Quantitative evaluation method and system for imbibition extraction efficiency of shale oil reservoir

Abstract

The invention provides a shale oil reservoir imbibition extraction efficiency quantitative evaluation method and system, and relates to the technical field of oil and gas field development, and the method comprises the steps: extracting the morphological characteristics of an imbibition network for a fracture network structure formed after a target reservoir is fractured, so as to construct an imbibition physical model; enabling the imbibition physical model to saturate crude oil and formation water according to original formation conditions to obtain an imbibition physical model in a saturated state; and carrying out an imbibition efficiency quantitative evaluation experiment through the imbibition physical model in the saturated state so as to calculate the imbibition extraction efficiency of the imbibition liquid. According to the method, various problems of difficulty in quantitative evaluation of the continental facies shale oil imbibition efficiency and the like at present are solved, and the reconstruction effect of continental facies shale oil gas accumulation fracturing can be effectively improved.

Description

Technical Field

[0001] The present invention relates to the technical field of oil and gas field development, and in particular to a method and system for quantitatively evaluating the imbibition and recovery efficiency of a shale oil reservoir. Background Art

[0002] Shale oil and gas development is experiencing rapid growth both domestically and internationally. However, the complex sedimentary environment of continental shale oil and gas in China, resulting in the development of reservoir interlayers and high clay mineral content, presents significant challenges for engineering reconstruction. In particular, the small pore throats and strong capillary forces in continental shale deposits hinder the flow of oil-phase fluids. Notably, continental shale deposits have high clay mineral content and strong hydration and imbibition. During the development of some blocks, it was found that hydration and imbibition can help induce small and micro-scale fractures, increase the complexity of the fracture network, and thus improve oil and gas recovery.

[0003] In recent years, to effectively utilize the increasing complexity of reservoir fractures caused by imbibition hydration, imbibition agents have been added to fracturing fluids during some shale oil reservoir construction operations to maximize the reservoir's imbibition efficiency and, consequently, enhance oil recovery. Mining sites typically conduct imbibition experiments on cores to evaluate the efficiency of selected imbibition agents. However, due to the high heterogeneity of shale oil reservoirs, reproducible core experiments are difficult to conduct, making quantitative evaluation of imbibition efficiency challenging.

[0004] In response to the problems of the prior art, the present invention provides a method and system for quantitatively evaluating the imbibition and recovery efficiency of shale oil reservoirs. Summary of the Invention

[0005] In order to overcome the defects of the prior art, the present invention provides a method for quantitatively evaluating the imbibition and recovery efficiency of shale oil reservoirs, the method comprising:

[0006] Based on the fracture network structure formed after the target reservoir is fractured, the morphological characteristics of the imbibition network are extracted to construct an imbibition physical model;

[0007] saturating the imbibition physical model with crude oil and formation water according to original formation conditions to obtain the imbibition physical model in a saturated state;

[0008] By using the imbibition physical model under saturated conditions, a quantitative evaluation experiment on imbibition efficiency is carried out to calculate the imbibition recovery efficiency of the imbibition liquid.

[0009] According to one embodiment of the present invention, the imbibition physical model is constructed by the following steps:

[0010] Study the pore throat structure characteristics of the target reservoir and determine the average pore radius;

[0011] Based on the morphological characteristics of the imbibition network and the average pore radius, the radius of each imbibition channel in the imbibition network and the node positions where different imbibition channels intersect are determined as structural parameters of the imbibition physical model;

[0012] The imbibition physical model is constructed based on the structural parameters.

[0013] According to one embodiment of the present invention, the structural parameters are determined by the following steps:

[0014] The rock sample cavity is used to characterize each imbibition pipeline, and the average pore radius is used as the cavity radius of each imbibition pipeline;

[0015] The nodes where different imbibition pipelines intersect are regarded as open nodes to represent the interconnection between different imbibition pipelines.

[0016] According to one embodiment of the present invention, the imbibition physical model under saturation state is obtained by the following steps:

[0017] determining the original oil saturation and the original water saturation under the original formation conditions;

[0018] The imbibition physical model is saturated with crude oil volume V1 and formation water volume V2 so that its oil saturation and water saturation are equal to the original oil saturation and the original water saturation, thereby obtaining the imbibition physical model in a saturated state.

