A device and method for testing the surface hydration inhibition of a drilling fluid

Abstract

The application relates to the technical field of surface hydration inhibition testing, and discloses a drilling fluid surface hydration inhibition testing device and method, which comprises a reaction tank, a nylon filter cloth, a first fixing frame and a second fixing frame are arranged in the reaction tank, one end of the nylon filter cloth is detachably connected with the first fixing frame, the other end of the nylon filter cloth is detachably connected with the second fixing frame, the first fixing frame is detachably connected with the inner wall at the top of the reaction tank, and the second fixing frame is detachably connected with the inner wall at the bottom of the reaction tank; the surface hydration inhibition performance of a drilling fluid is tested by XRD after testing, the device can be applied to the surface hydration inhibition testing of various water-based drilling fluids, and provides strong support for the development of drilling fluid technology.

Description

Technical Field

[0001] This invention relates to the field of surface hydration inhibition testing technology, and more specifically, to a drilling fluid surface hydration inhibition testing device and method. Background Technology

[0002] When drilling fluid comes into contact with clay minerals, the clay minerals undergo hydration. For example, montmorillonite clay minerals have a large number of exchangeable cations in their crystal structure. These cations attract water molecules, causing the clay minerals to expand in volume. This expansion may cause wellbore instability, leading to wellbore collapse, narrowing, and other complex situations, increasing drilling risks and costs.

[0003] Currently, the surface hydration inhibition performance of drilling fluids cannot be tested, mainly because surface hydration is too microscopic. It requires treating montmorillonite with drilling fluid before testing its microscopic properties (such as substrate spacing). The problem is that sodium montmorillonite cannot be directly added to the drilling fluid because it contains solid phases such as bentonite and barite, making it impossible to separate pure sodium montmorillonite. This prevents the analysis of the surface hydration inhibition performance of the drilling fluid. Summary of the Invention

[0004] The purpose of this application is to provide a drilling fluid surface hydration inhibition testing device, which can simulate the testing environment of the interaction between drilling fluid and formation clay minerals, providing a basis for accurately evaluating the surface hydration inhibition of drilling fluid.

[0005] Another objective of this application is to provide a method for testing the surface hydration inhibition of drilling fluids. This method can induce surface hydration of sodium montmorillonite to evaluate the surface hydration inhibition performance of drilling fluids. Different evaluation criteria can clearly define the degree of surface hydration inhibition of drilling fluids, facilitating researchers and engineers to adjust and optimize drilling fluid formulations based on test results to meet the needs of different drilling projects and improve the safety and efficiency of drilling operations. Furthermore, this testing method has a certain degree of versatility and can be applied to the surface hydration inhibition testing of various water-based drilling fluids, providing strong support for the development of drilling fluid technology.

[0006] To solve the above-mentioned technical problems, the technical solution adopted in this application is as follows:

[0007] On one hand, this application provides a drilling fluid surface hydration inhibition test device, including a reaction tank, a nylon filter cloth, a first fixing frame and a second fixing frame inside the reaction tank, one end of the nylon filter cloth is detachably connected to the first fixing frame and the other end is detachably connected to the second fixing frame, the first fixing frame is detachably connected to the inner wall of the top of the reaction tank and the second fixing frame is detachably connected to the inner wall of the bottom of the reaction tank.

[0008] By setting up a reaction vessel and equipping it with nylon filter cloth, a first fixing frame, and a second fixing frame, the selective permeability of the nylon filter cloth allows the sodium montmorillonite inside the nylon filter cloth to exchange or interact with the drilling fluid in the reaction vessel under certain conditions. This simulates the hydration inhibition of clay minerals (taking sodium montmorillonite as an example) in the formation by the drilling fluid under actual working conditions. Structurally, the nylon filter cloth can be easily installed and removed, while ensuring that it is in a stable position in the reaction vessel. This guarantees sufficient contact and reaction between the nylon filter cloth and the drilling fluid during the test, effectively constructing a test environment that simulates the interaction between drilling fluid and formation clay minerals. This provides a basic condition for accurately evaluating the surface hydration inhibition of drilling fluid. Furthermore, the detachable connection method facilitates the assembly, cleaning, and maintenance of the device, improving its practicality and operability.

[0009] This application creatively uses nylon filter cloth, which can reach tens of thousands of mesh sizes and has pores at the nanoscale. It is also more temperature resistant (nylon material generally has a minimum temperature resistance of 120℃ and a maximum temperature resistance of 250℃), solving the problem that the existing technology can only carry out the reaction at room temperature. This application can realize the inhibition evaluation under high temperature and high pressure.

