Well cementation flushing spacer fluid performance evaluation device and method

Abstract

The invention discloses a well cementation flushing spacer fluid performance evaluation device and method, and relates to the technical field of oil and gas field well cementation, and the well cementation flushing spacer fluid performance evaluation device comprises a wellbore loop simulation system, a temperature control system, a pressure control system, a circulating flow regulation monitoring system, a mud cake flushing visualization system and an analysis system; the wellbore loop simulation system comprises a loop flow channel and a flushing spacer fluid injection port; the mud cake washing visualization system comprises a rock core mounting bolt and a scanning device; the temperature control system comprises a spiral heating pipe, a heating controller and a temperature sensor; the pressure control system is used for adjusting and monitoring the pressure value in the loop flow channel; the circulating flow adjusting and monitoring system is used for adjusting and monitoring the flow value of the flushing spacer fluid in the loop flow channel; and the analysis system is used for determining an evaluation result of the flushing spacer fluid to be analyzed. The technical problems that in the prior art, errors are large, and the flushing effect of the well wall is difficult to judge are solved.

Description

Technical Field

[0001] The invention relates to the technical field of oil and gas field cementing, and in particular to a cementing flushing spacer fluid performance evaluation device and method. Background Art

[0002] With the expansion of oil and gas field exploration and development to deep and ultra-deep layers, as well as the development of unconventional oil and gas, in order to prevent the collapse and instability of broken formations, oil-based drilling fluids are increasingly widely used. Oil-based drilling fluids have the advantages of good inhibition, superior temperature resistance and strong wettability. They are widely used in complex formations such as shale, mudstone, salt-gypsum layers and high-temperature deep wells, and are an important technical means for unconventional drilling. Unlike traditional water-based drilling fluid systems, the cementing and completion projects of oil-based drilling fluids face many problems. Oil-based drilling fluids have strong adhesion and poor water wettability. They are difficult to flush during cementing. Residual oil-based drilling fluids and mud cakes affect cement slurry bonding, seriously reducing the quality of cementing bonding. The use of cementing flushing spacer fluids is the main technical means to solve these problems. Therefore, how to efficiently use cementing flushing spacer fluids to remove oil-based drilling fluids and mud cakes is a key problem faced by cementing after drilling construction.

[0003] The current cementing flushing spacer fluid performance evaluation device and method usually uses a mud cake made by drilling fluid on filter paper, which is attached to the rotor of a six-speed rotator, rotated in the flushing spacer fluid and the spacer fluid, and the mud cake is observed to fall. The mud cake prepared by the filter paper is quite different from the mud cake formed on the downhole rock, and the rotation to characterize the flushing degree is quite different from the downhole flushing working conditions. Therefore, this method has a series of problems such as large errors and unscientific characterization methods. It is difficult to accurately simulate the complex working conditions downhole and the working conditions such as the mud cake formed by the oil-based drilling fluid attached to the well wall, and it is difficult to determine the flushing effect on the well wall. Summary of the invention

[0004] The purpose of the present invention is to provide a cementing flushing spacer fluid performance evaluation device and method in order to solve at least one of the above technical problems.

[0005] In the first aspect, an embodiment of the present invention provides a cementing flushing spacer fluid performance evaluation device, including: a wellbore loop simulation system, a temperature control system, a pressure control system, a circulation flow regulation and monitoring system, a mud cake flushing visualization system and an analysis system; wherein the wellbore loop simulation system includes a loop flow channel and a flushing spacer fluid injection port; the flushing spacer fluid injection port is used to inject the flushing spacer fluid to be evaluated; the mud cake flushing visualization system includes a core mounting pin arranged in the loop flow channel and a scanning device arranged on the side of the core mounting pin; the core mounting pin is used to fix a core sample with a mud cake formed by oil-based drilling fluid; the scanning device is used to monitor the mud cake residue on the core sample; the temperature control system includes a device A spiral heating tube, a heating controller and temperature sensors arranged on both sides of the core mounting pin in the loop flow channel; the heating controller is used to control the spiral heating tube to heat the flushing spacer fluid in the loop flow channel; the temperature sensor is used to monitor the temperature value of the flushing spacer fluid before and after flushing the core sample; the pressure control system is used to adjust and monitor the pressure value in the loop flow channel; the circulation flow regulation and monitoring system is used to adjust and monitor the flow value of the flushing spacer fluid in the loop flow channel; the analysis system is used to determine the evaluation result of the flushing spacer fluid to be analyzed based on the mud cake residue, the flushing spacer fluid temperature value, the pressure value and the flushing spacer fluid flow value.