[0019] According to one embodiment of the present invention, a quantitative evaluation experiment of the absorption efficiency is carried out by the following steps:

[0020] In the edge imbibition pipe of the imbibition physical model under saturation, a fluid injection port and a fluid outflow port are selected;

[0021] Keep the fluid injection port and the fluid outflow port unobstructed, and close the remaining edge infiltration and absorption channels;

[0022] After injecting the imbibed liquid volume V3 through the fluid injection port, closing the fluid injection port;

[0023] The crude oil flowing out of the fluid outflow port is collected, and the volume of the crude oil flowing out is recorded as V4.

[0024] According to one embodiment of the present invention, the imbibition recovery efficiency of the imbibition liquid is calculated by the following steps: the imbibition recovery efficiency of the imbibition liquid is calculated by the outflowing crude oil volume V4 and the crude oil volume V1 saturated by the imbibition physical model.

[0025] According to one embodiment of the present invention, the imbibition efficiency of the imbibition liquid is calculated by the following expression:

[0026]

[0027] Where: η represents the imbibition recovery efficiency of the imbibition liquid, %; V4 represents the volume of crude oil flowing out of the fluid outflow port, mL; V1 represents the volume of crude oil saturated by the imbibition physical model, mL.

[0028] According to another aspect of the present invention, a storage medium is provided, which contains a series of instructions for executing the method steps described in any one of the above.

[0029] According to another aspect of the present invention, a quantitative evaluation system for imbibition and recovery efficiency of shale oil reservoirs is provided, wherein the system comprises the imbibition physical model as described in any one of the above items.

[0030] According to one embodiment of the present invention, the system further includes: a displacement pump, an imbibition liquid container, an outflow fluid collection device, a temperature control device, and a data analysis device, wherein the displacement pump is used to pump the imbibition liquid in the imbibition liquid container to the imbibition physical model in a saturated state, the outflow fluid collection device is used to collect the liquid flowing out of the imbibition physical model in a saturated state, the temperature control device is used to control the temperature environment during the imbibition efficiency quantitative evaluation experiment, and the data analysis device is used to calculate the imbibition extraction efficiency of the imbibition liquid.

[0031] The present invention provides a method and system for quantitatively evaluating the imbibition and recovery efficiency of shale oil reservoirs. Compared with existing technologies, the present invention has the following advantages: Based on a constructed imbibition physical model of shale oil reservoirs, the present invention establishes a quantitative evaluation method for imbibition and recovery efficiency. By extracting the morphological characteristics of the complex fracture network after target reservoir fracturing, an imbibition network morphology is constructed. Using 3D printing technology, an imbibition physical model is formed, and the imbibition and recovery efficiency of different fluids is evaluated. This method solves various problems currently encountered in quantitatively evaluating the imbibition efficiency of continental shale oil, such as the difficulty in conducting such evaluations, and can effectively improve the effectiveness of volumetric fracturing of continental shale oil and gas.

[0032] Other features and advantages of the present invention will be described in the following description, and in part will become apparent from the description, or will be understood by practicing the present invention. The purposes and other advantages of the present invention can be realized and obtained by the structures particularly pointed out in the description, claims and drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0033] The accompanying drawings are used to provide a further understanding of the present invention and constitute a part of the specification. Together with the embodiments of the present invention, they are used to explain the present invention and do not constitute a limitation of the present invention. In the accompanying drawings:

[0034] Figure 1A flowchart showing the steps of a method for quantitatively evaluating the imbibition and recovery efficiency of a shale oil reservoir according to one embodiment of the present invention is shown;

[0035] Figure 2 A schematic diagram showing the morphological characteristics of an imbibition network according to one embodiment of the present invention;

[0036] Figure 3 A schematic diagram of an imbibition physical model according to an embodiment of the present invention is shown;

[0037] Figure 4 A structural block diagram of a shale oil reservoir imbibition and recovery efficiency quantitative evaluation system according to an embodiment of the present invention is shown.

[0038] In the accompanying drawings, the same reference numerals are used for the same parts. In addition, the accompanying drawings are not drawn according to the actual scale.

