CO2-water relative permeability high-precision measuring and calculating method, device, medium and equipment

Abstract

The invention relates to a CO2-water relative permeability high-precision measuring and calculating method, device, medium and equipment. The method comprises the following steps: acquiring experimental data including pressure difference between two ends of a rock core and accumulated water yield by using an unsteady-state rock core displacement experiment; fitting the pressure difference between the two ends of the rock core recorded in the unsteady-state rock core displacement experiment, and predicting to obtain a steady-state pressure difference delta P infinity; an air-mercury capillary force curve is obtained through a mercury injection experiment, a smooth section of the curve is extended, and a starting pressure predicted value Pc, e is obtained; and correcting the pressure difference between the two ends of the rock core by using the steady-state pressure difference delta P infinity and the starting pressure predicted value Pc, e to obtain the corrected water-phase pressure difference delta Pw and CO2-phase pressure difference # imgabs0 # of the two ends of the rock core, and calculating the relative permeability of the water phase and the CO2 phase by using the corrected water-phase pressure difference delta Pw and CO2-phase pressure difference # imgabs1 # of the two ends of the rock core.

Description

Technical Field

[0001] The invention relates to a method, device, medium and equipment for high-precision calculation of CO2-water relative permeability, belonging to the technical field of geological storage of carbon dioxide. Background Art

[0002] CO2 geological storage has become one of the most important carbon emission reduction technologies in the world. In particular, storage in saline aquifers has extensive storage technology potential due to the widespread existence of saline aquifers and huge storage potential. The numerical simulation prediction of injection capacity, storage potential and storage safety in saline aquifers is greatly affected by the calculation accuracy of CO2-water relative permeability. CO2-water relative permeability is usually calculated through non-steady-state core displacement experiments. In the experiment, CO2 is injected into a core saturated with water, the pressure difference and liquid production at both ends of the core are recorded, and the data are processed using analytical methods to obtain the CO2-water relative permeability. However, the pressure difference data at both ends of the core directly obtained in the experiment includes the pressure difference caused by the capillary force of CO2-water. The CO2-water relative permeability obtained using uncorrected data will be lower than the actual value. Summary of the invention

[0003] In response to the above technical problems, the present invention provides a method, device, medium and equipment for high-precision measurement of CO2-water relative permeability. The method corrects the experimental data obtained through core displacement experiments and mercury injection experiments, and uses the corrected experimental data to calculate the CO2-water relative permeability to obtain a CO2-water relative permeability curve with higher accuracy.

[0004] A high-precision method for calculating CO2-water relative permeability, comprising:

[0005] The non-steady-state core displacement experiment was used to obtain experimental data including the pressure difference between the two ends of the core and the cumulative water production;

[0006] The pressure difference between the two ends of the core recorded in the non-steady-state core displacement experiment is fitted to predict the steady-state pressure difference ΔP ∞ ;

[0007] The air-mercury capillary force curve is obtained through mercury injection experiment, and the flat section of the curve is extended to obtain the starting pressure prediction value P c,e ;

[0008] Using the steady-state pressure difference ΔP ∞ , start pressure prediction value P c,e Correct the pressure difference at both ends of the core to obtain the corrected water phase pressure difference ΔP at both ends of the core w and CO2 phase pressure difference ΔP CO2 ;

[0009] Using the corrected water phase pressure difference ΔP at both ends of the core w and CO2 phase pressure difference ΔP CO2 , combined with the JBN method, the relative permeabilities of water phase and CO2 phase were calculated respectively.

[0010] The high-precision calculation method of CO2-water relative permeability preferably uses a non-steady-state core displacement experiment to obtain experimental data including the pressure difference at both ends of the core and the cumulative water production. The specific steps are as follows:

[0011] The washed and dried core is saturated with water by vacuum method;

[0012] Calculate the mass difference before and after saturation with water to obtain the core porosity;

[0013] The core is placed in a core holder and kept under certain temperature and pressure conditions for a certain period of time, during which water is injected at a certain speed;

[0014] After the temperature is constant, increase the water injection rate and measure the absolute permeability of the core;

[0015] Keep CO2 and water under certain temperature and pressure conditions for a certain period of time to obtain water-saturated CO2;

[0016] Water-saturated CO2 was injected into the core at a constant rate, and the pressure difference at both ends of the core and the cumulative water production were recorded.

