Shale oil and gas migration simulation system and evaluation method

Abstract

The present application provides a kind of shale oil gas migration simulation system and evaluation method, it is related to shale oil gas development technical field, including targeted path control module, simulation fluid filling module, dynamic process observation module and data processing module, targeted path control module is used to inject target plugging agent into core sample and plugging target area pore of core sample to form target oil gas migration path;Simulation fluid filling module can simulate formation temperature and pressure conditions and be used to fill simulation fluid with fluorescent agent to target oil gas migration path;Dynamic process observation module is used to carry out real-time visual observation and process parameter acquisition and upload to oil gas migration process in target oil gas migration path;Data processing module can be used to receive the data of dynamic process observation module and calculate the migration efficiency quantitative evaluation index of target oil gas migration path by preset algorithm.The present application can inject plugging agent into core sample to plugging target area pore, so as to be able to actively construct target oil gas migration path, realizes controllable simulation to shale oil gas migration path, so as to be able to more accurately establish the quantitative evaluation relationship between pore structure parameter and migration efficiency.

Description

Technical Field

[0001] This invention relates to the field of shale oil and gas development technology, and in particular to a shale oil and gas migration simulation system and evaluation method. Background Technology

[0002] Shale oil and gas, as an important component of unconventional oil and gas resources, has become a key area for increasing oil and gas reserves and production. However, shale reservoirs are characterized by low porosity and low permeability, with complex micro- and nano-scale pore networks within them. The migration paths and mechanisms of oil and gas within these reservoirs are extremely hidden and difficult to observe directly. This characteristic poses a significant challenge to accurately evaluating the migration efficiency of shale oil and gas. Currently, physical simulation experimental devices are commonly used in the industry to study oil and gas migration processes. However, existing physical simulation methods have significant limitations: on the one hand, it is difficult to actively control and precisely guide the migration paths of oil and gas in the complex pore system of shale during experiments; on the other hand, existing technologies cannot effectively establish a quantitative correspondence between specific pore structure parameters within shale (such as pore shape, size distribution, connectivity, etc.) and the dynamic behavior and final migration efficiency of oil and gas. This results in existing research mostly remaining at the macroscopic or static descriptive level, lacking the ability to systematically and dynamically observe and quantitatively analyze migration paths under controllable conditions. Current technologies for studying shale oil and gas migration processes are insufficient, particularly in areas such as controllable migration pathways, dynamic evolution characterization, and quantitative analysis of key parameters. This technological bottleneck restricts a deeper understanding of shale oil and gas migration mechanisms, thereby affecting the accurate formulation and optimization of efficient shale reservoir development strategies. Therefore, how to achieve controllable simulation of shale oil and gas migration pathways to establish a quantitative evaluation relationship between pore structure parameters and migration efficiency has become an urgent technical problem to be solved. Summary of the Invention

[0003] In order to overcome the above-mentioned defects of the prior art, the technical problem to be solved by the embodiments of the present invention is to provide a shale oil and gas migration simulation system and evaluation method for realizing controllable simulation of shale oil and gas migration paths.

[0004] The above-mentioned objectives of this invention can be achieved by the following technical solutions: This invention provides a shale oil and gas migration simulation system, comprising: A target path control module is used to inject a target plugging agent into a core sample to plug the target area pores of the core sample in order to form a target oil and gas migration path. A simulated fluid filling module is provided, which can contain the core sample and simulate formation temperature and pressure conditions. The simulated fluid filling module is used to fill the target oil and gas migration path with simulated fluid containing fluorescent agent. The dynamic process observation module is used to perform real-time visual observation and process parameter acquisition and uploading of the oil and gas migration process within the target oil and gas migration path; The data processing module is used to receive data from the dynamic process observation module and calculate the quantitative evaluation index of the migration efficiency of the target oil and gas migration path through a preset algorithm.

[0005] In a preferred embodiment of the present invention, the shale oil and gas migration simulation system further includes an atomic force microscope and a CT scanning device electrically connected to the data processing module. The atomic force microscope is used to scan the surface of the core sample to obtain nanoscale pore surface morphology parameters and upload them to the data processing module. The CT scanning device is used to scan the core sample to obtain a three-dimensional image of the internal pores and upload it to the data processing module. The data processing module is used to receive the nanoscale pore surface morphology parameters and the three-dimensional image of the internal pores and generate a digital core model through a preset program, and determine the target area pores and target plugging agent based on the digital core model.

[0006] In a preferred embodiment of the present invention, the targeted path control module includes a plugging reactor, a first core holder disposed in the plugging reactor, a dot matrix nozzle structure disposed in the plugging reactor, a plugging agent injection pipeline connected to the dot matrix nozzle structure, and at least one plugging agent container connected to the plugging agent injection pipeline. The plugging agent injection pipeline can inject a preset plugging agent from the plugging agent container into the core sample through the dot matrix nozzle structure to plug part of the pore size to form the target oil and gas migration path. The plugging agent injection pipeline is equipped with a flow meter, a first delivery pump, and a first pressure gauge.

[0007] In a preferred embodiment of the present invention, a plurality of the plugging agent containers are arranged in parallel, and the plurality of plugging agent containers are respectively used to store a plugging agent containing at least one of elastic particles, rigid particles, flexible microspheres, and nanogels.

