Fracturing fluid friction resistance testing device and method

Abstract

The invention belongs to the technical field of oil and gas reservoir development, and particularly relates to a fracturing fluid friction resistance testing device and method. The fracturing fluid friction resistance testing device comprises a simulation mechanism, the simulation mechanism comprises a cylinder, and at least one crack is formed in the cylinder wall of the cylinder; the pump is connected with a port of the barrel and pumps fluid into the barrel; the pressure measuring mechanism is arranged in the simulation mechanism, and the friction resistance value of the fluid in the simulation mechanism is calculated by measuring the pressure of different positions in the simulation mechanism through the pressure measuring mechanism.

Description

Technical Field

[0001] This invention belongs to the field of oil and gas reservoir development technology, specifically, it relates to a fracturing fluid friction testing device and a fracturing fluid friction testing method. Background Technology

[0002] Currently, segmented fracturing technology in horizontal wells has become a key technology for improving the recovery efficiency of low-permeability oil and gas reservoirs. This technology effectively improves oil and gas recovery rates by fracturing in stages within horizontal wells. With technological advancements, various fracturing fluid injection methods have emerged, such as variable viscosity and variable displacement injection technologies, as well as multi-stage alternating injection technologies. By altering the physical properties of the fracturing fluid, these methods optimize fracture formation and propagation, thereby enhancing fracturing effectiveness.

[0003] While horizontal well fracturing technology has achieved significant benefits in oil and gas extraction, several technical challenges remain. For example, how to accurately calculate and control pressure and fluid flow within fractures under conditions of varying viscosities and sand-to-fluid ratios in the mixed slurry. These issues directly affect fracture initiation and propagation, as well as the final fracturing outcome.

[0004] Therefore, it is necessary to develop a device that can simulate and test the frictional changes of mortars with different viscosities and different sand-liquid ratios in the cylinder and fracture throughout the entire process, so as to more comprehensively simulate the fluid behavior in the actual fracturing process and provide more accurate data support for optimizing fracturing design. Summary of the Invention

[0005] To address the technical problems described above, this invention aims to provide a fracturing fluid friction testing device that can simulate and test the friction changes of mortars with different viscosities and different sand-liquid ratios in the cylinder and fracture throughout the entire process.

[0006] This invention also proposes a method for testing the friction of fracturing fluids, which can simulate the fluid behavior in the actual fracturing process and provide more accurate data support for optimizing fracturing design.

[0007] According to the present invention, a fracturing fluid friction testing device is provided, comprising:

[0008] A simulation mechanism, the simulation mechanism including a cylinder, on the cylinder wall having at least one crack;

[0009] A pump connected to a port of the cylinder, the pump pumping fluid into the cylinder; and

[0010] A pressure measuring mechanism is installed within the simulation mechanism to measure the pressure at different locations within the simulation mechanism and calculate the frictional resistance of the fluid within the simulation mechanism.

[0011] In one specific embodiment, the simulation mechanism further includes an adjustment mechanism for adjusting the crack opening.

[0012] In one specific embodiment, the adjustment mechanism includes:

[0013] A sealing cylinder fitted over the outside of the cylinder body;

[0014] A fixing plate that is sealed and fixed between the cylinder body and the sealing cylinder; and

[0015] A movable plate with a sealed movement is disposed between the cylinder and the sealing cylinder. The crack is located between the fixed plate and the movable plate. The thickness of the movable plate is greater than the gap size of the crack. The opening of the crack is adjusted by adjusting the area of ​​the crack covered by the movable plate.

[0016] In one specific embodiment, the cylinder includes a vertical section and a horizontal section, the horizontal section is connected to the lower end of the vertical section, the pump is connected to the upper end of the vertical section, and the crack is provided in the horizontal section.

[0017] In one specific embodiment, the pressure measuring mechanism includes:

[0018] A first pressure gauge is installed at the upper end of the vertical section; and

[0019] A second pressure gauge is installed at the connection between the vertical section and the horizontal section;

[0020] The frictional resistance of the fluid in the vertical section is calculated using the pressure values ​​measured by the first and second pressure gauges.