[0017] The high-precision calculation method for CO2-water relative permeability preferably performs fitting on the pressure difference between the two ends of the core recorded in the non-steady-state core displacement experiment to predict and obtain the steady-state pressure difference ΔP ∞ , the specific steps are as follows:

[0018] Draw a curve of pressure difference at both ends of the core and injection volume;

[0019] Fit the pressure difference data after CO2 breaks through the core production end;

[0020] The fitting formula is used to predict the pressure difference at both ends of the core when the injection volume is a certain value, which is approximated as the pressure difference ΔP at both ends of the core when a large amount of CO2 is injected to achieve a steady state. ∞ .

[0021] The high-precision calculation method for CO2-water relative permeability, preferably, the fitting formula is as follows:

[0022]

[0023] In the formula, is the CO2 injection rate, ΔP m is the pressure difference between the two ends of the core measured experimentally, ΔP i is the water injection rate when measuring the absolute permeability of the core, q iis the water injection rate, is the PV number of injected CO2, b0, b1 and b2 are three fitting parameters.

[0024] The CO2-water relative permeability high-precision calculation method preferably obtains the air-mercury capillary force curve through mercury injection experiment, and extends the flat section of the curve to obtain the starting pressure prediction value P c,e , the specific steps are as follows:

[0025] A small core with the same properties as the core in the non-steady-state core flooding experiment was taken for mercury injection experiment to obtain the air-mercury capillary force curve;

[0026] Convert the air-mercury capillary force curve to the CO2-water capillary force curve;

[0027] Extend the flat section of the CO2-water capillary force curve to obtain the predicted starting pressure value P c,e .

[0028] In the method for high-precision measurement of CO2-water relative permeability, preferably, the calculation formula for converting the air-mercury capillary force curve into the CO2-water capillary force curve is as follows:

[0029]

[0030] In the formula, is the CO2-water capillary force, With σ 空气-汞 are the surface tensions of CO2-water and air-mercury, With θ 空气-汞 are the wetting angles of CO2-water and air-mercury, P c,空气-汞 It is the air-mercury capillary force directly measured in the mercury injection experiment.

[0031] The method for high-precision calculation of CO2-water relative permeability preferably uses a steady-state pressure difference ΔP ∞ , start pressure prediction value P c,e Correct the pressure difference at both ends of the core to obtain the corrected water phase pressure difference ΔP at both ends of the core w and CO2 phase pressure difference The specific steps are as follows:

[0032] The steady-state pressure difference ΔP ∞ Used to correct the pressure difference data at both ends of the core recorded in the experiment, so as to obtain the water phase pressure difference ΔP at both ends of the core w , the calculation formula is as follows:

[0033] ΔP w =ΔP m -ΔP ∞

[0034] The starting pressure prediction value P c,e Used to correct the pressure difference data at both ends of the core recorded in the experiment, so as to obtain the CO2 phase pressure difference at both ends of the core The calculation formula is as follows:

[0035]

[0036] The CO2-water relative permeability high-precision calculation method preferably uses the corrected water phase pressure difference ΔP at both ends of the core w and CO2 phase pressure difference The relative permeabilities of water phase and CO2 phase are calculated respectively by combining the JBN method. The calculation formula is as follows:

[0037]

[0038] In the formula, With k rw are the relative permeabilities of CO2 phase and water phase, T pW is the PV number of the produced water in the experiment, With μ w are the viscosities of the CO2 phase and the water phase, respectively.