[0008] In a preferred embodiment of the present invention, the simulated fluid filling module includes a filling reactor, a second core holder disposed in the filling reactor, a viewing window structure disposed on the filling reactor, and a fluid filling pipeline and a fluid discharge pipeline connecting the filling reactor. The fluid filling pipeline is connected to a fluid storage tank and is used to fill simulated fluid containing fluorescent agent into the target oil and gas migration path. The filling reactor is provided with a temperature and pressure control structure for simulating the formation temperature and pressure environment. The fluid filling pipeline is provided with a filling control valve, a second delivery pump, and a second pressure gauge.

[0009] In a preferred embodiment of the present invention, the dynamic process observation module includes: A mass measuring instrument, which is used to measure the mass of fluid entering the core sample in real time; A visualization observation component includes a fluorescence excitation light source, a light emitter for receiving the fluorescence excitation light source, a lens structure disposed between the light emitter and the window structure for adjusting the light, and a camera device for recording fluorescence images within the target oil and gas migration path.

[0010] In a preferred embodiment of the present invention, the shale oil and gas migration simulation system further includes a core cleaning module. The core cleaning module includes a third core holder with a clamping cavity, a cleaning pipeline connected to one end of the clamping cavity, and a waste liquid storage pipeline connected to the other end of the clamping cavity. The cleaning pipeline is connected to a cleaning agent tank and is equipped with a cleaning control valve and a third delivery pump. The waste liquid storage pipeline is connected to a waste liquid tank and is equipped with a third pressure gauge and a waste liquid control valve. The fluid discharge pipeline is connected to the waste liquid tank.

[0011] In a preferred embodiment of the present invention, the core cleaning module further includes heating devices disposed on both sides of the third core holder, and blowing devices disposed on the outside of the heating devices and facing the third core holder.

[0012] In a preferred embodiment of the present invention, the shale oil and gas migration simulation system further includes a conveyor belt for transporting the core sample, and the CT scanning device, the target path control module, the simulated fluid filling module, and the core cleaning module are arranged sequentially along the conveying direction of the conveyor belt.

[0013] This invention also provides a method for evaluating shale oil and gas migration, implemented using the aforementioned shale oil and gas migration simulation system. The method includes the following steps: The surface morphology parameters of the nanoscale pores and the three-dimensional structure image of the internal pores of the core sample are obtained and a digital core model is generated. Based on the digital core model, the location of the pores in the target area and the target sealing agent are determined. The target plugging agent is injected into the target area pores of the core sample to block the target area pores, thereby forming a target oil and gas migration path inside the core sample; The temperature and pressure conditions of the target formation are simulated, and a simulated fluid containing a fluorescent agent is injected into the target oil and gas migration path; Real-time visual observation of the oil and gas migration process within the target oil and gas migration path is performed, and migration process parameters are collected simultaneously. Based on the collected migration process parameters, a quantitative evaluation index of the migration efficiency of the target oil and gas migration path is calculated using a preset algorithm.

[0014] The technical solution of the present invention has the following significant beneficial effects: The shale oil and gas migration simulation system of this invention, through a targeted path control module, can inject a plugging agent into core samples to seal the pores in the target area, thereby actively constructing a preset, single target oil and gas migration path. This solves the problems of uncontrollable seepage paths and inability to isolate the influence of specific structures in existing core displacement experiments. Furthermore, the simulated fluid injection module can simulate formation temperature and pressure conditions and inject simulated fluids containing fluorescent agents into the target oil and gas migration path, providing a realistic geological environment background for the migration process. Moreover, the dynamic process observation module performs real-time visualization observation and process parameter acquisition of the migration process within the path, achieving in-situ, dynamic monitoring of migration behavior within the micropores of shale. Finally, the data processing module receives the above observation data and calculates a quantitative evaluation index of migration efficiency based on a preset algorithm, achieving precise quantification of the migration efficiency of a specific path. This invention, through the synergistic effect of its various modules, enables targeted control of the internal pore structure of shale, and achieves controllable simulation of shale oil and gas migration paths under formation temperature and pressure conditions. This allows for a more accurate establishment of a quantitative evaluation relationship between pore structure parameters and migration efficiency, providing reliable technical support for the study of shale oil and gas migration and accumulation patterns and efficient development. Attached Figure Description

[0015] To more clearly illustrate the technical solutions in the embodiments of the present invention, the accompanying drawings used in the description of the embodiments will be briefly introduced below. Obviously, the accompanying drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0016] The accompanying drawings described herein are for illustrative purposes only and are not intended to limit the scope of the invention in any way. Furthermore, the shapes and proportions of the components in the drawings are merely illustrative to aid in understanding the invention and do not specifically limit the shapes and proportions of the components. Those skilled in the art, guided by the teachings of this invention, can select various possible shapes and proportions to implement the invention according to specific circumstances.

[0017] Figure 1 This is a schematic diagram of one embodiment of the shale oil and gas migration simulation system described in this invention; Figure 2 This is a schematic diagram of the structure of one embodiment of the target path control module described in this invention; Figure 3This is a schematic diagram of one embodiment of the core cleaning module described in this invention.

