Experimental device and method for analyzing imbibition effect of capillary tube

Abstract

The embodiment of the invention provides an experimental device and method for analyzing the imbibition effect of a capillary tube, and belongs to the field of industrial analysis. The experimental device comprises a capillary tube, a sample cell, a drainage and injection module, a pressure sensor and a controller, the capillary tube comprises one or more capillary tubes; the sample pool comprises two sample cavities, each capillary tube is horizontally arranged, and two ends of each capillary tube are respectively positioned in the two sample cavities; the drainage and injection module is used for injecting a reagent into the sample cavity; the at least two pressure sensors are used for respectively measuring the pressure at the two ends of the capillary tube; the controller is used for controlling the drainage and injection module according to the pressure, measured by the pressure sensor, of the two ends of the capillary tube, and the pressure difference of the two ends of the capillary tube is controlled within a preset range. The embodiment of the invention can eliminate the interference of the pressure difference at the two ends of the capillary in the capillary imbibition analysis experiment, and ensure the accuracy of the analysis result.

Description

Technical Field

[0001] The invention relates to the field of industrial analysis, and in particular to an experimental device and method for analyzing capillary imbibition. Background Art

[0002] Capillary absorption refers to the mechanical coupling that occurs between the surfaces of liquids, gases, or solids under certain conditions, generating an observable mechanical force field.

[0003] Capillary imbibition has a wide range of applications in nature and industrial production. For example, in the process of using volume fracturing technology to exploit unconventional oil reservoirs, capillary force is used as the main driving force for oil recovery, and reagents are added to improve oil recovery efficiency to complete displacement oil recovery.

[0004] Therefore, it is necessary to analyze the displacement efficiency of different reagents under the action of capillary force and select reagents with high displacement efficiency for actual production. However, the experimental process is affected by various interference factors, resulting in inaccurate analysis results. Summary of the invention

[0005] The purpose of the embodiments of the present invention is to provide an experimental device and method for analyzing capillary imbibition. The embodiments of the present invention can solve or partially solve the problems existing in the prior art.

[0006] In order to achieve the above-mentioned object, an embodiment of the present invention provides an experimental device for analyzing capillary absorption, the device comprising: a capillary, a sample pool, a drainage module, a pressure sensor, and a controller;

[0007] The capillary comprises one or more capillaries;

[0008] The sample pool comprises two sample chambers, each capillary is placed horizontally and both ends of each capillary are respectively located in the two sample chambers;

[0009] The injection module is used to inject the reagent into the sample cavity;

[0010] The pressure sensor comprises at least two pressure sensors for respectively measuring the pressure at both ends of the capillary;

[0011] The controller is used to control the injection module according to the pressure at both ends of the capillary measured by the pressure sensor, so as to control the pressure difference at both ends of the capillary within a preset range.

[0012] Preferably, the sample pool comprises a partition, and the partition is used to separate the sample pool into the two sample chambers. A through hole for the capillary to pass through is provided on the partition, and a connection between the capillary and the through hole is sealed.

[0013] Preferably, the capillaries have the same length on both sides of the partition.

[0014] Preferably, the step of controlling the injection module according to the pressure at both ends of the capillary measured by the pressure sensor to control the pressure difference at both ends of the capillary within a preset range includes:

[0015] When the reagent begins to contact the body of the capillary, the reagent injection speed in the two sample chambers is controlled according to the following formula to control the pressure difference at both ends of the capillary within a preset range:

[0016] The numerical relationship between the pressures at both ends of the capillary tube satisfies:

[0017]

[0018] where ρ 1 , 2 are the densities of the reagents injected into the two sample chambers; S 1 , S 2 are the bottom areas of the two sample chambers respectively; V 1 、V 2 are the reagent flow rates injected into the two sample chambers, g represents the gravitational acceleration, P 3 Indicates the preset difference range of the pressure difference between the two ends.