[0006] Furthermore, the flushing spacer liquid injection port is provided with an injection port cover plate, and the injection port cover plate is sealed with the flushing spacer liquid injection port by bolts and a sealing rubber ring.

[0007] Furthermore, the temperature control system also includes a relay protector, and the heating controller and the spiral heating tube are electrically connected via the relay protector.

[0008] Furthermore, the spiral heating tube comprises a spiral heat-conducting tube, a heating resistance wire arranged inside the spiral heat-conducting tube, and heat-conducting oil filling the inner cavity of the spiral heat-conducting tube; both ends of the heating resistance wire are electrically connected to the relay protector.

[0009] Furthermore, there are two temperature sensors, which are symmetrically sealed and inserted into the front and rear side wall openings of the mud cake flushing visualization system.

[0010] Furthermore, the pressure control system includes an air compressor, a safety pressure relief valve, a pressure gauge and a pressure sensor; wherein the air compressor is connected to the side of the loop flow channel through a pressure pipeline, the safety pressure relief valve and the pressure gauge are both arranged on the pressure pipeline, and the pressure sensor is sealed and inserted in the side wall opening of the loop flow channel.

[0011] Furthermore, the circulation flow regulation and monitoring system includes: a circulation centrifugal pump, a flow regulator and a flow meter; the circulation centrifugal pump is arranged at the connection of the loop flow channel; the flow regulator is connected to the circulation centrifugal pump, and the flow meter is seal-inserted on the rear side of the loop flow channel; the flow regulator is used to control the circulation centrifugal pump to regulate the flow of the flushing isolation fluid in the loop flow channel; the flow meter is used to monitor the flow value of the flushing isolation fluid in the loop flow channel.

[0012] In a second aspect, an embodiment of the present invention further provides a cementing flushing spacer fluid performance evaluation method, which is applied to a cementing flushing spacer fluid performance evaluation device provided by the present invention; the method comprises: preparing a core sample with a mud cake formed by an oil-based drilling fluid based on the temperature and pressure conditions under cementing, and fixing the core sample on the core mounting pin; injecting the flushing spacer fluid to be evaluated into the loop flow channel through the flushing spacer fluid injection port; based on the temperature control system, the pressure control system and the circulating flow regulation and monitoring system, adjusting the flushing spacer fluid to be evaluated under the temperature, pressure and flow conditions of the flushing spacer fluid under simulated cementing to flush the surface mud cake of the core sample; obtaining the mud cake residue, flushing spacer fluid temperature value, pressure value and flushing spacer fluid flow value of the core sample during the flushing process of the core sample being flushed by the flushing spacer fluid to be evaluated; and determining the evaluation result of the flushing spacer fluid to be analyzed based on the mud cake residue, the flushing spacer fluid temperature value, the pressure value and the flushing spacer fluid flow value.

[0013] Furthermore, the evaluation results include flushing rate, flushing time, and residual amount of mud cake after flushing.

[0014] Furthermore, after determining the evaluation result of the flushing spacer fluid to be analyzed, the method further includes: optimizing the formulation and performance of the flushing spacer fluid to be analyzed based on the evaluation result.

[0015] The present invention provides a cementing flushing spacer fluid performance evaluation device and method, which can accurately simulate the temperature and pressure environment under actual cementing, improve the accuracy of flushing spacer fluid performance evaluation, and can collect and record various data during the flushing process in real time, providing strong support for evaluating the performance of the flushing spacer fluid, and alleviating the technical problems of large errors and difficulty in determining the flushing effect of the well wall in the prior art. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] In order to more clearly illustrate the implementation methods of the present application or the technical solutions in the prior art, the drawings required for use in the specific implementation methods or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are some implementation methods of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0017] Figure 1 A schematic diagram of the overall structure of a cementing flushing spacer fluid performance evaluation device provided by an embodiment of the present invention;

[0018] Figure 2 A flow chart of a cementing flushing spacer fluid performance evaluation method provided in an embodiment of the present invention.