[0039] A second aspect of the present invention provides a high-precision carbon dioxide-water relative permeability measurement device, comprising:

[0040] The first processing unit is used to obtain experimental data including the pressure difference at both ends of the core and the cumulative water production by using a non-steady-state core displacement experiment;

[0041] The second processing unit is used to fit the pressure difference between the two ends of the core recorded in the non-steady-state core displacement experiment, and predict the steady-state pressure difference ΔP ∞ ;

[0042] The third processing unit is used to obtain the air-mercury capillary force curve through the mercury injection experiment, and extend the flat section of the curve to obtain the starting pressure prediction value P c,e ;

[0043] The fourth processing unit is used to utilize the steady-state pressure difference ΔP ∞ , start pressure prediction value P c,e Correct the pressure difference at both ends of the core to obtain the corrected water phase pressure difference ΔP at both ends of the core w and CO2 phase pressure difference ΔP CO2 ;

[0044] The fifth processing unit is used to use the corrected water phase pressure difference ΔP at both ends of the core w and CO2 phase pressure difference ΔP CO2 , combined with the JBN method, the relative permeabilities of water phase and CO2 phase were calculated respectively.

[0045] A third aspect of the present invention provides a computer-readable storage medium having a computer program stored thereon, wherein the computer program, when executed by a processor, implements the steps of any one of the above-mentioned methods for high-precision measurement of CO2-water relative permeability.

[0046] A fourth aspect of the present invention provides a computer device, comprising a memory, a processor, and a computer program stored in the memory and executable on the processor, wherein the processor implements any one of the steps of the above-mentioned method for high-precision measurement of CO2-water relative permeability when executing the computer program.

[0047] The present invention adopts the above technical solution, which has the following advantages:

[0048] 1. The present invention provides a set of technical methods, which proposes a method for high-precision calculation of CO2-water relative permeability by correcting the experimental data recorded in the CO2-water two-phase core displacement experiment. The present invention provides a full-process operational technical method and implementation steps from experimental operation to data processing.

[0049] 2. The present invention corrects the experimental data obtained through core displacement experiments and mercury injection experiments, and uses the corrected experimental data to calculate the CO2-water relative permeability to obtain a CO2-water relative permeability curve with higher accuracy. BRIEF DESCRIPTION OF THE DRAWINGS

[0050] Figure 1 The capillary force P at the injection end provided by one embodiment of the present invention is c0 Prediction diagram;

[0051] Figure 2 A schematic diagram of the prediction of the CO2-water capillary force starting pressure provided in this embodiment of the present invention;

[0052] Figure 3 This is a comparison of the CO2-water relative permeability before and after correction provided in this embodiment of the present invention. DETAILED DESCRIPTION

[0053] In order to make the purpose, technical solution and advantages of the present invention clearer, the technical solution of the present invention is described clearly and completely below. Obviously, the described embodiments are 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 persons in the art without creative work are within the scope of protection of the present invention.

[0054] Unless otherwise defined, the technical or scientific terms used in the present invention shall have the usual meanings understood by persons with ordinary skills in the field to which the present invention belongs. The words "first", "second", "third", "fourth" and similar terms used in the present invention do not indicate any order, quantity or importance, but are only used to distinguish different components. Words such as "include" or "comprise" and the like mean that the elements or objects appearing before the word include the elements or objects listed after the word and their equivalents, without excluding other elements or objects. Words such as "connect" or "connected" and the like are not limited to physical or mechanical connections, but may include electrical connections, whether direct or indirect.

[0055] For ease of description, spatially relative terms may be used herein to describe the relationship of one element or feature relative to another element or feature as shown in the figures, such as "inside", "outside", "inner side", "outer side", "below", "above", etc. Such spatially relative terms are intended to include different orientations of the device in use or operation in addition to the orientation depicted in the figures.

[0056] CO2-water relative permeability is usually measured through non-steady-state core displacement experiments. In the experiment, CO2 is injected into a water-saturated core, the pressure difference and liquid production at both ends of the core are recorded, and the data are processed using analytical methods to obtain the CO2-water relative permeability. However, the pressure difference data at both ends of the core directly obtained in the experiment includes the pressure difference caused by the capillary force of CO2-water, and the CO2-water relative permeability obtained using uncorrected data will be lower than the actual value.