[0019] Preferably, when P 3 When it is equal to 0, the pressure at both ends of the capillary is equal, and the numerical relationship between the pressures at both ends of the capillary satisfies:

[0020]

[0021] The relationship between the flow rates of the reagents injected into the two sample chambers satisfies:

[0022]

[0023] Preferably, the experimental device further comprises a cover, a heating module, a pressurizing module, an image acquisition module, and a temperature sensor;

[0024] The cover is used to seal the sample cavity;

[0025] The heating module and the pressurizing module are connected to the controller;

[0026] The heating module is used to heat the sample cavity;

[0027] The pressurizing module is used to pressurize the sample chamber;

[0028] The image acquisition module is used to acquire images of the capillaries;

[0029] The temperature sensor is used to collect the temperature of the reagent in the sample pool;

[0030] The controller is also used to determine the moving distance of the reagent in the capillary according to the image of the capillary; according to the temperature measured by the temperature sensor, the controller controls the heating module to heat the temperature of the reagent in the sample pool cavity to a preset temperature.

[0031] Accordingly, an embodiment of the present invention further provides a method for analyzing capillary imbibition, using an experimental device for capillary imbibition, the method comprising:

[0032] saturating one or more capillaries with a first reagent;

[0033] The capillaries are placed horizontally with both ends of each capillary being located in the two sample chambers respectively;

[0034] Using the injection module to inject the first reagent and the second reagent into the two sample chambers respectively;

[0035] The pressure sensor measures the pressure at both ends of the capillary;

[0036] The controller controls the injection module according to the pressure at both ends of the capillary measured by the pressure sensor, so as to control the pressure difference at both ends of the capillary within a preset range;

[0037] The replacement efficiency of the reagent is calculated based on the volume change of the first reagent in the capillary.

[0038] Optionally, the controller controls the injection module according to the pressure at both ends of the capillary measured by the pressure sensor to control the pressure difference at both ends of the capillary within a preset range, including:

[0039] When the first reagent and the second reagent begin to contact the body of the capillary, the injection speed of the reagents in the two sample chambers is controlled according to the following formula to control the pressure difference at both ends of the capillary within a preset range:

[0040] The numerical relationship between the pressures at both ends of the capillary tube satisfies:

[0041]

[0042] where ρ 1 , 2 are the densities of the reagents injected into the two sample chambers; S 1 , S 2 are the bottom areas of the two sample chambers respectively; V 1 、V 2are the reagent flow rates injected into the two sample chambers, g represents the gravitational acceleration, P 3 Indicates the preset difference range of the pressure difference between the two ends.

[0043] Optional, when P 3 When it is equal to 0, the pressure at both ends of the capillary is equal, and the numerical relationship between the pressures at both ends of the capillary satisfies:

[0044]

[0045] The flow rate relationship of the injected reagents on both sides of the sample cell satisfies:

[0046]

[0047] Optionally, the calculation of the replacement efficiency of the reagent includes:

[0048]

[0049] Wherein, V is the volume of the first reagent in the capillary after the capillary is completely saturated; r is the pore size of the capillary; l is the moving distance of the first reagent; π is pi; and w is the replacement efficiency.

[0050] Optionally, the first reagent is unconventional reservoir crude oil, and the second reagent is a displacement agent.

[0051] Optionally, the method for analyzing capillary imbibition further includes: pressurizing the sample cavity to simulate the pressure of the unconventional reservoir; and heating the sample cavity to simulate the temperature of the unconventional reservoir.

[0052] Optionally, the color of the first reagent is different from that of the second reagent.

[0053] The experimental device for analyzing capillary imbibition provided in an embodiment of the present invention comprises a capillary, a sample pool, an injection module, a pressure sensor, and a controller, wherein the controller is used to control the injection module according to the pressure at both ends of the capillary measured by the pressure sensor, so as to control the pressure difference at both ends of the capillary within a preset range. During the experimental process of analyzing capillary imbibition, the interference of the pressure difference at both ends of the capillary is eliminated, thereby ensuring the accuracy of the analysis results, thereby selecting reagents with high replacement efficiency for industrial production.