[0018] The reference numerals in the above figures are as follows: 10. Core samples; 100. Targeted path control module; 110. Sealing reaction vessel; 120. First core holder; 130. Dot matrix nozzle structure; 140. Sealing agent injection pipeline; 141. Flow meter; 142. First delivery pump; 143. First pressure gauge; 150. Sealing agent container; 200. Simulated fluid filling module; 210. Filling reactor; 220. Second core holder; 230. Fluid filling pipeline; 231. Filling control valve; 232. Second delivery pump; 233. Second pressure gauge; 240. Fluid discharge pipeline; 250. Fluid storage tank; 300. Dynamic process observation module; 310. Mass measuring instrument; 320. Fluorescent excitation source; 330. Light emitter; 340. Lens structure; 350. Camera device; 400. Data Processing Module; 500. Atomic force microscope; 600. CT scanning equipment; 700. Core cleaning module; 710. Third core holder; 720. Cleaning pipeline; 721. Cleaning control valve; 722. Third delivery pump; 730. Waste liquid storage pipeline; 731. Third pressure gauge; 732. Waste liquid control valve; 740. Cleaning agent tank; 750. Waste liquid tank; 760. Heating device; 770. Blowing device; 800. Conveyor belt. Detailed Implementation

[0019] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0020] Implementation Method 1

[0021] Please refer to the following: Figure 1 , Figure 2 and Figure 3As shown, an embodiment of the present invention provides a shale oil and gas migration simulation system. This system includes a target path control module 100, a simulated fluid injection module 200, a dynamic process observation module 300, and a data processing module 400. The target path control module 100 injects a target plugging agent into a core sample 10 to seal the target area pores of the core sample 10, thereby forming a target oil and gas migration path. The simulated fluid injection module 200 can accommodate the core sample 10 and simulate formation temperature and pressure conditions. It is used to inject simulated fluid containing a fluorescent agent into the target oil and gas migration path. The dynamic process observation module 300 performs real-time visual observation and process parameter acquisition and uploading of the oil and gas migration process within the target oil and gas migration path. The data processing module 400 receives data from the dynamic process observation module 300 and calculates a quantitative evaluation index of the migration efficiency of the target oil and gas migration path using a preset algorithm.

[0022] Overall, this shale oil and gas migration simulation system can inject a plugging agent into the core sample 10 to seal the pores in the target area through the targeted path control module 100, thereby actively constructing a preset, single target oil and gas migration path, solving the problems of uncontrollable seepage paths and inability to isolate the influence of specific structures in existing core displacement experiments.

[0023] Furthermore, the simulated fluid injection module 200 can simulate formation temperature and pressure conditions and inject simulated fluids containing fluorescent agents into the target oil and gas migration path, providing a realistic geological environment background for the migration process. Moreover, the dynamic process observation module 300 performs real-time visual observation and process parameter acquisition of the migration process within this path, achieving in-situ, dynamic monitoring of migration behavior within the micropores of shale. Finally, the data processing module 400 receives the aforementioned observation data and calculates quantitative evaluation indicators of migration efficiency based on a preset algorithm, achieving precise quantification of the migration efficiency of a specific path.

[0024] This invention, through the synergistic effect of its various modules, enables targeted control of the internal pore structure of shale, and achieves controllable simulation of shale oil and gas migration paths under formation temperature and pressure conditions. This allows for a more accurate establishment of a quantitative evaluation relationship between pore structure parameters and migration efficiency, providing reliable technical support for the study of shale oil and gas migration and accumulation patterns and efficient development.

[0025] In an embodiment of the present invention, the shale oil and gas migration simulation system further includes an atomic force microscope 500 and a CT scanning device 600 electrically connected to the data processing module 400. The atomic force microscope 500 is used to scan the surface of the core sample 10 to obtain nanoscale pore surface morphology parameters and upload them to the data processing module 400; the CT scanning device 600 is used to scan the core sample 10 to obtain three-dimensional images of the internal pores and upload them to the data processing module 400; the data processing module 400 is used to receive the nanoscale pore surface morphology parameters and the three-dimensional images of the internal pores and generate a digital core model through a preset program, and determine the target area pores and target plugging agent based on the digital core model.

[0026] By combining an atomic force microscope 500 with a CT scanner 600, precise cross-scale characterization of the core sample 10, from nanoscale surface morphology to internal three-dimensional pore structure, was achieved. Specifically, the nanoscale pore surface morphology parameters acquired by the atomic force microscope 500 and the internal pore three-dimensional images acquired by the CT scanner 600 can be uploaded to the data processing module 400 and fused through a preset program to generate a high-precision digital core model.

[0027] Operators can use this model to determine and locate the pores in the target area, and accurately match the type and particle size of the target plugging agent to the pores, which significantly improves the accuracy, scientific nature and repeatability of the pre-designed transport path construction.

[0028] In embodiments of the present invention, designers may adjust the specific model and structure of the data processing module 400 according to usage needs, and no specific limitations are imposed here. Preferably, the data processing module 400 includes a computer.

[0029] In an embodiment of the present invention, the targeted path control module 100 includes a plugging reactor 110, a first core holder 120 disposed in the plugging reactor 110, a dot matrix nozzle structure 130 disposed in the plugging reactor 110, a plugging agent injection pipeline 140 connected to the dot matrix nozzle structure 130, and at least one plugging agent container 150 connected to the plugging agent injection pipeline 140. The plugging agent injection pipeline 140 can inject a preset plugging agent from the plugging agent container 150 into the core sample 10 through the dot matrix nozzle structure 130 to plug part of the pore size to form a target oil and gas migration path. The plugging agent injection pipeline 140 is equipped with a flow meter 141, a first delivery pump 142, and a first pressure gauge 143.

