurry preparation: 1000 mL of 4% OCMA bentonite slurry + 0.2% by mass of KPAM (2 g) + 1.0% by mass of LS-2 (10 g) + 2% by mass of RSTF (20 g) + 0.3% by mass of lime (3 g) + barite powder;

[0086] Base slurry + 3% sample (30 g), and the sample is the lubricating fluid loss reducer for drilling fluid prepared in Example 1; Base slurry + 3% sample means that the addition amount of the sample is 3% by mass of 1000 mL of the base slurry, that is, 30 g of the sample is added to 1000 ml of the base slurry.

[0087] After the above base slurry and base slurry + 3% sample are thermally rolled at 120 °C for 16 h respectively, the conventional properties are tested at 50 °C, and the high temperature and high pressure fluid loss is tested at 120 °C. The results are shown in Table 1 below.

[0088] Table 1 Performance test of polymer weighted drilling fluid system

[0089]

[0090] As can be seen from Table 1: In the polymer weighted drilling fluid system, before and after treatment with the sample, the HTHP fluid loss decreases from 20 ml to 12 ml, and the reduction rate reaches 40.0%; the adhesion coefficient Kf of the mud cake decreases from 0.1495 to 0.1051, and the reduction rate reaches 29.7%. It shows that the lubricating fluid loss reducer for drilling fluid in Example 1 has good fluid loss reduction ability and friction reduction ability, and also has a certain viscosity and shear reduction effect (the yield point YP in Table 1 decreases from 7 Pa to 3.5 Pa), and no other abnormal situations occur, indicating that the product has good compatibility in the polymer weighted drilling fluid system.

[0091] (2) Performance evaluation in polysulfonate weighted drilling fluid

[0092] Base slurry preparation: 900 ml of 6% OCMA native soil slurry + 200 ml of SMT (SMT: NaOH = 3:1, mass-volume concentration 1 / 5 N) + 70 g of SMC + 40 g of SMP-I (aqueous agent) + 20 g of LS-2 + 5 g of lime powder + 1300 g of barite powder, and the density of the obtained mud is 1.57 g / cm 3 .

[0093] Samples of the lubricating fluid loss reducer for drilling fluid prepared in Example 1 with 2% (20 g), 3% (30 g), 4% (40 g), and 5% (50 g) are added to the base slurry respectively, stirred for more than 1 hour, thermally rolled at 120 °C and 150 °C for 16 h, the conventional properties are tested at 50 °C, and the test temperatures of the high temperature and high pressure fluid loss are 120 °C and 150 °C respectively. The results are shown in Table 2 below.

[0094] Table 2 Performance test of polysulfonate drilling fluid system

[0095]

[0096]

[0097] As can be seen from Table 2, the samples have good effects on reducing high-temperature and high-pressure filtration loss and lubrication in the polysulfonate drilling fluid system. The products aged under different temperature conditions have good effects on reducing high-temperature and high-pressure water loss and mud cake adhesion coefficient at each dosage, and can control the high-temperature and high-pressure filtration loss of the drilling fluid at a lower dosage, improving the lubrication effect of the drilling fluid. The samples at each dosage have no adverse effects on other rheological parameters such as the apparent viscosity AV and plastic viscosity PV of the polysulfonate drilling fluid, and have good compatibility with the polysulfonate drilling fluid.

[0098] (3) Performance evaluation in high-density polysulfonate drilling fluid

[0099] The polysulfonate drilling fluid with a density of 2.25 g / cm prepared at room temperature 3 In the high-solid-content polysulfonate drilling fluid (i.e., the base slurry in Table 3 below), different amounts (mass-volume ratio, such as base slurry + 2% sample, that is, 20 g of the sample is added to 1000 ml of the base slurry) of the lubricating and filtration-reducing agent sample for drilling fluid prepared in Example 1 are added, and it is thermally rolled at 150 °C for 16 h. The conventional performance test temperature is 50 °C, and the test temperature for high-temperature and high-pressure filtration loss is 150 °C. The results are shown in Table 3 below. The specific preparation method of the polysulfonate drilling fluid can be carried out by using the prior art and will not be elaborated here.