[0057] Based on the above technical problems, the present invention provides a method, device, medium and equipment for high-precision measurement of CO2-water relative permeability. The method corrects the experimental data obtained through core displacement experiments and mercury injection experiments, and uses the corrected experimental data to calculate the CO2-water relative permeability to obtain a higher-precision CO2-water relative permeability curve.

[0058] like Figure 1 As shown, the CO2-water relative permeability high-precision measurement method provided by the present invention includes the following specific steps:

[0059] Step 1: Obtain experimental data from non-steady-state core flooding experiment

[0060] The CO2-water two-phase core flooding experiment was carried out in the laboratory using the non-steady-state method. The general steps are as follows:

[0061] 1) Saturate the washed and dried core with water by vacuum method;

[0062] 2) Calculate the mass difference before and after saturation with water by the law of mass conservation to obtain the core porosity;

[0063] 3) Place the core in the core holder and keep it under the experimental temperature and pressure conditions for 12 hours, during which time water is injected at a low rate (about 0.1 ml / min);

[0064] 4) After the temperature is constant, increase the water injection rate and measure the absolute permeability of the core;

[0065] 5) Keeping CO2 and water under experimental temperature and pressure conditions for more than 24 hours to obtain water-saturated CO2;

[0066] 6) Inject water-saturated CO2 into the core at a constant rate, generally more than 20 PV, and record the pressure difference at both ends of the core and the cumulative water production.

[0067] Step 2: Fit the core flooding experimental pressure difference data to predict the steady-state pressure difference ΔP ∞

[0068] The pressure difference between the two ends of the core recorded in the core flooding experiment is fitted to predict the steady-state pressure difference. The general steps are as follows:

[0069] 1) Draw a curve of the pressure difference at both ends of the core and the injection volume.

[0070] 2) Fitting the pressure difference data after CO2 breaks through the core output end, the fitting formula is as follows:

[0071]

[0072] In the formula, is the CO2 injection rate, ΔP m is the pressure difference between the two ends of the core measured experimentally, ΔP i is the water injection rate when measuring the absolute permeability of the core, q i is the water injection rate, is the PV number of injected CO2, b0, b1 and b2 are three fitting parameters. The determination method of the three fitting parameters b0, b1 and b2 can be determined by graphical method. The curve of pressure difference at both ends of the core and injection volume is as follows Figure 1 As shown, by changing the three fitting parameters, the fitting curve can best fit the experimental data. At this time, the three fitting parameters can be determined.

[0073] 3) Use the fitting formula to predict the pressure difference at both ends of the core when the injection volume is 100 PV, which is approximated as the pressure difference at both ends of the core when a large amount of CO2 is injected to achieve a steady state. The method is as follows Figure 1 shown.

[0074] Step 3: Mercury injection experiment to obtain the starting pressure P c,e

[0075] The air-mercury capillary force curve is obtained through mercury injection experiment, and then converted into CO2-water capillary force curve to obtain the starting pressure. The general steps are as follows:

[0076] 1) Take a small core with the same properties as the core in step 1 and conduct a mercury injection experiment to obtain the air-mercury capillary force curve.

[0077] 2) The air-mercury capillary force curve is converted into the CO2-water capillary force curve. The calculation formula is as follows:

[0078]

[0079] In the formula, is the CO2-water capillary force, With σ 空气-汞 are the surface tensions of CO2-water and air-mercury, With θ 空气-汞 are the wetting angles of CO2-water and air-mercury, P c,空气-汞 It is the air-mercury capillary force directly measured in the mercury injection experiment.

[0080] 3) Extend the flat section of the CO2-water capillary force curve to obtain the predicted value of the starting pressure, as follows Figure 2 shown.