[0010] Since only the liquid phase of the drilling fluid affects montmorillonite, and the solid phase has no effect, and existing technologies cannot separate pure sodium montmorillonite, excess solid phase components can hinder substrate testing, resulting in inaccurate test results. Therefore, this application creatively uses nylon filter cloth to wrap sodium montmorillonite and isolate it from the solid phase in the drilling fluid, allowing the liquid phase components to enter the nylon filter cloth and interact with the sodium montmorillonite. This can realistically reproduce the environment of sodium montmorillonite in the drilling fluid and also achieve the separation of sodium montmorillonite. In subsequent substrate testing, this solves the problem of the solid phase component affecting the test results, simulating the real environment while making the results more accurate and reliable.

[0011] In some embodiments of this application, the mesh count of the nylon filter cloth is greater than 80,000 mesh (0.1 micrometers).

[0012] In some embodiments of this application, both the first and second fixing frames are embedded with first magnetic blocks, and the top and bottom inner walls of the reaction vessel are embedded with second magnetic blocks. The first and second magnetic blocks have opposite magnetic poles. The mutual attraction between the magnetic poles achieves a fixed connection between the first fixing frame and the top inner wall of the reaction vessel, and between the second fixing frame and the bottom inner wall of the reaction vessel. This magnetic fixing method does not require additional complex connecting components; the fixing frame can be stably fixed to the inner wall of the reaction vessel solely by the magnetic force between the magnetic blocks. Compared with traditional fixing methods, magnetic fixing has the advantages of simple and quick operation, significantly shortening the assembly time of the device. Simultaneously, the absence of complex connecting structures reduces the space occupied inside the device, making the internal space of the reaction vessel more regular, which is beneficial for the layout of the nylon filter cloth and the flow of drilling fluid within the reaction vessel. Moreover, magnetic fixing allows for easy adjustment of the fixing frame position according to testing needs, enhancing the flexibility of the device. Furthermore, the magnetic blocks have a long service life and are not easily damaged, reducing the maintenance cost of the device.

[0013] In some embodiments of this application, the aforementioned reaction vessel is an aging vessel, which typically possesses good sealing performance, high temperature and pressure resistance, and a certain degree of corrosion resistance. During the drilling fluid surface hydration inhibition test, the drilling fluid and sodium montmorillonite within the nylon filter cloth need to be placed under specific temperature and pressure conditions for aging treatment to simulate the actual long-term operation of the drilling fluid downhole. The aging vessel can withstand the high temperatures and pressures that may occur during the test, preventing drilling fluid leakage and ensuring the stability of the test environment. The material and structural characteristics of the aging vessel enable it to provide a stable and reliable reaction environment for the test, ensuring the accuracy and repeatability of the test results. Its good sealing performance effectively prevents drilling fluid evaporation or external impurities from entering the reaction system, avoiding interference with the test results. Its high temperature and pressure resistance allows the device to adapt to a wide range of test temperature and pressure conditions, broadening its applicability and enabling it to simulate drilling fluid performance tests under different formation depths. Corrosion resistance extends the service life of the reaction vessel, reduces equipment replacement costs due to vessel corrosion, and improves the overall economy and durability of the device.

[0014] In some embodiments of this application, both the first and second fixing frames are provided with a clamping mechanism to clamp the two ends of the nylon filter cloth, thereby achieving detachable fixing.

[0015] It should be noted that the above-mentioned clamping mechanism is a commonly used structure in this field, which is sufficient to fix the nylon filter cloth, and is not limited here.

[0016] On the other hand, this application provides a method for testing the surface hydration inhibition of drilling fluid using an embodiment of the present application, which includes the following steps: S1, filling an aging tank with 400 mL of drilling fluid and inserting sodium montmorillonite into a nylon filter cloth; S2, fixing both ends of the nylon filter cloth with a first fixing frame and a second fixing frame; S3, fixing the second fixing frame to the bottom inner wall of the aging tank and the first fixing frame to the top inner wall of the aging tank; S4, raising the temperature of the roller furnace to a specified temperature, placing it into the aging tank and hot rolling it; S5, after hot rolling, cooling and opening the tank, removing the nylon filter cloth and sodium montmorillonite, and placing it in a centrifuge for centrifugation; S6, after centrifugation, pouring out the upper liquid and collecting the centrifuged sodium montmorillonite; S7, using XRD to test the substrate spacing of the centrifuged sodium montmorillonite, and evaluating the inhibition of drilling fluid through the substrate spacing.

[0017] In some embodiments of this application, the amount of sodium montmorillonite used in step S1 above is 8g.