[0021] In one specific embodiment, the pressure measuring mechanism further includes a third pressure gauge disposed within the horizontal section at the crack location, and calculates the fluid friction value within the horizontal section using the pressure values ​​measured by the second pressure gauge and the third pressure gauge.

[0022] In one specific embodiment, the pressure measuring mechanism further includes a fourth pressure gauge located between the fixed plate and the movable plate, which calculates the frictional resistance of the fluid passing through the crack using the pressure values ​​measured by the third and fourth pressure gauges.

[0023] In one specific embodiment, the fracturing fluid friction testing device further includes a recovery tank, which is connected to the end of the cylinder, and the annulus between the sealing cylinder and the cylinder is connected to the recovery tank.

[0024] In one specific embodiment, the fracturing fluid friction testing device further includes a camera, and the simulation mechanism is made of a transparent material. The camera is used to capture images of the fluid inside the simulation mechanism.

[0025] According to the present invention, a method for testing the friction resistance of fracturing fluids is also provided. The friction resistance values ​​of fluids with different viscosities and different sand-liquid ratios are tested using the fracturing fluid friction resistance testing device provided by the present invention, and empirical formulas for the friction resistance of fluids with different viscosities and different sand-liquid ratios are established. Attached Figure Description

[0026] The present invention will now be described with reference to the accompanying drawings.

[0027] Figure 1 A schematic diagram of one embodiment of the fracturing fluid friction testing apparatus according to the present invention is shown.

[0028] In the picture:

[0029] 1. Simulation mechanism; 11. Cylinder; 111. Vertical section; 112. Horizontal section; 12. Crack;

[0030] 2. Adjustment mechanism; 21. Fixed plate; 22. Moving plate; 23. Sealing cylinder;

[0031] 3. Pressure measuring mechanism; 31. First pressure gauge; 32. Second pressure gauge; 33. Third pressure gauge; 34. Fourth pressure gauge;

[0032] 4. Pump; 41. Sand tank; 42. Liquid tank;

[0033] 5. Camera; 6. Recycling tank; 7. Temperature control components; 8. Hydraulic mechanism; 9. Computer;

[0034] 100. Fracturing fluid friction testing device.

[0035] In this application, all drawings are schematic and are used only to illustrate the principles of the invention, and are not drawn to scale. Detailed Implementation

[0036] The invention will now be described with reference to the accompanying drawings.

[0037] It should be noted that the directional terms or qualifiers used in this application, such as "up," "down," "front," "back," "left," and "right," are all specific to the referenced material. Figure 1 In other words, they are not used to define the absolute position of the components involved, but can vary depending on the specific circumstances.

[0038] Figure 1 The structure of the fracturing fluid friction testing apparatus 100 according to the present invention is shown. Figure 1As shown, the fracturing fluid friction testing device 100 includes a simulation mechanism 1, a pump 4, and a pressure measuring mechanism 3.

[0039] The simulation mechanism 1 is constructed to roughly resemble the structure of an oil and gas well during the fracturing process, thereby simulating the wellbore environment in the fracturing process. In this embodiment, the simulation mechanism 1 includes a cylinder 11, and at least one crack 12 is provided on the cylinder wall of the simulation mechanism 1.

[0040] Pump 4 is connected to the upper port of cylinder 11, and can pump fluid into cylinder 11.

[0041] In a preferred embodiment, a sand tank 41 and a liquid tank 42 are connected upstream of the pump 4. By controlling the flow rate from the sand tank 41 and the liquid tank 42 to the pump 4, fluids with different sand-liquid ratios can be pumped into the cylinder 11.

[0042] The pressure measuring mechanism 3 is installed inside the simulation mechanism 1. The pressure measuring mechanism 3 can measure the pressure at different positions in the simulation mechanism 1. By measuring the pressure at different positions in the simulation mechanism 1 through the pressure measuring mechanism 3, the friction value of the fluid in the simulation mechanism 1 can be calculated.