[0054] Other features and advantages of the embodiments of the present invention will be described in detail in the subsequent detailed description. BRIEF DESCRIPTION OF THE DRAWINGS

[0055] The accompanying drawings are used to provide a further understanding of the embodiments of the present invention and constitute a part of the specification. Together with the following specific implementations, they are used to explain the embodiments of the present invention, but do not constitute a limitation on the embodiments of the present invention. In the accompanying drawings:

[0056] Figure 1 It is a structural schematic diagram of the experimental device provided by the present invention;

[0057] Figure 2 It is a left view of a partition included in the experimental device provided by the present invention;

[0058] Figure 3 It is a diagram of the capillary structure included in the sub-experimental device provided by the present invention;

[0059] Figure 4 is a flow chart of a method for analyzing capillary imbibition provided by the present invention;

[0060] Description of Reference Numerals

[0061] 1. The first injection module

[0062] 2. Heating module

[0063] 3. Capillary

[0064] 4. Image acquisition module

[0065] 5. Cover

[0066] 6. Sample pool

[0067] 7. Pressurization module

[0068] 8. Second injection module

[0069] 9. Temperature sensor

[0070] 10. Pressure sensor

[0071] 11. Controller DETAILED DESCRIPTION

[0072] The specific implementation of the embodiment of the present invention is described in detail below in conjunction with the accompanying drawings. It should be understood that the specific implementation described here is only used to illustrate and explain the embodiment of the present invention, and is not used to limit the embodiment of the present invention.

[0073] Figure 1 is a schematic diagram of the structure of the experimental device provided by the present invention, Figure 2 is a left view of a partition included in the experimental device provided by the present invention, Figure 3 It is a diagram of the capillary structure included in the experimental device provided by the present invention.

[0074] For example, Figure 1As shown, the experimental device for analyzing capillary absorption includes a capillary 3, a sample pool 6, a first discharge module 1, a second discharge module 8, a pressure sensor 10, and a controller 11;

[0075] The capillary tube may be one or more in number;

[0076] Further, combined with Figure 3 The structure of the capillary is introduced, such as Figure 3 As shown, the outer surface of the capillary body can be provided with a threaded joint to facilitate connection and fixation with the experimental device. Optionally, glass glue is used to seal the connection between the capillary and the threaded joint.

[0077] Optionally, the capillary tube is selected as a hydrophilic capillary tube or an oleophilic capillary tube according to different reservoir conditions, for example, a hydrophilic capillary tube is selected for a shale oil reservoir with integrated source and reservoir.

[0078] Accordingly, the number, pore size, and length of the capillaries can be selected according to the experimental conditions. For example, when analyzing the displacement efficiency of the displacing agent on the crude oil in the unconventional reservoir, 20 capillaries with a pore size of 0.1 mm and a length of 0.2 m can be selected to assemble the experimental device.

[0079] The sample pool comprises two sample chambers, each capillary is placed horizontally, and both ends of each capillary are respectively located in the two sample chambers;

[0080] The injection module is used to inject the reagent into the sample cavity;

[0081] The pressure sensor comprises at least two pressure sensors for respectively measuring the pressure at both ends of the capillary;

[0082] The controller is used to control the injection module according to the pressure at both ends of the capillary measured by the pressure sensor, so as to control the pressure difference at both ends of the capillary within a preset range. Preferably, the controller can be a computer.

[0083] The sample pool comprises a partition plate, which is used to separate the sample pool into the two sample chambers. A through hole for the capillary to pass through is arranged on the partition plate, and the connection between the capillary and the through hole is sealed.

[0084] Further, combined with Figure 2 The structure of the sample pool is introduced, such as Figure 2 As shown, the partition separates the sample pool into the two sample chambers, and a certain distance is maintained between the top of the partition and the top of the sample pool body. The partition body is provided with a plurality of parallel through holes for the capillary to pass through. The inner wall of the through hole can be provided with a thread to facilitate fixation with the capillary, and glass glue can also be used to seal the connection between the capillary and the through hole.

[0085] The capillaries have the same length on both sides of the partition.

[0086] The step of controlling the injection module according to the pressure at both ends of the capillary measured by the pressure sensor to control the pressure difference at both ends of the capillary within a preset range includes:

[0087] When the reagent begins to contact the body of the capillary, the reagent injection speed in the two sample chambers is controlled according to the following formula to control the pressure difference at both ends of the capillary within a preset range:

[0088] The numerical relationship between the pressures at both ends of the capillary tube satisfies:

[0089]

[0090] where ρ 1 , 2 are the densities of the reagents injected into the two sample chambers; S 1 , S 2 are the bottom areas of the two sample chambers respectively; V 1 、V 2 are the reagent flow rates injected into the two sample chambers, g represents the gravitational acceleration, P 3 Indicates the preset difference range of the pressure difference between the two ends.