[0018] In some embodiments of this application, in step S1 above, the sodium montmorillonite is high-purity sodium montmorillonite with a purity greater than 99%.

[0019] In some embodiments of this application, in step S4 above, the specified temperature is 25℃-230℃, the hot rolling time is 12-48h, and the roller furnace speed is 50r / min.

[0020] In some embodiments of this application, the temperature specified in step S4 above is 100℃-200℃.

[0021] In some embodiments of this application, the hot rolling time in step S4 above is 16-45 hours.

[0022] In some embodiments of this application, in step S5 above, the centrifugation parameters are a rotation speed of 10000 r / min and centrifugation at 25°C for 20 min.

[0023] In some embodiments of this application, in step S7 above, the XRD parameters are: diffraction wavelength λ = 0.154056 nm, operating voltage 40 kV, current 30 mA, and scanning angle 2θ = 3-40°.

[0024] In some embodiments of this application, the evaluation criteria for drilling fluid inhibition in step S7 are as follows: For sodium montmorillonite with a substrate spacing of less than 1.00 nm and 0 hydration layers (i.e., dry sodium montmorillonite), the surface hydration inhibition is evaluated as no hydration; for sodium montmorillonite with a substrate spacing of 1.00-1.30 nm and 1 hydration layer, the surface hydration inhibition is evaluated as good; for sodium montmorillonite with a substrate spacing of 1.30-1.50 nm and 2 hydration layers, the surface hydration inhibition is evaluated as good. The hydration inhibition evaluation was good; the surface hydration inhibition evaluation of sodium montmorillonite with a substrate spacing of 1.50-1.80 nm and 3 hydration layers was poor; the surface hydration inhibition evaluation of sodium montmorillonite with a substrate spacing of 1.80-2.00 nm and 4 hydration layers was poor; and the surface hydration inhibition evaluation of sodium montmorillonite with a substrate spacing greater than 2.00 nm and 5 or more hydration layers was non-inhibitory.

[0025] By controlling the amount of drilling fluid and sodium montmorillonite used, as well as the purity of the sodium montmorillonite, standardized starting conditions were provided for subsequent reactions. As a test subject, the interaction between drilling fluid and sodium montmorillonite is crucial for evaluating its hydration inhibition. Specific dosages and high-purity sodium montmorillonite ensure the consistency and repeatability of the reaction. Accelerating the reaction between drilling fluid and sodium montmorillonite by increasing temperature and extending reaction time simulates the actual working conditions of drilling fluid subjected to prolonged high temperatures downhole, allowing sufficient opportunities for components in the drilling fluid to undergo hydration inhibition-related reactions with sodium montmorillonite. Centrifugal force is used to separate adsorbed or bound substances from the sodium montmorillonite surface for accurate subsequent measurement of the lattice spacing. XRD technology, based on the interaction principle between X-rays and crystalline materials, determines the crystal structure and lattice spacing by measuring the position and intensity of diffraction peaks, thus reflecting the hydration state of sodium montmorillonite and evaluating the drilling fluid's ability to inhibit surface hydration. Strict control of parameters at each step, such as drilling fluid dosage, sodium montmorillonite purity, reaction temperature, time, centrifugation conditions, and XRD test parameters, improves the accuracy and reliability of test results, providing a scientific and effective means for drilling fluid research and development, quality control, and performance evaluation. Different evaluation criteria can clearly define the degree of surface hydration inhibition of drilling fluids, facilitating researchers and engineers to adjust and optimize drilling fluid formulations based on test results to meet the needs of different drilling projects and improve the safety and efficiency of drilling operations. Furthermore, this testing method has a certain degree of versatility and can be applied to the surface hydration inhibition testing of various types of drilling fluids, providing strong support for the development of drilling fluid technology.

[0026] Compared with the prior art, the embodiments of the present invention have at least the following advantages or beneficial effects:

[0027] 1. Since drilling fluid also contains solid phases (bentonite, barite, and sealing materials), if sodium montmorillonite is directly added in, it cannot be removed, thus solving the sodium montmorillonite separation problem.

[0028] 2. Existing inhibition tests are all conducted at room temperature, which solves the problem of evaluating inhibition under high temperature and high pressure.

[0029] 3. In the prior art, evaluation is done through filtrate, but the content of treatment agents in the filtrate is different from that in drilling fluid because mud cake will adsorb and retain some of it, so it is not accurate. The present invention uses nylon filter cloth, which is soft and does not form mud cake on its surface when rolling, thus making it more accurate.