[0043] In existing technologies, when injecting fracturing fluid into a well to implement fracturing processes, it is necessary to consider the effects of the fracturing fluid's viscosity, flow rate, and friction value on the fracturing process. However, there is currently no method to obtain the friction value of the fracturing fluid in the well. Usually, empirical formulas are used to calculate the friction value of the fracturing fluid in the well, which cannot guarantee the accuracy of the friction value.

[0044] This invention simulates the downhole environment in a fracturing process using a simulation mechanism 1. During the test, pump 4 pumps fluid into the cylinder 11 of the simulation mechanism 1 to simulate fluid flow in the fracturing process. Under the influence of friction, the pressure inside the simulation mechanism 1 gradually changes from upstream to downstream. Therefore, while pumping fluid into the cylinder 11, the pressure measuring mechanism 3 measures the pressure at multiple locations within the simulation mechanism 1, and calculates the friction value of the fluid in that well section based on the pressure difference at different locations.

[0045] In one specific embodiment, the cylinder 11 includes a vertical section 111 and a horizontal section 112, such as Figure 1 As shown, the central axis of the vertical section 111 is set vertically, and the central axis of the horizontal section 112 is set horizontally. The left end of the horizontal section 112 is connected to the lower end of the vertical section 111, and the pump 4 is connected to the upper end of the vertical section 111. Multiple fractures 12 are sequentially arranged on the cylinder wall of the horizontal section 112 along the axial direction of the horizontal section 112. This arrangement more realistically simulates the downhole environment in the segmented and clustered fracturing process of a horizontal well.

[0046] According to the present invention, the pressure measuring mechanism 3 includes a first pressure gauge 31 and a second pressure gauge 32. For example... Figure 1 As shown, a first pressure gauge 31 is installed at the upper end of the inner cavity of the vertical section 111 to measure the pressure in the upper cavity of the vertical section 111. A second pressure gauge 32 is installed at the connection between the vertical section 111 and the horizontal section 112 to measure the pressure in the inner cavity at the connection between the vertical section 111 and the horizontal section 112. The frictional resistance of the fluid in the vertical section 111 is calculated using the pressure values ​​measured by the first pressure gauge 31 and the second pressure gauge 32. Specifically, the frictional resistance of the fluid in the vertical section 111 is the frictional resistance experienced by the fluid when flowing between the first pressure gauge 31 and the second pressure gauge 32, and the formula for calculating this frictional resistance is:

[0047] F h =P1+ρhg-P2;

[0048] Where P2 is the reading of the second pressure gauge 32, in MPa;

[0049] P1 is the reading of the first pressure gauge 31, in MPa;

[0050] h is the height difference between the first pressure gauge 31 and the second pressure gauge 32, in meters;

[0051] g is the acceleration due to gravity;

[0052] ρ is the density of the fluid, in units of 10⁻⁶. 3 kg / m 3 ;

[0053] F h This is the frictional resistance value, in MPa.

[0054] According to a preferred embodiment of the present invention, the simulation mechanism 1 further includes an adjustment mechanism 2 for adjusting the opening of the crack 12. The number of adjustment mechanisms 2 corresponds to the number of cracks 12. In this embodiment, three cracks 12 are arranged axially on the cylinder wall of the horizontal section 112, and correspondingly, the three adjustment mechanisms 2 are adapted to the three cracks 12 respectively.

[0055] like Figure 1 As shown, in this embodiment, the adjustment mechanism 2 is constructed in a generally square shape. It should be noted that the structure of the adjustment mechanism 2 is not limited to a square shape; it can also be circular or other shapes.

[0056] Specifically, the adjusting mechanism 2 includes a sealing cylinder 23, a fixed plate 21, and a movable plate 22. In this embodiment, the sealing cylinder 23 is constructed as a square cylinder structure and is coaxially and intermittently sleeved on the outside of the horizontal section 112 of the cylinder body 11. That is to say, there is an annular space between the outer wall of the cylinder body 11 and the inner wall of the sealing cylinder 23.