[0039] The meanings of the reference numerals in the accompanying drawings are as follows: 10 - imbibition physical model; 1 - fluid injection port; 2 - fluid outflow port; 20 - displacement pump; 30 - imbibition liquid container; 40 - outflow end fluid collection device; 50 - temperature control device; 60 - data analysis device. DETAILED DESCRIPTION

[0040] To make the objectives, technical solutions and advantages of the present invention more clear, embodiments of the present invention are described in further detail below with reference to the accompanying drawings.

[0041] Prior art (CN105547958B) relates to a spontaneous imbibition measurement method for shale. Prior art (CN112255159B) discloses a comprehensive evaluation method for the hydration capacity of heterogeneous shale reservoirs. Prior art (CN114034597B) relates to a shale core high-temperature and high-pressure saturation, fracturing, and imbibition integrated device and experimental method thereof. Prior art (CN110320228B) discloses a test and analysis method and device for the oil recovery efficiency of CO2 injection and imbibition in shale oil reservoirs. Prior art (CN114076723A) provides a quantitative study method for imbibition in saline shale reservoirs. Prior art (CN108333098B) relates to a shale gas reservoir micro-fracture high-temperature and high-pressure visualization gas-water two-phase seepage experimental device that simulates the gas-liquid two-phase seepage law in shale under high temperature and high pressure.

[0042] However, all of the above existing technologies use cores (rock samples, etc.) to conduct imbibition experiments to evaluate the imbibition efficiency of the preferred imbibition agent. Due to the strong heterogeneity of shale oil reservoirs, repeatable core experiments are difficult to conduct, making quantitative evaluation of imbibition efficiency difficult.

[0043] The prior art (CN115824924A) discloses a high-temperature and high-pressure resistant imbibition visualization system and imbibition parameter measurement method, which achieves the effect of simulating the imbibition process under high-temperature and high-pressure conditions and visually observing the complete imbibition process. However, it does not construct an imbibition physical model according to the complex fracture network morphology after real reservoir fracturing, and cannot solve the current technical problem of the difficulty in quantitatively evaluating the imbibition efficiency of continental shale oil. Since the imbibition characteristics of different shale oil and gas blocks vary greatly, the prior art (CN115824924A) does not reflect the differences for specific oil and gas blocks and is not very instructive.

[0044] In response to the above-mentioned defects of the prior art, the present invention proposes a quantitative evaluation method and system for the imbibition and recovery efficiency of shale oil reservoirs to solve the problem of poor repeatability of shale oil reservoir imbibition experiments, improve the scientific nature of the evaluation of imbibition and recovery efficiency, and provide technical support for increasing shale oil reserves and production.

[0045] Figure 1 A flowchart showing the steps of a method for quantitatively evaluating the imbibition and recovery efficiency of a shale oil reservoir according to an embodiment of the present invention is shown.

[0046] like Figure 1 As shown, in step S101, the morphological characteristics of the imbibition network are extracted from the fracture network structure formed after hydraulic fracturing of the target reservoir to construct an imbibition physical model 10. Specifically, based on the extraction of the morphological characteristics of the complex fracture network after hydraulic fracturing of the target reservoir, an imbibition network morphology is constructed, and the imbibition physical model 10 is formed using 3D printing. Furthermore, the fracture network structure refers to the complex network system of hydraulic fractures and artificial fractures formed after (large-scale) hydraulic fracturing.

[0047] In one embodiment, in step S101 , an imbibition physical model 10 is constructed through steps S1011 - S1013 .

[0048] In step S1011, the pore throat structure characteristics of the target reservoir are studied and the average pore radius is determined. Specifically, the pore throat structure characteristics of the target reservoir are studied and the average pore radius is recorded as r1.

[0049] In step S1012, the radius of each imbibition channel in the imbibition network and the locations of the nodes where different imbibition channels intersect are determined based on the morphological characteristics of the imbibition network and the average pore radius. These are used as structural parameters of the imbibition physical model 10. Specifically, the structural parameters are determined by: using the rock sample cavity to represent each imbibition channel, using the average pore radius as the cavity radius of each imbibition channel; and using the nodes where different imbibition channels intersect as open nodes to indicate the interconnection between the different imbibition channels.