[0030] By cooperating with the sealing reactor 110, the first core holder 120, the dot matrix nozzle structure 130, and the matching sealing agent injection pipeline 140 and sealing agent container 150, and with the monitoring and control of the flow meter 141, the first delivery pump 142 and the first pressure gauge 143, the precise control of the injection position, angle, flow rate and pressure of the sealing agent is achieved.

[0031] Specifically, the dot matrix nozzle structure 130 includes multiple nozzles, which can be arranged to form a multi-angle dot matrix nozzle according to usage requirements. The dot matrix-distributed nozzles support selective injection into the target area pores inside the core from multiple directions, thereby enabling the controllable sealing of non-target areas for pores of different sizes and shapes. This precisely constructs a preset single oil and gas migration physical path, ensuring the repeatability of the sealing process and the accuracy of path construction. It provides a reliable sample basis for subsequent comparative and quantitative migration simulation experiments under real geological temperature and pressure conditions.

[0032] Furthermore, a temperature and pressure sensor is installed in the sealing reactor 110. The temperature and pressure data in the sealing reactor 110 can be accurately obtained through the temperature and pressure sensor, thereby providing data reference for the sealing process.

[0033] In an embodiment of the present invention, multiple plugging agent containers 150 are arranged in parallel, and the multiple plugging agent containers 150 are respectively used to store a plugging agent containing at least one of elastic particles, rigid particles, flexible microspheres, and nanogels.

[0034] By setting up multiple plugging agent containers 150, flexible storage and rapid switching of various types of plugging agents, such as elastic particles, rigid particles, flexible microspheres, and nanogels, are achieved. The most suitable plugging agent can be matched and selected based on the location and size of the target area pores.

[0035] Specifically, for large-diameter pores and cracks, deformable elastic particles are injected to tightly adhere to the pore walls using their elastic deformation capabilities; for medium-diameter pores, a composite system of rigid inorganic particles and flexible microspheres is used, with rigid particles bridging and flexible microspheres synergistically filling to achieve tight sealing; for small-diameter pores, nanogels are selected, relying on their swelling and solidification properties within the pores to achieve effective sealing.

[0036] All plugging agents can be precisely injected through the dot matrix nozzle structure 130 inside the plugging reactor 110, thereby achieving refined and differentiated targeted plugging of multi-scale and multi-type pore networks within the core sample 10, significantly improving the accuracy and reliability of constructing preset transport paths in complex pore structures.

[0037] In an embodiment of the present invention, the simulated fluid filling module 200 includes a filling reactor 210, a second core holder 220 disposed in the filling reactor 210, a viewing window structure disposed on the filling reactor 210, and a fluid filling pipeline 230 and a fluid discharge pipeline 240 connecting the filling reactor 210. The fluid filling pipeline 230 is connected to a fluid storage tank 250 and is used to fill simulated fluid containing fluorescent agent into the target oil and gas migration path. The filling reactor 210 is provided with a temperature and pressure control structure for simulating the formation temperature and pressure environment. The fluid filling pipeline 231 is provided with a filling control valve 231, a second delivery pump 232, and a second pressure gauge 233.

[0038] By integrating a filling reactor 210 with a temperature and pressure control structure and a viewing window structure, a second core holder 220, and a fluid filling pipeline 230 equipped with a filling control valve 231, a second delivery pump 232, and a second pressure gauge 233, the accurate reproduction of the formation environment and high-precision control of the filling process are achieved.

[0039] Specifically, the filling reactor 210 can accurately simulate the temperature and pressure conditions of the target formation through a temperature and pressure control structure; the second core holder 220 ensures the stable sealing and positioning of the core under high pressure; the simulated fluid with fluorescent agent is accurately pumped into the target oil and gas migration path through the fluid filling pipeline 230; at the same time, the transparent window structure provides a direct observation channel for external observation equipment.

[0040] The simulated fluid filling module 200 ensures that migration experiments can be conducted in a real geomechanical and fluid dynamic context, providing essential and reliable environmental conditions and hardware foundation for subsequent in-situ, dynamic visualization observation and quantitative parameter acquisition of oil and gas migration behavior.

[0041] Designers can determine the specific construction of the temperature and pressure control structure according to the usage requirements, and no specific restrictions are imposed here. For example, the temperature and pressure control structure includes an electric heating jacket and an insulation layer installed on the filling reactor 210. The electric heating jacket can simulate and regulate the formation temperature. In addition, the temperature and pressure control structure also includes a confining pressure sleeve installed inside the filling reactor 210. The confining pressure sleeve can cover the core sample 10, and the confining pressure sleeve can work with the pressurization device to simulate and regulate the formation confining pressure.

[0042] In an embodiment of the present invention, the dynamic process observation module 300 includes a mass measuring instrument 310 and a visualization observation component. The mass measuring instrument 310 is used to measure the mass of fluid entering the core sample 10 in real time. The visualization observation component includes a fluorescence excitation light source 320, a light emitter 330 for receiving the fluorescence excitation light source 320, a lens structure 340 disposed between the light emitter 330 and the window structure for adjusting the light, and a camera device 350 for recording fluorescence images within the target oil and gas migration path.