[0057] Both the fixed plate 21 and the movable plate 22 are constructed as roughly square plate structures. A hole adapted to the outer wall of the horizontal section 112 is provided in the middle of the fixed plate 21 and the movable plate 22. The horizontal section 112 passes through the hole in the fixed plate 21 and the movable plate 22.

[0058] The wall of the hole in the fixing plate 21 is fixedly sealed to the outer wall of the horizontal section 112, and the edge of the fixing plate 21 is fixedly sealed to the sealing cylinder 23. In this configuration, the fixing plate 21 closes one end of the annular space between the sealing cylinder 23 and the horizontal section 112.

[0059] The wall of the movable plate 22 is in a movable sealing fit with the outer wall of the horizontal section 112, and the edge of the movable plate 22 is in a movable sealing fit with the inner wall of the sealing cylinder 23. In this configuration, the movable plate 22 closes the end of the annular space between the sealing cylinder 23 and the horizontal section 112 that is away from the fixed plate 21, and the movable plate 22 can move axially relative to the fixed plate 21. The thickness of the movable plate 22 is greater than the gap size of the crack 12, and the crack 12 is located between the movable plate 22 and the fixed plate 21. When the movable plate 22 moves relative to the fixed plate 21, it can change the area of ​​the crack 12 it covers. Therefore, by adjusting the position of the movable plate 22, the opening of the crack 12 can be adjusted, thereby allowing testing of cracks 12 of various sizes.

[0060] Furthermore, the fracturing fluid friction testing device 100 also includes a hydraulic mechanism 8, which is connected to the movable plate 22. The hydraulic mechanism 8 can control the movable plate 22 to move axially along the horizontal section 112, thereby adjusting the opening of the fracture 12.

[0061] According to the present invention, the pressure measuring mechanism 3 further includes a third pressure gauge 33 disposed within the horizontal section 112 at the crack 12, thereby measuring the pressure at the crack 12 within the cavity of the horizontal section 112. The frictional resistance value of the fluid within the horizontal section 112 is calculated using the pressure values ​​measured by the second pressure gauge 32 and the third pressure gauge 33. The frictional resistance value of the fluid within the horizontal section 112 is the frictional resistance experienced by the fluid when flowing between the second pressure gauge 32 and the third pressure gauge 33, and the formula for calculating this frictional resistance value is the same as the formula for calculating the frictional resistance value of the fluid within the vertical section 111 described above.

[0062] According to the present invention, the pressure measuring mechanism 3 further includes a fourth pressure gauge 34, which is located between the fixed plate 21 and the movable plate 22, thereby measuring the pressure between the fixed plate 21 and the movable plate 22. The frictional resistance of the fluid passing through the crack 12 is calculated using the pressure values ​​measured by the third pressure gauge 33 and the fourth pressure gauge 34. The frictional resistance of the fluid passing through the crack 12 is the frictional resistance experienced by the fluid when flowing between the third pressure gauge 33 and the fourth pressure gauge 34, and the formula for calculating this frictional resistance is the same as the formula for calculating the frictional resistance of the fluid in the vertical section 111 described above.

[0063] According to a preferred embodiment of the present invention, the fracturing fluid friction testing device 100 further includes a recovery tank 6, which is connected to the end of the cylinder 11, and the annulus between the sealing cylinder 23 of each adjusting mechanism 2 and the cylinder 11 is connected to the recovery tank 6. The recovery tank 6 is capable of recovering fluid.

[0064] In a preferred embodiment, the fracturing fluid friction testing device 100 also includes a camera 5. The simulation mechanism 1 is made of a transparent material, and the camera 5 is used to capture images of the fluid inside the simulation mechanism 1. Specifically, the cylinder 11 and the adjustment mechanism 2 of the simulation mechanism 1 are made of transparent epoxy resin fiberglass material to observe and analyze the flow characteristics and flow conditions of the fluid, as well as the propagation process of the fracture 12.

[0065] In a preferred embodiment, the fracturing fluid friction testing device 100 further includes a temperature control component 7 to control the temperature of the simulation mechanism 1. In this embodiment, the temperature control component 7 uses an oil bath to control the temperature of the simulation mechanism 1. This setup simulates the requirements under actual oilfield conditions, thereby improving the operating efficiency of the experimental device and the accuracy of the data.