[0050] In one embodiment, based on the extraction of complex fracture network morphological characteristics of the target reservoir after fracturing, the imbibition network morphology is constructed, such as Figure 2 As shown, the radius of each imbibition pipeline is r1, and the node position where different imbibition pipelines intersect is an open node, which can realize the interconnection of different imbibition pipelines.

[0051] In step S1013, the imbibition physical model 10 is constructed based on the structural parameters. Specifically, by means of 3D printing, Figure 2 Printing forms the imbibition physical model 10, the imbibition physical model 10 has a length and a width of L and a thickness of h. Figure 3 As shown in Figure 1, the imbibition channel is represented by a rock sample cavity with a cavity radius of r1.

[0052] like Figure 1 As shown, in step S102, according to the original formation conditions, the imbibition physical model 10 is saturated with crude oil and formation water to obtain the imbibition physical model 10 in a saturated state.

[0053] In one embodiment, in step S102, the imbibition physical model 10 in a saturated state is obtained by the following steps: determining the original oil saturation and the original water saturation under the original formation conditions; saturating the imbibition physical model 10 with the crude oil volume V1 and the formation water volume V2 so that its oil saturation and water saturation are equal to the original oil saturation and the original water saturation, thereby obtaining the imbibition physical model 10 in a saturated state.

[0054] Specifically, the imbibition physical model 10 is saturated with crude oil volume V1 and formation water volume V2 so that its oil saturation and water saturation are equal to the original oil saturation and water saturation under formation conditions.

[0055] like Figure 1 As shown, in step S103, an imbibition efficiency quantitative evaluation experiment is carried out through the imbibition physical model 10 under saturation state to calculate the imbibition recovery efficiency of the imbibition liquid.

[0056] Specifically, after the imbibition physical model 10 is saturated with crude oil and formation water according to the formation oil saturation and water saturation in step S102, a quantitative evaluation of the imbibition efficiency is performed in step S103 to calculate the imbibition recovery efficiency of the imbibition liquid.

[0057] It should be noted that, depending on the actual situation, different imbibition liquids can be selected to conduct the imbibition efficiency quantitative evaluation experiment, and the present invention does not limit the type of imbibition liquid.

[0058] In one embodiment, in step S103, a quantitative evaluation experiment of imbibition efficiency is carried out through the following steps: in the edge imbibition pipe of the imbibition physical model 10 under saturation, a fluid injection port 1 and a fluid outflow port 2 are selected; the fluid injection port 1 and the fluid outflow port 2 are kept unobstructed, and the remaining edge imbibition pipes are closed; after injecting an imbibition liquid volume V3 through the fluid injection port 1, the fluid injection port 1 is closed; and the crude oil flowing out of the fluid outflow port 2 is collected, and the volume of the crude oil flowing out is recorded as V4.

[0059] In one embodiment, in step S103 , the imbibition recovery efficiency of the imbibition liquid is calculated by the following steps: the imbibition recovery efficiency η of the imbibition liquid is calculated by the outflowing crude oil volume V4 and the crude oil volume V1 saturated by the imbibition physical model 10 .

[0060] Specifically, the edges of the seepage pipe of the imbibition physical model 10 are kept closed except for the fluid injection port 1 and the fluid outflow port 2. Figure 3 As shown, 1 is the fluid injection port, 2 is the fluid outflow port, and the imbibition physical model 10 is placed in the Figure 4 The quantitative evaluation system shown in the figure was used to quantitatively evaluate imbibition efficiency. During the experiment, a volume of imbibition liquid (V3) was injected at a slow flow rate through fluid injection port 1. After this, fluid injection port 1 was closed and the volume of crude oil (V4) flowing out of fluid outlet port 2 was observed. This allowed the imbibition recovery efficiency (η) of the imbibition liquid to be calculated.

[0061] In one embodiment, in step S103, the imbibition efficiency of the imbibition liquid is calculated using the following expression:

[0062]

[0063] Where: η represents the imbibition recovery efficiency of the imbibition liquid, %; V4 represents the volume of crude oil flowing out of the fluid outflow port, mL; V1 represents the volume of crude oil saturated by the imbibition physical model, mL.

