A drilling fluid dynamic filtration and mud cake quality evaluation simulation device and test method

Abstract

This invention belongs to the technical field of drilling fluid performance testing in the oil and gas industry, specifically relating to a simulation device and test method for dynamic filtration loss and mud cake quality evaluation of drilling fluid. The device of this invention is organically composed of a base, a fixed support, a container bracket, a high-pressure transparent container, a stirring mechanism, a heating mechanism, a regulator, a gas source pressure distribution mechanism, a measuring cylinder, and a sensing mechanism. This invention overcomes the shortcomings of existing testing instruments, enabling direct observation and testing of drilling fluid filtration loss and mud cake quality changes under dynamic conditions. The device of this invention is simple to operate, safe and reliable; moreover, its simple structure and low manufacturing cost facilitate its promotion to research and production units.

Description

Technical Field

[0001] This invention belongs to the field of drilling fluid performance testing technology in the oil and gas industry, specifically relating to a simulation device and test method for dynamic filtration loss and mud cake quality evaluation of drilling fluid. Background Technology

[0002] Drilling fluid filtration loss and mud cake quality are important indicators for judging the performance of drilling fluid. Drilling fluid with low filtration loss allows only a small amount of fluid to enter the formation pores and fractures, which reduces clay hydration and dispersion, and also decreases hydraulic wedge action, thus enhancing wellbore stability. To reduce drilling fluid filtration loss, the drilling fluid needs to form a thin and dense mud cake under pressure differential. Furthermore, the mud cake must have good toughness, adhere tightly to the wellbore, and not be easily broken by drilling fluid erosion. This is an important standard for measuring mud cake quality.

[0003] Existing drilling fluid loss meters measure filtration loss under static conditions, providing data that only reflects the static filtration properties of the drilling fluid. However, in actual drilling operations, the drilling fluid flows within the wellbore, resulting in dynamic filtration loss. Therefore, the filtration loss measured by conventional loss meters differs significantly from the actual downhole conditions, failing to effectively guide field operations. Furthermore, previously, the quality of the drilling fluid cake could only be evaluated based on the magnitude of drilling fluid filtration loss, but the magnitude of filtration loss is not directly related to cake quality, and small differences in filtration loss cannot determine cake quality. Currently, there is a lack of effective methods for evaluating the quality of drilling fluid-formed cakes; therefore, a testing instrument that can reflect both the dynamic filtration properties of the drilling fluid and the quality of the drilling fluid cake is needed. Summary of the Invention

[0004] This invention provides a simulation device and test method for evaluating dynamic filtration loss and mud cake quality of drilling fluid, with the aim of providing a method capable of...

[0005] To achieve the above objectives, the technical solution adopted by the present invention is as follows:

[0006] A simulation device for evaluating dynamic filtration loss and mud cake quality of drilling fluid, including

[0007] Base;

[0008] The fixed bracket is fixed to the base;

[0009] Container holder, the container holder is fixed to the base and placed inside the fixed bracket;

[0010] High-pressure transparent container, placed on a container rack;

[0011] The stirring mechanism has its upper part connected to a fixed support, and its lower part passes through the high-pressure transparent container and extends into the high-pressure transparent container.

[0012] Heating mechanism, which is connected to the high-pressure transparent container;

[0013] The regulator is placed on the base and is electrically connected to both the stirring mechanism and the heating mechanism. It is used to turn on the power and adjust the speed of the stirring mechanism and the temperature of the heating mechanism.

[0014] The gas source pressure distribution mechanism is connected to the top of the high-pressure transparent container and communicates with the inside of the high-pressure transparent container to pressurize the inside of the high-pressure transparent container.

[0015] The graduated cylinder is placed inside the container holder and is located directly below the high-pressure transparent container.

[0016] The sensing mechanism is connected to the top of the high-pressure transparent container, and the sensing end of the sensing mechanism is placed inside the high-pressure transparent container.

[0017] The fixed support includes two columns, which are vertically connected to the base; the upper parts of the two columns are symmetrically equipped with lifting devices, and a fixed plate is horizontally connected between the lifting devices; the fixed plate is connected to the upper part of the stirring mechanism.

[0018] The container holder is a frame structure, with at least one through hole at the top for the bottom of the high-pressure transparent container to pass through; the interior of the container holder has space for placing a measuring cylinder.

[0019] The high-pressure transparent container includes at least a transparent container body, which is a transparent ring with open top and bottom. An upper sealing flange is provided on the upper surface of the transparent container body, and a filter screen seat flange is provided on the lower surface. The upper sealing flange has a through hole for connecting to a stirring mechanism, a heating mechanism, a sensing mechanism, and the filter screen seat flange. A through hole is opened at the center of the filter screen seat flange, and a filter screen with filter paper is placed on the upper opening of the through hole. The filter screen with filter paper is fixed to the filter screen seat flange by a filter screen cover, and both the filter screen and the filter screen cover are placed inside the transparent container body. A filter nozzle is connected to the lower opening of the through hole, and a filter nozzle switch is connected to the filter nozzle. A measuring cylinder is placed on a base directly below the filter nozzle. The filter screen seat flange and the upper sealing flange are connected by multiple external tie rods.

[0020] Both the filter seat flange and the upper sealing flange are circular disc-shaped structures, with their outer diameters larger than the outer diameter of the transparent container body. The through holes for connection between the filter seat flange and the upper sealing flange are located on their outer edges. The through hole for connecting the heating mechanism is located on the upper sealing flange between the outer wall of the transparent container body and the external tie rod. The through hole for connecting the stirring mechanism is located at the center of the upper sealing flange. The pressure resistance of the transparent container body is no greater than 1.5 MPa.

[0021] The stirring mechanism includes a stirring motor, a coupling, a stirring shaft, and an impeller. The stirring motor is connected to a fixed bracket, and the output end of the stirring motor is connected to one end of the coupling. The other end of the coupling passes through the upper surface of the high-pressure transparent container and is connected to the upper end of the stirring shaft placed inside the high-pressure transparent container. The lower end of the stirring shaft is connected to an impeller, and there is a gap between the impeller and the bottom of the high-pressure transparent container.

[0022] The gas source pressure dividing mechanism includes an inlet valve stem, a pipeline, and a gas source pressure divider; the inlet valve stem is connected to the upper surface of the high-pressure transparent container and communicates with the interior of the high-pressure transparent container; the inlet valve stem is connected to the gas source pressure divider through a pipeline.

