A modified sulfonated phenolic resin, its preparation method and application

Abstract

This invention relates to a modified sulfonated phenolic resin, its preparation method, and its applications. The modified sulfonated phenolic resin of this invention serves as a high-temperature stabilizer for drilling fluids. Its preparation process is simple and low-cost. Drilling fluids formulated with the modified sulfonated phenolic resin of this invention exhibit excellent medium-pressure filtration loss reduction performance, high-temperature and high-pressure filtration loss reduction performance, and salt resistance.

Description

Technical Field

[0001] This invention relates to the field of drilling fluid technology, and in particular to a modified sulfonated phenolic resin, its preparation method, and its application. Background Technology

[0002] Drilling fluid is a general term for various circulating fluids that fulfill the needs of drilling operations through multiple functions. Based on the base fluid and main treatment agent, drilling fluids are generally classified into gas-based drilling fluids, water-based drilling fluids, and oil-based drilling fluids. Currently, water-based drilling fluids have advantages such as low cost, simple preparation, treatment, and maintenance, wide availability of treatment agents, many types to choose from, and easy performance control. They also have a good effect on protecting oil and gas reservoirs, making them a commonly used drilling fluid system for drilling oil and gas reservoirs both domestically and internationally. However, it is generally accepted that oil-based drilling fluids represent a future development trend. Although the cost per well is relatively higher for oil-based drilling fluids, their reusability makes them more cost-effective for larger oil and gas wells. Furthermore, compared to water-based drilling fluids, oil-based drilling fluids offer several advantages, including resistance to high temperatures and salt / calcification, improved wellbore stability, better lubrication, and less damage to oil and gas reservoirs. Therefore, oil-based drilling fluids have become an important means of drilling high-temperature deep wells, highly deviated directional wells, horizontal wells, and various complex formations. They can also be widely used as unsticking fluids, perforation completion fluids, workover fluids, and core sampling fluids.

[0003] Oil-based drilling fluids refer to drilling fluids with oil as the continuous phase. As early as the 1920s, practical experience revealed the following disadvantages of using crude oil: low shear strength, difficulty in suspending barite, high filtration loss, and the volatile components in crude oil easily causing fires. Therefore, two types of oil-based drilling fluids with diesel oil as the continuous phase gradually developed: all-oil-based drilling fluids and water-in-oil emulsion drilling fluids. In all-oil-based drilling fluids, water is a useless component, and its water content should not exceed 7%; while in water-in-oil drilling fluids, water is a necessary component uniformly dispersed in the diesel oil, and its water content is generally 10%–60%. However, the formulation cost of oil-based drilling fluids is much higher than that of water-based drilling fluids, and their use often has a serious impact on the ecological environment near the well site. Furthermore, the mechanical drilling rate is generally lower compared to using water-based drilling fluids. Furthermore, while diesel-based drilling fluids can withstand high temperatures of 200℃ to 250℃ and exhibit strong stability under high pressure, preventing contamination during drilling and maintaining fluid performance stability, they also have drawbacks. High formulation costs, a low flash point (55℃) making them flammable and resulting in lower drilling rates; additionally, diesel fuel is highly toxic and can severely damage reservoirs. These disadvantages significantly limit the widespread application of oil-based drilling fluids. To improve drilling rates, low-colloidal water-in-oil emulsion drilling fluids were widely used starting in the mid-1970s. To protect the ecological environment and meet the needs of offshore drilling, low-toxicity water-in-oil emulsion drilling fluids with mineral oil as the base oil were gradually promoted and used starting in the early 1980s. These low-toxicity oil-based drilling fluids mainly include paraffin oil-based drilling fluids, refined white oil-based drilling fluids, VersaClean low-toxicity drilling fluids, and vegetable oil-based drilling fluids.