[0019] In the figure: 1. loop flow channel, 2. flushing isolation fluid injection port, 3. core installation pin, 4. scanning device, 5. spiral heating tube, 6. heating controller, 7. temperature sensor, 8. relay protection, 9. air compressor, 10. safety pressure relief valve, 11. pressure gauge, 12. pressure sensor, 13. pressure pipeline, 14. circulating centrifugal pump, 15. flow regulator, 16. flow meter, 17. main control terminal, 18. signal converter. DETAILED DESCRIPTION

[0020] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0021] Embodiment 1

[0022] Figure 1 Schematic diagram of the overall structure of a cementing flushing spacer fluid performance evaluation device provided according to an embodiment of the present invention. Figure 1 As shown, the device includes: a wellbore loop simulation system, a temperature control system, a pressure control system, a circulation flow regulation monitoring system, a mud cake flushing visualization system and an analysis system; wherein,

[0023] The wellbore loop simulation system comprises a loop flow channel 1 and a flushing spacer fluid injection port 2; the flushing spacer fluid injection port 2 is used to inject the flushing spacer fluid to be evaluated.

[0024] Preferably, the loop flow channel 1 is welded from high-strength metal. The flushing spacer liquid injection port 2 is provided with an injection port cover plate, and the injection port cover plate is sealed with the flushing spacer liquid injection port 2 by bolts and a sealing rubber ring.

[0025] Specifically, the mud cake flushing visualization system includes a core installation pin 3 arranged in the loop flow channel 1 and a scanning device 4 arranged on the side of the core installation pin 3. The core installation pin 3 is used to fix the core sample with the mud cake formed by the oil-based drilling fluid; the scanning device 4 is used to monitor the residual amount of mud cake on the core sample.

[0026] Specifically, the core installation pin 3 is sealed and inserted in the front loop flow channel 1. When the evaluation device sets the downhole parameters to be simulated, the sealing isolation baffle of the core installation pin 3 is opened.

[0027] Preferably, the scanning device 4 is a CT scanning device, which is fixed around the core installation pin 3, and its scanning interface is the mud cake section formed by the core.

[0028] Specifically, the temperature control system includes a spiral heating tube 5 arranged in the loop flow channel 1, a heating controller 6 and temperature sensors 7 arranged on both sides of the core mounting pin 3 in the loop flow channel 1; the heating controller 6 is used to control the spiral heating tube 5 to heat the flushing isolation fluid in the loop flow channel 1; the temperature sensor 7 is used to monitor the temperature value of the flushing isolation fluid before and after flushing the core sample.

[0029] Specifically, Figure 1 As shown, the heating controller 6 is fixed on the side of the loop flow channel 1; the temperature control system also includes a relay protector 8, and the heating controller 6 and the spiral heating tube 5 are electrically connected through the relay protector 8. The heating controller 6 controls the temperature adjustment of the entire temperature control system.

[0030] In an optional implementation provided by an embodiment of the present invention, the spiral heating tube 5 includes a spiral heat conducting tube, a heating resistance wire arranged inside the spiral heat conducting tube, and heat conducting oil filling the inner cavity of the spiral heat conducting tube; wherein both ends of the heating resistance wire are electrically connected to the relay protector 8.

[0031] In an optional implementation provided by the embodiment of the present invention, the number of temperature sensors 7 is two, which are symmetrically sealed and inserted into the front and rear side wall openings of the mud cake flushing visualization system.

[0032] In the embodiment of the present invention, the pressure control system is used to adjust and monitor the pressure value in the loop flow channel 1.

[0033] Specifically, the pressure control system includes an air compressor 9, a safety pressure relief valve 10, a pressure gauge 11 and a pressure sensor 12; wherein the air compressor 9 is connected to the side of the loop flow channel 1 through a pressure pipeline 13, the safety pressure relief valve 10 and the pressure gauge 11 are both arranged on the pressure pipeline 13, and the pressure sensor 12 is sealed and inserted in the side wall opening of the loop flow channel 1.

[0034] Specifically, Figure 1As shown, there are two safety pressure relief valves 10, which are respectively arranged between the air compressor 9 and the pressure-pressurizing pipeline 13, and between the pressure-pressurizing pipeline 13 and the loop flow channel 1, for respectively ensuring that the residual pressure in the air compressor 9 can be released after the pressure-pressurizing, and for depressurizing the loop flow channel 1 after the evaluation is completed. The pressure gauge 11 is arranged at the connection between the pressure-pressurizing pipeline 13 and the loop flow channel 1, for real-time observation of the pressure indication of the air compressor 9 on the loop flow channel 1.