[0081] Step 4: Correct the experimental data

[0082] Due to the existence of CO2-water capillary force, the pressure difference between the two ends of the core recorded in the core displacement experiment is not equal to the single-phase pressure difference of the water phase or CO2 phase at the two ends of the core. In order to calculate the relative permeability of the water phase or CO2 phase, the pressure difference data at the two ends of the core recorded in the experiment needs to be corrected in two ways to obtain the single-phase pressure difference of the water phase and CO2 phase at the two ends of the core respectively. The correction method recommended by the present invention is as follows:

[0083] 1) Assume that a large amount of CO2 is injected until steady state occurs. At this time, the water phase in the core no longer flows. The pressure difference between the two ends of the core recorded in the experiment will be equal to the pressure difference between the two ends of the CO2 phase core. Therefore, the ΔP calculated in step 2 can be ∞ Used to correct the pressure difference data at both ends of the core recorded in the experiment, so as to obtain the water phase pressure difference ΔP at both ends of the core w The calculation formula is as follows:

[0084] ΔP w =ΔP m -ΔP ∞

[0085] 2) Considering that the capillary force starting pressure is the minimum pressure difference at which the CO2 phase starts to flow, the P measured in step 3 can be c,e Used to correct the pressure difference data at both ends of the core recorded in the experiment, so as to obtain the CO2 phase pressure difference at both ends of the core The calculation formula is as follows:

[0086]

[0087] Step 5: Calculate CO2-water relative permeability using the corrected experimental data

[0088] Based on the single-phase pressure difference of the water phase and the CO2 phase obtained in step 4, the relative permeabilities of the water phase and the CO2 phase are calculated respectively in combination with the JBN method. The calculation formula is as follows:

[0089]

[0090] In the formula, With k rw are the relative permeabilities of CO2 phase and water phase, T pW is the PV number of the produced water in the experiment, With μ w are the viscosities of the CO2 phase and the water phase, respectively.

[0091] The technical solution of the present invention is described in detail below with reference to specific examples.

[0092] Taking a core displacement experiment as an example, the relative permeability was calculated using the corrected and uncorrected experimental data, and compared with the relative permeability obtained by iterative fitting of numerical simulation. The comparison results show that the relative permeability of the CO2 phase calculated using the above correction method is 2%-12.5% ​​more accurate than the uncorrected method in the water saturation range of 0.56-0.76, and the relative permeability of the water phase is 22.1%-23.5% more accurate in the same water saturation range. Figure 3 shown.

[0093] A second aspect of the present invention provides a high-precision carbon dioxide-water relative permeability measurement device, comprising:

[0094] The first processing unit is used to obtain experimental data including the pressure difference at both ends of the core and the cumulative water production by using a non-steady-state core displacement experiment;

[0095] The second processing unit is used to fit the pressure difference between the two ends of the core recorded in the non-steady-state core displacement experiment, and predict the steady-state pressure difference ΔP ∞ ;

[0096] The third processing unit is used to obtain the air-mercury capillary force curve through the mercury injection experiment, and extend the flat section of the curve to obtain the starting pressure prediction value P c,e ;

[0097] The fourth processing unit is used to utilize the steady-state pressure difference ΔP ∞ , start pressure prediction value Pc,e Correct the pressure difference at both ends of the core to obtain the corrected water phase pressure difference ΔP at both ends of the core w and CO2 phase pressure difference ΔP CO2 ;

[0098] The fifth processing unit is used to use the corrected water phase pressure difference ΔP at both ends of the core w and CO2 phase pressure difference ΔP CO2 , combined with the JBN method, the relative permeabilities of water phase and CO2 phase were calculated respectively.

[0099] A third aspect of the present invention provides a computer-readable storage medium having a computer program stored thereon, wherein the computer program, when executed by a processor, implements the steps of any one of the above-mentioned methods for high-precision measurement of CO2-water relative permeability.

[0100] A fourth aspect of the present invention provides a computer device, comprising a memory, a processor, and a computer program stored in the memory and executable on the processor, wherein the processor implements any one of the steps of the above-mentioned method for high-precision measurement of CO2-water relative permeability when executing the computer program.