[0091] Accordingly, when P 3 When it is equal to 0, the pressure at both ends of the capillary is equal, and the numerical relationship between the pressures at both ends of the capillary satisfies:

[0092]

[0093] The relationship between the flow rates of the reagents injected into the two sample chambers satisfies:

[0094]

[0095] Controlling the pressure difference at both ends of the capillary within a preset range can eliminate the influence of the pressure difference at both ends of the capillary on the experimental results, thereby ensuring the accuracy of the analysis results.

[0096] Correspondingly, the experimental device further includes a cover 5, a heating module 2, a pressurizing module 7, an image acquisition module 4, and a temperature sensor 9;

[0097] The cover is used to seal the sample chamber, and accordingly, the cover can be made of a transparent material to facilitate observation of the interior of the sample pool;

[0098] The heating module and the pressurizing module are connected to the controller. The heating module is used to heat the sample cavity. Accordingly, the heating module can be an oil bath or a water bath.

[0099] The pressurizing module is used to pressurize the sample cavity to a preset pressure value, and the image acquisition module is used to acquire an image of the capillary;

[0100] The temperature sensor is used to collect the temperature of the reagent in the sample pool;

[0101] Accordingly, multiple temperature sensors can be configured to further ensure that the observation data is continuous and uninterrupted, so that the collected data is more accurate.

[0102] The controller is also used to determine the moving distance of the reagent in the capillary according to the image of the capillary; according to the temperature measured by the temperature sensor, the controller controls the heating module to heat the temperature of the reagent in the sample pool cavity to a preset temperature.

[0103] Accordingly, the controller can be used to adjust and set corresponding control parameters according to experimental conditions, such as the pressure difference between the two ends of the capillary, the preset temperature, and the preset pressure. At the same time, the parameters of each experimental link can be controlled to make the experimental device run more stably.

[0104] For ease of understanding, Figure 4 A method for analyzing capillary imbibition provided by an embodiment of the present invention comprises:

[0105] S401, saturating one or more capillaries to absorb the first reagent;

[0106] The first reagent is unconventional reservoir crude oil, and oil-soluble dye can be added for dyeing to deepen the color of the unconventional reservoir crude oil, thereby facilitating the distinction between the colors of the first reagent and the second reagent.

[0107] For example, prepare a proper amount of unconventional reservoir crude oil, add oil-soluble dye, place 20 capillaries with a pore size of 0.1mm and a length of 0.2m into it, make the capillaries saturated with crude oil, and select the 10 most saturated capillaries to install in the through holes on the partition of the sample pool.

[0108] S402, placing the capillaries horizontally with both ends of each capillary being located in the two sample chambers respectively;

[0109] S403, injecting the first reagent and the second reagent into the two sample chambers respectively using the injection module;

[0110] Wherein, the second reagent is a displacing agent, and the displacing agent may be a surfactant.

[0111] S404, the pressure sensor measures the pressure at both ends of the capillary;

[0112] S405, the controller controls the injection module according to the pressure at both ends of the capillary measured by the pressure sensor, so as to control the pressure difference at both ends of the capillary within a preset range;

[0113] Furthermore, when the reagent begins to contact the body of the capillary, the injection speed of the reagent in the two sample chambers is controlled according to the following formula to control the pressure difference between the two ends of the capillary within a preset range:

[0114] The numerical relationship between the pressures at both ends of the capillary tube satisfies:

[0115]

[0116] where ρ 1 , 2 are the densities of the reagents injected into the two sample chambers; S 1 , S 2 are the bottom areas of the two sample chambers respectively; V 1 、V 2 are the reagent flow rates injected into the two sample chambers, g represents the gravitational acceleration, P 3 Indicates the preset difference range of the pressure difference between the two ends.

[0117] Accordingly, when P 3 When it is equal to 0, the pressure at both ends of the capillary is equal, and the numerical relationship between the pressures at both ends of the capillary satisfies:

[0118]

[0119] The relationship between the flow rates of the reagents injected into the two sample chambers satisfies:

[0120]

[0121] S406. Calculate the replacement efficiency of the reagent according to the volume change of the first reagent in the capillary.

