Drilling fluid surface hydration inhibition testing device and method

Abstract

The invention relates to the technical field of surface hydration inhibition testing, and provides a drilling fluid surface hydration inhibition testing device and method.The device comprises a reaction tank, 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, and the other end of the nylon filter cloth is detachably connected with the second fixing frame; one end of the first fixing frame is detachably connected with the bottom of the reaction tank, the other end of the first fixing frame is detachably connected with the second fixing frame, the first fixing frame is detachably connected with the inner wall of the top of the reaction tank, and the second fixing frame is detachably connected with the inner wall of the bottom of the reaction tank. And the method is suitable for testing the surface hydration inhibition of various water-based drilling fluids, and provides powerful support for the development of a drilling fluid technology.

Description

Technical Field

[0001] The present invention relates to the technical field of surface hydration inhibition testing, and more particularly, to a device and method for testing the surface hydration inhibition of drilling fluids. Background Art

[0002] When a drilling fluid contacts clay minerals, the clay minerals will undergo a hydration process. For example, montmorillonite clay minerals have a large number of exchangeable cations in their crystal structures, and these cations will attract water molecules, causing the volume of the clay minerals to expand. This expansion may lead to instability of the wellbore, resulting in complex situations such as wellbore collapse and hole shrinkage, increasing the drilling risk and cost.

[0003] Currently, it is impossible to test the surface hydration inhibition performance of drilling fluids, mainly because surface hydration is too microscopic. It is necessary to use the drilling fluid to treat montmorillonite and then test the microscopic properties of the montmorillonite (such as the basal spacing). The problem is that it is impossible to directly put sodium montmorillonite into the drilling fluid because there are also solids such as bentonite and barite in the drilling fluid, so it is impossible to separate pure sodium montmorillonite. As a result, it is impossible to analyze the surface hydration inhibition of the drilling fluid. Summary of the Invention

[0004] An object of the present application is to provide a device for testing the surface hydration inhibition of drilling fluids, which can simulate the test environment of the interaction between the drilling fluid and formation clay minerals, providing a basic condition for accurately evaluating the surface hydration inhibition of the drilling fluid.

[0005] Another object of the present application is to provide a method for testing the surface hydration inhibition of a device for testing the surface hydration inhibition of drilling fluids, which can form surface hydration of sodium montmorillonite to evaluate the surface hydration inhibition performance of the drilling fluid. Different evaluation criteria can clearly define the quality of the surface hydration inhibition of the drilling fluid, facilitating researchers and engineering technicians to adjust and optimize the drilling fluid formula according to the test results to meet the requirements of different drilling projects, improving the safety and efficiency of drilling operations. At the same time, this test method has a certain generality 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 technical problems, the technical solution adopted in the present application is as follows:

[0007] On the one hand, an embodiment of the present application provides a device for testing the surface hydration inhibition of drilling fluids, including a reaction tank. Inside the reaction tank, there are 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 tank, and the second fixing frame is detachably connected to the inner wall of the bottom of the reaction tank.

[0008] A reaction tank is provided, and a nylon filter cloth, a first fixing frame and a second fixing frame are arranged in the reaction tank. The property of the nylon filter cloth that can selectively transmit substances is utilized to allow the sodium montmorillonite in the nylon filter cloth to exchange substances or interact with the drilling fluid in the reaction tank under certain conditions, thereby simulating the hydration inhibition of clay minerals (taking sodium montmorillonite as an example) in the formation by the drilling fluid under actual working conditions. The nylon filter cloth can be conveniently installed and removed in structure, and at the same time, the nylon filter cloth is ensured to be in a stable position in the reaction tank, ensuring sufficient contact and reaction between the nylon filter cloth and the drilling fluid during the test. A test environment simulating the interaction between the drilling fluid and the clay minerals in the formation can be effectively constructed, which provides basic conditions for accurately evaluating the surface hydration inhibition of the drilling fluid. The detachable connection method is convenient for assembly, cleaning and maintenance of the device, thereby improving the practicality and operability of the device.