[0043] By combining the mass measuring instrument 310 with the visualization observation components, synchronous, in-situ, and quantitative monitoring of shale oil and gas migration processes was achieved.

[0044] Specifically, both the sealing reactor 110 and the filling reactor 210 are equipped with a mass measuring instrument 310. The mass measuring instrument 310 can accurately measure the mass of the sealing agent or fluid entering the core sample 10 in real time, providing continuous mass data for the migration process.

[0045] Furthermore, the visualization observation component uses a fluorescent excitation light source 320, a lens structure 340, and a high-speed camera device 350 to excite, image, and record the target oil and gas migration path through a window structure, thereby dynamically capturing the migration trajectory and distribution characteristics of the fluorescently labeled fluid in micropores.

[0046] By combining the mass measuring instrument 310 with the visualization observation component, the macroscopic mass changes and microscopic transport behavior of the fluid can be accurately correlated in time and space. This provides a high-precision, high-spatiotemporal-resolution direct observation basis for subsequent quantitative calculation of transport efficiency based on multi-source data fusion, and significantly improves the accuracy of experimental results.

[0047] Designers may adjust the specific model and structure of the camera device 350 according to usage requirements, and no specific restrictions are imposed here. Preferably, the camera device 350 is a high-speed camera.

[0048] In an embodiment of the present invention, the shale oil and gas migration simulation system further includes a core cleaning module 700. The core cleaning module 700 includes a third core holder 710 with a clamping cavity, a cleaning pipeline 720 connected to one end of the clamping cavity, and a waste liquid storage pipeline 730 connected to the other end of the clamping cavity. The cleaning pipeline 720 is connected to a cleaning agent tank 740. A cleaning control valve 721 and a third delivery pump 722 are provided on the cleaning pipeline 720. The waste liquid storage pipeline 730 is connected to a waste liquid tank 750. A third pressure gauge 731 and a waste liquid control valve 732 are provided on the waste liquid storage pipeline 730. A fluid discharge pipeline 240 is connected to the waste liquid tank 750.

[0049] The core cleaning module 700 enables deep cleaning and restoration of the core sample 10 after the experiment. Under controlled pressure and flow rate, the core cleaning module 700 can directionally pump the cleaning agent into the core sample 10, effectively dissolving and removing residual sealing agents and simulated fluids inside the core. It can also safely discharge waste liquid to the waste liquid tank 750 for centralized treatment, significantly improving the cleaning efficiency and cleanliness of the core sample 10 and ensuring its reusability in subsequent control experiments.

[0050] Furthermore, by connecting the fluid discharge pipeline 240 to the waste liquid tank 750, the simulated fluid containing fluorescent agent can also be discharged to the waste liquid tank 750 for centralized treatment after flowing out of the target oil and gas migration path, thereby improving the utilization rate of the waste liquid tank 750.

[0051] In an embodiment of the present invention, the core cleaning module 700 further includes heating devices 760 disposed on both sides of the third core holder 710, and blowing devices 770 disposed on the outside of the heating devices 760 and facing the third core holder 710.

[0052] By adding a heating device 760 and a blowing device 770 on both sides of the third core holder 710, the cleaning and drying process is further enhanced and optimized.

[0053] Specifically, the heating device 760 can assist in heating the cleaning agent flowing through the core sample 10, thereby improving its chemical activity and dissolution efficiency, ensuring the effectiveness of residue removal. After cleaning, the blowing device 770 can blow warm air into the third core holder 710 to accelerate the evaporation of residual liquid inside the core sample 10, achieving rapid and uniform drying. This significantly shortens the cycle from the end of the experiment to the return of the core sample 10 to its ready-to-use state, effectively preventing changes in pore structure and subsequent experimental errors caused by incomplete cleaning or dampness, and significantly improving the reusability of the core sample 10.

[0054] In an embodiment of the present invention, the shale oil and gas migration simulation system further includes a conveyor belt 800 for transporting core samples 10. Along the conveying direction of the conveyor belt 800, a CT scanning device 600, a target path control module 100, a simulated fluid filling module 200, and a core cleaning module 700 are arranged in sequence.

[0055] By setting up a conveyor belt 800 and sequentially integrating the CT scanning device 600, the target path control module 100, the simulated fluid filling module 200, and the core cleaning module 700 along the conveying direction, a complete automated experimental production line is constructed. The core sample 10 can be transported along the conveyor belt 800, realizing the sequential flow of the core sample 10 from initial scanning, path construction, transport simulation to post-cleaning. There is no need for manual handling between each process, which significantly improves experimental efficiency and reduces the risk of human error and sample damage.

[0056] Implementation Method 2

[0057] An embodiment of the present invention provides a method for evaluating shale oil and gas migration, implemented using the shale oil and gas migration simulation system described in Embodiment 1. The method for evaluating shale oil and gas migration includes the following steps: Step S1: Obtain the nanoscale pore surface morphology parameters and internal pore three-dimensional structure image of core sample 10 and generate a digital core model. Based on the digital core model, determine the location of the target pores and the target sealing agent. Step S2: Inject the target sealing agent into the target area pores of core sample 10 to seal the target area pores and form the target oil and gas migration path inside core sample 10; Step S3: Simulate the temperature and pressure conditions of the target formation and inject simulated fluid containing fluorescent agent into the target oil and gas migration path; Step S4: Perform real-time visual observation of the oil and gas migration process within the target oil and gas migration path, and simultaneously collect migration process parameters; Step S5: Based on the collected migration process parameters, calculate the quantitative evaluation index of the migration efficiency of the target oil and gas migration path using a preset algorithm.