[0101] The present invention is described in terms of flowcharts and / or block diagrams of methods, devices (systems), and computer program products according to specific embodiments. It should be understood that each process and / or block in the flowchart and / or block diagram, as well as the combination of processes and / or blocks in the flowchart and / or block diagram, can be implemented by computer program instructions. These computer program instructions can be provided to a processor of a general-purpose computer, a special-purpose computer, an embedded processor, or other programmable data processing device to generate a machine, so that the instructions executed by the processor of the computer or other programmable data processing device generate instructions for implementing the processes in the flowchart and / or block diagram. Figure 1 A process or multiple processes and / or boxes Figure 1 A device that provides the functions specified in a block or multiple blocks.

[0102] These computer program instructions may also be stored in a computer-readable memory capable of directing a computer or other programmable data processing device to operate in a specific manner, so that the instructions stored in the computer-readable memory produce an article of manufacture comprising an instruction device, which implements the process Figure 1 A process or multiple processes and / or boxes Figure 1 A function specified in one or more boxes.

[0103] These computer program instructions can also be loaded onto a computer or other programmable data processing device so that a series of operating steps are executed on the computer or other programmable device to produce a computer-implemented process, thereby providing instructions for implementing the process. Figure 1A process or multiple processes and / or boxes Figure 1 The steps for the functions specified in one or more boxes.

[0104] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit it. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or make equivalent replacements for some of the technical features therein. However, these modifications or replacements do not deviate the essence of the corresponding technical solutions from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A high-precision method for calculating CO2-water relative permeability, characterized in that: include: The non-steady-state core displacement experiment was used to obtain experimental data including the pressure difference between the two ends of the core and the cumulative water production; The pressure difference between the two ends of the core recorded in the non-steady-state core displacement experiment is fitted to predict the steady-state pressure difference ΔP ∞ ; The air-mercury capillary force curve is obtained by mercury injection experiment, and the flat section of the curve is extended to obtain the starting pressure prediction value P. c,e ; Using the steady-state pressure difference ΔP ∞ , start pressure prediction value P c,e Correct the pressure difference at both ends of the core to obtain the corrected water phase pressure difference ΔP at both ends of the core w and CO2 phase pressure difference ΔP CO2 ; Using the corrected water phase pressure difference ΔP at both ends of the core w and CO2 phase pressure difference ΔP CO2 , combined with the JBN method, the relative permeabilities of water phase and CO2 phase were calculated respectively.

2. The method for high-precision calculation of CO2-water relative permeability according to claim 1, characterized in that: The non-steady-state core displacement experiment was used to obtain experimental data including the pressure difference at both ends of the core and the cumulative water production. The specific steps are as follows: The washed and dried core is saturated with water by vacuum method; Calculate the mass difference before and after saturation with water to obtain the core porosity; The core is placed in a core holder and kept under certain temperature and pressure conditions for a certain period of time, during which water is injected at a certain speed; After the temperature is constant, increase the water injection rate and measure the absolute permeability of the core; Keep CO2 and water under certain temperature and pressure conditions for a certain period of time to obtain water-saturated CO2; Water-saturated CO2 was injected into the core at a constant rate, and the pressure difference at both ends of the core and the cumulative water production were recorded.

3. The high-precision method for calculating CO2-water relative permeability according to claim 1, characterized in that: The pressure difference between the two ends of the core recorded in the non-steady-state core displacement experiment is fitted to predict the steady-state pressure difference ΔP ∞ , the specific steps are as follows: Draw a curve of pressure difference at both ends of the core and injection volume; Fit the pressure difference data after CO2 breaks through the core production end; The fitting formula is used to predict the pressure difference at both ends of the core when the injection volume is a certain value, which is approximated as the pressure difference ΔP at both ends of the core when a large amount of CO2 is injected to achieve a steady state. ∞ .

4. The method for high-precision calculation of CO2-water relative permeability according to claim 3 is characterized in that: The fitting formula is as follows: In the formula, is the CO2 injection rate, ΔP m is the pressure difference between the two ends of the core measured experimentally, ΔP i is the water injection rate when measuring the absolute permeability of the core, q i is the water injection rate, is the PV number of injected CO2, b0, b1 and b2 are three fitting parameters.