[0009] The present application creatively adopts nylon filter cloth, which can reach tens of thousands of meshes and nanometer pores. It is also more temperature-resistant (nylon material generally has a minimum temperature resistance of 120°C and a maximum temperature of 250°C), solving the problem that the prior art can only react at room temperature. The present application can realize inhibitory evaluation under high temperature and high pressure.

[0010] Since the only effect of drilling fluid on montmorillonite is the liquid phase components in the drilling fluid, the solid phase has no effect. However, the existing technology cannot separate pure sodium montmorillonite, and the excess solid phase components will hinder the substrate detection, resulting in inaccurate test results. Therefore, the present application creatively uses nylon filter cloth to wrap the sodium montmorillonite and isolate the solid phase in the drilling fluid, so that the liquid phase components enter the nylon filter cloth and react with the sodium montmorillonite, thereby truly restoring the environment of the sodium montmorillonite in the drilling fluid and realizing the separation of the sodium montmorillonite. In the subsequent substrate detection, the problem of the influence of the solid phase components on the detection effect is solved, and the real environment is simulated while making the results more accurate and reliable.

[0011] In some embodiments of the present application, the mesh number of the nylon filter cloth is greater than 80,000 mesh (0.1 micron).

[0012] In some embodiments of the present application, the above-mentioned first fixing frame and the second fixing frame are both embedded with first magnetic blocks, and the inner walls of the top and bottom of the reaction tank are both embedded with second magnetic blocks. The first magnetic blocks and the second magnetic blocks have opposite magnetic poles. By using the mutual attraction between magnetic poles, the fixed connection between the first fixing frame and the inner wall of the top of the reaction tank, and between the second fixing frame and the inner wall of the bottom of the reaction tank is realized. This magnetic fixing method does not require additional complex connecting components. Only relying on the magnetic force between the magnetic blocks can the fixing frame be stably fixed on the inner wall of the reaction tank. Compared with the traditional fixing method, the magnetic fixing has the advantages of simple and fast operation, which can greatly shorten the assembly time of the device. At the same time, since no complex connection structure is used, the space occupied inside the device is reduced, making the internal space of the reaction tank more regular, which is beneficial to the layout of the nylon filter cloth in the reaction tank and the flow of the drilling fluid. Moreover, the magnetic fixing is convenient for adjusting the position of the fixing frame at any time according to the test requirements, 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.

[0013] In some embodiments of the present application, the above-mentioned reaction tank is an aging tank, and the aging tank usually has good sealing performance, high temperature and high pressure resistance performance, and certain corrosion resistance. During the test of the surface hydration inhibition performance of the drilling fluid, it is necessary to place the sodium montmorillonite in the drilling fluid and the nylon filter cloth in a specific temperature and pressure environment for aging treatment to simulate the actual situation of the drilling fluid working underground for a long time. The aging tank can withstand the high temperature and certain pressure that may be generated during the test, prevent the leakage of the drilling fluid, and ensure the stability of the test environment. The material and structural characteristics of the aging tank 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 can effectively prevent the volatilization of the drilling fluid or the entry of external impurities into the reaction system, avoiding interference with the test results. The high temperature and high pressure resistance performance enables the device to adapt to a wide range of test temperature and pressure conditions, broadening the application range of the device, and it can be used to simulate the performance test of the drilling fluid under different depth formation conditions. The corrosion resistance extends the service life of the reaction tank, reduces the equipment replacement cost caused by the corrosion of the tank body, and improves the overall economy and durability of the device.

[0014] In some embodiments of the present application, the above-mentioned first fixing frame and the second fixing frame are both provided with clamping mechanisms, and the two ends of the nylon filter cloth are clamped through the clamping mechanisms to complete detachable fixing.

[0015] It should be noted that the above-mentioned clamping mechanism is a common structure in the art, and it only needs to meet the fixing effect on the nylon filter cloth, and is not limited herein.