[0023] The sensing mechanism includes a laser sensor and a laser display; the laser sensor is connected to the upper surface of the high-pressure transparent container, and the sensing end of the laser sensor is placed inside the high-pressure transparent container; the laser sensor and the laser display are electrically connected.

[0024] The heating mechanism is an electric heating rod; the electric heating rod is fixedly connected to the high-pressure transparent container and is located inside the transparent container body.

[0025] A simulation test method for evaluating dynamic filtration loss and mud cake quality of drilling fluid, using a simulation device for evaluating dynamic filtration loss and mud cake quality of drilling fluid, includes the following steps.

[0026] S1: Place the filter screen on the filter screen holder flange in the high-pressure transparent container, install the filter paper on the filter screen, tighten the filter screen cover, and put it into the transparent container body of the high-pressure transparent container. Pour the drilling fluid to be tested into the transparent container body, and then place the filter screen holder flange on the container bracket.

[0027] S2: Connect the stirring mechanism and laser sensor, and fix the upper sealing flange and filter seat flange with external tie rods;

[0028] S3: Connect the heating mechanism, and turn on the power supply through the regulator, adjust the speed and stirring time of the stirring shaft, and adjust the heating temperature of the heating mechanism;

[0029] S4: Open the air source pressure divider mechanism and adjust the air source pressure divider in the air source pressure divider mechanism to the preset fixed air pressure;

[0030] S5: The stirring mechanism continues to stir. After heating to the preset temperature, the filtrate is collected through a graduated cylinder. After a preset time or until no more filtrate is filtered out, the volume of filtrate entering the graduated cylinder is recorded. This volume of filtrate is the dynamic filtration loss FL. 动 ;

[0031] S6: Close the gas source pressure distribution mechanism, stirring mechanism and heating mechanism, open the upper sealing flange, pour out the drilling fluid in the transparent container body, and then pour clean water or separately prepared drilling fluid into the transparent container body. Use external tie rods to fix the upper sealing flange and filter screen seat flange, set the stirring mechanism speed, observe and obtain the change data of the mud cake thickness deposited on the filter paper by laser sensor test;

[0032] S7: Based on the data on the change in mud cake thickness obtained in S6, evaluate the quality of the dynamically formed mud cake using the drilling fluid, analyze the impact of changes in a certain component in the drilling fluid on filtration loss and mud cake quality, or analyze the impact of drilling fluid viscosity on the mud cake's erosion resistance; the specific analysis methods are as follows:

[0033] The method for analyzing the impact of changes in a certain component in drilling fluid on filtration loss and mud cake quality is as follows: When the content of a certain component in drilling fluid increases, the filtration loss of drilling fluid gradually increases, and the mud cake thickness difference also gradually increases. In this case, the mud cake has poor erosion resistance and poor mud cake quality.

[0034] The method for analyzing the effect of drilling fluid viscosity on the erosion resistance of mud cake is as follows: when the drilling fluid viscosity increases, the mud cake thickness difference gradually decreases, indicating that the greater the drilling fluid viscosity, the weaker the erosion ability of the mud cake; when the drilling fluid viscosity increases, the mud cake thickness difference gradually increases, indicating that the greater the drilling fluid viscosity, the stronger the erosion ability of the mud cake.

[0035] Beneficial effects:

[0036] (1) The drilling fluid dynamic filtration loss and mud cake quality evaluation simulation device of the present invention is organically composed of a base, a fixed support, a container bracket, a high-pressure transparent container, a stirring mechanism, a heating mechanism, a regulator, a gas source pressure distribution mechanism, a measuring cylinder and a sensing mechanism. It overcomes the shortcomings of existing testing instruments and can intuitively observe and test the filtration loss of drilling fluid under dynamic conditions and quantitatively analyze the quality of mud cake.

[0037] (2) The device of the present invention is easy to operate, safe and reliable, and has a simple structure and low manufacturing cost, which is conducive to its promotion to scientific research and production units.

[0038] The above description is merely an overview of the technical solution of the present invention. In order to better understand the technical means of the present invention and to implement it in accordance with the contents of the specification, the preferred embodiments of the present invention are described in detail below with reference to the accompanying drawings. Attached Figure Description

[0039] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0040] Figure 1 This is a schematic diagram of the structure of the device of the present invention.

[0041] In the picture:

[0042] 1. Base; 2. Fixed bracket; 3. Container bracket; 4. High-pressure transparent container; 4-1. Transparent container body; 4-2. Upper sealing flange; 4-3. Filter screen seat flange; 4-4. External tie rod; 4-5. Filter nozzle; 4-6. Filter nozzle switch; 4-7. Filter screen cover; 5. Electric heating rod; 6. Laser sensor; 7. Coupling; 8. Stirring motor; 9. Lifting device; 10. Gas source pressure divider; 11. Regulator; 11-1. Power switch; 11-2. Timer knob; 11-3. Temperature control knob; 11-4. Speed ​​control knob; 12. Laser display; 12-1. Digital display screen; 12-2. Laser control switch; 13. Air inlet valve rod; 14. Stirring shaft; 15. Impeller; 16. Measuring cylinder. Detailed Implementation

[0043] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only a part of the embodiments of the present invention, and not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the scope of protection of the present invention.

[0044] Example 1:

[0045] according to Figure 1 The drilling fluid dynamic filtration loss and mud cake quality evaluation simulation device shown includes:

[0046] Base 1;

[0047] Fixed bracket 2, fixed to base 1;

[0048] Container bracket 3 is fixed on base 1 and placed inside container bracket 3;

[0049] High-pressure transparent container 4 is placed on container bracket 3;

[0050] The stirring mechanism has its upper part connected to the fixed support 2, and its lower part passes through the high-pressure transparent container 4 and extends into the high-pressure transparent container 4.

[0051] Heating mechanism, which is connected to the high-pressure transparent container 4;

[0052] Regulator 11 is placed on base 1 and is electrically connected to stirring mechanism and heating mechanism respectively. It is used to turn on power and adjust the speed of stirring mechanism and the temperature of heating mechanism.

[0053] The gas source pressure distribution mechanism is connected to the inside of the high-pressure transparent container 4 through the top of the high-pressure transparent container 4, and is used to pressurize the inside of the high-pressure transparent container 4.