[0004] All of the aforementioned paraffin oil-based drilling fluids, refined white oil-based drilling fluids, Versa Clean low-toxicity drilling fluids, or vegetable oil-based drilling fluids require the addition of oil-based drilling fluid treatment agents during formulation. These include, for example, filtration reducers, viscosity modifiers, flocculants, shale inhibitors, plugging agents, viscosity reducers, emulsifiers, high-temperature stabilizers, and wetting agents. The role of high-temperature stabilizers is to maintain the original properties (mainly rheological and filtration stability) of the drilling fluid under elevated temperatures. Commonly used stabilizers include sulfonated phenolic resins and their modified forms, sulfates, sulfonated lignite modifiers, organic sulfonated polymers, thiol-containing heterocyclic compounds, and reducing agents that prevent oxidative degradation of organic matter at elevated temperatures.

[0005] Currently, the more mature and publicly available technologies include:

[0006] 1) CN104140789A discloses an oil-based drilling fluid used in the petroleum drilling field, and more specifically, relates to a high-temperature filtration reduction agent for oil-based drilling fluids and its preparation method. The filtration reduction agent is made from raw materials including humic acid resin, low-boiling-point alcohol, and organic amine. The filtration reduction agent exhibits good filtration reduction effects in diesel-based, mineral oil-based, and synthetic-based drilling fluid systems, and its temperature resistance can reach 200℃.

[0007] 2) CN103725268A discloses a high-temperature resistant oil-based drilling fluid emulsifier, composed of the following components: Emulsifier A: a long-chain alkyl fatty alcohol amide nonionic surfactant; Emulsifier B: a sulfonate; Emulsifier C: a stearate; the mass ratio of Emulsifier A: Emulsifier B: Emulsifier C is 1.5~2.5:0.8~1.2:1. Emulsifier B is selected from one or more of petroleum sulfonate iron, sodium alkylbenzene sulfonate, sodium alkyl aryl sulfonate, and sodium alkyl succinate sulfonate. Emulsifier C is selected from one or two of polyoxyethylene stearate or zinc stearate. Its high-temperature resistance can reach 180℃.

[0008] 3) CN104403646A discloses a high-temperature resistant oil-based drilling fluid emulsifier, which is mainly prepared from the following components by weight: 500-700 parts fatty acid, 70-120 parts tetraethylenepentamine, 50-100 parts xylene, and 200-300 parts white oil; wherein the white oil is preferably No. 3 white oil. It is suitable for temperatures below 220℃ and densities between 0.9 and 2.2 g / cm³. 3 Diesel and white oil-based drilling fluid systems with oil-water ratios in the range of 70:30 to 90:10 address issues such as demulsification, deterioration of rheological properties, and barite sedimentation caused by high-temperature degradation of emulsifiers in drilling fluid systems.

[0009] 4) CN105154036A discloses a high-temperature resistant emulsifier for oil-based drilling fluids, which is composed of the following raw materials in parts by weight: oleic acid: 12-30; oleic acid diethanolamide: 1-10; sodium fatty alcohol polyoxyethylene ether carboxylate: 1-10. The preparation method includes weighing the raw materials, adding oleic acid and oleic acid diethanolamide to a mixer and mixing for 10-20 minutes, then adding sodium fatty alcohol polyoxyethylene ether carboxylate and mixing evenly. This disclosed emulsifier can withstand temperatures up to 200℃ and is suitable for drilling fluids with various oil-to-water ratios.

[0010] 5) CN104263328A discloses a high-temperature resistant oil-based drilling fluid emulsifier, which is prepared by reacting the following components in parts by weight: 9-12 parts polyolefin, 1-3 parts maleic anhydride, 18-22 parts xylene, 3-5 parts polyethylene polyamine, 2-4 parts polyethylene glycol, and 1-3 parts octylphenol polyoxyethylene ether. It also provides a method for preparing this emulsifier. The disclosed emulsifier exhibits better emulsification of water-in-oil drilling fluid systems with diesel and white oil as the continuous phase, and also possesses extremely strong high-temperature resistance. It can maintain a high demulsification voltage in oil-based drilling fluids before and after 200℃, thus ensuring the long-term emulsification stability, rheological properties, and anti-fouling ability of oil-based drilling fluids.