[0016] On the other hand, an embodiment of the present application provides a method for testing the surface hydration inhibition of drilling fluid, which includes the following steps: S1. Fill 400 mL of drilling fluid into the aging tank, and load sodium montmorillonite into the nylon filter cloth; S2. Fix both ends of the nylon filter cloth with the first fixing frame and the second fixing frame; S3. Fix the second fixing frame on the inner wall of the bottom of the aging tank, and fix the first fixing frame on the inner wall of the top of the aging tank; S4. Raise the temperature of the roller furnace to the specified temperature, put the aging tank in and perform hot rolling; S5. After the hot rolling is completed, cool and open the tank, take out the nylon filter cloth, and take out the sodium montmorillonite, and place it in a centrifuge for centrifugation; S6. After centrifugation, pour out the upper liquid, collect the centrifuged sodium montmorillonite; S7. Use XRD to test the basal spacing of the centrifuged sodium montmorillonite, and evaluate the inhibition of the drilling fluid through the basal spacing.

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

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

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

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

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

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

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

[0024] In some embodiments of the present application, in the above step S7, the evaluation criteria for the inhibition of the drilling fluid are as follows: the basal spacing of sodium montmorillonite is less than 1.00 nm, and the number of hydration layers is 0, that is, dry sodium montmorillonite, and the surface hydration inhibition is evaluated as anhydrous; the basal spacing of sodium montmorillonite is 1.00 - 1.30 nm, and the number of hydration layers is 1 layer of hydrated sodium montmorillonite, and the surface hydration inhibition is evaluated as having good inhibition; the basal spacing of sodium montmorillonite is 1.30 - 1.50 nm, and the number of hydration layers is 2 layers of hydrated sodium montmorillonite, and the surface hydration inhibition is evaluated as having relatively good inhibition; the basal spacing of sodium montmorillonite is 1.50 - 1.80 nm, and the number of hydration layers is 3 layers of hydrated sodium montmorillonite, and the surface hydration inhibition is evaluated as having relatively poor inhibition; the basal spacing of sodium montmorillonite is 1.80 - 2.00 nm, and the number of hydration layers is 4 layers of hydrated sodium montmorillonite, and the surface hydration inhibition is evaluated as having poor inhibition; the basal spacing of sodium montmorillonite is greater than 2.00 nm, and the number of hydration layers is more than 5 layers of hydrated sodium montmorillonite, and the surface hydration inhibition is evaluated as having no inhibition.

[0025] By controlling the dosages of the drilling fluid and sodium montmorillonite as well as the purity of sodium montmorillonite, standardized starting conditions are provided for subsequent reactions. The drilling fluid is used as the test object, and its interaction with sodium montmorillonite is the key to evaluating its hydration inhibition. Specific dosages and high-purity sodium montmorillonite can ensure the consistency and repeatability of the reaction. By increasing the temperature and prolonging the time, the reaction between the drilling fluid and sodium montmorillonite is accelerated to simulate the actual working condition of the drilling fluid being subjected to high temperature for a long time underground, so that the components in the drilling fluid have sufficient opportunities to react with sodium montmorillonite related to hydration inhibition. The substances adsorbed or bound on the surface of sodium montmorillonite are separated by centrifugal force to accurately measure the basal spacing of sodium montmorillonite subsequently. The XRD technology is based on the principle of the interaction between X-rays and crystalline substances, and determines the crystal structure and lattice spacing by measuring the position and intensity of diffraction peaks, thereby reflecting the hydration state of sodium montmorillonite and then evaluating the inhibition ability of the drilling fluid on its surface hydration. By strictly controlling the parameters of each step, such as the dosage of the drilling fluid, the purity of sodium montmorillonite, the reaction temperature, time, centrifugation conditions, and XRD test parameters, etc., the accuracy and reliability of the test results can be improved, providing a scientific and effective means for the research and development, quality control, and performance evaluation of the drilling fluid. Different evaluation criteria can clearly define the quality of the surface hydration inhibition of the drilling fluid, facilitating researchers and engineering technicians to adjust and optimize the drilling fluid formula according to the test results to meet the requirements of different drilling projects and improve the safety and efficiency of drilling operations. At the same time, this test method has a certain generality and can be applied to the surface hydration inhibition tests 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 there are also solids (bentonite, barite, plugging materials) in the drilling fluid, if montmorillonite is directly put in, it cannot be taken out, thus solving the problem of montmorillonite separation.