[0054] Measuring cylinder 16 is placed inside the container holder and is located directly below the high-pressure transparent container 4;

[0055] The sensing mechanism is connected to the top of the high-pressure transparent container 4, and the sensing end of the sensing mechanism is placed inside the high-pressure transparent container 4.

[0056] In practical use, the fixed bracket 2 is used to connect and fix the stirring mechanism; the container bracket 3 is used to place the high-pressure transparent container 4; the stirring mechanism is used to stir the drilling fluid to be tested in the high-pressure transparent container 4; the heating mechanism is used to heat the drilling fluid to be tested to ensure that the drilling fluid to be tested is at the preset test temperature; the regulator 11 is used to adjust the rotation speed, stirring time and heating temperature of the stirring mechanism; the gas source pressure distribution mechanism is connected to an external gas source to adjust the pressure of the external gas source on the high-pressure transparent container 4; the measuring cylinder 16 is used to collect the liquid filtered from the bottom of the high-pressure transparent container 4; the high-pressure transparent container 4 is used to contain the drilling fluid to be tested. Under the action of stirring and temperature, some components in the drilling fluid to be tested will be deposited at the bottom of the high-pressure transparent container 4 to form a mud cake. The sensing mechanism is used to sense and receive the mud cake thickness information deposited at the bottom of the high-pressure transparent container 4; by using the high-pressure transparent container 4, the changes in the mud cake inside can be directly observed. Through the setting of the sensing mechanism, the quality of the mud cake can be precisely and quantitatively analyzed.

[0057] The regulator 11 in this embodiment adopts existing technology and is equipped with at least a power switch 11-1, a timer knob 11-2, a temperature control knob 11-3, and a speed control knob 11-4. The power switch 11-1 controls the start and stop of the stirring and heating mechanisms; the timer knob 11-2 adjusts the stirring time; the temperature control knob 11-3 adjusts the heating temperature; and the speed control knob 11-4 adjusts the stirring speed. The regulator 11 has an adjustable speed range of 0–2000 r / min, an adjustable temperature range of 0–200℃, and an adjustable time range of 0–120 min.

[0058] This invention overcomes the shortcomings of existing testing instruments, allowing for intuitive observation and testing of drilling fluid filtration loss and mud cake quality under dynamic conditions. This invention is simple to operate and safe and reliable.

[0059] Example 2:

[0060] according to Figure 1 The drilling fluid dynamic filtration loss and mud cake quality evaluation simulation device shown differs from Embodiment 1 in that: the fixed support 2 includes two columns, which are vertically connected to the base 1; the upper parts of the two columns are symmetrically provided with lifting devices 9, and a fixed plate is horizontally connected between the lifting devices 9; the fixed plate is connected to the stirring motor 8 at the top of the stirring mechanism.

[0061] In actual use, the upper parts of the two columns are symmetrically equipped with lifting devices 9. By adjusting the lifting devices 9, the height of the fixed plate can be adjusted, and at the same time, the stirring mechanism can be moved up and down, so that the stirring motor 8 can be smoothly connected to the stirring shaft 14 through the coupling 7 in the stirring mechanism.

[0062] The lifting device 9 in this embodiment includes a crank handle, a connecting rod, and a threaded rod. The crank handle is vertically fixed to the upper surface of one end of the connecting rod, and the threaded rod is vertically fixed to the lower surface of one end of the connecting rod. The crank handle and the threaded rod are arranged parallel to each other. Threaded holes are respectively opened on the upper central axis of the two columns, and the threaded rod is threaded into the threaded holes. When it is necessary to adjust the height of the stirring motor 8, the crank handle is cranked, and the crank handle drives the threaded rod to move up and down in the threaded holes, thereby adjusting the height of the fixed plate and achieving the purpose of adjusting the height of the stirring motor 8.

[0063] Example 3:

[0064] according to Figure 1 The drilling fluid dynamic filtration loss and mud cake quality evaluation simulation device shown differs from Embodiment 1 in that: the container bracket 3 is a frame structure, and its top is provided with at least one through hole for the bottom of the high-pressure transparent container 4 to pass through; the container bracket 3 has a space inside for placing the measuring cylinder 16.

[0065] In actual use, the bottom of the container holder 3 is fixed to the base 1, and the high-pressure transparent container 4 is placed on the container holder 3. The measuring cylinder 16 is placed on the base 1 and inside the container holder 3 directly below the high-pressure transparent container 4. This not only makes it convenient for the measuring cylinder 16 to collect the filtered liquid from the bottom of the high-pressure transparent container 4, but also makes it convenient to put the measuring cylinder 16 away.

[0066] Example 4:

[0067] according to Figure 1The drilling fluid dynamic filtration loss and mud cake quality evaluation simulation device shown differs from Embodiment 1 in that: the high-pressure transparent container 4 includes at least a transparent container body 4-1, which is a transparent ring with open top and bottom. An upper sealing flange 4-2 is provided on the upper surface of the transparent container body 4-1, and a filter screen seat flange 4-3 is provided on the lower surface of the transparent container body 4-1. The upper sealing flange 4-2 has through holes for connecting to the stirring mechanism, heating mechanism, induction mechanism, and filter screen seat flange 4-3. A through hole is opened at the center of 4-3. A filter screen is installed on the upper opening of the through hole, and filter paper is installed on the filter screen. The filter screen with filter paper is fixed to the filter screen seat flange 4-3 by the filter screen cover 4-7, and both the filter screen and the filter screen cover 4-7 are placed inside the transparent container body 4-1. A filter nozzle 4-5 is connected to the lower opening of the through hole, and a filter nozzle switch 4-6 is connected to the filter nozzle 4-5. A measuring cylinder 16 is placed on the base 1 directly below the filter nozzle 4-5. The filter screen seat flange 4-3 and the upper sealing flange 4-2 are connected by multiple external tie rods 4-4.

[0068] Furthermore, both the filter seat flange 4-3 and the upper sealing flange 4-2 are circular disc-shaped structures, with their outer diameters larger than the outer diameter of the transparent container body 4-1. The through holes for connecting the filter seat flange 4-3 and the upper sealing flange 4-2 are located on their outer edges. The through hole for connecting the heating mechanism is located on the upper sealing flange 4-2 between the outer wall of the transparent container body 4-1 and the external tie rod 4-4. The through hole for connecting the stirring mechanism is located at the center of the upper sealing flange 4-2. The pressure resistance of the transparent container body 4-1 is no greater than 1.5 MPa.