[0011] However, most of the current high-temperature stabilizers have problems such as complex preparation processes or high costs, and the drilling fluids formulated with them have limited filtration loss reduction and salt resistance properties.

[0012] Therefore, it is crucial to develop a high-temperature stabilizer that can solve the above-mentioned technical problems. Summary of the Invention

[0013] To address the shortcomings of existing technologies, the present invention aims to provide a modified sulfonated phenolic resin, its preparation method, and its application. The modified sulfonated phenolic resin, as a high-temperature stabilizer for drilling fluids, has a simple preparation process and low cost. The drilling fluid formulated with the modified sulfonated phenolic resin exhibits excellent medium-pressure filtration loss reduction performance, high-temperature and high-pressure filtration loss reduction performance, and salt resistance.

[0014] To achieve this objective, the present invention adopts the following technical solution:

[0015] In a first aspect, the present invention provides a modified sulfonated phenolic resin, the structure of which is shown in Formula I:

[0016]

[0017] Where m is an integer greater than 2, such as 3, 5, 10, 15, 20, 25, 30, 35, 40, etc.

[0018] n1 and n2 are independent positive integers, such as 1, 3, 5, 10, 15, 20, 25, 30, 35, 40, etc.

[0019] R1 is selected from hydroxyl, cyano, nitro, amino, carboxyl, acetyl, or halogen;

[0020] R2, R4 and R5 are each independently selected from C1-C6 alkane groups (e.g., C2, C3, C4, C5, etc.), carbonyl groups, or C1-C10 alkane groups (e.g., C2, C3, C4, C5, C6, C7, C8, C9, etc.).

[0021] R3 and R6 are each independently selected from C1-C10 alkane groups (e.g., C2, C3, C4, C5, C6, C7, C8, C9, etc.) or C2-C10 alkenyl groups (e.g., C3, C4, C5, C6, C7, C8, C9, etc.).

[0022] In this invention, the modified sulfonated phenolic resin of the structure forms a stable structure with other components of the drilling fluid, thereby improving the overall temperature resistance of the drilling fluid. As a high-temperature stabilizer for drilling fluid, the prepared drilling fluid has good medium-pressure filtration loss reduction performance, high-temperature and high-pressure filtration loss reduction performance, and salt and temperature resistance performance.

[0023] In this invention, the high-temperature stabilizer refers to an oil-based drilling fluid with a temperature resistance of 180-200℃, such as 185℃, 190℃, 195℃, etc.

[0024] In this invention, C1-C6 alkane groups refer to alkane groups with 1-6 carbon atoms in the main chain, and the same applies to C1-C10 alkane groups and C2-C10 alkenyl groups.

[0025] Preferably, m is an integer greater than 2, such as 3, 4, 5, 6, etc.

[0026] Preferably, n1 and n2 are each independently 1-5, for example 2, 3, 4, etc.

[0027] Preferably, the groups of R2, R4 and R5 are the same.

[0028] Preferably, the groups of R3 and R6 are the same.

[0029] Preferably, the modified sulfonated phenolic resin comprises any one or a combination of at least two of the following polymers: sodium hydroxydimethylbenzenesulfonate-sodium trimethylbenzenesulfonate polymer, sodium carboxydimethylbenzenesulfonate-sodium trimethylbenzenesulfonate polymer, and sodium cyanodimethylbenzenesulfonate-sodium trimethylbenzenesulfonate polymer. Typical but non-limiting combinations include: a combination of sodium hydroxydimethylbenzenesulfonate-sodium trimethylbenzenesulfonate polymer and sodium carboxydimethylbenzenesulfonate-sodium trimethylbenzenesulfonate polymer, a combination of sodium carboxydimethylbenzenesulfonate-sodium trimethylbenzenesulfonate polymer and sodium cyanodimethylbenzenesulfonate-sodium trimethylbenzenesulfonate polymer, etc.