[0028] 2. In the prior art, the inhibition tests are all carried out at room temperature, and the present invention solves the problem of inhibition evaluation under high temperature and high pressure.

[0029] 3. In the prior art, the evaluation is carried out through the filtrate, but the content of treatment agents in the filtrate is different from that in the drilling fluid. Because the filter cake will adsorb and intercept a part, it is inaccurate. The present invention uses a nylon filter cloth. The nylon filter cloth is soft and in a rolling state, and no filter cake will be formed on the surface of the nylon filter cloth, so it is more accurate.

[0030] 4. In the prior art, high temperature and high pressure filtration loss is first carried out, and then the filtrate acts on the montmorillonite, while in this application, the drilling fluid directly acts on the montmorillonite, reducing the step of high temperature and high pressure filtration loss and being more simplified.

[0031] 5. An inhibition evaluation standard is formulated. BRIEF DESCRIPTION OF THE DRAWINGS

[0032] In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the following will briefly introduce the drawings required to be used in the embodiments. It should be understood that the following drawings only show some embodiments of the present invention, and therefore should not be regarded as limiting the scope. For those of ordinary skill in the art, other related drawings can be obtained based on these drawings without creative efforts.

[0033] Figure 1 It is a schematic structural diagram of a device for testing the surface hydration inhibition of a drilling fluid provided by this application.

[0034] Reference numerals: 100 - reaction tank; 110 - second magnetic block; 200 - nylon filter cloth; 300 - first fixing frame; 310 - first magnetic block; 400 - second fixing frame; 500 - sodium montmorillonite. DETAILED DESCRIPTION OF THE EMBODIMENTS

[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. For those conditions not specified in the embodiments, they are carried out according to conventional conditions or the conditions recommended by the manufacturer. For the reagents or instruments not specified by the manufacturer, they are all conventional products that can be obtained through commercial purchase.

[0036] It should be noted that, without conflict, the embodiments in this application and the features in the embodiments can be combined with each other. The following will refer to specific embodiments to detail this application.

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

[0038] Embodiment 1

[0039] Please refer to Figure 1 , Figure 1 which shows the structural schematic diagram of the embodiment of the present application.

[0040] The present application provides a device for testing the surface hydration inhibition of drilling fluid, including a reaction tank 100. Inside the reaction tank 100, there are 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 the detachable connection between the first fixing frame 300, the second fixing frame 400, and the reaction tank 100, the above-mentioned first fixing frame 300 and second fixing frame 400 are both embedded with first magnetic blocks 310, and the inner walls of the top and bottom of the reaction tank 100 are both embedded with second magnetic blocks 110. The first magnetic blocks 310 and the second magnetic blocks 110 have opposite magnetic poles. By using the mutual attraction between the magnetic poles, the fixed connection between the first fixing frame 300 and the inner wall of the top of the reaction tank 100, and the second fixing frame 400 and the inner wall of the bottom of the reaction tank 100 is realized. This magnetic force fixing method does not require additional complex connection components. Only relying on the magnetic force between the magnetic blocks can the fixing frame be stably fixed on the inner wall of the reaction tank 100. Compared with the traditional fixing method, the magnetic force fixing has the advantages of simple and fast operation, which can greatly shorten the assembly time of the device. At the same time, since no complex connection structure is used, the space occupied inside the device is reduced, making the internal space of the reaction tank 100 more regular, which is beneficial to the layout of the nylon filter cloth 200 in the reaction tank 100 and the flow of the drilling fluid. Moreover, the magnetic force fixing is convenient for adjusting the position of the fixing frame at any time according to the test requirements, 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 the reaction tank 100, the above-mentioned reaction tank 100 is an aging tank, which usually has good sealing performance, high temperature and high pressure resistance performance, and certain corrosion resistance. During the test of the surface hydration inhibition performance of the drilling fluid, it is necessary to place the drilling fluid and the sodium montmorillonite 500 in the nylon filter cloth 200 under a specific temperature and pressure environment for aging treatment to simulate the actual situation of the drilling fluid working underground for a long time. The aging tank can withstand the high temperature and certain pressure that may be generated during the test, prevent the leakage of the drilling fluid, and ensure the stability of the test environment. The material and structural characteristics of the aging tank enable it to provide a stable and reliable reaction environment for the test, guarantee the accuracy and repeatability of the test results. Its good sealing performance can effectively prevent the volatilization of the drilling fluid or the entry of external impurities into the reaction system, avoiding interference with the test results. The high temperature and high pressure resistance performance enables the device to adapt to a wide range of test temperature and pressure conditions, broadening the application range of the device, and it can be used for simulating the performance test of the drilling fluid under different deep formation conditions. The corrosion resistance extends the service life of the reaction tank 100, reduces the equipment replacement cost caused by the corrosion of the tank body, and improves the overall economy and durability of the device.

