Physical model system for salt water reservoir multi-scale reaction transportation process

Abstract

The invention discloses a physical model system for a multi-scale reaction transportation process of a salt water reservoir, which comprises a physical modeling module and a numerical solution module, and is characterized in that the physical modeling module is used for realizing unbalanced mass transfer through micron-scale multi-field coupling modeling, providing a physical basis for cross-scale parameter transmission, and solving the numerical solution module; the physical modeling module comprises a geometric reconstruction module, a multi-field coupling module and a multi-physical process collaboration module, the numerical solution module is used for realizing efficient solution of a pore scale multi-field coupling model, the pore scale and the Darcy scale are associated with each other, and the numerical solution module comprises an initialization module, an iteration solution module and a multi-scale parameter generation module; by constructing a pore size modeling and numerical solution dual-module cooperative system, high-precision three-dimensional reconstruction and multi-field coupling dynamic simulation of a micron-sized pore structure are realized, and deep association of a fluid transportation mechanism on a micro-pore scale and fluid transportation on a macro-Darcy scale is realized through scale upgrading.

Description

Technical Field

[0001] The present invention relates to the technical field of geological storage and oil and gas production, and in particular to a physical model system for a multi-scale reaction and transport process in a saline reservoir. Background Art

[0002] From the perspective of achieving carbon neutrality and ensuring energy security, the development of Carbon Dioxide Capture, Utilization and Storage (CCUS) coupled with renewable energy is an important technical guarantee for achieving the goal. The total proven geological storage capacity of CO2 is 8 to 55 trillion tons, of which the storage capacity of deep saline aquifers accounts for more than 95%, and is considered to be an ideal CO2 storage site. Saline aquifer storage of CO2 refers to a technology that injects captured and separated CO2 into deep underground saline aquifers, displaces the saline water in the formation, and relies on the pore space of the formation to store CO2;

[0003] On the one hand, as the instructions Figure 3 As shown in Figure 1, the porous rock medium within the CO2 storage formation is inherently multiscale, with complex internal spatial arrangements ranging from millimeters to nanometers. Furthermore, the injected CO2 gradually dissolves into the saline water, forming carbonic acid, which lowers the pH of the water and further dissolves solid minerals such as calcite. Therefore, the CO2 storage process in saline aquifers is a typical multiscale reaction and transport process.

[0004] The mineralization reactions within the multi-scale cores described above convert free CO2 into a solid mineral state, changing the wettability and pore structure of the solid surface, significantly impacting the transport of CO2 within the reservoir and the economic and safety assessments of carbon sequestration. Therefore, a coupled modeling system integrating pore-scale microscopic mechanisms and macro-engineering effects was established to accurately characterize the mathematical models of multiphase flow, heat and mass transfer, chemical reactions, and the dynamic evolution of pore structure involved in carbon dioxide storage scenarios. Through cross-scale parameter transfer and efficient numerical solutions, the complex interaction mechanisms from the pore to the reservoir scale are revealed, which is of great significance to the economic and safety assessments of carbon sequestration projects and their large-scale deployment.

[0005] However, traditional continuum media models rely on the homogenization assumption and cannot capture the impact of dynamic structural evolution such as mineral dissolution at the pore scale on seepage capacity. Direct simulation of the pore scale of a million-level grid is extremely time-consuming. Traditional upscaling methods ignore non-equilibrium mass transfer mechanisms, resulting in accumulated parameter transfer errors. Therefore, the present invention proposes a physical model system for the multi-scale reaction and transport process of saline reservoirs to address the problems existing in the prior art. Summary of the Invention

[0006] In response to the above problems, the purpose of the present invention is to propose a simulation system for the multi-scale reaction and transport process of saline reservoirs. The system realizes high-precision three-dimensional reconstruction of micron-level pore structure and fast and efficient dynamic simulation of multi-field coupling by constructing a dual-module collaborative system of pore size mathematical model and numerical solution based on multi-scale information, which solves the limitations of traditional methods such as single field coupling, inability to reflect multi-scale information of reservoir pores and efficiency of large-scale core seepage calculation; by coupling multi-field and multi-scale information to the pore scale model, a deep correlation between multi-scale information and seepage simulation is realized, and combined with efficient and parallel mesoscopic numerical calculation methods, the simulation of the internal reaction seepage process of large-scale cores and the prediction of the core macroscopic seepage parameters are realized.

[0007] To achieve the objectives of the present invention, the present invention is implemented through the following technical solutions: a physical model system for the multi-scale reaction and transport process of a saltwater reservoir, including a physical modeling module and a numerical solution module. The physical modeling module is used to realize flow and mass transfer simulation based on real reconstruction of the digital core through micron-level multi-field coupling modeling, providing a physical basis for cross-scale parameter transfer. The physical modeling module includes a geometric reconstruction module, a multi-field coupling module and a multi-physical process collaboration module. The numerical solution module is used to realize efficient solution of the pore-scale model and realize the coupling and efficient solution between the microscopic pore-scale flow and the macroscopic seepage equation. The numerical solution module includes an initialization module, an iterative solution module and a multi-scale parameter generation module.