[0100] Table 3 Performance test of high-density polysulfonate drilling fluid system

[0101]

[0102] As can be seen from Table 3, after adding the sample to the high-density drilling fluid, the high-temperature and high-pressure filtration loss is controlled and the lubricity is improved; and as the dosage of the sample increases, the filtration-reducing effect and lubricity are further improved, and the dosage of 5% - 7% can meet the requirements of on-site drilling construction; after adding the sample, parameters such as the apparent viscosity AV and yield point YP of the drilling fluid do not change significantly, and there is no foaming situation. Therefore, the product of Example 1 of the present invention has good high-temperature filtration loss reduction and lubrication effects, and has good compatibility with the drilling fluid system.

[0103] (4) Performance evaluation in KCL polysulfonate drilling fluid

[0104] Base mud preparation: 800 ml of 6% OCMA native mud + 300 ml of SMT (SMT: NaOH = 3:1, mass - volume concentration 1 / 5N) + 30 ml of FA367 (mass - volume concentration 1 / 100N) + 20 g of LV - CMC + 70 g of SMC + 40 g of SMP - I (aqueous agent) + 4 g of lime + 2000 g of barite + 80 g of KCL, with a density of 1.90 g / cm 3 .

[0105] Add different amounts (mass - volume ratio, e.g., base mud + 2% sample means adding 20 g of sample to 1000 ml of base mud) of the sample to the base mud respectively, then heat - roll at 150°C for 16 h respectively. The conventional performance test temperature is 50°C, and the high - temperature and high - pressure filtration loss test temperature is 150°C. The results are shown in Table 4 below.

[0106] Table 4 Performance test of KCL polysulfonate drilling fluid system

[0107]

[0108] As can be seen from Table 4, after adding the sample to the KCL polysulfonate system, both the high - temperature and high - pressure filtration loss and lubricity are controlled. When the addition amount is 4%, the mud cake adhesion coefficient drops from 0.1763 to 0.1228, and the reduction rate reaches 30.3%; when the addition amount reaches 7%, the mud cake adhesion coefficient is less than 0.1. Thus, it can be seen that the product of the embodiment of the invention has good high - temperature resistance and filtration loss reduction ability and lubrication effect. And it has good compatibility with other treatment agents in the drilling fluid and has no adverse effect on rheology.

[0109] The reagent information used in each of the above - mentioned embodiments is as shown in Table 5 below.

[0110] Table 5 Information table of each reagent

[0111]

[0112]

[0113] Thus, the lubricating and filtration - loss - reducing agent for drilling fluid of the embodiment of the invention has the following effects:

[0114] Evaluated according to the requirements of the standard Q / SY 17088 - 2016 "Technical Specification for Liquid Lubricants for Drilling Fluids", the reduction rate of the mud cake adhesion coefficient reaches about 55%, and the reduction rate of the lubrication coefficient reaches about 84.0%. It can significantly improve the comprehensive lubrication performance of the drilling fluid, thereby reducing the friction resistance and torque of the drill string, playing a role in increasing the drilling speed and reducing downhole accidents; the reduction rate of the filtration loss under high - temperature and high - pressure reaches about 63%, having good high - temperature resistance and filtration loss reduction effect, which can improve the mud cake quality and sealing performance; the high - temperature resistance ability reaches 150°C; the viscosity effect is low and the foaming property is low.

[0115] In the polymer weighted drilling fluid system, it has good filtration loss reduction ability and friction reduction ability, and also has a certain viscosity and shear reduction effect. Without other abnormal situations occurring, it indicates that this product has good compatibility in the polymer weighted drilling fluid system.

[0116] In the polysulfonate weighted drilling fluid system, it has good high temperature and high pressure filtration loss reduction effect and lubrication effect, can achieve controlling the high temperature and high pressure filtration loss volume of the drilling fluid at a lower dosage, and improve the lubrication effect of the drilling fluid. It has no adverse effect on other rheological parameters and has good compatibility with the polysulfonate drilling fluid.