[0043] To achieve the connection and fixation of the nylon filter cloth 200, the above-mentioned first fixing frame 300 and second fixing frame 400 are both provided with clamping mechanisms, and the clamping mechanisms can achieve the detachable fixation of both ends of the nylon filter cloth 200.

[0044] During use, open the aging tank, fill it with the drilling fluid, put the 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. Adsorb the first fixing frame 300 on the inner wall of the top of the aging tank through the first magnet 310 and the second magnet 110, and adsorb the second fixing frame 400 on 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 be started.

[0045] Embodiment 2

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

[0047] S1. Fill 400 mL of the drilling fluid in the aging tank. 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 asphalt + 0.2% NaOH + 45% barite. Load 8 g of sodium montmorillonite 500 into the nylon filter cloth 200.

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

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

[0050] S4. Raise the temperature of the roller furnace to 150 °C, put it into the aging tank for hot rolling for 16 h, and the rotation speed of the roller furnace is 50 r / min.

[0051] S5. After the hot rolling is completed, cool and open the tank, take out the nylon filter cloth 200, and take out the sodium montmorillonite 500, and place it in a centrifuge. Set the rotation speed to 10000 r / min and centrifuge at 25 °C for 20 min.

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

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

[0054] Table 1

[0055] Base spacing Number of hydration layers Evaluation of surface hydration inhibition Less than 1.00 nm Dry montmorillonite No hydration 1.00 - 1.30 nm Montmorillonite with 1 - layer hydration Good inhibition 1.30 - 1.50 nm Montmorillonite with 2 - layer hydration Better inhibitor 1.50 - 1.80 nm Montmorillonite with 3 - layer hydration Poorer inhibition 1.80 - 2.00 nm Montmorillonite with 4 - layer hydration Poor inhibition Greater than 2.00 nm Montmorillonite with 5 or more layers of hydration No inhibition

[0056] In this embodiment, the basal spacing of the sodium montmorillonite 500 measured by XRD is 1.45 nm. Referring to Table 1, it is concluded that the potassium-based polysulfonate drilling fluid system has good inhibition of the drilling fluid.

[0057] Comparative Example 1

[0058] In this Comparative Example 1, the inhibition of the potassium-based polysulfonate drilling fluid system was evaluated using a conventional method in the prior art. The specific method is as follows:

[0059] (1) Core preparation: Place the bentonite in an oven and dry it at 105 °C (with an error controlled within ±3 °C) for 4 h. Weigh 10.00 g of the dried bentonite and put it into the measuring cylinder of the shale dilatometer. After maintaining a pressure of 4.0 MPa on a press for 5 min, obtain the core required for measuring the linear expansion rate, and record the core height ΔL;

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

[0061] (3) After installing the measuring cylinder with the core on the shale dilatometer, add each sample solution to the measuring cylinder and record the initial reading R 0 and the readings R X at different times, and at the same time conduct a blank test with distilled water.