[0069] In practical use, the transparent container body 4-1 is a transparent ring with open top and bottom, facilitating observation of the drilling fluid and sediment inside during the test. Multiple external tie rods 4-4 securely fix the upper sealing flange 4-2 to the filter seat flange 4-3, ensuring that the high-pressure transparent container 4 can withstand the pressure applied during the test.

[0070] In practical applications, firstly, place the filter screen on the filter screen holder flange 4-3 in the high-pressure transparent container 4, and then install filter paper on the filter screen. After tightening the filter screen cover 4-7 to fix the filter paper, place it into the transparent container body 4-1 of the high-pressure transparent container 4. In this embodiment, the filter paper used is Φ90mm drilling fluid special filter paper. Then, pour the drilling fluid to be tested into the transparent container body 4-1, and then place the filter screen holder flange 4-3 on the container bracket 3. Subsequently, install the stirring shaft 14 in the stirring mechanism, the electric heating rod 5 in the heating mechanism, and the laser sensor 6 in the sensing mechanism on the upper sealing flange 4-2. Then, cover the transparent container body 4-1 with the upper sealing flange 4-2, align the through holes for installing the external tie rod 4-4 on the upper sealing flange 4-2 and the filter screen holder flange 4-3, and fix the upper sealing flange 4-2 and the filter screen holder flange 4-3 with the external tie rod 4-4. After performing the relevant operations, the test results can be obtained.

[0071] In this embodiment, the filter cover 4-7 consists of a filter screen and a sealing cover, used to fix the filter paper. The filter nozzle switch 4-6 installed on the filter nozzle 4-5 is used to control the flow of filtrate.

[0072] In this embodiment, the high-pressure transparent container 4 has a maximum pressure-bearing capacity of 1.5 MPa to ensure that the test can closely approximate the actual situation downhole, making the obtained test data more practical.

[0073] Example 5:

[0074] according to Figure 1 The drilling fluid dynamic filtration loss and mud cake quality evaluation simulation device shown differs from Embodiment 1 in that: the stirring mechanism includes a stirring motor 8, a coupling 7, a stirring shaft 14, and an impeller 15; the stirring motor 8 is connected to a fixed bracket 2, the output end of the stirring motor 8 is connected to one end of the coupling 7, and the other end of the coupling 7 passes through the upper surface of the high-pressure transparent container 4 and is connected to the upper end of the stirring shaft 14 placed inside the high-pressure transparent container 4; the lower end of the stirring shaft 14 is connected to the impeller 15, and there is a gap between the impeller 15 and the bottom of the high-pressure transparent container 4.

[0075] In actual use, the stirring motor 8 is fixed to the top of the fixed bracket 2 with screws, and the stirring shaft 14 is connected to the stirring motor 8 through the coupling 7, which facilitates installation and disassembly.

[0076] Example 6:

[0077] according to Figure 1The drilling fluid dynamic filtration loss and mud cake quality evaluation simulation device shown differs from Embodiment 1 in that: the gas source pressure dividing mechanism includes an air inlet valve rod 13, a pipeline, and a gas source pressure divider 10; the air inlet valve rod 13 is connected to the upper surface of the high-pressure transparent container 4 and communicates with the interior of the high-pressure transparent container 4; the air inlet valve rod 13 is connected to the gas source pressure divider 10 through a pipeline.

[0078] In actual use, the external air source is regulated by the air source pressure divider 10 and then input into the high-pressure transparent container 4 through the air inlet valve rod 13. This ensures the supply and stability of the internal pressure of the high-pressure transparent container 4, and ensures that the test can be closer to the actual situation downhole, providing accurate data support for the subsequent testing of drilling fluid loss.

[0079] Example 7:

[0080] according to Figure 1 The drilling fluid dynamic filtration loss and mud cake quality evaluation simulation device shown differs from Embodiment 1 in that: the sensing mechanism includes a laser sensor 6 and a laser display 12; the laser sensor 6 is connected to the upper surface of the high-pressure transparent container 4, and the sensing end of the laser sensor 6 is placed inside the high-pressure transparent container 4; the laser sensor 6 and the laser display 12 are electrically connected.

[0081] In practical use, the laser sensor 6 acquires data on the thickness change of the mud cake deposited at the bottom of the high-pressure transparent container 4 and sends the data to the laser display 12, which displays the change in mud cake thickness data, thereby providing support for the effective evaluation of the quality of the mud cake formed by the drilling fluid.

[0082] The laser sensor 6 and laser display 12 in this embodiment adopt existing technology. The laser display 12 is equipped with at least a digital display screen 12-1 and a laser control switch 12-2 to facilitate the activation of the laser sensor 6 and the observation of the acquired data.

[0083] The laser sensor used in this embodiment has a measurement distance of 100mm and a measurement accuracy of 0.05mm.

[0084] Example 8:

[0085] according to Figure 1 The drilling fluid dynamic filtration loss and mud cake quality evaluation simulation device shown differs from Embodiment 1 in that: the heating mechanism uses an electric heating rod 5; the electric heating rod 5 is fixedly connected to the high-pressure transparent container 4 and is placed inside the transparent container body 4-1 of the high-pressure transparent container 4.

[0086] In actual use, the heating mechanism uses an electric heating rod 5 for heating, which is flexible, convenient, and low in cost.

[0087] Example 9:

[0088] according to Figure 1The drilling fluid dynamic filtration loss and mud cake quality evaluation simulation device shown differs from Embodiment 1 in that: the fixed support 2 includes two columns, which are vertically connected to the base 1; symmetrically arranged lifting devices 9 are mounted on the upper parts of the two columns, and a fixed plate is horizontally connected between the lifting devices 9; the fixed plate is connected to the stirring motor 8 of the stirring mechanism; the container bracket 3 is a frame structure, with at least one through hole at its top for the bottom of the high-pressure transparent container 4 to pass through, and an internal space for placing the measuring cylinder 16; the high... The transparent container 4 includes at least a transparent container body 4-1, which is a transparent ring with open top and bottom. An upper sealing flange 4-2 is provided on the upper surface of the transparent container body 4-1, and a filter screen seat flange 4-3 is provided on the lower surface of the transparent container body 4-1. The upper sealing flange 4-2 has a through hole for connecting to the stirring mechanism, heating mechanism, induction mechanism, and filter screen seat flange 4-3. A through hole is opened at the center of the filter screen seat flange 4-3, and a filter screen is provided at the upper opening of the through hole. The filter screen, containing filter paper, is fixed to the filter screen holder flange 4-3 via a filter screen cover 4-7, and both the filter screen and the filter screen cover 4-7 are placed inside the transparent container body 4-1. A filter nozzle 4-5 is connected to the lower opening of the through hole, and a filter nozzle switch 4-6 is connected to the filter nozzle 4-5. A measuring cylinder 16 is placed on the base 1 directly below the filter nozzle 4-5. The filter screen holder flange 4-3 and the upper sealing flange 4-2 are connected by multiple external tie rods 4-4. Both the filter screen holder flange 4-3 and the upper sealing flange 4-2 are... It has a circular disc-shaped structure, and the outer diameter of both is larger than the outer diameter of the transparent container body 4-1; the through holes for connecting the filter screen seat flange 4-3 and the upper sealing flange 4-2 are opened on the outer edges of the filter screen seat flange 4-3 and the upper sealing flange 4-2; the through hole for connecting the heating mechanism is located on the upper sealing flange 4-2 between the outer wall of the transparent container body 4-1 and the external tie rod 4-4; the through hole for connecting the stirring mechanism is located at the center of the upper sealing flange 4-2; the pressure resistance of the transparent container body 4-1 is not greater than 1.5MPa; The stirring mechanism includes a stirring motor 8, a coupling 7, a stirring shaft 14, and an impeller 15; The stirring motor 8 is connected to a fixed plate; The output end of the stirring motor 8 is connected to one end of the coupling 7, and the other end of the coupling 7 passes through the upper sealing flange 4-2 and is connected to the upper end of the stirring shaft 14 placed inside the transparent container body 4-1; The lower end of the stirring shaft 14 is connected to the impeller 15, and there is a gap between the impeller 15 and the filter screen cover 4-7; The gas source pressure distribution mechanism includes an inlet valve stem 13, a pipeline, and a gas source pressure divider 10; The inlet valve stem 13 is connected to the upper... The sealing flange 4-2 is connected to the interior of the transparent container body 4-1; the inlet valve stem 13 is connected to the gas source pressure divider 10 via a pipeline; the sensing mechanism includes a laser sensor 6 and a laser display 12; the laser sensor 6 is connected to the sealing flange 4-2, and the sensing end of the laser sensor 6 is placed inside the transparent container body 4-1; the laser sensor 6 and the laser display 12 are electrically connected; the heating mechanism uses an electric heating rod 5; the electric heating rod 5 is fixedly connected to the sealing flange 4-2 and placed inside the transparent container body 4-1.

[0089] In practical use, firstly, install filter paper on the filter screen holder flange 4-3 in the high-pressure transparent container 4, tighten the filter screen cover 4-7, and place it into the transparent container body 4-1 of the high-pressure transparent container 4. Pour the drilling fluid to be tested into the transparent container body 4-1, and then place the filter screen holder flange 4-3 on the container bracket 3. Next, install the stirring shaft 14 in the stirring mechanism and the laser sensor 6 in the sensing mechanism on the upper sealing flange 4-2, and then cover the transparent container body 4-1 with the upper sealing flange 4-2. Align the through holes of the external tie rod 4-4 on the upper sealing flange 4-2 and the filter screen seat flange 4-3, and fix the upper sealing flange 4-2 and the filter screen seat flange 4-3 with the external tie rod 4-4; fix the stirring motor 8 in the stirring mechanism on the fixed bracket 2, adjust the height of the fixed bracket 2, and connect the stirring shaft 14 to the stirring motor 8 through the coupling 7; then connect the heating mechanism to the top of the high-pressure transparent container 4, turn on the regulator 11, and adjust the stirring shaft through the regulator 11 to connect the power supply. 14. Set the rotation speed and stirring time, and the heating temperature of the heating mechanism; then, open the gas source pressure divider mechanism and adjust the gas source pressure divider in the gas source pressure divider mechanism to a fixed gas pressure; after the stirring and heating time is over, place the measuring cylinder 16 directly below the filter nozzle 4-5 in the high-pressure transparent container 4, open the filter nozzle switch 4-6, and the measuring cylinder 16 collects the filtrate. Record the volume of the filtrate entering the measuring cylinder 16; then, open the upper sealing flange 4-2, pour out the drilling fluid in the transparent container body 4-1, and then add clean water or separately prepared drilling fluid. Pour the mixture into the transparent container body 4-1. Install and fix the upper sealing flange 4-2 and the filter screen seat flange 4-3 using the method described above. After adjusting the speed of the stirring mechanism, turn on the laser sensor 6. By visually observing and measuring the data from the laser sensor 6, obtain the change in the thickness of the mud cake deposited on the filter screen. Evaluate the quality of the mud cake dynamically formed by the drilling fluid, analyze the impact of changes in a certain component in the drilling fluid on filtration loss and mud cake quality, or analyze the impact of drilling fluid viscosity on the mud cake's erosion resistance.

[0090] The technical solution of this invention overcomes the shortcomings of existing testing instruments, enabling direct observation and testing of drilling fluid filtration loss and mud cake quality under dynamic conditions. The experimental operation using this invention is simple, safe, and reliable.

[0091] Example 10:

[0092] A simulation test method for evaluating dynamic filtration loss and mud cake quality of drilling fluid, using a simulation device for evaluating dynamic filtration loss and mud cake quality of drilling fluid, includes the following steps.

[0093] S1: Place the filter screen on the filter screen seat flange 4-3 in the high-pressure transparent container 4, install the filter paper on the filter screen, tighten the filter screen cover 4-7, and then put it into the transparent container body 4-1 of the high-pressure transparent container 4. Pour the drilling fluid to be tested into the transparent container body 4-1, and then place the filter screen seat flange 4-3 on the container bracket 3.

[0094] S2: Connect the stirring mechanism and laser sensor 6, and fix the upper sealing flange 4-2 and filter screen seat flange 4-3 with the external tie rod 4-4;

[0095] S3: Connect the heating mechanism, and turn on the power supply through the regulator 11, adjust the speed and stirring time of the stirring shaft 14, and the heating temperature of the heating mechanism;

[0096] S4: Open the air source pressure divider mechanism and adjust the air source pressure divider in the air source pressure divider mechanism to the preset fixed air pressure;

[0097] S5: The stirring mechanism continues to stir. After heating to the preset temperature, the filtrate is collected through the measuring cylinder 16. After waiting for a preset time or until the filtrate stops flowing out, the volume of the filtrate entering the measuring cylinder 16 is recorded. This volume of filtrate is the dynamic filtration loss FL. 动 ;

[0098] S6: Close the gas source pressure distribution mechanism, stirring mechanism and heating mechanism, open the upper sealing flange 4-2, pour out the drilling fluid in the transparent container body 4-1, and then pour clean water or separately prepared drilling fluid into the transparent container body 4-1. Use the external tie rod 4-4 to fix the upper sealing flange 4-2 and the filter screen seat flange 4-3, set the stirring mechanism speed, and observe and test the change data of the mud cake thickness deposited on the filter paper by the laser sensor 6.