[0035] Specifically, the pressure sensor 12 is used to monitor the pressure value in the loop flow channel 1 in real time.

[0036] In the embodiment of the present invention, the circulation flow regulating and monitoring system is used to regulate and monitor the flow value of the flushing spacer liquid in the loop flow channel 1.

[0037] Specifically, Figure 1 As shown, the circulation flow regulation and monitoring system includes: a circulation centrifugal pump 14, a flow regulator 15 and a flow meter 16; wherein the circulation centrifugal pump 14 is arranged at the connection between the rear side and the right side of the loop flow channel 1; the flow regulator 15 is connected to the circulation centrifugal pump 14, and the flow meter 16 is sealed and inserted in the rear side of the loop flow channel 1.

[0038] Specifically, the flow regulator 15 is used to control the circulating centrifugal pump 14 to adjust the flow of the flushing isolation liquid in the loop flow channel 1;

[0039] The flow meter 16 is used to monitor the flow value of the flushing isolation liquid in the loop flow channel 1.

[0040] In an embodiment of the present invention, the analysis system is used to determine the evaluation result of the flushing spacer fluid to be analyzed based on the mud cake residue, the flushing spacer fluid temperature value, the pressure value and the flushing spacer fluid flow value.

[0041] Specifically, Figure 1 As shown, the analysis system includes a main control terminal 17 and a signal converter 18; wherein the central control terminal 17 is connected to the signal converter 18, and the signal converter 18 is respectively connected to the temperature sensor 7, the pressure sensor 12, the flow meter 16 and the scanning device 4 through data lines.

[0042] Specifically, the signal converter 18 is used to receive the mud cake residue, the flushing spacer liquid temperature value, the pressure value and the flushing spacer liquid flow value, and send them to the main control terminal 17 .

[0043] Preferably, the main control terminal 17 includes a main control computer.

[0044] Embodiment 2

[0045] Figure 21 is a flow chart of a cementing flushing spacer fluid performance evaluation method provided in an embodiment of the present invention, and the method is applied to a cementing flushing spacer fluid performance evaluation device provided in an embodiment of the present invention. Figure 2 As shown, the method specifically comprises the following steps:

[0046] Step S202 , preparing a core sample with a mud cake formed by oil-based drilling fluid based on the temperature and pressure conditions under cementing, and fixing the core sample on the core installation pin 3 .

[0047] Specifically, a core with a diameter of 25 mm and a length of 10 mm was taken, and according to the actual temperature and pressure conditions downhole, a high-temperature and high-pressure core displacement device was used to simulate the wellbore temperature and pressure to produce the mud cake required for the experimental conditions.

[0048] Then the core sample with mud cake is installed and fixed on the core installation pin 3. During installation, ensure that the mud cake end face of the core is in full contact with the flushing isolation fluid to be analyzed in the loop flow channel 1. A sealing isolation baffle is installed on the core installation pin 3. Before the parameters of the temperature control system, pressure control system and circulation flow regulation and monitoring system reach the actual downhole level, the sealing isolation baffle is closed.

[0049] Step S204 , injecting the flushing spacer liquid to be evaluated into the loop flow channel 1 through the flushing spacer liquid injection port 2 .

[0050] Specifically, the flushing spacer fluid to be evaluated is injected into the wellbore loop simulation system from the flushing fluid injection port 2. After the injection of the flushing spacer fluid to be evaluated is completed, the injection port cover is covered, the high-strength bolts and the sealing rubber ring are tightened to make it sealed and pressure-bearing, and the data acquisition and analysis system is turned on. Through the scanning device 4, various data of the flushing process, such as the flow rate, pressure, temperature of the flushing fluid, the residual amount of mud cake on the core, etc., are collected and recorded in real time.

[0051] Step S206, based on the temperature control system, the pressure control system and the circulation flow regulation and monitoring system, the flushing spacer fluid to be evaluated is adjusted under the temperature, pressure and flow conditions of the flushing spacer fluid under simulated cementing to flush the surface mud cake of the core sample.