[0062] According to the standard "SY / T6335 - 1997", the linear expansion rates of different inhibitors were evaluated. The calculation formula for the linear expansion rate is shown in Equation 1:

[0063] In the formula, Sr is the linear expansion rate of bentonite; ΔR is the expansion amount of bentonite, obtained from (R X - R 0 ), in mm; ΔL is the core height, in mm.

[0064] According to Equation 1, the Sr of the potassium - based polysulfonate drilling fluid system is 12%, and the inhibition evaluation is excellent. From the results, it can be seen that the evaluation results in Comparative Example 1 are consistent with those in Example 2, which proves the feasibility and accuracy of the evaluation method in Example 2.

[0065] Comparative Example 2

[0066] This Comparative Example 2 is basically the same as Example 2. The difference is that 500 sodium montmorillonite is not placed in the nylon filter cloth 200, but is directly put into the aging tank to contact the drilling fluid system. After the experiment, the basal spacing measured by XRD is 1.67 nm, and the inhibition evaluation is poor. From the results, it can be seen that the results in Comparative Example 2 are inconsistent with those in Example 2 and Comparative Example 1. This is because when 500 sodium montmorillonite acts with the drilling fluid, the solid components in the drilling fluid also contact 500 sodium montmorillonite. Although the solid components have no effect on surface hydration, the solid components remaining on 500 sodium montmorillonite interfere with the results during the XRD basal detection, resulting in inaccurate results. And it is difficult to separate the solid components from 500 sodium montmorillonite, and it is also difficult to completely separate them. Therefore, even if separation treatment is carried out, the obtained basal detection results are still inaccurate, thus causing inaccuracy in the evaluation results.

[0067] Example 3

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

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

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

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

[0072] S4. Raise the temperature of the roller furnace to 100 °C, put it into the aging tank for hot rolling for 16 h, and the rotation speed of the roller furnace is 50 r / min.

[0073] S5. After the hot rolling is completed, cool and open the tank, take out the nylon filter cloth 200, and take out the sodium montmorillonite 500, and place it in a centrifuge. Set the rotation speed to 10,000 r / min and centrifuge for 20 min at 25 °C.

[0074] S6. Pour out the upper liquid after centrifugation, and collect the centrifuged sodium montmorillonite 500.

[0075] S7. Use XRD, set the parameters as diffraction wavelength λ = 0.154056 nm, working voltage of 40 kV, current of 30 mA, scanning angle 2θ = 3 - 40°, test the basal spacing of the centrifuged sodium montmorillonite 500, and evaluate the inhibition of the drilling fluid through the basal spacing. The evaluation method is shown in Table 1:

[0076] Table 1

[0077] Base spacing Number of hydration layers Evaluation of surface hydration inhibition Less than 1.00 nm Dry montmorillonite No hydration 1.00 - 1.30 nm Montmorillonite with 1 - layer hydration Good inhibition 1.30 - 1.50 nm Montmorillonite with 2 - layer hydration Better inhibitor 1.50 - 1.80 nm Montmorillonite with 3 - layer hydration Poorer inhibition 1.80 - 2.00 nm Montmorillonite with 4 - layer hydration Poor inhibition Greater than 2.00 nm Montmorillonite with 5 or more layers of hydration No inhibition

[0078] In this embodiment, the basal spacing of the sodium montmorillonite 500 measured by XRD is 1.55 nm. Referring to Table 1, it is concluded that the surface hydration inhibition of the polymer drilling fluid system is poor.

[0079] Comparative Example 3

[0080] In this Comparative Example 3, the inhibition of the polymer drilling fluid system is evaluated by using the conventional method in the prior art, and the specific method is to use the rolling recovery test.

[0081] In this experiment, the rolling recovery rate (120 °C, 16 h) of the polymer drilling fluid system on the shale is used as the evaluation index, and the specific test steps are as follows:

[0082] (1) Screen the collected drill cuttings with a double-layer sampling sieve with hole side lengths of 3.27 mm and 2.0 mm respectively, and collect the drill cuttings passing through the sieve with a hole side length of 3.2 mm.