[0030] 4. In the prior art, high-temperature and high-pressure filtration is performed first, and then the filtrate and montmorillonite are used for action. However, this application directly uses drilling fluid and montmorillonite for action, which reduces the high-temperature and high-pressure filtration steps and simplifies the process.

[0031] 5. Inhibition evaluation criteria were established. Attached Figure Description

[0032] To more clearly illustrate the technical solutions of the embodiments of the present invention, the accompanying drawings used in the embodiments will be briefly introduced below. It should be understood that the following drawings only show some embodiments of the present invention and should not be regarded as a limitation on the scope. For those skilled in the art, other related drawings can be obtained based on these drawings without creative effort.

[0033] Figure 1 A schematic diagram of a drilling fluid surface hydration inhibition testing device provided in this application.

[0034] Icons: 100 - Reaction vessel; 110 - Second magnetic block; 200 - Nylon filter cloth; 300 - First fixing frame; 310 - First magnetic block; 400 - Second fixing frame; 500 - Sodium montmorillonite. Detailed Implementation

[0035] To make the objectives, technical solutions, and advantages of the embodiments of this application clearer, the technical solutions in the embodiments of this application will be clearly and completely described below. Where specific conditions are not specified in the embodiments, conventional conditions or conditions recommended by the manufacturer shall apply. Reagents or instruments whose manufacturers are not specified are all conventional products that can be purchased commercially.

[0036] It should be noted that, unless otherwise specified, the embodiments and features described in this application can be combined with each other. The present application will now be described in detail with reference to specific embodiments.

[0037] The features and performance of this application will be further described in detail below with reference to the embodiments.

[0038] Example 1

[0039] Please refer to Figure 1 , Figure 1 The diagram shown is a structural schematic of an embodiment of this application.

[0040] This application provides a drilling fluid surface hydration inhibition testing device, including a reaction tank 100. The reaction tank 100 is provided with a nylon filter cloth 200, a first fixing frame 300 and a second fixing frame 400. One end of the nylon filter cloth 200 is detachably connected to the first fixing frame 300 and the other end is detachably connected to the second fixing frame 400. The first fixing frame 300 is detachably connected to the inner wall of the top of the reaction tank 100 and the second fixing frame 400 is detachably connected to the inner wall of the bottom of the reaction tank 100.

[0041] To achieve a detachable connection between the first fixing frame 300, the second fixing frame 400, and the reaction vessel 100, both the first fixing frame 300 and the second fixing frame 400 are embedded with a first magnetic block 310, and both the top inner wall and the bottom inner wall of the reaction vessel 100 are embedded with a second magnetic block 110. The first magnetic block 310 and the second magnetic block 110 have opposite magnetic poles. Utilizing the mutual attraction between the magnetic poles, the first fixing frame 300 is fixed to the top inner wall of the reaction vessel 100, and the second fixing frame 400 is fixed to the bottom inner wall of the reaction vessel 100. This magnetic fixing method does not require additional complex connecting components; the fixing frame can be stably fixed to the inner wall of the reaction vessel 100 solely by the magnetic force between the magnetic blocks. Compared with traditional fixing methods, magnetic fixing has the advantages of simple and quick operation, which can greatly shorten the assembly time of the device. At the same time, since no complex connecting structure is used, the internal space occupied by the device is reduced, making the internal space of the reaction vessel 100 more regular, which is beneficial for the layout of the nylon filter cloth 200 within the reaction vessel 100 and the flow of drilling fluid. Moreover, magnetic fixing allows for easy adjustment of the fixture position according to testing needs, enhancing the flexibility of the device. In addition, the magnetic blocks have a long service life and are not easily damaged, reducing the maintenance cost of the device.

[0042] To further define the type of reaction vessel 100, the aforementioned reaction vessel 100 is an aging vessel. Aging vessels typically possess good sealing performance, high-temperature and high-pressure resistance, and a certain degree of corrosion resistance. During the drilling fluid surface hydration inhibition test, the drilling fluid and sodium montmorillonite 500 within the nylon filter cloth 200 need to be placed in a specific temperature and pressure environment for aging treatment to simulate the actual long-term operation of the drilling fluid downhole. The aging vessel can withstand the high temperatures and pressures that may occur during the test, preventing drilling fluid leakage and ensuring the stability of the test environment. The material and structural characteristics of the aging vessel enable it to provide a stable and reliable reaction environment for the test, ensuring the accuracy and repeatability of the test results. Its good sealing performance effectively prevents drilling fluid evaporation or external impurities from entering the reaction system, avoiding interference with the test results. Its high-temperature and high-pressure resistance allows the device to adapt to a wide range of test temperature and pressure conditions, broadening its applicability. It can be used to simulate drilling fluid performance tests under different formation depths. Corrosion resistance extends the service life of the reaction vessel 100, reduces equipment replacement costs due to vessel corrosion, and improves the overall economy and durability of the device.