[0052] Specifically, the heating controller 6 is set to the temperature required for simulating the downhole and maintained, the air compressor 9 is turned on, the pressure is pressed into the evaluation device, the pressure gauge 11 is observed to reach the pressure required for simulating the downhole, the air compressor 9 is turned off, the safety relief valve 10 between the pressure-pressurizing pipeline 13 and the evaluation device is closed, the safety relief valve 10 between the air compressor 9 and the pressure-pressurizing pipeline 13 is opened, and the residual pressure in the air compressor 9 is discharged. At the same time, the circulating centrifugal pump 14 is turned on, the parameters of the flow meter 16 are observed, and after the flow rate reaches the simulated wellbore, the sealing isolation baffle of the core installation pin 3 is opened to allow the mud cake end face of the core to fully contact with the flushing isolation fluid to be analyzed in the wellbore loop.

[0053] Step S208, obtaining the mud cake residue, flushing spacer fluid temperature, pressure and flushing spacer fluid flow rate of the core sample during the flushing process of the core sample with the flushing spacer fluid to be evaluated.

[0054] Step S210, determining the evaluation result of the flushing spacer fluid to be analyzed based on the residual amount of mud cake, the temperature value, the pressure value and the flow value of the flushing spacer fluid.

[0055] Preferably, the evaluation results include flushing rate, flushing time, and residual amount of mud cake after flushing.

[0056] Preferably, after step S210, the method further comprises: optimizing the formulation and performance of the flushing isolation fluid to be analyzed based on the evaluation result.

[0057] Specifically, based on the evaluation results, the formulation and performance of the flushing spacer fluid are optimized to improve its use effect in cementing operations.

[0058] Preferably, after the evaluation is completed, the heating controller 6, the circulating centrifugal pump 14, and the scanning device 4 are turned off, and the safety pressure relief valve 10 between the pressure testing pipeline 13 and the evaluation device is opened to slowly release the pressure. When the pressure is released to below 0.1 MPa through the pressure sensor 12, the flushing spacer fluid injection port 2 is opened, and the loop flow channel 1 is depressurized to no pressure. The flushing spacer fluid is recovered and the core on the core installation pin 3 is removed, and then the equipment and instruments are cleaned, and the test is completed.

[0059] From the above description, it can be seen that the embodiment of the present invention provides a cementing flushing spacer fluid performance evaluation device and method, which has the following technical effects compared with the prior art:

[0060] (1) It can more accurately simulate the actual downhole temperature, pressure environment and wellbore, and improve the accuracy of the performance evaluation of the flushing spacer fluid.

[0061] (2) It can collect and record various data during the flushing process in real time, providing strong support for evaluating the performance of the flushing isolation fluid.

[0062] (3) The evaluation indicators are comprehensive and objective, and can fully reflect the performance of the flushing isolation fluid.

[0063] (4) By optimizing the formulation and performance of the flushing spacer fluid, its use effect in cementing operations can be improved, the risk of annular crossflow channels can be reduced, and the cementing quality can be improved.

[0064] It will be apparent to those skilled in the art that the invention is not limited to the details of the exemplary embodiments described above and that the invention can be implemented in other specific forms without departing from the spirit or essential features of the invention. Therefore, the embodiments should be considered exemplary and non-limiting in all respects, and the scope of the invention is defined by the appended claims rather than the foregoing description, and it is intended that all variations falling within the meaning and scope of the equivalent elements of the claims be included in the invention. Any reference numeral in a claim should not be considered as limiting the claim to which it relates.

[0065] In addition, it should be understood that although the present specification is described according to implementation modes, not every implementation mode contains only one independent technical solution. This description of the specification is only for the sake of clarity. Those skilled in the art should regard the specification as a whole. The technical solutions in each embodiment may also be appropriately combined to form other implementation modes that can be understood by those skilled in the art.