[0066] In a preferred embodiment, the fracturing fluid friction testing device 100 further includes a computer 9, which is electrically connected to the pressure measuring mechanism 3 and the pump 4.

[0067] In a preferred embodiment, the fracturing fluid friction testing device 100 further includes a temperature measuring mechanism, which is located in the same position as the pressure measuring mechanism 3.

[0068] According to the present invention, in a specific embodiment, the inner diameter of the cylinder 11 is set to any one of 20mm, 30mm or 40mm, the wall thickness of the cylinder 11 is determined based on the internal pressure resistance of 30MPa, the wall compressive strength of the crack 12 is also determined according to the same compressive strength, and this compressive strength test should also be carried out at a maximum temperature of 150°C.

[0069] The height of the vertical segment 111 is based on the height of the laboratory building, and in this embodiment it is set to 2000mm. The length of the horizontal segment 112 is set to 3000-4000mm. The width of the crack 12 is adjustable from 10 to 20mm.

[0070] Pump 4 uses a conventional ESCO pump or a screw pump with a certain sand-addition speed to ensure that the maximum sand-to-liquid ratio can reach over 45%. The volumes of both sand tank 41 and liquid tank 42 are set to 4–5 m³. 3 .

[0071] The maximum temperature of the temperature control component 7 can be designed to be 150℃.

[0072] According to the present invention, a method for testing the friction resistance of fracturing fluids is provided. The friction resistance values ​​of fluids with different viscosities and different sand-to-liquid ratios are tested using the fracturing fluid friction resistance testing device provided by the present invention, and empirical formulas for the friction resistance of fluids with different viscosities and different sand-to-liquid ratios are established.

[0073] When conducting fracturing fluid friction test, the fracturing fluid friction test device 100 provided according to the present invention is first assembled and functionally tested. After the test is successful, the next step is carried out.

[0074] Frictional resistance was checked using clean water at different injection rates. Specifically, clean water was pumped into the cylinder 11 at different rates using pump 4, and the readings from the first pressure gauge 31, the second pressure gauge 32, the third pressure gauge 33, and the fourth pressure gauge 34 were recorded. Based on the readings from these gauges, the frictional resistance values ​​of the clean water in the vertical section 111, the horizontal section 112, and the crack 12 were calculated.

[0075] According to the present invention, pure fracturing fluid of different viscosities is sequentially injected into the cylinder 11 at different discharge rates using pump 4, and the values ​​of the first pressure gauge 31, the second pressure gauge 32, the third pressure gauge 33, and the fourth pressure gauge 34 are recorded. Based on the values ​​of the first pressure gauge 31, the second pressure gauge 32, the third pressure gauge 33, and the fourth pressure gauge 34, the frictional resistance values ​​of the pure fracturing fluid of different viscosities are calculated for the vertical section 111, the horizontal section 112, and the fracture 12. The frictional resistance values ​​of each segment calculated in this step are compared and analyzed with the frictional resistance values ​​of the clean water segments at the corresponding discharge rates in step two. The drag reduction rate of the fracturing fluid at different viscosities and discharge rates is calculated and compared with the drag reduction rate of the clean water segments at the corresponding discharge rates. During this process, the previous fracturing fluid is drained before injecting fracturing fluid of different viscosities.

[0076] According to the present invention, mortar with different sand-liquid ratios is injected sequentially into the cylinder 11 at different discharge rates using pump 4, and the values ​​of the first pressure gauge 31, the second pressure gauge 32, the third pressure gauge 33, and the fourth pressure gauge 34 are recorded. Based on the values ​​of the first pressure gauge 31, the second pressure gauge 32, the third pressure gauge 33, and the fourth pressure gauge 34, the frictional resistance values ​​of the mortar with different sand-liquid ratios in the vertical section 111, the horizontal section 112, and the crack 12 are calculated respectively. The frictional resistance values ​​of each segment calculated in this step are compared and analyzed with the frictional resistance values ​​of each segment of clear water under the corresponding discharge rate in step two. The drag reduction rate of the fracturing fluid under different viscosities and discharge rates is calculated and compared with the drag reduction rate of each segment of clear water under the corresponding discharge rate. During this process, the previous mortar is drained before injecting the mortar with different sand-liquid ratios. Furthermore, the viscosity changes of mortars with different sand-liquid ratios were tested using a sand-containing rheometer and a conventional rheometer, and it was determined which ones could form a viscous fingering effect.