[0099] S7: Based on the data on the change in mud cake thickness obtained in S6, evaluate the quality of the dynamically formed mud cake using the drilling fluid, analyze the impact of changes in a certain component in the drilling fluid on filtration loss and mud cake quality, or analyze the impact of drilling fluid viscosity on the mud cake's erosion resistance; the specific analysis methods are as follows:

[0100] The method for analyzing the impact of changes in a certain component in drilling fluid on filtration loss and mud cake quality is as follows: When the content of a certain component in drilling fluid increases, the filtration loss of drilling fluid gradually increases, and the mud cake thickness difference also gradually increases. In this case, the mud cake has poor erosion resistance and poor mud cake quality.

[0101] The method for analyzing the effect of drilling fluid viscosity on the erosion resistance of mud cake is as follows: when the drilling fluid viscosity increases, the mud cake thickness difference gradually decreases, indicating that the greater the drilling fluid viscosity, the weaker the erosion ability of the mud cake; when the drilling fluid viscosity increases, the mud cake thickness difference gradually increases, indicating that the greater the drilling fluid viscosity, the stronger the erosion ability of the mud cake.

[0102] In practical application, firstly, place the filter screen on the filter screen holder flange 4-3 in the high-pressure transparent container 4, install filter paper on the filter screen, tighten the filter screen cover 4-7 to fix the filter paper, and then place it into the transparent container body 4-1 of the high-pressure transparent container 4. Pour the drilling fluid to be tested into the transparent container body 4-1, and then place the filter screen holder flange 4-3 on the container bracket 3. Next, install the stirring shaft 14 in the stirring mechanism and the laser sensor 6 in the sensing mechanism on the upper sealing flange 4-2. Then, cover the transparent container body 4-1 with the upper sealing flange 4-2, align the through holes for installing the external tie rod 4-4 on the upper sealing flange 4-2 and the filter screen holder flange 4-3, and fix the upper sealing flange 4-2 and the filter screen holder flange 4-3 with the external tie rod 4-4. Finally, fix the stirring motor 8 in the stirring mechanism on the fixed bracket 2. Adjust the height of the fixed bracket 2, and connect the stirring shaft 14 to the stirring motor 8 through the coupling 7; insert the heating rod of the heating mechanism into the transparent container body 4-1 from the top of the high-pressure transparent container 4, and connect the heating mechanism to the regulator 11; then, turn on the regulator, connect the power supply through the regulator, and adjust the speed and stirring time of the stirring shaft 14, and the heating temperature of the heating mechanism; then, turn on the gas source pressure divider mechanism and adjust the gas source pressure divider in the gas source pressure divider mechanism to the preset fixed gas pressure; the stirring mechanism continues to stir, and after heating to the preset temperature, place the measuring cylinder 16 directly below the filter nozzle 4-5 in the high-pressure transparent container 4, turn on the filter nozzle switch 4-6, and the measuring cylinder 16 collects the filtrate. After waiting for the preset time or until the filtrate no longer filters out, record the volume of filtrate entering the measuring cylinder 16. This volume of filtrate is the dynamic filtration loss FL. 动 Afterwards, shut down the gas source pressure distribution mechanism, stirring mechanism, and heating mechanism. Open the upper sealing flange 4-2, pour out the drilling fluid from the transparent container body 4-1, and then pour clean water or separately prepared drilling fluid into the transparent container body 4-1. Fix the upper sealing flange 4-2 to the filter screen seat flange 4-3 using the method in S2. Set the stirring mechanism speed, turn on the laser sensor 6, and observe and obtain the change data of the mud cake thickness deposited on the filter paper by testing through the laser sensor 6. Based on the obtained mud cake thickness change data, evaluate the quality of the dynamically formed mud cake using the drilling fluid, analyze the impact of changes in a certain component in the drilling fluid on filtration loss and mud cake quality, or analyze the impact of drilling fluid viscosity on mud cake erosion resistance. The specific analysis methods are as follows:

[0103] The method for analyzing the impact of changes in a certain component in drilling fluid on filtration loss and mud cake quality is as follows: When the content of a certain component in drilling fluid increases, the filtration loss of drilling fluid gradually increases, and the thickness of mud cake also gradually increases. In this case, the mud cake has poor erosion resistance and poor mud cake quality.

[0104] The method for analyzing the effect of drilling fluid viscosity on the erosion resistance of mud cake is as follows: when the drilling fluid viscosity increases, the mud cake thickness difference gradually decreases, indicating that the greater the drilling fluid viscosity, the weaker the erosion ability of the mud cake; when the drilling fluid viscosity increases, the mud cake thickness difference gradually increases, indicating that the greater the drilling fluid viscosity, the stronger the erosion ability of the mud cake.

[0105] The adoption of the technical solution of this invention allows for the simple and convenient acquisition of drilling fluid filtration evaluation data that is closer to the actual situation in the well.

[0106] Example 11:

[0107] An experiment was conducted using a drilling fluid dynamic filtration loss and mud cake quality evaluation simulation device to investigate the effect of KCl content in drilling fluid on its filtration loss and mud cake quality.

[0108] (1) Four groups of drilling fluid base slurries were prepared with the following formula: 2% bentonite + 0.05% NaOH + 0.2% xanthan gum + 0.2% filtration loss reducer + 2% emulsified asphalt + 5% limestone. 0%, 5%, 10% and 15% KCl were added respectively to test the effect of KCl addition on drilling fluid filtration loss and the quality of the mud cake formed.

[0109] (2) Insert Ф90mm filter paper into the filter screen seat flange 4-3, press the filter screen cover 4-7 tightly, and place it at the bottom of the transparent container body 4-1. Pour the drilling fluid to be tested into the transparent container body 4-1, and install and fix the high pressure transparent container 4.