5. The high-precision method for calculating CO2-water relative permeability according to claim 1, characterized in that: The air-mercury capillary force curve is obtained through mercury injection experiment, and the flat section of the curve is extended to obtain the starting pressure prediction value P c,e , the specific steps are as follows: A small core with the same properties as the core in the non-steady-state core flooding experiment was taken for mercury injection experiment to obtain the air-mercury capillary force curve; Convert the air-mercury capillary force curve to the CO2-water capillary force curve; Extend the flat section of the CO2-water capillary force curve to obtain the predicted starting pressure value P c,e .

6. The method for high-precision calculation of CO2-water relative permeability according to claim 5, characterized in that: The calculation formula for converting the air-mercury capillary force curve into the CO2-water capillary force curve is as follows: In the formula, is the CO2-water capillary force, With σ 空气-汞 are the surface tensions of CO2-water and air-mercury, With θ 空气-汞 are the wetting angles of CO2-water and air-mercury, P c,空气-汞 It is the air-mercury capillary force directly measured in the mercury injection experiment.

7. The method for high-precision calculation of CO2-water relative permeability according to claim 1, characterized in that: Using the steady-state pressure difference ΔP ∞ , start pressure prediction value P c,e Correct the pressure difference at both ends of the core to obtain the corrected water phase pressure difference ΔP at both ends of the core w and CO2 phase pressure difference The specific steps are as follows: The steady-state pressure difference ΔP ∞ Used to correct the pressure difference data at both ends of the core recorded in the experiment, so as to obtain the water phase pressure difference ΔP at both ends of the core w , the calculation formula is as follows: ΔP w =ΔP m -ΔP ∞ The starting pressure prediction value P c,e Used to correct the pressure difference data at both ends of the core recorded in the experiment, so as to obtain the CO2 phase pressure difference at both ends of the core The calculation formula is as follows:

8. The method for high-precision calculation of CO2-water relative permeability according to claim 1, characterized in that: Using the corrected water phase pressure difference ΔP at both ends of the core w and CO2 phase pressure difference The relative permeabilities of water phase and CO2 phase are calculated respectively by combining the JBN method. The calculation formula is as follows: In the formula, With k rw are the relative permeabilities of CO2 phase and water phase, T pW is the PV number of the produced water in the experiment, With μ w are the viscosities of the CO2 phase and the water phase, respectively.

9. A high-precision carbon dioxide-water relative permeability measurement device, characterized in that: include: The first processing unit is used to obtain experimental data including the pressure difference at both ends of the core and the cumulative water production by using a non-steady-state core displacement experiment; The second processing unit is used to fit the pressure difference between the two ends of the core recorded in the non-steady-state core displacement experiment, and predict the steady-state pressure difference ΔP ∞ ; The third processing unit is used to obtain the air-mercury capillary force curve through the mercury injection experiment, and extend the flat section of the curve to obtain the starting pressure prediction value P c,e ; The fourth processing unit is used to utilize the steady-state pressure difference ΔP ∞ , start pressure prediction value P c,e Correct the pressure difference at both ends of the core to obtain the corrected water phase pressure difference ΔP at both ends of the core w and CO2 phase pressure difference ΔP CO2 ; The fifth processing unit is used to use the corrected water phase pressure difference ΔP at both ends of the core w and CO2 phase pressure difference ΔP CO2 , combined with the JBN method, the relative permeabilities of water phase and CO2 phase were calculated respectively.

10. A computer-readable storage medium having a computer program stored thereon, characterized in that: When the computer program is executed by a processor, the steps of the method for high-precision measurement of CO2-water relative permeability according to any one of claims 1 to 8 are implemented.

11. A computer device comprising a memory, a processor and a computer program stored in the memory and executable on the processor, characterized in that: When the processor executes the computer program, the steps of the method for high-precision measurement of CO2-water relative permeability according to any one of claims 1-8 are implemented.

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