[0077] According to a specific embodiment of the present invention, fluids of different viscosities are sequentially injected into the cylinder 11 by a pump 4. In this embodiment, fluids of different viscosities are obtained by controlling the sand-to-liquid ratio of the fluids. First, the entire cylinder 11 and the crack 12 are filled with a high-viscosity fluid, and then a low-viscosity fluid is injected to replace the high-viscosity fluid. At the same time, the viscosity and fingering of the fluid throughout the entire process in the cylinder 11 and the crack 12 are observed.

[0078] It is easy to understand that the high viscosity fluid and low viscosity fluid in this embodiment are relative, that is, the viscosity of the high viscosity fluid is higher than that of the low viscosity fluid.

[0079] To monitor fluid characteristics and flow conditions, different color-coding schemes are used to distinguish fluids of different viscosities, enabling the monitoring of flow boundaries and the viscous fingering effect. Simultaneously, camera 5 records subtle changes in fluid flow in real time, while pressure measurement mechanism 3 and temperature testing mechanism record pressure and temperature changes in real time. During fracturing, the alternation of fracturing fluids or mixed slurries with different sand ratios and viscosities will cause changes in frictional resistance if the viscous fingering effect occurs. Experiments can identify the critical point where the viscous fingering effect appears, allowing for the optimization of fracturing parameters.

[0080] During the process of low-viscosity fluid replacing high-viscosity fluid, the frictional values ​​of each segment are recorded and calculated when the replacement interface is located between the first pressure gauge 31 and the second pressure gauge 32, between the second pressure gauge 32 and the third pressure gauge 33, and between the third pressure gauge 33 and the fourth pressure gauge 34. This provides more accurate data support for fracturing design of fluids with different viscosities and different sand-liquid ratios during fracturing.

[0081] Based on experimental results, empirical formulas for frictional resistance of each segment of fluid injection with different viscosities and sand-to-liquid ratios were established. The frictional resistance F of each segment of fluid injection with different viscosities and sand-to-liquid ratios was also determined. hy This refers to the frictional resistance experienced by fluids with different viscosities and sand-to-liquid ratios in each segment. The empirical formula for frictional resistance is as follows:

[0082]

[0083] Wherein: F hy The friction value is calculated based on the readings of the pressure gauges at the beginning and end of the segment.

[0084] Q is the fracturing displacement, in meters (m). 3 / min;

[0085] m is the number of fluid types within this segment;

[0086] υ m It is the viscosity of the m-th fluid present in this segment, in mPa·s;

[0087] K m It is the sand-liquid ratio corresponding to the m-th type of fluid present in this segment, in %;

[0088] a、b m c m These are empirical coefficients. The values ​​of the above parameters are obtained through multiple experiments and substituted into the empirical formula for friction resistance. Through data fitting, a and b are derived. m c m The most suitable value.

[0089] This invention takes into account the influence of changes in the viscosity and sand-liquid ratio of the mixed mortar on friction. This invention can be used to test the friction of the entire wellbore and fracture system.

[0090] In the description of this invention, it should be understood that the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of indicated technical features. Therefore, a feature defined as "first" or "second" may explicitly or implicitly include one or more of that feature. In the description of this invention, "a plurality of" means two or more, unless otherwise explicitly specified.

[0091] In this invention, unless otherwise explicitly specified and limited, the terms "installation," "connection," "linking," and "fixing," etc., should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection of two components. Those skilled in the art can understand the specific meaning of the above terms in this invention according to the specific circumstances.