[0058] The shale oil and gas migration evaluation method described in this invention forms a complete and closed-loop research chain through steps such as digital core modeling, targeted path construction, formation environment simulation, dynamic process observation and quantitative data analysis.

[0059] This shale oil and gas migration evaluation method can plan experimental schemes based on high-precision digital models, and then achieve controllable and visual simulation of shale micro-migration behavior through precise physical sealing and fluid injection under real temperature and pressure conditions. It can also accurately quantify migration efficiency through real-time acquisition of multi-dimensional data.

[0060] This shale oil and gas migration evaluation method significantly improves the pertinence, repeatability, and reliability of the experiment, providing strong support for a deeper understanding of the shale oil and gas migration mechanism and the formulation of efficient development strategies.

[0061] Specifically, during the preliminary preparation phase, data collection is conducted to obtain background information on the shale strata in the study area, including geological data such as the depth of the target layer, sedimentary environment, thermal evolution history, and burial history; data such as shale core porosity, permeability, and pore type are also obtained.

[0062] Next, material preparation is required. The process of controlling oil and gas migration paths and simulating oil and gas migration requires the following materials, including shale core samples, different types of plugging agents, simulated fluids, fluorescent agents, and cleaning agents.

[0063] Among these, multiple types of plugging agents are used. These agents need to meet characteristics such as size adaptation, surface affinity, and controllable curing to achieve precise matching with the pores in the target area. Based on pore size, for large-diameter pores and cracks, deformable elastic particles with a particle size of 1 / 2 the pore diameter are selected. These particles can undergo elastic deformation under pressure, filling the pores and adhering to the pore walls. For medium-diameter pores, a composite system of rigid inorganic particles and flexible polymers is used. The rigid particles act as bridges, while the flexible microspheres fill the gaps, forming a tight seal. For small-diameter pores, nanogels are used. After entering the pores, they swell and solidify, thereby blocking the pores.

[0064] Simulated fluid: Based on the chemical composition and physical properties of shale oil and gas in the target area, simulated fluids are prepared to determine data such as fluid density and viscosity.

[0065] Fluorescent agents: Specific fluorescent agents that do not affect the properties of the simulated fluid are added to the simulated fluid. These fluorescent agents can exhibit noticeable fluorescence under specific light sources for observation.

[0066] Cleaning agent: Prepare a cleaning agent that can dissolve the sealing agent material in order to unclog the blocked pores and restore the shale core sample to its initial state.

[0067] Then, the equipment is prepared, including the target path control module 100, the simulated fluid filling module 200, the dynamic process observation module 300, the data processing module 400, the atomic force microscope 500, and the CT scanning equipment 600.

[0068] Specifically, the Atomic Force Microscope 500 (AFM) is a molecular-level channel identification device used to scan shale samples. The data processing module 400 is used for molecular dynamics simulations. The AFM probe is checked for integrity and cleanliness. The probe is installed, the AFM scanning mode is adjusted, the scanning rate is set to obtain the required spatial resolution, and the intensity is set for scanning the sample. The data processing module 400 is then activated to perform molecular dynamics simulations, establishing a molecular model to simulate various molecular states under different pore sizes.

[0069] The targeted path control module 100 is a shale oil and gas migration path sealing device. It checks and tests the sealing performance of the sealing reactor 110 to ensure that the sealing agent can enter the core sample 10 without leakage during the sealing process. It also checks whether the temperature and pressure sensors are functioning properly to ensure they can correctly respond to changes in ambient temperature and pressure during the sealing process and provide feedback adjustments. Finally, it ensures that the valve control components are functioning correctly and that various types of sealing agents can be added as needed.

[0070] The CT scanning device 600 can use multi-energy spectral CT scanning imaging, which utilizes the absorption differences of different substances by X-rays of different energies to improve the ability to identify different components, acquire high-resolution three-dimensional images of the model, and establish a digital model.

[0071] The dynamic process observation module 300 uses a fluorescent light source to illuminate the shale, causing the fluorescent agent in the migrating fluid to emit light. A high-speed camera records the migration path of oil and gas in the shale pores, and a high-precision mass measuring instrument 310 records the amount of fluid entering the shale pores. The dynamic and real-time observable shale oil and gas migration path is then presented on a computer for subsequent calculation of migration efficiency.

[0072] AFM testing was used to scan core sample 10. The AFM probe entered the sample surface in various ways to generate three-dimensional images, obtaining information on the throat size, shape, surface roughness, and mineral composition distribution of the nanoscale pores in the shale sample. This provides realistic model parameters for molecular dynamics simulations and precise coordinates for targeted plugging. The characterization process requires strict control of environmental interference and operational errors to avoid damaging the sample.

[0073] By using computer molecular dynamics simulations, corresponding hydrocarbon molecule models were constructed and their migration was simulated under pore channels of different sizes. This revealed the relationship between different hydrocarbon molecules and pore channel sizes during hydrocarbon migration, providing a foundation for subsequent control of shale pore structure.