[0110] (3) Turn on the power switch 11-1 in the regulator, slowly adjust the speed to 2000 r / min, and adjust the temperature to 50℃;

[0111] (4) Connect the gas source pressure divider 10 to the external gas source, adjust the input gas pressure to 0.69MPa through the gas source pressure divider 10, set the test time to 30min, and start collecting the filtrate;

[0112] (5) After 30 minutes, record the filtration loss as FL. 动 The filtration loss (FL) under static conditions was measured using an SD6B medium-pressure fluid loss meter at the same pressure of 0.69 MPa and a measurement time of 30 min, and was compared with the API (American Petroleum Institute) static filtration loss. 静 Compare them;

[0113] (6) Pour out the drilling fluid from the high-pressure transparent container 4, pour in clean water, reinstall the instrument, turn on the laser sensor 6, test the mud cake thickness, and record it as d1.

[0114] (7) Turn on the mixer, adjust the speed to 2000 r / min, and mix for 10 min. Measure the thickness of the mud cake again and record it as d2. Calculate the change in mud cake thickness as Δd, as shown in Table 1:

[0115] Table 1. Effects of KCl dosage on drilling fluid filtration loss and mud cake formation quality.

[0116] sample <![CDATA[FL 静 / mL]]> <![CDATA[FL 动 / mL]]> <![CDATA[d1 / mm]]> <![CDATA[d2 / mm]]> Δd / mm base slurry 6.6 11.4 1.05 0.95 0.10 Base slurry + 5% KCl 6.8 15.2 1.25 1.00 0.25 Base slurry + 10% KCl 8.2 20.5 1.90 1.30 0.60 Base slurry + 15% KCl 10.6 27.8 2.25 1.45 0.80

[0117] Table 1 shows that as the KCl content increases, the drilling fluid filtration loss gradually increases, and the mud cake thickness also gradually increases. For the same drilling fluid, the filtration loss under dynamic conditions is greater than that under static conditions. As the KCl content in the drilling fluid increases, Δd also gradually increases, indicating that the mud cake has poorer erosion resistance, is more porous, and has lower quality. Therefore, the data obtained through this invention is closer to the true value of drilling fluid filtration loss in the wellbore and allows for quantitative analysis of mud cake quality.

[0118] Example 12:

[0119] Experiment on the effect of drilling fluid viscosity on mud cake erosion resistance.

[0120] (1) Prepare the drilling fluid base slurry + 10% KCl as described in Example 11, and use the drilling fluid dynamic filtration loss and mud cake quality evaluation simulation device to press out mud cake and measure the mud cake thickness.

[0121] (2) Pour out the drilling fluid from the high-pressure transparent container 4, add clean water and prepared CMC aqueous solutions with concentrations of 2%, 4%, 6% and 8% respectively, and install the instrument;

[0122] (3) Repeat step (7) in Example 11, record the thickness of the mud cake, and compare it with the thickness of the base slurry mud cake. The results are shown in Table 2.

[0123] Table 2. Effect of drilling fluid viscosity on mud cake erosion resistance

[0124]

[0125] As shown in Table 2, the difference in mud cake thickness gradually decreases as the drilling fluid viscosity increases, indicating that the greater the drilling fluid viscosity, the weaker its ability to scour the mud cake.

[0126] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

[0127] Where there is no conflict, those skilled in the art can combine the relevant technical features in the above examples according to the actual situation to achieve the corresponding technical effects. Specific details of the various combinations will not be elaborated here.

[0128] It should be noted that all directional indications (such as up, down, left, right, front, back, etc.) in the embodiments of the present invention are only used to explain the relative positional relationship and movement of each component in a certain specific posture (as shown in the figure). If the specific posture changes, the directional indication will also change accordingly.

[0129] Furthermore, the use of terms such as "first" and "second" in this invention is for descriptive purposes only and should not be construed as indicating or implying their relative importance or implicitly specifying the number of technical features indicated. Therefore, a feature defined with "first" or "second" may explicitly or implicitly include at least one of those features.

[0130] The above description is merely a preferred embodiment of the present invention. The present invention is not limited to the embodiments shown herein, but is to be accorded the widest scope consistent with the principles and novel features disclosed herein. Any simple modifications, equivalent variations, and alterations made to the above embodiments based on the technical essence of the present invention shall still fall within the scope of the present invention.

Claims

1. A simulation device for evaluating dynamic filtration loss and mud cake quality of drilling fluid, characterized in that: include Base (1); Fixed bracket (2), fixed bracket (2) is fixed on base (1); Container bracket (3) is fixed on the base (1) and placed inside the fixed bracket (2); High-pressure transparent container (4), the high-pressure transparent container (4) is placed on container bracket (3); The stirring mechanism has its upper part connected to the fixed support (2) and its lower part passing through the high-pressure transparent container (4) and extending into the high-pressure transparent container (4). A heating mechanism is connected to a high-pressure transparent container (4); The regulator (11) is placed on the base (1) and is electrically connected to the stirring mechanism and the heating mechanism respectively. It is used to turn on the power supply and adjust the speed of the stirring mechanism and the temperature of the heating mechanism. The gas source pressure distribution mechanism is connected to the top of the high-pressure transparent container (4) and communicates with the inside of the high-pressure transparent container (4) to pressurize the inside of the high-pressure transparent container (4); Measuring cylinder (16) is placed inside container bracket (3) and located directly below high-pressure transparent container (4); The sensing mechanism is connected to the top of the high-pressure transparent container (4), and the sensing end of the sensing mechanism is placed inside the high-pressure transparent container (4). The high-pressure transparent container (4) includes at least a transparent container body (4-1), which is a transparent ring with open top and bottom. An upper sealing flange (4-2) is provided on the upper surface of the transparent container body (4-1), and a filter screen seat flange (4-3) is provided on the lower surface of the transparent container body (4-1). The upper sealing flange (4-2) has a through hole for connecting with the stirring mechanism, heating mechanism, induction mechanism, and filter screen seat flange (4-3). A through hole is opened at the center of the filter screen seat flange (4-3), with the upper opening of the through hole... A filter screen is provided on the top, and filter paper is provided on the filter screen. The filter screen with filter paper is fixed to the filter screen seat flange (4-3) by a filter screen cover (4-7), and both the filter screen and the filter screen cover (4-7) are placed inside the transparent container body (4-1); a filter nozzle (4-5) is connected to the lower opening of the through hole, and a filter nozzle switch (4-6) is connected to the filter nozzle (4-5). A measuring cylinder (16) is placed on the base directly below the filter nozzle (4-5); the filter screen seat flange (4-3) and the upper sealing flange (4-2) are connected by multiple external tie rods (4-4); The sensing mechanism includes a laser sensor (6) and a laser display (12); the laser sensor (6) is connected to the upper surface of the high-pressure transparent container (4), and the sensing end of the laser sensor (6) is placed inside the high-pressure transparent container (4); the laser sensor (6) and the laser display (12) are electrically connected.