[0092] In the description of this specification, references to terms such as "one embodiment," "some embodiments," "example," "specific example," or "some examples," etc., indicate that a specific feature, structure, material, or characteristic described in connection with that embodiment or example is included in at least one embodiment or example of the invention. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples.

[0093] Finally, it should be noted that the above description is merely a preferred embodiment of the present invention and does not constitute any limitation on the present invention. Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art can still modify the technical solutions described in the foregoing embodiments or make equivalent substitutions for some of the technical features. 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.

Claims

1. A fracturing fluid friction testing device, characterized in that, include: The simulation mechanism (1) includes a cylinder (11) with at least one crack (12) on the cylinder wall. A pump (4) connected to the port of the cylinder (11) pumps fluid into the cylinder (11); as well as The pressure measuring mechanism (3) installed in the simulation mechanism (1) measures the pressure at different positions in the simulation mechanism (1) and calculates the friction value of the fluid in the simulation mechanism (1).

2. The fracturing fluid friction testing device according to claim 1, characterized in that, The simulation mechanism (1) also includes an adjustment mechanism (2) for adjusting the opening of the crack (12).

3. The fracturing fluid friction testing device according to claim 2, characterized in that, The adjustment mechanism (2) includes: A sealing cylinder (23) fitted over the outside of the cylinder body (11); A fixing plate (21) is fixed between the cylinder (11) and the sealing cylinder (23); and A movable plate (22) is installed between the cylinder (11) and the sealing cylinder (23) in a sealed manner. The crack (12) is located between the fixed plate (21) and the movable plate (22). The thickness of the movable plate (22) is greater than the gap size of the crack (12). The opening of the crack (12) is adjusted by adjusting the area of ​​the movable plate (22) that blocks the crack (12).

4. The fracturing fluid friction testing device according to claim 3, characterized in that, The cylinder (11) includes a vertical section (111) and a horizontal section (112). The horizontal section (112) is connected to the lower end of the vertical section (111). The pump (4) is connected to the upper end of the vertical section (111). The crack (12) is provided in the horizontal section (112).

5. The fracturing fluid friction testing device according to claim 4, characterized in that, The pressure measuring mechanism (3) includes: A first pressure gauge (31) is installed at the upper end of the vertical section (111); and A second pressure gauge (32) is installed at the connection between the vertical section (111) and the horizontal section (112); The frictional value of the fluid in the vertical section (111) is calculated using the pressure values ​​measured by the first pressure gauge (31) and the second pressure gauge (32).

6. The fracturing fluid friction testing device according to claim 5, characterized in that, The pressure measuring mechanism (3) further includes a third pressure gauge (33) located in the crack (12) within the horizontal section (112), which calculates the friction value of the fluid within the horizontal section (112) based on the pressure values ​​measured by the second pressure gauge (32) and the third pressure gauge (33).

7. The fracturing fluid friction testing device according to claim 6, characterized in that, The pressure measuring mechanism (3) further includes a fourth pressure gauge (34), which is located between the fixed plate (21) and the movable plate (22). The pressure values ​​measured by the third pressure gauge (33) and the fourth pressure gauge (34) are used to calculate the friction value of the fluid passing through the crack (12).

8. The fracturing fluid friction testing device according to claim 3, characterized in that, The fracturing fluid friction test device also includes a recovery tank (6), which is connected to the end of the cylinder (11), and the annulus between the sealing cylinder (23) and the cylinder (11) is connected to the recovery tank (6).

9. The fracturing fluid friction testing device according to any one of claims 1 to 8, characterized in that, The fracturing fluid friction test device also includes a camera (5). The simulation mechanism (1) is made of transparent material, and the camera (5) is used to capture the fluid inside the simulation mechanism (1).

10. A method for testing the friction resistance of fracturing fluid, characterized in that, The friction values ​​of fluids with different viscosities and different sand-liquid ratios were tested using the fracturing fluid friction testing device according to any one of claims 1 to 9, and empirical formulas for friction of fluids with different viscosities and different sand-liquid ratios were established.

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