[0030] In a second aspect, the present invention provides a method for preparing the modified sulfonated phenolic resin described in the first aspect, the method comprising the following steps: subjecting aldehyde reactants and phenol reactants to a first reaction under the action of an acid catalyst, then subjecting them to a second reaction under the action of an alkaline catalyst, and then subjecting them to a sulfonation reaction to obtain the modified sulfonated phenolic resin.

[0031] Preferably, the temperatures of the first reaction, the second reaction, and the sulfonation reaction are each independently 100-120°C;

[0032] Preferably, the time for the first reaction is 120-420 min, such as 150 min, 200 min, 250 min, 300 min, 350 min, 400 min, etc.

[0033] Preferably, the second reaction takes 90-120 minutes, such as 95 minutes, 100 minutes, 105 minutes, 110 minutes, 115 minutes, etc.

[0034] Preferably, the sulfonation reaction time is 60-360 min, such as 100 min, 150 min, 200 min, 250 min, 300 min, 350 min, etc.

[0035] Preferably, the sulfonating agent is added in 3-8 stages (e.g., 4, 5, 6, 7, etc.) during the sulfonation reaction.

[0036] Preferably, after the sulfonation reaction, the process further includes cooling and drying.

[0037] Preferably, the temperature of the cooled discharge is 60-70℃, such as 62℃, 64℃, 66℃, 68℃, etc.

[0038] Preferably, the aldehyde reactants include any one or a combination of at least two of formaldehyde, paraformaldehyde, acetaldehyde, or paraacetaldehyde, wherein typical but non-limiting combinations include: a combination of formaldehyde and paraformaldehyde, a combination of acetaldehyde and paraacetaldehyde, a combination of formaldehyde, paraformaldehyde, acetaldehyde, and paraacetaldehyde, etc.

[0039] Preferably, the phenolic reactants include any one or a combination of at least two of phenol, catechol, resorcinol, o-cresol, or p-cresol, wherein typical but non-limiting combinations include: a combination of phenol and catechol, a combination of resorcinol, o-cresol, and p-cresol, a combination of phenol, catechol, resorcinol, o-cresol, and p-cresol, etc.

[0040] Preferably, the acid catalyst comprises any one or a combination of at least two of hydrochloric acid, sulfuric acid, acetic acid, formic acid, or p-toluenesulfonic acid, wherein typical but non-limiting combinations include: a combination of hydrochloric acid and sulfuric acid, a combination of acetic acid, formic acid, and p-toluenesulfonic acid, a combination of hydrochloric acid, sulfuric acid, acetic acid, formic acid, and p-toluenesulfonic acid, etc.

[0041] Preferably, the alkaline catalyst comprises any one or a combination of at least two of sodium hydroxide, calcium hydroxide, or potassium hydroxide, wherein typical but non-limiting combinations include: a combination of sodium hydroxide and calcium hydroxide, a combination of calcium hydroxide and potassium hydroxide, a combination of sodium hydroxide, calcium hydroxide, and potassium hydroxide, etc.

[0042] Preferably, the sulfonating agent comprises the reaction product of a sulfate reactant and an aldehyde reactant.

[0043] In this invention, the modified sulfonated phenolic resin of the aforementioned structure serves as a high-temperature stabilizer for drilling fluids, and its preparation process is simple and low-cost.

[0044] Thirdly, the present invention provides a stabilizer comprising the modified sulfonated phenolic resin described in the second aspect.

[0045] Fourthly, the present invention provides a drilling fluid comprising the stabilizer described in the third aspect.

[0046] Preferably, the drilling fluid comprises a base slurry, sulfonated lignite, and the stabilizer described in the third aspect;

[0047] Preferably, the drilling fluid comprises the following components in parts by weight:

[0048]

[0049]

[0050] In this invention, the emulsifier is present in parts by weight of 0-6 parts, such as 1 part, 2 parts, 3 parts, 3.5 parts, 4 parts, 4.5 parts, 5 parts, 5.5 parts, etc.

[0051] The organic soil is in the form of 3-6 parts by weight, such as 3.5 parts, 4 parts, 4.5 parts, 5 parts, 5.5 parts, etc.