[0122] Furthermore, the crude oil in the capillary is absorbed and moved under the action of capillary force, the image acquisition module acquires the image of the capillary, the controller determines the moving distance of the reagent in the capillary according to the image of the capillary, and calculates the volume change of the first reagent in the capillary in combination with the capillary pore size parameters.

[0123] The replacement efficiency of the reagent is calculated as:

[0124]

[0125] Wherein, v is the volume of the first reagent in the capillary after the capillary is completely saturated, r is the pore size of the capillary; l is the moving distance of the first reagent; π is pi; and w is the replacement efficiency.

[0126] Furthermore, the method for analyzing capillary imbibition also includes:

[0127] The sample cavity is pressurized to simulate the pressure of the unconventional reservoir; the sample cavity is heated to simulate the temperature of the unconventional reservoir. Preferably, the pressurizing module pressurizes the sample pool to 2MPa, and the heating module heats the sample pool to 80°C. The heating module is preferably an oil bath, and the heating temperature can be 50-150°C.

[0128] The experimental device and analysis method provided by the present invention are specifically introduced below in conjunction with the embodiments.

[0129] Example 1

[0130] This example introduces an experimental setup.

[0131] like Figure 1 As shown, the experimental device includes: a first injection module 1 and a second injection module 8, a heating module 2, a capillary 3, an image acquisition module 4, a cover 5, a sample pool 6, a pressurizing module 7, a temperature sensor 9, a pressure sensor 10, and a controller 11.

[0132] The sample pool is made of aluminosilicate glass material. The sample pool is transparent and visible, which is convenient for observing the changes of experimental reagents in the pool during the experiment. Moreover, the main body of the sample pool can withstand a pressure of 2Mpa, which can ensure the safety and stability of the experimental device when simulating the pressure of unconventional reservoirs in the experiment.

[0133] A fixed partition is provided in the middle of the sample pool, such as Figure 2 As shown, the partition separates the sample pool into the two sample chambers, and the top of the partition is kept at a certain distance from the sample pool cover 5. The partition body is provided with a plurality of parallel distributed through holes for the capillary to pass through. The inner wall of the through hole is provided with a thread to facilitate the fixation with the capillary, and glass glue can also be used to seal the connection between the capillary and the through hole.

[0134] like Figure 3 As shown, a threaded joint is provided on the outer surface of the capillary body to facilitate connection and fixation with the experimental device, and glass glue is used to seal the connection between the capillary and the threaded joint.

[0135] Select 20 capillaries with a pore size of 0.1 mm and a length of 0.2 m to make parallel samples and assemble the experimental device. Hydrophilic capillaries are selected for shale oil reservoirs with integrated source and reservoir.

[0136] The heating module is an oil bath box, which is used to heat the sample pool to simulate the temperature of unconventional reservoirs.

[0137] Two pressure sensors are provided, respectively located at the two ends of the capillary in the sample cell, to monitor the pressure at the two ends of the capillary.

[0138] Two injection modules are provided, wherein the first injection module 1 injects a displacement agent into a sample cavity of the sample pool, wherein the displacement agent is a surfactant, and the second injection module 8 injects unconventional reservoir crude oil into another sample cavity, and the two injection modules start injection simultaneously.

[0139] Correspondingly, when the reagent begins to contact the capillary body, the controller controls the injection module according to the pressure at both ends of the capillary measured by the pressure sensor to control the pressure difference at both ends of the capillary within a preset range. This operation is used to eliminate the interference of the pressure difference at both ends of the capillary on the capillary force absorption effect.

[0140] A pressurizing module is set up to pressurize the entire sample pool. On the one hand, it can simulate the pressure of unconventional reservoirs, and on the other hand, it can prevent the surfactant from vaporizing under high temperature conditions.

[0141] The image acquisition module is used to acquire images of the capillaries in real time.

[0142] The temperature sensor is located inside the sample pool and is used to monitor the overall temperature in the sample pool in real time.