[0043] In order to connect and fix the nylon filter cloth 200, both the first fixing frame 300 and the second fixing frame 400 are provided with a clamping mechanism, which can realize the detachable fixing of both ends of the nylon filter cloth 200.

[0044] When using the aging tank, open it and fill it with drilling fluid. Place sodium montmorillonite 500 into the nylon filter cloth 200. Use the clamping mechanism to connect one end of the nylon filter cloth 200 to the first fixing frame 300 and the other end to the second fixing frame 400. Attach the first fixing frame 300 to the inner wall of the top of the aging tank using the first magnetic block 310 and the second magnetic block 110. Attach the second fixing frame 400 to the inner wall of the bottom of the aging tank to complete the fixation of the nylon filter cloth 200 in the aging tank. After closing the aging tank, the experiment can begin.

[0045] Example 2

[0046] This embodiment 2 provides a method for testing the surface hydration inhibition of drilling fluid using a device, including the following steps:

[0047] S1. Fill the aging tank with 400mL of drilling fluid. The drilling fluid is a potassium-based polysulfonate drilling fluid system, which consists of 2% bentonite + 3% sulfonated lignite + 3% sulfonated resin + 7% potassium chloride + 2% sulfonated pitch + 0.2% NaOH + 45% barite. 8g of sodium montmorillonite 500g is placed in a 200g nylon filter cloth.

[0048] S2. Fix both ends of the nylon filter cloth 200 using the first fixing bracket 300 and the second fixing bracket 400.

[0049] S3. Fix the second fixing bracket 400 to the bottom inner wall of the aging tank, and fix the first fixing bracket 300 to the top inner wall of the aging tank.

[0050] S4. Raise the temperature of the roller furnace to 150℃, place it in the aging tank for hot rolling for 16 hours, and keep the roller furnace speed at 50r / min.

[0051] S5. After the hot rolling is complete, cool and open the can, remove 200g of nylon filter cloth and 500g of sodium montmorillonite, and place them in a centrifuge. Set the speed to 10000r / min and centrifuge at 25℃ for 20min.

[0052] S6. After centrifugation, pour out the upper liquid and collect 500g of sodium montmorillonite after centrifugation.

[0053] S7. Using XRD, with parameters set as follows: diffraction wavelength λ = 0.154056 nm, working voltage 40 kV, current 30 mA, and scanning angle 2θ = 3-40°, the substrate spacing of the centrifuged sodium montmorillonite 500 was measured. The inhibition of the drilling fluid was evaluated based on the substrate spacing. The evaluation method is shown in Table 1.

[0054] Table 1

[0055] Less than 1.00nm dry montmorillonite Anhydrous 1.00~1.30nm 1 layer of hydrated montmorillonite Good inhibitory properties 1.30~1.50nm Two layers of hydrated montmorillonite Inhibitors are better 1.50~1.80nm 3-layer hydrated montmorillonite Poor inhibition 1.80~2.00nm 4 layers of hydrated montmorillonite Poor inhibition Greater than 2.00nm 5 or more layers of hydrated montmorillonite Non-inhibitory

[0056] In this embodiment, the inter-basin spacing of sodium montmorillonite 500 was measured to be 1.45 nm by XRD. According to Table 1, the potassium-based polysulfonate drilling fluid system has good drilling fluid inhibition properties.

[0057] Comparative Example 1

[0058] Comparative Example 1 uses conventional methods in the prior art to evaluate the inhibition properties of the potassium-based polysulfonate drilling fluid system. The specific steps are as follows:

[0059] (1) Core preparation: Bentonite was placed in an oven and dried at 105℃ (error controlled within ±3℃) for 4 hours. 10.00g of dried bentonite was weighed and put into the measuring cylinder of the shale dilatometer. After being pressed at 4.0MPa for 5 minutes, the core required for determining the linear expansion rate was obtained, and the core height ΔL was recorded.

[0060] (2) Sample solution preparation: Add 3.00g of different inhibitors to three 300mL distilled waters respectively, and stir for 20min to completely dissolve them.

[0061] (3) After installing the core-filled measuring cylinder on the shale expansion instrument, add the sample solutions to the measuring cylinder and record the initial reading R0 and the readings R after different times. X Meanwhile, a blank test was conducted using distilled water.