[0052] The sulfonated lignite is present in 3-5 parts by weight, such as 3.5 parts, 4 parts, 4.5 parts, etc.

[0053] The calcium oxide is present in 3-5 parts by weight, such as 3.5 parts, 4 parts, 4.5 parts, etc.

[0054] The calcium carbonate is in the form of 3-6 parts by weight, such as 3.5 parts, 4 parts, 4.5 parts, 5 parts, 5.5 parts, etc.

[0055] The stabilizer is present in 3-6 parts by weight, such as 3.5 parts, 4 parts, 4.5 parts, 5 parts, 5.5 parts, etc.

[0056] The wetting agent is present in parts by weight of 0-3 parts, such as 1 part, 2 parts, 3 parts, etc.

[0057] The weight of the barite is 0-5 parts, for example, 1 part, 2 parts, 3 parts, 3.5 parts, 4 parts, 4.5 parts, etc.

[0058] Preferably, the base slurry comprises any one or a combination of two of white oil, diesel oil, diesel oil, or an aqueous solution of calcium chloride, wherein typical but non-limiting combinations include: a combination of white oil and diesel oil, a combination of diesel oil and an aqueous solution of calcium chloride, a combination of white oil, diesel oil, diesel oil, and an aqueous solution of calcium chloride, etc.

[0059] Compared with the prior art, the present invention has the following beneficial effects:

[0060] (1) The modified sulfonated phenolic resin of the present invention is a high-temperature stabilizer for drilling fluid. The preparation process is simple and the cost is low. The drilling fluid formulated with the modified sulfonated phenolic resin of the present invention has good medium-pressure filtration loss reduction performance, high-temperature and high-pressure filtration loss reduction performance and salt resistance performance.

[0061] (2) The drilling fluid formulated with the modified sulfonated phenolic resin of the present invention has an apparent viscosity between 34-44 mPa·s, a plastic viscosity between 29-35 mPa·s, a medium-pressure filtration loss of less than 1 mL, and a high-temperature and high-pressure filtration loss of less than 3.5 mL. Detailed Implementation

[0062] The technical solution of the present invention will be further illustrated below through specific embodiments. Those skilled in the art should understand that the embodiments described are merely illustrative of the present invention and should not be construed as limiting the invention in any way.

[0063] In this invention, the procurement information of the raw materials involved in each embodiment is as follows:

[0064] White oil: Purchased from Jingmen Petrochemical Company in Hubei Province, type 5 white oil;

[0065] Emulsifier: Purchased from Henan Defanke Petroleum Additives Co., Ltd., model DFK-14;

[0066] Organic soil: Purchased from Panjin Petrochemical Company, brand name is white oil-based drilling fluid organic soil-II;

[0067] Ultrafine calcium carbonate: purchased from Baoding Jinshi Mining Co., Ltd., type I;

[0068] Calcium oxide: purchased from Benxi Changsheng Calcium Industry Co., Ltd., type CaO;

[0069] Lignite resin: purchased from Anhui Luhai Petroleum Additives Co., Ltd.

[0070] Wetting agent: purchased from Panjin Petrochemical Company, model GW-WET;

[0071] Barite: Purchased from Shaanxi Antaishan Weiye Mining Co., Ltd.;

[0072] Paraformaldehyde: Purchased from Liaoning Quanrui Reagent Co., Ltd.

[0073] Paraacetaldehyde: purchased from Liaoning Quanrui Reagent Co., Ltd.;

[0074] Sulfonating agent: purchased from Liaoning Quanrui Reagent Co., Ltd.;

[0075] Formic acid catalyst: purchased from Liaoning Quanrui Reagent Co., Ltd.;

[0076] Carboxylic acid catalysts: purchased from Liaoning Quanrui Reagent Co., Ltd.

[0077] Preparation Example 1

[0078] This preparation example provides a modified sulfonated phenolic resin, wherein the modified sulfonated phenolic resin is a sodium hydroxydimethylbenzenesulfonate-sodium trimethylbenzenesulfonate polymer.