[0143] The controller is preferably a computer, which is connected to the injection module, pressurization module, image acquisition module, pressure sensor, temperature sensor, and heating module of the experimental device. The controller is also used to determine the moving distance of the reagent in the capillary according to the image of the capillary; according to the temperature measured by the temperature sensor, the controller controls the heating module to heat the temperature of the reagent in the sample pool cavity to a preset temperature.

[0144] The first injection module 1 injects a displacement agent into a sample chamber of the sample pool, and the second injection module 8 injects unconventional reservoir crude oil into another sample chamber. Before the two reagents come into contact with the capillary tube, the controller controls the injection speed of the reagents in the two sample chambers to be equal;

[0145] When the reagent begins to contact the body of the capillary, the reagent injection speed in the two sample chambers is controlled according to the following formula to control the pressure difference at both ends of the capillary within a preset range:

[0146] The numerical relationship between the pressures at both ends of the capillary tube satisfies:

[0147]

[0148] where ρ 1 , 2 are the densities of the reagents injected into the two sample chambers; S 1 , S 2 are the bottom areas of the two sample chambers respectively; V 1 、V 2 are the reagent flow rates injected into the two sample chambers, g represents the gravitational acceleration, P 3 Indicates the preset difference range of the pressure difference between the two ends.

[0149] Accordingly, when P 3 When it is equal to 0, the pressure at both ends of the capillary is equal, and the numerical relationship between the pressures at both ends of the capillary satisfies:

[0150]

[0151] The relationship between the flow rates of the reagents injected into the two sample chambers satisfies:

[0152]

[0153] Example 2

[0154] This example uses the experimental device provided in Example 1 to analyze the capillary imbibition effect and select the surfactant with the highest oil displacement efficiency for shale reservoirs. Specifically, the following steps are included:

[0155] S11, selecting an appropriate amount of unconventional reservoir crude oil, wherein the unconventional reservoir crude oil is shale reservoir oil, adding an oil-soluble dye, assembling 20 capillaries with a pore diameter of 0.1 mm and a length of 0.2 m, and placing them therein to fully saturate and absorb the shale reservoir oil;

[0156] S12, select 10 capillaries that are most fully saturated among the 20 capillaries and install them in the through holes of the partition in the sample pool;

[0157] S13, the first injection module 1 injects a displacing agent into one of the sample cavities of the sample pool, wherein the displacing agent is a first surfactant, and the second injection module 8 injects shale reservoir oil into another sample cavity;

[0158] The controller controls the injection module according to the pressure at both ends of the capillary measured by the pressure sensor, so as to control the pressure difference at both ends of the capillary within a preset range, and the controller is preferably a computer;

[0159] Correspondingly, the numerical relationship between the pressures at both ends of the capillary tube satisfies:

[0160]

[0161] where ρ1 , 2 are the densities of the reagents injected into the two sample chambers; S 1 , S 2 are the bottom areas of the two sample chambers respectively; V 1 、V 2 are the reagent flow rates injected into the two sample chambers, g represents the gravitational acceleration, P 3 Indicates the preset difference range of the pressure difference between the two ends.

[0162] Accordingly, when P 3 When it is equal to 0, the pressure at both ends of the capillary is equal, and the numerical relationship between the pressures at both ends of the capillary satisfies:

[0163]

[0164] The relationship between the flow rates of the reagents injected into the two sample chambers satisfies:

[0165]

[0166] After the two cavities of the sample pool are filled with liquid, the cover is closed and sealed;

[0167] S14, the pressurizing module pressurizes the sample pool to 2MPa, and after the pressurization is completed, the sample pool is heated to 80°C using an oil bath;

[0168] S15, the image acquisition module acquires the image of the capillary, and the controller determines the movement distance S1=0.126m of the shale reservoir oil in the capillary at 3 minutes based on the image of the capillary;

[0169] S16. Replace the displacing agent, use the second to fifth surfactants respectively, repeat steps S11 to S15, and record the corresponding shale reservoir oil movement distances S2 to S5 in the capillary when using different displacing agents. S2 to S5 are S2=0.08, S3=0.114, S4=0.005, and S5=0.010 respectively.

[0170] S17. According to the displacement efficiency formula, the displacement efficiencies of the first to fifth surfactants are calculated. For the shale reservoir oil, the first surfactant, i.e., the nano-yield enhancer, has the best effect, with an oil recovery rate of 63%.