2. The drilling fluid dynamic filtration loss and mud cake quality evaluation simulation device as described in claim 1, characterized in that: The fixed support (2) includes two columns, which are vertically connected to the base (1); the upper parts of the two columns are symmetrically provided with lifting devices (9), and a fixed plate is horizontally connected between the lifting devices (9); the fixed plate is connected to the upper part of the stirring mechanism.

3. The drilling fluid dynamic filtration loss and mud cake quality evaluation simulation device as described in claim 1, characterized in that: The container bracket (3) is a frame structure, and its top is provided with at least a through hole for the bottom of the high-pressure transparent container (4) to pass through; the interior of the container bracket (3) is provided with space for placing a measuring cylinder (16).

4. The drilling fluid dynamic filtration loss and mud cake quality evaluation simulation device as described in claim 1, characterized in that: Both the filter seat flange (4-3) and the upper sealing flange (4-2) are circular disc-shaped structures, and their outer diameters are larger than the outer diameter of the transparent container body (4-1). The through holes for connecting the filter seat flange (4-3) and the upper sealing flange (4-2) are located on the outer edges of the filter seat flange (4-3) and the upper sealing flange (4-2). The through hole for connecting the heating mechanism is located on the upper sealing flange (4-2) between the outer wall of the transparent container body (4-1) and the external tie rod (4-4). The through hole for connecting the stirring mechanism is located at the center of the upper sealing flange (4-2). The pressure resistance of the transparent container body (4-1) is no more than 1.5 MPa.

5. The drilling fluid dynamic filtration loss and mud cake quality evaluation simulation device as described in claim 1, characterized in that: The stirring mechanism includes a stirring motor (8), a coupling (7), a stirring shaft (14), and an impeller (15). The stirring motor (8) is connected to a fixed bracket (2). The output end of the stirring motor (8) is connected to one end of the coupling (7). The other end of the coupling (7) passes through the upper surface of the high-pressure transparent container (4) and is connected to the upper end of the stirring shaft (14) placed inside the high-pressure transparent container (4). The lower end of the stirring shaft (14) is connected to the impeller (15), and there is a gap between the impeller (15) and the bottom of the high-pressure transparent container (4).

6. The drilling fluid dynamic filtration loss and mud cake quality evaluation simulation device as described in claim 1, characterized in that: The gas source pressure divider mechanism includes an inlet valve stem (13), a pipeline, and a gas source pressure divider (10); the inlet valve stem (13) is connected to the upper surface of the high-pressure transparent container (4) and communicates with the interior of the high-pressure transparent container (4); the inlet valve stem (13) is connected to the gas source pressure divider (10) through a pipeline.

7. The drilling fluid dynamic filtration loss and mud cake quality evaluation simulation device as described in claim 1, characterized in that: The heating mechanism is an electric heating rod (5); the electric heating rod (5) is fixedly connected to the high-pressure transparent container (4) and is located inside the transparent container body (4-1) of the high-pressure transparent container (4).

8. A simulation test method for evaluating dynamic filtration loss and mud cake quality of drilling fluid, characterized in that: The drilling fluid dynamic filtration loss and mud cake quality evaluation simulation device as described in any one of claims 1-7 includes the following steps: S1: Place the filter screen on the filter screen seat flange (4-3) in the high-pressure transparent container (4), install the filter paper on the filter screen, tighten the filter screen cover (4-7), and then put it into the transparent container body (4-1) of the high-pressure transparent container (4). Pour the drilling fluid to be tested into the transparent container body (4-1), and then place the filter screen seat flange (4-3) on the container bracket (3). S2: Connect the stirring mechanism and the laser sensor (6), and fix the upper sealing flange (4-2) and the filter seat flange (4-3) with the external tie rod (4-4); S3: Connect the heating mechanism, and turn on the power supply through the regulator (11), adjust the speed and stirring time of the stirring shaft (14), and the heating temperature of the heating mechanism; S4: Open the air source pressure divider mechanism and adjust the air source pressure divider in the air source pressure divider mechanism to the preset fixed air pressure; S5: The stirring mechanism continues to stir. After heating to the preset temperature, the filtrate is collected through the measuring cylinder (16). After waiting for the preset time or until the filtrate stops filtering out, the volume of the filtrate entering the measuring cylinder (16) is recorded. This volume of filtrate is the dynamic filtrate loss FL. S6: Close the gas source pressure distribution mechanism, stirring mechanism and heating mechanism, open the upper sealing flange (4-2), pour out the drilling fluid in the transparent container body (4-1), and then pour clean water or separately prepared drilling fluid into the transparent container body (4-1). Use the external tie rod (4-4) to fix the upper sealing flange (4-2) and the filter screen seat flange (4-3), set the stirring mechanism speed, observe and test the change data of the mud cake thickness of the drilling fluid deposited on the filter paper through the laser sensor (6); S7: Based on the data on the change in mud cake thickness obtained in S6, evaluate the quality of the dynamically formed mud cake using the drilling fluid, analyze the impact of changes in a certain component in the drilling fluid on filtration loss and mud cake quality, or analyze the impact of drilling fluid viscosity on the mud cake's erosion resistance; the specific analysis methods are as follows: The method for analyzing the impact of changes in a certain component in drilling fluid on filtration loss and mud cake quality is as follows: When the content of a certain component in drilling fluid increases, the filtration loss of drilling fluid gradually increases, and the mud cake thickness difference also gradually increases. In this case, the mud cake has poor erosion resistance and poor mud cake quality. The method for analyzing the effect of drilling fluid viscosity on the erosion resistance of mud cake is as follows: when the drilling fluid viscosity increases, the mud cake thickness difference gradually decreases, indicating that the greater the drilling fluid viscosity, the weaker the erosion ability of the mud cake; when the drilling fluid viscosity increases, the mud cake thickness difference gradually increases, indicating that the greater the drilling fluid viscosity, the stronger the erosion ability of the mud cake.

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