Claims

1. A cementing flushing spacer fluid performance evaluation device, characterized in that: include: Wellbore loop simulation system, temperature control system, pressure control system, circulation flow regulation monitoring system, mud cake flushing visualization system and analysis system; among them, The wellbore loop simulation system comprises a loop flow channel and a flushing spacer fluid injection port; the flushing spacer fluid injection port is used to inject the flushing spacer fluid to be evaluated; The mud cake flushing visualization system comprises a core installation pin arranged in the loop flow channel and a scanning device arranged on the side of the core installation pin; the core installation pin is used to fix the core sample with mud cake formed by oil-based drilling fluid; the scanning device is used to monitor the residual amount of mud cake on the core sample; The temperature control system includes a spiral heating tube arranged in the loop flow channel, a heating controller and temperature sensors arranged on both sides of the core installation pin in the loop flow channel; the heating controller is used to control the spiral heating tube to heat the flushing spacer fluid in the loop flow channel; the temperature sensor is used to monitor the temperature value of the flushing spacer fluid before and after flushing the core sample; The pressure control system is used to adjust and monitor the pressure value in the loop flow channel; The circulation flow regulating and monitoring system is used to regulate and monitor the flow value of the flushing spacer liquid in the loop flow channel; The analysis system is used to determine the evaluation result of the flushing spacer fluid to be analyzed based on the mud cake residue, the flushing spacer fluid temperature value, the pressure value and the flushing spacer fluid flow value.

2. The cementing flushing spacer fluid performance evaluation device according to claim 1, characterized in that: The flushing spacer liquid injection port is provided with an injection port cover plate, and the injection port cover plate is sealed with the flushing spacer liquid injection port by bolts and a sealing rubber ring.

3. The cementing flushing spacer fluid performance evaluation device according to claim 1, characterized in that: The temperature control system further comprises a relay protector, and the heating controller and the spiral heating tube are electrically connected via the relay protector.

4. The cementing flushing spacer fluid performance evaluation device according to claim 3, characterized in that: The spiral heating tube comprises a spiral heat-conducting tube, a heating resistance wire arranged inside the spiral heat-conducting tube and heat-conducting oil filling the inner cavity of the spiral heat-conducting tube; two ends of the heating resistance wire are electrically connected to the relay protector.

5. The cementing flushing spacer fluid performance evaluation device according to claim 1, characterized in that: There are two temperature sensors, which are symmetrically sealed and inserted into the front and rear side wall openings of the mud cake flushing visualization system.

6. The cementing flushing spacer fluid performance evaluation device according to claim 1, characterized in that: The pressure control system includes an air compressor, a safety pressure relief valve, a pressure gauge and a pressure sensor; wherein the air compressor is connected to the side of the loop flow channel through a pressure pipeline, the safety pressure relief valve and the pressure gauge are both arranged on the pressure pipeline, and the pressure sensor is sealed and inserted in the side wall opening of the loop flow channel.

7. The cementing flushing spacer fluid performance evaluation device according to claim 1, characterized in that: The circulation flow regulation and monitoring system comprises: a circulation centrifugal pump, a flow regulator and a flow meter; the circulation centrifugal pump is arranged at the connection of the loop flow channel; the flow regulator is connected to the circulation centrifugal pump, and the flow meter is sealed and inserted at the rear side of the loop flow channel; The flow regulator is used to control the circulating centrifugal pump to adjust the flow of the flushing isolation liquid in the loop flow channel; The flow meter is used to monitor the flow value of the flushing isolation liquid in the loop flow channel.

8. A method for evaluating the performance of cementing flushing spacer fluid, characterized in that: A cementing flushing spacer fluid performance evaluation device applied to claim 1; the method comprises: Prepare a core sample with a mud cake formed by oil-based drilling fluid based on the temperature and pressure conditions under cementing, and fix the core sample on the core installation pin; Injecting the flushing spacer liquid to be evaluated into the loop flow channel through the flushing spacer liquid injection port; Based on the temperature control system, the pressure control system and the circulation flow rate regulation and monitoring system, the flushing spacer fluid to be evaluated is adjusted under the temperature, pressure and flow rate conditions of the flushing spacer fluid simulated under cementing conditions to flush the surface mud cake of the core sample; Obtaining the residual amount of mud cake, the temperature value, the pressure value and the flow value of the flushing spacer fluid of the core sample during the flushing process of the flushing spacer fluid to be evaluated; An evaluation result of the flushing spacer fluid to be analyzed is determined based on the residual amount of the mud cake, the temperature value of the flushing spacer fluid, the pressure value, and the flow value of the flushing spacer fluid.

9. The method according to claim 8, characterized in that: The evaluation results include flushing rate, flushing time, and residual amount of mud cake after flushing.

10. The method according to claim 8, characterized in that: After determining the evaluation result of the flushing spacer fluid to be analyzed, the method further includes: optimizing the formulation and performance of the flushing spacer fluid to be analyzed based on the evaluation result.

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