[0008] A further improvement is that the geometric reconstruction module is used to construct a multi-valued three-dimensional digital core based on CT scan images and adopt a multi-objective segmentation algorithm based on deep learning.

[0009] A further improvement is that the size of single pores in the three-dimensional digital core in the geometric reconstruction module ranges from 40 to 200 μm.

[0010] A further improvement is that the multi-field coupling module is used to establish an inhibitory relationship between the occupation of pore space by the carbon dioxide gas phase and the expansion of the dominant channel, simulating the carbon dioxide-brine displacement path.

[0011] A further improvement is that the multi-physical process collaborative module is used to achieve in-depth collaborative modeling of carbon dioxide-brine two-phase flow, thermodynamic phase change, and mineral dissolution and precipitation, breaking through the limitations of traditional single-field coupling.

[0012] A further improvement is that the initialization module in the numerical solution module is used to realize the initialization of the lattice Boltzmann model, including the initialization of parameters such as the distribution function, flow field, temperature field, and phase field.

[0013] A further improvement is that the iterative solution module in the numerical solution module is based on multi-scale physics and numerical models, directly solving the multi-phase reaction transport equation at the pore scale to realize the simulation of multi-field reaction transport processes in real cores.

[0014] A further improvement is that the multi-scale parameter generation module in the numerical solution module is used to obtain the macroscopic seepage parameters of the core based on the pore-scale flow data by characterizing the volume average of the voxels, providing a theoretical basis for large-scale calculations.

[0015] The beneficial effects of the present invention are as follows: by constructing a dual-module collaborative system of pore size modeling and numerical solution, the present invention realizes high-precision three-dimensional reconstruction and multi-field coupling dynamic simulation of micron-level pore structure, which solves the limitations of traditional methods in accurately analyzing complex pore networks, cross-scale parameter segmentation and single field coupling; through the cross-scale parameter bidirectional transmission mechanism, the microscopic interface dynamics and macroscopic reservoir behavior are deeply correlated, and combined with the micro-macro seamless coupling algorithm, the efficient solution of multiphase reaction transport equations and reservoir migration prediction are realized. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] Figure 1 This is a system architecture diagram of the present invention;

[0017] Figure 2 This is a diagram of the physical modeling module system architecture of the present invention;

[0018] Figure 3 This is a diagram of the numerical solution module system architecture of the present invention;

[0019] Figure 4 This is a schematic diagram of the microscopic pores of the present invention. DETAILED DESCRIPTION

[0020] In order to deepen the understanding of the present invention, the present invention will be further described in detail below with reference to the examples. The examples are only used to explain the present invention and do not constitute a limitation on the scope of protection of the present invention.

[0021] Based on this, according to Figure 1 、 Figure 2 、 Figure 3 、 Figure 4 As shown, this embodiment provides a physical model system for the multi-scale reaction and transport process of saline reservoirs, including a pore-scale modeling module and a numerical solution module, wherein the pore-scale modeling module includes a geometric reconstruction module, a multi-field coupling module and a multi-physical process collaboration module, and the numerical solution module is used to realize the efficient solution of the above-mentioned multi-field and multi-scale mathematical model.

[0022] The geometric reconstruction module reconstructs acquired 3D rock cores into digital cores suitable for pore-scale simulation. During operation, a CT scan image of the 3D rock core is input, and the CT slices are subjected to noise reduction and contrast enhancement. The processed image is then subjected to multi-value segmentation using the SegmentAnything Model (SAM), which labels the different mineral components. The grayscale values ​​of the image for each mineral component are normalized to obtain the porosity of each pixel. In the porous region, the porosity is 1, in the solid region, the porosity is 0, and in the transition region between pores and solid, the porosity ranges from 0 to 1. Finally, by stacking the images, a numerical model of the 3D pore structure is generated. This solution identifies the different mineral components through segmentation and uses normalized grayscale values ​​to represent the porosity. Because it does not require a precise solid-pore boundary, it overcomes the inability of traditional binary or multi-value segmentation methods to accurately determine the pore-solid boundary. Furthermore, this solution does not require high CT scan resolution, and can even reduce the image resolution through downsampling to improve subsequent computational efficiency, providing a physical foundation for efficient model solution.

[0023] The multi-field coupling module is used to establish mathematical equations for multi-field coupling such as fluid flow and component transport, clarify the quantitative coupling relationship between multi-field parameters, and provide a theoretical basis for simulating the inhibitory relationship between the occupation of pore space by carbon dioxide gas and the expansion of dominant channels, and simulating the carbon dioxide-brine displacement path. It solves the dynamic coupling problem of multiple physical fields in the carbon dioxide-brine displacement process, avoids the limitations of traditional single-factor models, accurately predicts the heterogeneous migration path of carbon dioxide, optimizes injection strategies to inhibit the premature formation of dominant channels, and improves storage efficiency.

[0024] The multi-physical process collaborative module is used to achieve in-depth collaborative modeling of multi-physical processes such as two-phase flow, thermodynamic phase change, and mineral dissolution and precipitation, breaking through the limitations of traditional single physical processes and providing the necessary means for simulating multi-physical field coupling processes in aquifer carbon sequestration.