[0064] In summary, the present invention establishes a quantitative evaluation method for imbibition recovery efficiency based on the constructed shale oil reservoir imbibition physical model 10. By extracting the complex fracture network morphology characteristics of the target reservoir after fracturing, an imbibition network morphology is constructed. Using 3D printing technology, the imbibition physical model 10 is constructed to evaluate the imbibition recovery efficiency of different fluids, effectively improving the efficiency of volumetric fracturing of continental shale oil and gas.

[0065] The method and system for quantitatively evaluating the imbibition and extraction efficiency of shale oil reservoirs provided by the present invention may also be used in conjunction with a computer-readable storage medium having a computer program stored thereon. The computer program is executed to implement the method for quantitatively evaluating the imbibition and extraction efficiency of shale oil reservoirs. A computer program is capable of executing computer instructions, which include computer program code. The computer program code may be in source code form, object code form, executable file, or some intermediate form.

[0066] Computer-readable storage media may include: any entity or device that can carry computer program code, recording media, USB flash drives, mobile hard drives, magnetic disks, optical disks, computer memory, read-only memory (ROM), random access memory (RAM), electrical carrier signals, telecommunication signals, and software distribution media, etc.

[0067] It should be noted that the content contained in computer-readable storage media can be appropriately increased or decreased according to the requirements of legislation and patent practices in the jurisdiction. For example, in some jurisdictions, according to legislation and patent practices, computer-readable storage media do not include electrical carrier signals and telecommunications signals.

[0068] Figure 4 A structural block diagram of a shale oil reservoir imbibition and recovery efficiency quantitative evaluation system according to an embodiment of the present invention is shown.

[0069] According to another aspect of the present invention, a quantitative evaluation system for imbibition recovery efficiency of shale oil reservoirs is provided, which includes an imbibition physical model 10.

[0070] In one embodiment, Figure 4 As shown, a quantitative evaluation system for shale oil reservoir imbibition recovery efficiency also includes: a displacement pump 20, an imbibition liquid container 30, an outflow end fluid collection device 40, a temperature control device 50, and a data analysis device 60.

[0071] Specifically, the displacement pump 20 is used to pump the imbibed liquid in the imbibed liquid container 30 to the imbibed physical model 10 in a saturated state, the outflow end fluid collection device 40 is used to collect the liquid flowing out of the imbibed physical model 10 in a saturated state, the temperature control device 50 is used to control the temperature environment during the imbibed efficiency quantitative evaluation experiment, and the data analysis device 60 is used to calculate the imbibed liquid's imbibed extraction efficiency.

[0072] In summary, the present invention establishes a quantitative evaluation method for imbibition recovery efficiency based on a constructed shale oil reservoir imbibition recovery efficiency quantitative evaluation system. By extracting the complex fracture network morphology characteristics of the target reservoir after fracturing, an imbibition network morphology is constructed. Using 3D printing technology, an imbibition physical model 10 is formed. The imbibition recovery efficiency quantitative evaluation system is used to evaluate the imbibition recovery efficiency of different fluids, thereby improving the scientific nature of the imbibition efficiency evaluation of heterogeneous shale oil reservoirs.

[0073] In one embodiment, the quantitative evaluation method and system for shale oil reservoir imbibition and recovery efficiency provided by the present invention are illustrated by way of examples.

[0074] (1) The pore throat structure characteristics of the target reservoir were studied, and the average pore radius r1 was 35 nm.

[0075] (2) Based on the extraction of complex fracture network morphology characteristics of the target reservoir after fracturing, the imbibition network morphology is constructed. The radius of each imbibition pipeline is 35 nm. The nodes where different pipelines intersect are open nodes, which can realize the interconnection of different pipelines.

[0076] (3) Using 3D printing, a rock sample imbibition model (imbibition physical model 10) was printed. The model was 50 cm long and wide, and 20 cm thick. The imbibition channel was characterized by a rock sample cavity with a cavity radius of 35 nm.

[0077] (4) The rock sample imbibition model is saturated with 120 mL of crude oil and 26 mL of formation water so that its oil saturation and water saturation are equal to the original oil saturation and water saturation under formation conditions.

[0078] (5) Except for the fluid injection port 1 and the fluid outflow port 2, the edges of the seepage pipe of the rock sample imbibition model are kept open, and the rest of the pipe edges are kept closed. 1 is the fluid injection port, and 2 is the fluid outflow port. Figure 4 The quantitative evaluation system shown in the figure was used to quantitatively evaluate imbibition efficiency. After injecting 30 mL of imbibition liquid at a slow flow rate into fluid injection port 1 and closing it, the volume of crude oil flowing out of fluid outlet port 2 (40 mL) was observed. The imbibition recovery efficiency, η, of the imbibition liquid was calculated to be 33%.