[0062] According to standard SY / T6335-1997, the linear swelling rate of the non-toxic inhibitor was evaluated. The formula for calculating the linear swelling rate is shown in Equation 1:

[0063] In the formula, Sr is the linear swelling rate of bentonite; ΔR is the swelling amount of bentonite, which is determined by (R... X -R0) is obtained, mm; ΔL is the core height, mm.

[0064] According to Formula 1, the Sr content of the potassium-based polysulfonate drilling fluid system is 12%, and the inhibition evaluation is excellent. According to the results, the evaluation results in Comparative Example 1 are consistent with the results in Example 2, which proves the feasibility and accuracy of the evaluation method in Example 2.

[0065] Comparative Example 2

[0066] Comparative Example 2 is basically the same as Example 2, except that the sodium montmorillonite 500 was not placed in the nylon filter cloth 200, but was directly placed in the aging tank to contact the drilling fluid system. After the experiment, the XRD measured the substrate spacing to be 1.67 nm, and the inhibition evaluation was poor. As can be seen from the results, the results in Comparative Example 2 are inconsistent with the results in Example 2 and Comparative Example 1. This is because when sodium montmorillonite 500 reacts with the drilling fluid, the solid components in the drilling fluid also come into contact with sodium montmorillonite 500. Although the solid components do not affect surface hydration, the solid components remaining on the sodium montmorillonite 500 during XRD substrate detection interfere with the results, causing inaccurate results. Separating the solid components from sodium montmorillonite 500 is difficult and also difficult to completely separate. Therefore, even if separation treatment is performed, the obtained substrate detection results are still inaccurate, thus causing inaccurate evaluation results.

[0067] Example 3

[0068] This embodiment 3 provides a method for testing the surface hydration inhibition of drilling fluid using a device, including the following steps:

[0069] S1. Fill the aging tank with 400mL of drilling fluid. The drilling fluid is a polymer drilling fluid system, which consists of 3% bentonite + 0.2% cationic polyacrylamide + 0.3% polyanionic cellulose + 0.1% xanthan gum + 0.5% polyamine inhibitor + 30% barite. 8g of sodium montmorillonite 500 is placed in the nylon filter cloth 200.

[0070] S2. Fix both ends of the nylon filter cloth 200 using the first fixing bracket 300 and the second fixing bracket 400.

[0071] S3. Fix the second fixing bracket 400 to the bottom inner wall of the aging tank, and fix the first fixing bracket 300 to the top inner wall of the aging tank.

[0072] S4. Raise the temperature of the roller furnace to 100℃, place it in the aging tank for hot rolling for 16 hours, and keep the roller furnace speed at 50r / min.

[0073] S5. After the hot rolling is complete, cool and open the can, remove 200g of nylon filter cloth and 500g of sodium montmorillonite, and place them in a centrifuge. Set the speed to 10000r / min and centrifuge at 25℃ for 20min.

[0074] S6. After centrifugation, pour out the upper liquid and collect 500g of sodium montmorillonite after centrifugation.

[0075] S7. Using XRD, with parameters set as follows: diffraction wavelength λ = 0.154056 nm, working voltage 40 kV, current 30 mA, and scanning angle 2θ = 3-40°, the substrate spacing of the centrifuged sodium montmorillonite 500 was measured. The inhibition of the drilling fluid was evaluated based on the substrate spacing. The evaluation method is shown in Table 1.

[0076] Table 1

[0077] Less than 1.00nm dry montmorillonite Anhydrous 1.00~1.30nm 1 layer of hydrated montmorillonite Good inhibitory properties 1.30~1.50nm Two layers of hydrated montmorillonite Inhibitors are better 1.50~1.80nm 3-layer hydrated montmorillonite Poor inhibition 1.80~2.00nm 4 layers of hydrated montmorillonite Poor inhibition Greater than 2.00nm 5 or more layers of hydrated montmorillonite Non-inhibitory

[0078] In this embodiment, the intersubstrate spacing of sodium montmorillonite 500 was measured to be 1.55 nm by XRD. According to Table 1, the surface hydration inhibition of the polymer drilling fluid system is poor.

[0079] Comparative Example 3

[0080] Comparative Example 3 uses conventional methods in the prior art to evaluate the inhibition of the polymer drilling fluid system, specifically by using a rolling recovery test.

[0081] In this experiment, the rolling recovery rate of shale in the polymer drilling fluid system (120℃, 16h) was used as the evaluation index. The specific test steps are as follows:

[0082] (1) The collected drill cuttings were sieved using a double-layer sieve with aperture side lengths of 3.27 mm and 2.0 mm, and the cuttings that passed through the sieve with an aperture side length of 3.2 mm were collected.