[0079] The modified sulfonated phenolic resin is obtained by the following preparation method, which includes the following steps:

[0080] (1) 150g of paraformaldehyde, 50g of formaldehyde and 200g of phenol were reacted in a reactor at 100℃ for 280min under the action of 20g of formic acid catalyst (specifically formic acid HCOOH).

[0081] (2) Continue to add 32g of sodium hydroxide catalyst to the reactor and react for 100min, keeping the temperature at 110℃. Add 200g of sulfonating agent (specifically sodium bisulfite) in 3 portions and react for 180min.

[0082] (3) After the reaction is complete, the material is discharged at a lower temperature, and the temperature is maintained at 60°C. The product is obtained by spray drying.

[0083] Preparation Example 2

[0084] This preparation example provides a modified sulfonated phenolic resin, wherein the modified sulfonated phenolic resin is a sodium carboxydimethylbenzenesulfonate-sodium trimethylbenzenesulfonate polymer.

[0085] The modified sulfonated phenolic resin is obtained by the following preparation method, which includes the following steps:

[0086] (1) 50g formaldehyde, 150g paraacetaldehyde and 200g phenol were reacted in a reactor at 110℃ for 300min under the action of 20g carboxylic acid catalyst (specifically benzoic acid).

[0087] (2) Continue to add 32g of sodium hydroxide catalyst to the reactor and react for 98min, keeping the temperature at 105℃. Add 200g of sulfonating agent (specifically sodium bisulfite) in 5 portions and react for 290min.

[0088] (3) After the reaction is complete, the material is discharged at a lower temperature, and the temperature is maintained at 70°C. The product is obtained by spray drying.

[0089] Example 1

[0090] This embodiment provides a drilling fluid with a density of 1.65 g / cm³. 3 The drilling fluid comprises the following components in parts by weight:

[0091] 100 parts base slurry (white oil) + 4 parts organic clay + 3 parts calcium oxide + 3 parts ultrafine calcium carbonate + 3 parts lignite resin + 3 parts modified phenolic resin as described in Preparation Example 1 + 1 part wetting agent + 370g barite.

[0092] Example 2

[0093] This embodiment provides a drilling fluid with a density of 1.65 g / cm³. 3 The drilling fluid comprises the following components in parts by weight:

[0094] 90 parts base slurry (white oil) + 3 parts emulsifier + 10 parts calcium chloride aqueous solution (concentration of 30-80%) + 4 parts organic clay + 3 parts calcium oxide + 3 parts ultrafine calcium carbonate + 3 parts lignite resin + 3 parts modified phenolic resin as described in Preparation Example 2 + 1 part wetting agent + 370g barite.

[0095] Example 3

[0096] This embodiment provides a drilling fluid with a density of 1.65 g / cm³. 3 The drilling fluid comprises the following components in parts by weight:

[0097] 80 parts base slurry (white oil) + 4 parts emulsifier + 20 parts calcium chloride aqueous solution (calcium chloride aqueous solution, concentration of 30-80%) + 4 parts organic clay + 3 parts calcium oxide + 3 parts ultrafine calcium + 3 parts lignite resin + 3 parts modified phenolic resin as described in Preparation Example 1 + 1 part wetting agent + 370g barite.

[0098] Example 4

[0099] This embodiment provides a drilling fluid with a density of 1.65 g / cm³. 3The drilling fluid comprises the following components in parts by weight:

[0100] 70 parts base slurry (white oil) + 5 parts emulsifier + 30 parts calcium chloride aqueous solution (calcium chloride aqueous solution, concentration 30-80%) + 4 parts organic clay + 3 parts calcium oxide + 3 parts ultrafine calcium carbonate + 3 parts lignite resin + 3 parts modified phenolic resin as described in Preparation Example 1 + 1 part wetting agent + 370g barite.

[0101] Comparative Example 1

[0102] The difference between this comparative example and Example 2 is that it does not include modified phenolic resin; otherwise, it is the same as Example 1.