[0025] The numerical solution module is mainly used to achieve the rapid solution of the above-mentioned multi-field and multi-scale mathematical equations. In the present invention, the lattice Boltzmann method is mainly used for pore-scale calculation and solution. The model used in the flow process is the general seepage model for solving the unified NS equation; the phase interface tracking part adopts the phase field LB model; the two realize the multiphase flow process of CO2-salt water in the reservoir through velocity coupling; the reaction between fluid and solid is reflected in the source term of the evolution equation, and the evolution of solid structure is realized through the VOF method.

[0026] The initialization module includes initialization of flow field velocity, pressure, density, concentration field, and phase field distribution. The initialization module provides two initialization methods. The first is to give the initial macro-quantity distribution in a given space. Based on the initial macro-quantity, the equilibrium distribution function is directly used to simplify the distribution function. The other initialization method is to obtain the value of the initial distribution function after the initial macro-quantity is given, and then the moment of the distribution function is obtained to obtain the initial pressure field distribution. Through the initialization module, the initial values ​​of the simulation calculation are reasonably given to improve the efficiency and accuracy of the calculation.

[0027] The iterative solution module is a process of performing calculations based on initial conditions. This process is also divided into two modes. The first is for steady-state problems. After setting the convergence standard, it determines whether the convergence standard is met every 1,000 iterations. If it is met, the calculation is completed; if not, the calculation continues. The second is for non-steady-state problems. After setting the length of time to be studied, the calculation is stopped when the iteration reaches that time. To improve computing efficiency, the iterative solution module is implemented in parallel on a single GPU based on CUDA-C++, and the computing efficiency is increased by 30 times compared to a single-threaded CPU.

[0028] The multi-scale parameter generation module is based on the pore-scale flow data obtained by the iterative solution module, such as velocity and phase distribution, and obtains the porosity, relative permeability curve and effective reaction specific surface area of ​​the tested core through the volume averaging method combined with the Darcy equation, providing an accurate reference for the prediction of the macroscopic seepage parameters of the sampled reservoir. The above shows and describes the basic principles, main features and advantages of the present invention. Those skilled in the art should understand that the present invention is not limited to the above-mentioned embodiments. The above-mentioned embodiments and descriptions are only for explaining the principles of the present invention. Without departing from the spirit and scope of the present invention, the present invention will have various changes and improvements, and these changes and improvements all fall within the scope of the invention to be protected. The scope of protection claimed in the present invention is defined by the attached claims and their equivalents.

Claims

1. A physical model system for multi-scale reaction and transport processes in saline reservoirs, characterized by: It includes a physical modeling module and a numerical solution module. The physical modeling module is used to realize flow and mass transfer simulation based on real reconstruction of digital core through micron-level multi-field coupling modeling, providing a physical basis for cross-scale parameter transfer. The physical modeling module includes a geometric reconstruction module, a multi-field coupling module and a multi-physical process collaboration module. The numerical solution module is used to realize efficient solution of pore-scale models and realize the coupling and efficient solution between microscopic pore-scale flow and macroscopic seepage equations. The numerical solution module includes an initialization module, an iterative solution module and a multi-scale parameter generation module.

2. The physical model system for multi-scale reaction transport process in saltwater reservoirs according to claim 1, characterized in that: The geometric reconstruction module is used to construct a multi-valued three-dimensional digital core based on CT scan images and adopt a multi-objective segmentation algorithm based on deep learning.

3. The physical model system for multi-scale reaction transport process in saltwater reservoirs according to claim 2, characterized in that: The single pore size range of the three-dimensional digital core in the geometric reconstruction module is 40 to 200 μm.

4. The physical model system for multi-scale reaction transport process in saltwater reservoirs according to claim 1, characterized in that: The multi-field coupling module is used to establish the inhibitory relationship between the occupation of pore space by the carbon dioxide gas phase and the expansion of the dominant channel, and to simulate the carbon dioxide-brine displacement path.

5. The physical model system for multi-scale reaction transport process in saline reservoirs according to claim 1, characterized in that: The multi-physical process collaborative module is used to achieve in-depth collaborative modeling of carbon dioxide-brine two-phase flow, thermodynamic phase change, and mineral dissolution and precipitation, breaking through the limitations of traditional single-field coupling.

6. The physical model system for multi-scale reaction transport process in saltwater reservoirs according to claim 1, characterized in that: The initialization module in the numerical solution module is used to realize the initialization of the lattice Boltzmann model, including the initialization of parameters such as the distribution function, flow field, temperature field, and phase field.

7. The physical model system for multi-scale reaction and transport processes in saline reservoirs according to claim 1, characterized in that: The iterative solution module in the numerical solution module is based on multi-scale physics and numerical models, and directly solves the multi-phase reaction transport equation at the pore scale to realize the simulation of the multi-field reaction transport process in the real core.

8. The physical model system for multi-scale reaction and transport processes in saline reservoirs according to claim 1, characterized in that: The multi-scale parameter generation module in the numerical solution module is used to obtain the macroscopic seepage parameters of the core based on the pore-scale flow data by characterizing the volume averaging of the voxels, providing a theoretical basis for large-scale calculations.

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