[0171] The calculation formula of the surfactant replacement efficiency is:

[0172]

[0173] Wherein, V is the volume of shale reservoir oil in the capillary after the capillary is completely saturated, r is the pore size of the capillary; l is the moving distance of the first reagent; π is pi; and w is the replacement efficiency.

[0174] S18. In oil production, the application of screened surfactants, namely nano-yield enhancers, has produced beneficial effects in actual production.

[0175] In actual field application, a new well GY14, with a reservoir depth of 2170.48m and a reservoir temperature of 100.9℃, was added with nano oil displacement agent at a ratio of 0.3% during the on-site fracturing fluid stage. The well was constructed in 45 sections and the cumulative oil output was 881.29m 3 The oil return rate is low, at 0.98%, and the effect is good.

[0176] Those skilled in the art will appreciate that the embodiments of the present application may be provided as methods, systems, or computer program products. Therefore, the present application may adopt the form of a complete hardware embodiment, a complete software embodiment, or an embodiment in combination with software and hardware. Moreover, the present application may adopt the form of a computer program product implemented in one or more computer-usable storage media (including but not limited to disk storage, CD-ROM, optical storage, etc.) that include computer-usable program code.

[0177] The present application is described with reference to the flowcharts and / or block diagrams of the methods, devices (systems), and computer program products according to the embodiments of the present application. It should be understood that each process and / or box in the flowchart and / or block diagram, as well as the combination of the processes and / or boxes 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.

[0178] 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.

[0179] 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 1 A process or multiple processes and / or boxes Figure 1 The steps for the functions specified in one or more boxes.

[0180] In a typical configuration, a computing device includes one or more processors (CPU), input / output interfaces, network interfaces, and memory.

[0181] The memory may include non-permanent memory in a computer-readable medium, random access memory (RAM) and / or non-volatile memory in the form of read-only memory (ROM) or flash RAM. The memory is an example of a computer-readable medium.

[0182] Computer readable media include permanent and non-permanent, removable and non-removable media that can be implemented by any method or technology to store information. Information can be computer readable instructions, data structures, program modules or other data. Examples of computer storage media include, but are not limited to, phase change memory (PRAM), static random access memory (SRAM), dynamic random access memory (DRAM), other types of random access memory (RAM), read-only memory (ROM), electrically erasable programmable read-only memory (EEPROM), flash memory or other memory technology, compact disk read-only memory (CD-ROM), digital versatile disk (DVD) or other optical storage, magnetic cassettes, magnetic tape magnetic disk storage or other magnetic storage devices or any other non-transmission media that can be used to store information that can be accessed by a computing device. As defined herein, computer readable media does not include temporary computer readable media (transitory media), such as modulated data signals and carrier waves.

[0183] It should also be noted that the terms "include", "comprises" or any other variations thereof are intended to cover non-exclusive inclusion, so that a process, method, commodity or device including a series of elements includes not only those elements, but also other elements not explicitly listed, or also includes elements inherent to such process, method, commodity or device. In the absence of more restrictions, the elements defined by the sentence "comprises a ..." do not exclude the existence of other identical elements in the process, method, commodity or device including the elements.

[0184] The above are only embodiments of the present application and are not intended to limit the present application. For those skilled in the art, the present application may have various changes and variations. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present application should be included within the scope of the claims of the present application.

Claims

1. An experimental device for analyzing capillary imbibition, characterized in that: Including capillary, sample pool, injection module, pressure sensor, controller; The capillary comprises one or more capillaries; The sample pool comprises two sample chambers, each capillary is placed horizontally and both ends of each capillary are respectively located in the two sample chambers; The injection module is used to inject the reagent into the sample cavity; the pressure sensor includes at least two pressure sensors, which are used to measure the pressure at both ends of the capillary respectively; The controller is used to control the injection module according to the pressure at both ends of the capillary measured by the pressure sensor, so as to control the pressure difference at both ends of the capillary within a preset range.

2. The experimental device according to claim 1, characterized in that: The sample pool comprises a partition plate, which is used to separate the sample pool into the two sample chambers. A through hole for the capillary to pass through is arranged on the partition plate, and the connection between the capillary and the through hole is sealed.