[0079] In summary, the present invention provides a method and system for quantitatively evaluating the imbibition and recovery efficiency of shale oil reservoirs. Compared with the existing technology, the present invention has the following advantages: Based on the constructed imbibition physical model of shale oil reservoirs, the present invention establishes a quantitative evaluation method for imbibition and recovery efficiency. By extracting the complex fracture network morphology characteristics of the target reservoir after fracturing, an imbibition network morphology is constructed. With the help of 3D printing technology, an imbibition physical model is formed, and the imbibition and recovery efficiency of different fluids is evaluated. This solves various problems such as the difficulty in quantitatively evaluating the imbibition efficiency of continental shale oil, and can effectively improve the volume fracturing transformation effect of continental shale oil and gas.

[0080] It should be understood that the embodiments disclosed herein are not limited to the specific structures, processing steps, or materials disclosed herein, but should extend to equivalent substitutions of these features understood by those skilled in the relevant art. It should also be understood that the terminology used herein is for the purpose of describing specific embodiments only and is not intended to be limiting.

[0081] In the description of the present invention, unless otherwise specified, "plurality" means two or more; terms such as "upper," "lower," "left," "right," "inner," "outer," "front end," "rear end," "head," and "tail" indicate positions or relationships based on those shown in the accompanying drawings. These terms are intended solely to facilitate the description of the present invention and simplify the description. They do not indicate or imply that the devices or components referred to must have a specific orientation, be constructed, or operate in a specific orientation. Therefore, they should not be construed as limiting the present invention. Furthermore, terms such as "first," "second," and "third" are used for descriptive purposes only and should not be construed as indicating or implying relative importance.

[0082] In the description of the present invention, it should be noted that, unless otherwise expressly specified or limited, the terms "connected" and "connection" should be understood in a broad sense. For example, they can refer to fixed connection, detachable connection, or integral connection; mechanical connection, electrical connection; direct connection, or indirect connection through an intermediary. Those skilled in the art will understand the specific meanings of the above terms in the present invention based on the specific circumstances.

[0083] Certain terms are used throughout this application document to indicate specific system components. As will be appreciated by those skilled in the art, different names may be used to indicate the same component, and thus this application document is not intended to distinguish between components that are only different in name but not in function. In this application document, the terms "comprise," "include," and "have" are used in an open format and should therefore be interpreted as meaning "including, but not limited to...". In addition, the terms "substantially," "substantially," or "approximately" that may be used herein refer to industry-accepted tolerances for the corresponding terms. The term "coupling," as used herein, includes direct coupling and indirect coupling via another component, element, circuit, or module, wherein for indirect coupling, the intervening component, element, circuit, or module does not change the information of the signal but can adjust its current level, voltage level, and / or power level. Inferred coupling (e.g., one element is coupled to another element by inference) includes direct and indirect coupling between two elements in the same manner as "coupling."

[0084] References in this specification to "one embodiment" or "an embodiment" mean that a particular feature, structure, or characteristic described in connection with the embodiment is included in at least one embodiment of the present invention. Therefore, appearances of the phrases "one embodiment" or "an embodiment" in various places throughout this specification do not necessarily refer to the same embodiment.

[0085] The embodiments of the present invention are presented for purposes of illustration and description and are not intended to be exhaustive or to limit the invention to the disclosed forms. Many modifications and variations will be apparent to those skilled in the art. The embodiments are chosen and described in order to better illustrate the principles of the invention and its practical application and to enable those skilled in the art to understand the invention and design various embodiments with various modifications as suited for specific applications.

[0086] Although the embodiments disclosed herein are as described above, the contents described herein are merely embodiments for facilitating understanding of the present invention and are not intended to limit the present invention. Any person skilled in the art of the present invention may make any modifications and changes in the form and details of the implementation without departing from the spirit and scope disclosed herein. However, the scope of patent protection of the present invention shall still be subject to the scope defined by the appended claims.