[0083] (2) Take 50.0 g (accurate to 0.1 g) of the prepared drill cuttings, put them into a high-temperature tank containing 350 mL of the evaluation liquid, and tighten the lid.

[0084] (3) Put the high-temperature tank filled with the sample into a drilling fluid roller furnace at 120 °C ± 3 °C and roll for 16 h.

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

[0086] (5) Put the sieved remaining rock samples into a forced-air constant-temperature drying oven at 105 °C ± 3 °C and dry them for 4 h. Take them out and cool, and let them stand in the air for 24 h, then weigh them (accurate to 0.1 g) and calculate the one-time rolling recovery rate (R).

[0087] The rolling recovery rate R obtained from the above experimental steps is 95%, and the inhibitory evaluation is excellent. From the results, it can be seen that the evaluation results of Comparative Example 3 and Example 3 are inconsistent.

[0088] Comparative Example 4

[0089] This Comparative Example 4 is basically the same as Comparative Example 1. The difference is that the drilling fluid system is a polymer drilling fluid system. According to Equation 1, the Sr of the polymer drilling fluid system is 31%, indicating poor inhibition, which is consistent with the results in Example 3 and inconsistent with the rolling recovery experimental results in Comparative Example 3. This is because during the clay hydration process, after the clay absorbs water, the crystal layers first expand, and when the expansion reaches a certain degree, dispersion will occur. The rolling recovery rate mainly evaluates the dispersion ability. However, when the clay absorbs water and swells but has not yet dispersed, 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 effects evaluated in Comparative Example 3. Therefore, 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 Example 4 provides a method for testing the surface hydration inhibition of a drilling fluid, including the following steps:

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

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

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

[0095] S4. Raise the temperature of the roller furnace to 230 °C, put the aging tank into it and heat-roll for 48 h, and the rotation speed of the roller furnace is 50 r / min.

[0096] S5. After the hot rolling is completed, cool and open the can, take out the nylon filter cloth 200, and take out the sodium montmorillonite 500, and place them into a centrifuge. Set the rotation speed to 10,000 r / min and centrifuge for 20 min at 25 °C.

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

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

[0099] Table 1

[0100] Base spacing Number of hydration layers Evaluation of surface hydration inhibition Less than 1.00 nm Dry montmorillonite No hydration 1.00 - 1.30 nm Montmorillonite with 1 - layer hydration Good inhibition 1.30 - 1.50 nm Montmorillonite with 2 - layer hydration Better inhibitor 1.50 - 1.80 nm Montmorillonite with 3 - layer hydration Poorer inhibition 1.80 - 2.00 nm Montmorillonite with 4 - layer hydration Poor inhibition Greater than 2.00 nm Montmorillonite with 5 or more layers of hydration No inhibition

[0101] In this example, the basal spacing of the sodium montmorillonite 500 measured by XRD is 2.01 nm. Referring to Table 1, it can be concluded that the surface hydration of the ordinary high-solids drilling fluid has no inhibition.

[0102] Comparative Example 5

[0103] This Comparative Example 5 is basically the same as Comparative Example 1. The difference is that the drilling fluid system is an ordinary high-clay drilling fluid. After the experiment, the Sr of the ordinary high-clay drilling fluid is obtained as 55% according to Equation 1, indicating poor inhibition or no inhibition. Since there is no clear evaluation standard table, the inhibition strength can only be roughly estimated by the Sr value. Through this value, it can be inferred that the inhibition of this drilling fluid system is poor or there is no inhibition, which is consistent with the result of Example 4, further indicating the feasibility and accuracy of the evaluation method in Example 4. However, since the inhibition evaluation standard is clarified in this application, it can be more accurately obtained that this drilling fluid system has no inhibition, rather than the experimental conclusion in Comparative Example 5 where it is impossible to determine whether the inhibition is poor or there is no inhibition. 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 according to the on-site situation, and determine the selection and dosage of inhibitors.