[0103] Performance testing

[0104] The drilling fluids described in Examples 1-4 and Comparative Example 1 were tested as follows:

[0105] 1. Use a variable frequency high-temperature roller heating furnace for aging rolling for 16 hours at an aging temperature of 190℃.

[0106] 2. The test was conducted using a six-speed rotational viscometer. The method of use is as follows:

[0107] (1) Take out the instrument and check whether each rotating part, electrical appliance and power plug are safe and reliable.

[0108] (2) Rotate the outer cylinder to the left to remove it. Rotate the inner cylinder counterclockwise and push it upwards to engage with the conical end of the inner cylinder shaft. Perform the movements gently to avoid deformation or damage to the instrument's inner cylinder shaft. Rotate the outer cylinder to the right to install it.

[0109] (3) Connect the power supply to 220V, 50Hz.

[0110] (4) Press the three-position switch to adjust the high speed or low speed.

[0111] (5) When the instrument is rotating, gently pull the red handle of the speed change lever to change the required speed according to the marking.

[0112] (6) Rotate the instrument at 300 r / min and 600 r / min and observe that the outer rotating cylinder should not swing. If it swings, stop the machine and reinstall the outer rotating cylinder.

[0113] (7) Rotate at 300 r / min and check if the pointer on the dial is swinging at zero. If the pointer is not at zero, it should be checked.

[0114] (8) Pour the stirred liquid into the liquid cup of the six-speed rotary viscometer up to the scale line, so that the sample liquid surface is flush with the upper end of the outer cylinder.

[0115] (9) Rotate it at 600 r / min, and heat it with a six-speed rotary viscometer cup heating jacket until the liquid temperature reaches 50℃, and then perform the test. Taking Φ600 as an example: rotate at a speed of 600 r / min, and when the scale reaches a stable reading, record the reading at a speed of 600 r / min.

[0116] (10) After the test, turn off the power, loosen the tray handwheel, and remove the sample cup. Gently turn the outer rotating cylinder counterclockwise to remove it, and rotate the inner cylinder counterclockwise and apply vertical downward force to remove the inner cylinder. Clean the outer rotating cylinder and dry it. Install the outer rotating cylinder on the instrument. When cleaning the inner cylinder, use your fingers to block the conical hole to prevent dirt and liquid from entering the cavity. Place the inner cylinder separately in a fixed position inside the box.

[0117] 2. Medium-pressure water loss is tested using a medium-pressure filter. The method of use is as follows:

[0118] (1) Confirm that all parts of the instrument are clean and dry, and that the “O” seal is intact. Pour drilling fluid into the slurry cup until the liquid level is level with the liquid level line, place the seal and filter paper, cover it, and connect the graduated cylinder to the bottom of the filtrate.

[0119] (2) Pressurize and time. The pressure applied is 100 psi, and the gas source is compressed air, nitrogen, or carbon dioxide.

[0120] (3) After 30 minutes, read the volume of the collected filtrate and close the pressure regulating valve. Remove the graduated cylinder and read and record the volume of the collected filtrate (unit: ml).

[0121] (4) Depressurize, clean thoroughly, dry, and put back in its original place.

[0122] 3. High-temperature and high-pressure water loss is tested using a high-temperature and high-pressure filtration analyzer. The usage method is as follows:

[0123] (1) Connect the heating mantle and the corresponding voltage power supply, and insert the thermometer into the thermometer hole. Heat the heating mantle to 6°C higher than the selected measurement temperature, and use a thermostat to keep the temperature constant throughout the test.

[0124] (2) Stir the sample for 10 minutes. At the same time, close the lower valve of the slurry cup and fill the slurry cup to the graduation mark. Place the filter paper on top, put the slurry cup back on, and close the upper valve.

[0125] (3) Place the slurry cup into the heating jacket and insert the thermometer into the thermometer hole.