[0083] (2) Take 50.0g (accurate to 0.1g) of the prepared drill cuttings, put them into a high-temperature container containing 350mL of evaluation solution, and seal it tightly.

[0084] (3) Place the high-temperature container containing the sample into a drilling fluid roller furnace at 120℃±3℃ and roll it for 16 hours.

[0085] (4) After constant temperature rolling for 16 hours, remove the high-temperature container and cool it to room temperature. Pour all the liquid and rock sample in the container onto a sieve with a perforation side length of 0.42 mm, and wet-wash it in a tank of tap water for 1.0 min.

[0086] (5) Place the sieved rock sample in a forced-air constant temperature drying oven at 105℃±3℃ and dry for 4 hours. Remove and cool, and let stand in the air for 24 hours. Then weigh (accurate to 0.1g) and calculate the single rolling recovery rate (R).

[0087] The rolling recovery rate R was 95% obtained from the above experimental steps, and the inhibition evaluation was excellent. The results show that the evaluation results of Comparative Example 3 and Example 3 are inconsistent.

[0088] Comparative Example 4

[0089] Comparative Example 4 is basically the same as Comparative Example 1, except that the drilling fluid system is a polymer drilling fluid system. According to Formula 1, the Sr of the polymer drilling fluid system is 31%, indicating poor inhibition, which is consistent with the results in Example 3. However, it is inconsistent with the results of the rolling recovery experiment in Comparative Example 3. This is because the clay hydration process is due to the expansion of the crystal layer after the clay absorbs water. When the expansion reaches a certain extent, dispersion will occur. The rolling recovery rate mainly evaluates the dispersion ability. However, when the clay absorbs water and expands, dispersion has not yet occurred. The rolling recovery rate test will consider the inhibition to be good, which is obviously inconsistent with the facts. In actual use, this drilling fluid system is difficult to achieve the technical effect evaluated in Comparative Example 3. Therefore, by combining Example 3, Comparative Example 3 and Comparative Example 4, it can be concluded that the evaluation results of rolling recovery are not accurate.

[0090] Example 4

[0091] This embodiment 4 provides a method for testing the surface hydration inhibition of drilling fluid using a device, including the following steps:

[0092] S1. Fill the aging tank with 400mL of drilling fluid. The drilling fluid is a common high-content drilling fluid, which is composed of 10% bentonite + 0.2% sodium hydroxide + 0.1% xanthan gum. 8g of sodium montmorillonite 500 is placed in the 200mm nylon filter cloth.

[0093] S2. Fix both ends of the nylon filter cloth 200 using the first fixing bracket 300 and the second fixing bracket 400.

[0094] S3. Fix the second fixing bracket 400 to the bottom inner wall of the aging tank, and fix the first fixing bracket 300 to the top inner wall of the aging tank.

[0095] S4. Raise the temperature of the roller furnace to 230℃, place it in the aging tank for hot rolling for 48 hours, and rotate the roller furnace at 50r / min.

[0096] S5. After the hot rolling is complete, cool and open the can, remove 200g of nylon filter cloth and 500g of sodium montmorillonite, and place them in a centrifuge. Set the speed to 10000r / min and centrifuge at 25℃ for 20min.

[0097] S6. After centrifugation, pour out the upper liquid and collect 500g of sodium montmorillonite after centrifugation.

[0098] S7. Using XRD, with parameters set as follows: diffraction wavelength λ = 0.154056 nm, working voltage 40 kV, current 30 mA, and scanning angle 2θ = 3-40°, the substrate spacing of the centrifuged sodium montmorillonite 500 was measured. The inhibition of the drilling fluid was evaluated based on the substrate spacing. The evaluation method is shown in Table 1.

[0099] Table 1

[0100] Less than 1.00nm Dry montmorillonite Anhydrous 1.00~1.30nm 1 layer of hydrated montmorillonite Good inhibitory properties 1.30~1.50nm Two layers of hydrated montmorillonite Inhibitors are better 1.50~1.80nm 3-layer hydrated montmorillonite Poor inhibition 1.80~2.00nm 4 layers of hydrated montmorillonite Poor inhibition Greater than 2.00nm 5 or more layers of hydrated montmorillonite Non-inhibitory

[0101] In this embodiment, the interfacial spacing of sodium montmorillonite 500 was measured to be 2.01 nm by XRD. According to Table 1, the surface hydration of ordinary high-content drilling fluid is not inhibited.