[0117] In the high density polysulfonate drilling fluid, the high temperature and high pressure filtration loss volume is controlled and the lubricity is improved. Moreover, with the increase of the sample dosage, the filtration loss reduction effect and lubricity are further improved. A dosage of 5% - 7% can meet the requirements of on-site drilling construction. Parameters such as the apparent viscosity AV and yield point YP of the drilling fluid do not change significantly, there is no foaming situation, it has good high temperature resistance and filtration loss reduction and lubrication effects, and has good compatibility with the drilling fluid system.

[0118] In the KCL polysulfonate system, both the high temperature and high pressure filtration loss volume and lubricity are controlled. When the dosage is 4%, the mud cake adhesion coefficient drops from 0.1763 to 0.1228, and the reduction rate reaches 30.3%. When the dosage reaches 7%, the mud cake adhesion coefficient is less than 0.1. It has good high temperature resistance and filtration loss reduction ability and lubrication effect, and has good compatibility with other treatment agents in the drilling fluid and has no adverse effect on the rheology.

[0119] In each embodiment of the present invention, the instruments, equipment, etc. involved in the process are all known equipment, and the methods not mentioned in the process are all known technologies, which will not be elaborated here.

[0120] The specific embodiments described above further elaborate on the purpose, technical solution and beneficial effects of the present invention. It should be understood that the above is only the specific embodiments of the present invention and is not used to limit the protection scope of the present invention. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention should be included in the protection scope of the present invention.

Claims

1. A lubricating fluid loss reducer for drilling fluid, characterized in that, It includes the following components in parts by weight: 32 to 33 parts of water, 9.5 to 10.5 parts of PSC-I, 9.5 to 10.5 parts of SMP-I aqueous solution, 10 to 11 parts of FA367 solution, 12.5 to 13.5 parts of waste engine oil, 14.5 to 15.5 parts of emulsified asphalt, and 8.5 to 9.5 parts of diesel emulsion; The FA 367 solution is prepared from FA 367 and an aqueous solution, and the mass ratio of FA 367 to water is 1:50; The diesel emulsion is prepared from diesel and an emulsifier, and the mass ratio of diesel to the emulsifier is 2:

1.

2. The preparation method of a lubricating fluid loss reducer for drilling fluid according to claim 1, characterized in that, It includes: 1) Add the formulated amounts of PSC-I, SMP-I aqueous solution, FA367 solution, waste engine oil, and emulsified asphalt into water, and carry out mixing and stirring; 2) Dropwise add the prepared diesel emulsion into the mixed system obtained in step 1), and carry out stirring and emulsification reaction to obtain the lubricating fluid loss reducer for drilling fluid.

3. The preparation method of a lubricating fluid loss reducer for drilling fluid according to claim 2, characterized in that In step 1), sequentially add the formulated amounts of PSC-I, SMP-I aqueous solution, FA367 solution, waste engine oil, and emulsified asphalt into water, and the temperature of the water is 30°C to 40°C.

4. The preparation method of a lubricating fluid loss reducer for drilling fluid according to claim 3, characterized in that, In step 1), after adding each component in the formulated amount to water each time, stir for 20 min, and then add the subsequent components.

5. The preparation method of a lubricating fluid loss reducer for drilling fluid according to claim 2, characterized in that During the mixing and stirring process in step 1), control the temperature at 30°C to 40°C.

6. The preparation method of a lubricating fluid loss reducer for drilling fluid according to claim 2, characterized in that, In step 2), after the diesel emulsion is added dropwise into the mixed system over a time of more than 40 min, continue stirring for 20 min.

7. The preparation method of a lubricating fluid loss reducer for drilling fluid according to claim 6, characterized in that, During the process of dropwise adding the diesel emulsion in step 2), control the temperature of the system at 40°C to 50°C.

8. The preparation method of a lubricating fluid loss reducer for drilling fluid according to claim 2, characterized in that, The temperature of the stirring and emulsification reaction is 55°C to 65°C, and the time is 30 min to 40 min.

9. The lubricating fluid loss reducer for drilling fluid according to claim 1 or the lubricating fluid loss reducer for drilling fluid prepared by the preparation method according to any one of claims 2 to 8 has the functions of improving the lubricating performance of the drilling fluid, reducing the mud cake adhesion coefficient, and reducing the fluid loss volume.

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