[0074] The physical model is scanned from all angles using CT scanning imaging technology. The attenuation difference of X-rays when penetrating the object is due to different materials. Data is collected through multi-angle scanning and then reconstructed by computer to generate a three-dimensional image.

[0075] Based on the data collected in the early stage, combined with AFM testing and CT scanning, the obtained data were coupled to establish a three-dimensional digital core of shale and determine a three-dimensional coordinate system for subsequent control.

[0076] After establishing a three-dimensional shale core, the diameter D of different pore channels inside the core was calculated by computer. throat,i and length L throat,i The maximum amount of oil and gas, Q, that can be accommodated in passages with different pore sizes was calculated using computer numerical simulation. max,i .

[0077] In shale targeted pore plugging, the first step is to construct targeted delivery channels, artificially altering the seepage direction of the core or reservoir to allow the plugging agent to bypass non-targeted high-permeability channels and flow directionally into the pre-defined target pore area. A combination of temporary plugging regulation and seepage control achieves a displacement-guided effect. Targeted transport channels, i.e., target oil and gas migration paths, are created through methods such as differential pressure regulation, guiding the plugging agent to migrate directionally along these channels.

[0078] Then, targeted plugging agent injection is performed to determine the location of the pore channels to be plugged. Different plugging agents are selected according to the size of the pore channels. For large-diameter pores and cracks, deformable elastic particles are selected. These particles can elastically deform to fill the pores and conform to the pore walls. For medium-diameter pores, a composite system of rigid inorganic particles and flexible polymers is used. The rigid particles bridge the gaps, and the flexible microspheres fill the cracks to form a tight seal. For small-diameter pores, nanogels are used. After entering the pores, they swell and solidify to block the pores. The plugging agent is injected from different positions and at different angles through multi-position, multi-angle nozzles within the plugging reactor 110.

[0079] In shale oil and gas migration simulation, the preparation of the charging fluid is crucial. The key to preparing the charging fluid is to add fluorescent substances without altering its properties. Actual oil and gas samples or substitutes are selected based on requirements. The fluid is stirred thoroughly and impurities are filtered out. After preparation, the fluorescence intensity of the fluid is verified, and the viscosity (μ) of both liquids and gases is measured.

[0080] Then, sample filling was performed. After sealing the internal pore channels of the shale, the temperature and pressure in the reactor were adjusted to fill the shale core sample with hydrocarbons. During the filling process, the hydrocarbon migration along the path was observed by irradiation with a fluorescent excitation light source 320, and the amount of hydrocarbon Q passing through each pore channel i was measured. i Record the time t from the start to the end of oil and gas migration in each pore canal. i .

[0081] After filling, the shale core samples are cleaned to remove the sealing agent and oil and gas fluids inside the pore channels, and the cores are dried to ensure that the shale is restored to its initial state, which is convenient for subsequent simulation experiments.

[0082] Based on the above data, a comprehensive evaluation of oil and gas migration efficiency is conducted, wherein the i-th pore channel size effect term is: When the size of the grate is larger than the molecular dynamic diameter:

[0083] When the roar diameter is smaller than the molecular dynamic diameter, S size,i Take 0.

[0084] In the formula, D throat,i d is the feature size of the i-th roar; m,i The dynamic diameter of the oil and gas molecules is denoted as ...

[0085] The i-th pore canal shape effect term is:

[0086] In the formula, L throat,i Let i be the length of the i-th shout; The transport characteristic index at point i is: ; In the formula, The viscosity of the fluid is Pa·s; Oil and gas migration efficiency at point i for: ; In the formula, Q i / t i Let m be the flow rate of the i-th pore channel. 3 / s; Overall transport efficiency for: ; After obtaining the comprehensive evaluation index of hydrocarbon migration efficiency under the controlled path, the core sample 10 was restored to its initial state using the core cleaning module 700. This process was repeated multiple times, controlling different paths to obtain the comprehensive evaluation index of hydrocarbon migration efficiency for each path. Finally, the relationship between hydrocarbon migration efficiency and migration path was established.

[0087] All articles and references disclosed herein, including patent applications and publications, are incorporated herein by reference for various purposes. The term “substantially constitutes…” used to describe a combination should include the identified element, component, part, or step, as well as other elements, components, parts, or steps that do not substantially affect the essential novelty of the combination. The use of the terms “comprising” or “including” to describe combinations of elements, components, parts, or steps herein also contemplates embodiments substantially constituted by such elements, components, parts, or steps. The use of the term “may” herein is intended to indicate that any described attribute “may” include is optional. Multiple elements, components, parts, or steps can be provided by a single integrated element, component, part, or step. Alternatively, a single integrated element, component, part, or step can be divided into multiple separate elements, components, parts, or steps. The disclosure of “a” or “an” used to describe an element, component, part, or step does not imply exclusion of other elements, components, parts, or steps.

[0088] The various embodiments in this specification are described in a progressive manner, with each embodiment focusing on its differences from other embodiments. Similar or identical parts between embodiments can be referred to interchangeably. The above embodiments are only for illustrating the technical concept and features of the present invention, and are intended to enable those skilled in the art to understand the content of the present invention and implement it accordingly. They should not be construed as limiting the scope of protection of the present invention. All equivalent changes or modifications made according to the spirit and essence of the present invention should be covered within the scope of protection of the present invention.