3. The experimental device according to claim 2, characterized in that: The capillaries have the same length on both sides of the partition.

4. The experimental device according to claim 1, characterized in that: The step of controlling the injection module according to the pressure at both ends of the capillary measured by the pressure sensor to control the pressure difference at both ends of the capillary within a preset range includes: When the reagent begins to contact the body of the capillary, the reagent injection speed in the two sample chambers is controlled according to the following formula to control the pressure difference at both ends of the capillary within a preset range: The numerical relationship between the pressures at both ends of the capillary tube satisfies: Wherein ρ1 and ρ2 are the densities of the reagents injected into the two sample cavities respectively; S1 and S2 are the bottom areas of the two sample cavities respectively; V1 and V2 are the flow rates of the reagents injected into the two sample cavities respectively, g represents the acceleration of gravity, and P3 represents the preset difference range of the pressure difference at both ends.

5. The experimental device according to claim 4, characterized in that: When P3 is equal to 0, the pressures at both ends of the capillary are equal, and the numerical relationship between the pressures at both ends of the capillary satisfies: The relationship between the flow rates of the reagents injected into the two sample chambers satisfies:

6. The experimental device according to claim 1, characterized in that: The experimental device also includes a cover, a heating module, a pressurizing module, an image acquisition module, and a temperature sensor; The cover is used to seal the sample cavity; The heating module and the pressurizing module are connected to the controller; The heating module is used to heat the sample cavity; The pressurizing module is used to pressurize the sample chamber; The image acquisition module is used to acquire images of the capillaries; The temperature sensor is used to collect the temperature of the reagent in the sample pool; The controller is also used to determine the moving distance of the reagent in the capillary according to the image of the capillary; according to the temperature measured by the temperature sensor, the controller controls the heating module to heat the temperature of the reagent in the sample pool cavity to a preset temperature.

7. A method for analyzing capillary imbibition, characterized in that: The method utilizes the experimental device described in any one of claims 1 to 6, and the method comprises: saturating one or more capillaries with a first reagent; The capillaries are placed horizontally with both ends of each capillary being located in the two sample chambers respectively; Using the injection module to inject the first reagent and the second reagent into the two sample chambers respectively; The pressure sensor measures the pressure at both ends of the capillary; The controller controls the injection module according to the pressure at both ends of the capillary measured by the pressure sensor, so as to control the pressure difference at both ends of the capillary within a preset range; The replacement efficiency of the reagent is calculated based on the volume change of the first reagent in the capillary.

8. The method according to claim 7, characterized in that The controller controls the injection module according to the pressure at both ends of the capillary measured by the pressure sensor to control the pressure difference at both ends of the capillary within a preset range, including: When the first reagent and the second reagent begin to contact the body of the capillary, the injection speed of the reagents in the two sample chambers is controlled according to the following formula to control the pressure difference at both ends of the capillary within a preset range: The numerical relationship between the pressures at both ends of the capillary tube satisfies: Wherein ρ1 and ρ2 are the densities of the reagents injected into the two sample cavities respectively; S1 and V2 are the bottom areas of the two sample cavities respectively; V1 and V2 are the flow rates of the reagents injected into the two sample cavities respectively, g represents the acceleration of gravity, and P3 represents the preset difference range of the pressure difference at both ends.

9. The method according to claim 8, characterized in that When P3 is equal to 0, the pressures at both ends of the capillary are equal, and the numerical relationship between the pressures at both ends of the capillary satisfies: The flow rate relationship of the injected reagents on both sides of the sample cell satisfies:

10. The method according to claim 7, characterized in that The calculation of the replacement efficiency of the reagent includes: Wherein, V is the volume of the first reagent in the capillary after the capillary is completely saturated, r is the pore size of the capillary; l is the moving distance of the first reagent; π is pi; and w is the replacement efficiency.

11. The method according to claim 7, characterized in that The first reagent is unconventional reservoir crude oil, and the second reagent is a displacement agent.

12. The method according to claim 11, characterized in that The method for analyzing capillary imbibition also includes: Pressurizing the sample cavity to simulate the pressure of the unconventional reservoir; The sample chamber is heated to simulate the temperature of the unconventional reservoir.

13. The method according to claim 10, characterized in that The first reagent has a different color from the second reagent.

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