Claims

1. A quantitative evaluation method for the imbibition recovery efficiency of shale oil reservoirs, characterized in that: The method comprises: Based on the fracture network structure formed after the target reservoir is fractured, the morphological characteristics of the imbibition network are extracted to construct an imbibition physical model; saturating the imbibition physical model with crude oil and formation water according to original formation conditions to obtain the imbibition physical model in a saturated state; By using the imbibition physical model under saturated conditions, a quantitative evaluation experiment on imbibition efficiency is carried out to calculate the imbibition recovery efficiency of the imbibition liquid.

2. A quantitative evaluation method for shale oil reservoir imbibition and recovery efficiency according to claim 1, characterized in that: The imbibition physical model is constructed by the following steps: Study the pore throat structure characteristics of the target reservoir and determine the average pore radius; Based on the morphological characteristics of the imbibition network and the average pore radius, the radius of each imbibition channel in the imbibition network and the node positions where different imbibition channels intersect are determined as structural parameters of the imbibition physical model; The imbibition physical model is constructed based on the structural parameters.

3. A quantitative evaluation method for shale oil reservoir imbibition and recovery efficiency according to claim 2, characterized in that: The structural parameters are determined by the following steps: The rock sample cavity is used to characterize each imbibition pipeline, and the average pore radius is used as the cavity radius of each imbibition pipeline; The nodes where different imbibition pipelines intersect are regarded as open nodes to represent the interconnection between different imbibition pipelines.

4. A quantitative evaluation method for shale oil reservoir imbibition and recovery efficiency according to any one of claims 1 to 3, characterized in that: The imbibition physical model under saturated state is obtained by the following steps: determining the original oil saturation and the original water saturation under the original formation conditions; The imbibition physical model is saturated with crude oil volume V1 and formation water volume V2 so that its oil saturation and water saturation are equal to the original oil saturation and the original water saturation, thereby obtaining the imbibition physical model in a saturated state.

5. A quantitative evaluation method for shale oil reservoir imbibition and recovery efficiency according to claim 4, characterized in that: The quantitative evaluation experiment of the absorption efficiency was carried out by the following steps: In the edge imbibition pipe of the imbibition physical model under saturation, a fluid injection port and a fluid outflow port are selected; Keep the fluid injection port and the fluid outflow port unobstructed, and close the remaining edge infiltration and absorption channels; After injecting the imbibed liquid volume V3 through the fluid injection port, closing the fluid injection port; The crude oil flowing out of the fluid outflow port is collected, and the volume of the crude oil flowing out is recorded as V4.

6. A quantitative evaluation method for shale oil reservoir imbibition and recovery efficiency according to claim 5, characterized in that: The imbibition recovery efficiency of the imbibition liquid is calculated by the following steps: the imbibition recovery efficiency of the imbibition liquid is calculated by the outflowing crude oil volume V4 and the crude oil volume V1 saturated by the imbibition physical model.

7. A quantitative evaluation method for shale oil reservoir imbibition recovery efficiency according to claim 5 or 6, characterized in that: The imbibition extraction efficiency of the imbibition liquid is calculated by the following expression: Where: η represents the imbibition recovery efficiency of the imbibition liquid, %; V4 represents the volume of crude oil flowing out of the fluid outflow port, mL; V1 represents the volume of crude oil saturated by the imbibition physical model, mL.

8. A storage medium, characterized in that: It contains a series of instructions for executing the method steps according to any one of claims 1 to 7.

9. A quantitative evaluation system for shale oil reservoir imbibition and recovery efficiency, characterized by: The system comprises the imbibition physics model according to any one of claims 1-7.

10. A shale oil reservoir imbibition and recovery efficiency quantitative evaluation system according to claim 9, characterized in that: The system further includes: a displacement pump, an imbibition liquid container, an outflow fluid collection device, a temperature control device, and a data analysis device, wherein the displacement pump is used to pump the imbibition liquid in the imbibition liquid container to the imbibition physical model in a saturated state, the outflow fluid collection device is used to collect liquid flowing out of the imbibition physical model in a saturated state, the temperature control device is used to control the temperature environment during the imbibition efficiency quantitative evaluation experiment, and the data analysis device is used to calculate the imbibition extraction efficiency of the imbibition liquid.

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