[0104] The embodiments described above are some, but not all, of the embodiments of the present invention. The detailed description of the embodiments of the present invention is not intended to limit the scope of the present invention claimed, but merely represents selected embodiments of the present invention. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present invention without creative efforts shall fall within the scope of protection of the present invention.

Claims

1. A drilling fluid surface hydration inhibition test device, characterized in that: include: A reaction tank, wherein a nylon filter cloth, a first fixing frame and a second fixing frame are arranged 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.

2. A drilling fluid surface hydration inhibition testing device according to claim 1, characterized in that: The first fixing frame and the second fixing frame are both embedded with a first magnetic block, the top inner wall and the bottom inner wall of the reaction tank are both embedded with a second magnetic block, and the magnetic poles of the first magnetic block and the second magnetic block are different from each other.

3. A drilling fluid surface hydration inhibition testing device according to claim 1, characterized in that: The reaction tank is an aging tank.

4. A drilling fluid surface hydration inhibition testing device according to claim 1, characterized in that: The mesh number of the nylon filter cloth is greater than 80,000 meshes (0.1 micron).

5. A testing method based on the drilling fluid surface hydration inhibition testing device according to any one of claims 1 to 4, characterized in that: The following steps are involved: S1. Fill the aging tank with 400 mL of drilling fluid, and fill the nylon filter cloth with high-purity sodium montmorillonite, the purity of which is greater than 99%; S2, fixing two ends of the nylon filter cloth with the first fixing frame and the second fixing frame; S3, fixing the second fixing frame on the bottom inner wall of the aging tank, and fixing the first fixing frame on the top inner wall of the aging tank; S4, raising the temperature of the roller furnace to a specified temperature, placing the aging tank in the aging tank and hot rolling; S5, after the hot rolling is completed, the can is cooled and opened, the nylon filter cloth and the sodium montmorillonite are taken out, and they are placed in a centrifuge for centrifugation; S6, pour out the upper liquid after centrifugation, and collect the sodium montmorillonite after centrifugation; S7. Using XRD, the basal spacing of the sodium montmorillonite after centrifugation was tested, and the inhibition of the drilling fluid was evaluated by the basal spacing.

6. The method according to claim 5, characterized in that In step S4, the specified temperature is 25°C-230°C, the hot rolling time is 12-48h, and the roller furnace speed is 50r / min.

7. The method according to claim 5, characterized in that In step S4, the specified temperature is 100°C-200°C.

8. The method according to claim 5, 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.

9. The method according to claim 5, characterized in that In step S7, the XRD parameters are: diffraction wavelength λ=0.154056 nm, operating voltage 40 kV, current 30 mA, scanning angle 2θ=3-40°.

10. The method according to claim 5, characterized in that In step S7, the evaluation criteria for the inhibition of the drilling fluid are: the sodium montmorillonite base spacing is less than 1.00nm, the number of hydration layers is 0, that is, dry sodium montmorillonite, and the surface hydration inhibition is evaluated as no hydration; the sodium montmorillonite base spacing is 1.00-1.30nm, the number of hydration layers is 1 layer of hydrated sodium montmorillonite, and the surface hydration inhibition is evaluated as good inhibition; the sodium montmorillonite base spacing is 1.30-1.50nm, the number of hydration layers is 2 layers of hydrated sodium montmorillonite, and the surface hydration inhibition is evaluated as good inhibition. The valence is good inhibition; the sodium montmorillonite basal spacing is 1.50-1.80nm, the number of hydration layers is 3 layers of hydrated sodium montmorillonite, and the surface hydration inhibition is evaluated as poor inhibition; the sodium montmorillonite basal spacing is 1.80-2.00nm, the number of hydration layers is 4 layers of hydrated sodium montmorillonite, and the surface hydration inhibition is evaluated as poor inhibition; the sodium montmorillonite basal spacing is greater than 2.00nm, the number of hydration layers is more than 5 layers of hydrated sodium montmorillonite, and the surface hydration inhibition is evaluated as no inhibition.

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