[0102] Comparative Example 5

[0103] Comparative Example 5 is basically the same as Comparative Example 1, except that the drilling fluid system is ordinary high-clay drilling fluid. After the experiment, according to Equation 1, the Sr of the ordinary high-clay drilling fluid is 55%, indicating poor or no inhibition. Since there is no clear evaluation standard, the strength of inhibition can only be roughly estimated from the Sr value. Through this value, it can be inferred that the drilling fluid system has poor or no inhibition, which is consistent with the results of Example 4. This further demonstrates the feasibility and accuracy of the evaluation method in Example 4. However, since this application clarifies the inhibition evaluation standard, it can more accurately determine that the drilling fluid system has no inhibition, rather than the experimental conclusion of poor or no inhibition that could not be determined in Comparative Example 5. Therefore, the evaluation effect of this application is more accurate and reliable, and provides an evaluation standard to facilitate construction personnel to accurately determine the inhibition effect based on the site conditions, and to determine the selection and dosage of inhibitors.

[0104] The embodiments described above are some, but not all, embodiments of the present invention. The detailed description of the embodiments of the present invention is not intended to limit the scope of the claimed invention, but merely to illustrate selected embodiments. All other embodiments obtained by those skilled in the art based on the embodiments of the present invention without inventive effort are within the scope of protection of the present invention.

Claims

1. A method for testing the surface hydration inhibition of drilling fluid, characterized in that, The test was conducted using a drilling fluid surface hydration inhibition testing device. The device includes a reaction vessel containing a nylon filter cloth, a first fixing frame, and a second fixing frame. One end of the nylon filter cloth is detachably connected to the first fixing frame, and the other end is detachably connected to the second fixing frame. The first fixing frame is detachably connected to the inner wall of the top of the reaction vessel, and the second fixing frame is detachably connected to the inner wall of the bottom of the reaction vessel. The nylon filter cloth has a mesh size greater than 80,000 mesh. The reaction vessel is an aging vessel. The testing method includes the following steps: S1. Fill the aging tank with 400 mL of drilling fluid, and fill the nylon filter cloth with high-purity sodium montmorillonite, which has a purity greater than 99%. S2. Fix both ends of the nylon filter cloth using the first fixing bracket and the second fixing bracket; S3. Fix the second fixing bracket to the bottom inner wall of the aging tank, and fix the first fixing bracket to the top inner wall of the aging tank; S4. Raise the temperature of the roller furnace to the specified temperature, place it in the aging tank and heat-roll it; S5. After the hot rolling is completed, cool and open the can, take out the nylon filter cloth and the sodium montmorillonite, and put them into a centrifuge for centrifugation; S6. After centrifugation, pour out the upper liquid and collect the sodium montmorillonite after centrifugation. S7. Using XRD, the interbase spacing of the centrifuged sodium montmorillonite was tested, and the inhibition of the drilling fluid was evaluated by the interbase spacing.

2. The method according to claim 1, characterized in that, Both the first and second fixing frames are equipped with a first magnetic block, and the top and bottom inner walls of the reaction vessel are equipped with a second magnetic block. The first and second magnetic blocks have opposite magnetic poles.

3. The method according to claim 1, characterized in that, In step S4, the specified temperature is 25℃-230℃, the hot rolling time is 12-48h, and the roller furnace speed is 50r / min.

4. The method according to claim 1, characterized in that, In step S4, the specified temperature is 100℃-200℃.

5. The method according to claim 1, characterized in that, In step S5, the centrifugation parameters are a rotation speed of 10000 r / min and centrifugation at 25°C for 20 min.

6. The method according to claim 1, characterized in that, In step S7, the evaluation criteria for drilling fluid inhibition are as follows: Sodium montmorillonite with a substrate spacing of less than 1.00 nm and 0 hydration layers (i.e., dry sodium montmorillonite) is evaluated as having no hydration when its surface hydration inhibition is assessed. Sodium montmorillonite with a substrate spacing of 1.00-1.30 nm and 1 hydration layer is evaluated as having good surface hydration inhibition. Sodium montmorillonite with a substrate spacing of 1.30-1.50 nm and two hydrated layers was evaluated as having good surface hydration inhibition. Sodium montmorillonite with a substrate spacing of 1.50-1.80 nm and 3 hydration layers was evaluated as having poor surface hydration inhibition. Sodium montmorillonite with a substrate spacing of 1.80-2.00 nm and 4 hydrated layers was evaluated as having poor surface hydration inhibition. Sodium montmorillonite with a substrate spacing greater than 2.00 nm and more than 5 hydration layers was evaluated as having no surface hydration inhibition.

Images