Claims

1. A shale oil and gas migration simulation system, characterized in that, include: A targeted path control module is provided, which is used to inject a target plugging agent into a core sample to block the target area pores of the core sample to form a target oil and gas migration path. The targeted path control module includes a plugging reactor, a first core holder disposed in the plugging reactor, a dot matrix nozzle structure disposed in the plugging reactor, a plugging agent injection pipeline connected to the dot matrix nozzle structure, and at least one plugging agent container connected to the plugging agent injection pipeline. The plugging agent injection pipeline can inject a preset plugging agent from the plugging agent container into the core sample through the dot matrix nozzle structure to block part of the pores to form the target oil and gas migration path. The plugging agent injection pipeline is equipped with a flow meter, a first delivery pump, and a first pressure gauge. A simulated fluid filling module is provided, which can contain the core sample and simulate formation temperature and pressure conditions. The simulated fluid filling module is used to fill the target oil and gas migration path with simulated fluid containing fluorescent agent. The dynamic process observation module is used to perform real-time visual observation and process parameter acquisition and uploading of the oil and gas migration process within the target oil and gas migration path; The data processing module is capable of receiving data from the dynamic process observation module and calculating the quantitative evaluation index of the migration efficiency of the target oil and gas migration path through a preset algorithm. An atomic force microscope, electrically connected to the data processing module, is used to scan the surface of the core sample to obtain nanoscale pore surface morphology parameters and upload them to the data processing module. A CT scanning device, which is electrically connected to the data processing module, is used to scan the core sample to obtain a three-dimensional image of the internal pores and upload it to the data processing module. The data processing module is used to receive the surface morphology parameters of the nanoscale pores and the three-dimensional image of the internal pores, generate a digital core model through a preset program, and determine the target area pores and target plugging agent based on the digital core model.

2. The shale oil and gas migration simulation system as described in claim 1, characterized in that, Multiple plugging agent containers are arranged in parallel, and each of the multiple plugging agent containers is used to store a plugging agent containing at least one of elastic particles, rigid particles, flexible microspheres, and nanogels.

3. The shale oil and gas migration simulation system as described in claim 1, characterized in that, The simulated fluid filling module includes a filling reactor, a second core holder disposed in the filling reactor, a viewing window structure disposed on the filling reactor, and a fluid filling pipeline and a fluid discharge pipeline connecting the filling reactor. The fluid filling pipeline is connected to a fluid storage tank and is used to fill simulated fluid containing fluorescent agent into the target oil and gas migration path. The filling reactor is equipped with a temperature and pressure control structure for simulating the formation temperature and pressure environment. The fluid filling pipeline is equipped with a filling control valve, a second delivery pump, and a second pressure gauge.

4. The shale oil and gas migration simulation system as described in claim 3, characterized in that, The dynamic process observation module includes: A mass measuring instrument, which is used to measure the mass of fluid entering the core sample in real time; A visualization observation component includes a fluorescence excitation light source, a light emitter for receiving the fluorescence excitation light source, a lens structure disposed between the light emitter and the window structure for adjusting the light, and a camera device for recording fluorescence images within the target oil and gas migration path.

5. The shale oil and gas migration simulation system as described in claim 3, characterized in that, The shale oil and gas migration simulation system also includes a core cleaning module. The core cleaning module includes a third core holder with a clamping cavity, a cleaning pipeline connected to one end of the clamping cavity, and a waste liquid storage pipeline connected to the other end of the clamping cavity. The cleaning pipeline is connected to a cleaning agent tank and is equipped with a cleaning control valve and a third delivery pump. The waste liquid storage pipeline is connected to a waste liquid tank and is equipped with a third pressure gauge and a waste liquid control valve. The fluid discharge pipeline is connected to the waste liquid tank.

6. The shale oil and gas migration simulation system as described in claim 5, characterized in that, The core cleaning module also includes heating devices disposed on both sides of the third core holder, and air blowing devices disposed on the outside of the heating devices and facing the third core holder.

7. The shale oil and gas migration simulation system as described in claim 5, characterized in that, The shale oil and gas migration simulation system also includes a conveyor belt for transporting the core sample. Along the conveying direction of the conveyor belt, the CT scanning equipment, the target path control module, the simulated fluid filling module, and the core cleaning module are arranged in sequence.

8. A method for evaluating shale oil and gas migration, characterized in that, The shale oil and gas migration simulation system as described in any one of claims 1 to 7 is used to implement the shale oil and gas migration evaluation method, which includes the following steps: The surface morphology parameters of the nanoscale pores and the three-dimensional structure image of the internal pores of the core sample are obtained and a digital core model is generated. Based on the digital core model, the location of the pores in the target area and the target sealing agent are determined. The target plugging agent is injected into the target area pores of the core sample to block the target area pores, thereby forming a target oil and gas migration path inside the core sample; The temperature and pressure conditions of the target formation are simulated, and a simulated fluid containing a fluorescent agent is injected into the target oil and gas migration path; Real-time visual observation of the oil and gas migration process within the target oil and gas migration path is performed, and migration process parameters are collected simultaneously. Based on the collected migration process parameters, a quantitative evaluation index of the migration efficiency of the target oil and gas migration path is calculated using a preset algorithm.

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