[0126] (4) Connect the pressurization manifold to the upper and lower valves and secure it with a T-pin. With the air valve closed, apply a pressure of 0.7 MPa to the upper manifold. Open the upper air valve to introduce air pressure and heat it to the selected temperature.

[0127] (5) When the temperature reaches the set temperature, increase the upper air pressure to 4.2 MPa. Apply 0.7 MPa pressure to the lower manifold and open the lower air valve. Maintain a pressure difference of 3.5 MPa between the upper and lower ends. During the entire 30-minute measurement process, maintain the preset temperature (±3°C), collect the filtrate, and record the results. The sample should not be heated in the cup for more than 1 hour.

[0128] (6) After the measurement is completed, close the upper and lower air valves, release the pressure and pull out the "T" pin. Slowly open the upper valve stem 1 / 2-1 turn to release the pressure. After that, clean it, wipe it dry and put it back in its original place.

[0129] The test results are summarized in Table 1.

[0130] Table 1

[0131]

[0132]

[0133] Table 1 shows that the drilling fluid formulated with the modified sulfonated phenolic resin of this invention has an apparent viscosity between 34-44 mPa·s, a plastic viscosity between 29-35 mPa·s, a medium-pressure filtration loss of less than 1 mL, and a high-temperature, high-pressure filtration loss of less than 3.5 mL. The modified sulfonated phenolic resin of this invention, as a high-temperature stabilizer for drilling fluids, has a simple preparation process and low cost. The drilling fluid formulated with the modified sulfonated phenolic resin of this invention exhibits good medium-pressure filtration loss reduction performance, high-temperature, high-pressure filtration loss reduction performance, and salt resistance.

[0134] Analysis of Comparative Example 1 and Example 2 shows that the performance of Comparative Example 1 is not as good as that of Example 2, proving that the drilling fluid formulated with the modified sulfonated phenolic resin of the present invention has better performance.

[0135] The present invention has been illustrated with the above embodiments to explain the detailed method of the present invention. However, the present invention is not limited to the detailed method described above, that is, it does not mean that the present invention must rely on the detailed method described above to be implemented. Those skilled in the art should understand that any improvements to the present invention, equivalent substitutions of the raw materials of the product of the present invention, addition of auxiliary components, selection of specific methods, etc., all fall within the protection scope and disclosure scope of the present invention.

Claims

1. A drilling fluid, characterized in that, The drilling fluid comprises the following components in parts by weight: 100 parts white oil 4 parts organic soil 3 parts of lignite resin 3 parts calcium oxide 3 parts of ultrafine calcium carbonate 3 parts modified phenolic resin 1 part wetting agent 370g of barite; The modified phenolic resin is a sodium hydroxydimethylbenzenesulfonate-sodium trimethylbenzenesulfonate polymer.

2. The drilling fluid according to claim 1, characterized in that, The preparation method of the modified sulfonated phenolic resin includes the following steps: The aldehyde reactants and phenol reactants undergo a first reaction under the action of an acid catalyst, followed by a second reaction under the action of an alkaline catalyst, and then a sulfonation reaction is carried out to obtain the modified sulfonated phenolic resin. The aldehyde reactants are formaldehyde and paraformaldehyde; the phenol reactants are phenol; the acid catalyst is formic acid; and the base catalyst is sodium hydroxide. During the sulfonation reaction, the sulfonating agent is added in 3-8 batches; the sulfonating agent is sodium bisulfite.

3. The drilling fluid according to claim 2, characterized in that, The temperatures for the first reaction, the second reaction, and the sulfonation reaction are each independently 100-120°C.

4. The drilling fluid according to claim 2, characterized in that, The duration of the first reaction is 120-420 min.

5. The drilling fluid according to claim 2, characterized in that, The second reaction takes 90-120 minutes.

6. The drilling fluid according to claim 2, characterized in that, The sulfonation reaction takes 60-360 minutes.

7. The drilling fluid according to claim 2, characterized in that, The sulfonation reaction is followed by cooling and drying operations.

8. The drilling fluid according to claim 7, characterized in that, The temperature of the cooled discharge material is 60-70℃.

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