CN-121978774-A - Method and related equipment for determining hydrogen and water permeability curve of underground hydrogen storage

CN121978774ACN 121978774 ACN121978774 ACN 121978774ACN-121978774-A

Abstract

The invention discloses a method and related equipment for determining a hydrogen and water permeability curve of an underground hydrogen storage, and relates to the field of underground space engineering, wherein the method comprises the steps of acquiring a microcomputerized tomography image of a rock sample in a hydrogen flooding process; the method comprises the steps of carrying out characterization unit body analysis on a pore structure of a microcomputerized tomography image to construct a first pore structured grid model, wherein the first pore structured grid model is used for characterizing the pore structure of a rock sample, the first pore structured grid model comprises a coordinate system of the pore structure, mapping wettability distribution data to the first pore structured grid model through corresponding coordinate positions by taking the coordinate system of the first pore structured grid model as a reference to obtain a second pore structured grid model, the wettability distribution data is obtained by calculating along three-phase contact lines of rock, hydrogen and water extracted from the microcomputerized tomography image, and carrying out two-phase flow simulation operation of water flooding hydrogen on the second pore structured grid model to obtain a hydrogen and water infiltration curve of a hydrogen storage library.

Inventors

PENG JIAJUN
SONG RUI
LIU JIANJUN
YANG CHUNHE

Assignees

中国科学院武汉岩土力学研究所

Dates

Publication Date: 20260505
Application Date: 20260202

Claims (10)

1. A method for determining a hydrogen-water permeability curve of an underground hydrogen storage reservoir, comprising: acquiring a microcosmic computer tomography image of a rock sample in a hydrogen flooding process, wherein the rock sample is a detection sample acquired from a hydrogen storage library in nature; Performing characterization unit body analysis on the pore structure of the microscopic computer tomography image to construct a first pore structured grid model, wherein the first pore structured grid model is used for characterizing the pore structure of the rock sample, the first pore structured grid model is a geometric structure model, and the first pore structured grid model comprises a coordinate system of the pore structure; Mapping wettability distribution data to the first pore structured grid model through corresponding coordinate positions by taking a coordinate system of the first pore structured grid model as a reference to obtain a second pore structured grid model, wherein the wettability distribution data is obtained by calculation along three-phase contact lines of rock, hydrogen and water extracted from the microcomputerized tomography image; And performing two-phase flow simulation operation of water-driven hydrogen on the second pore structured grid model to obtain a hydrogen and water permeability curve of the hydrogen storage library, wherein the two-phase flow simulation operation of water-driven hydrogen is a simulation operation of displacing a hydrogen gas phase in the second pore structured grid model with a water phase.
2. The method of claim 1, wherein the acquiring a microcomputerized tomographic image of a rock sample during hydrogen flooding includes: acquiring a microcomputerized tomography image under the simulated operation of hydrogen flooding on the rock sample, wherein the simulated operation of hydrogen flooding is used for simulating the gas injection operation of a hydrogen storage library; Carrying out noise reduction treatment on the microcomputerized tomography image by utilizing a median filtering technology; And (3) utilizing a watershed segmentation technology to segment the microcomputerized tomography image so as to extract hydrogen and water in the rock pore space.
3. The method of claim 1, wherein the characterizing a cell volume analysis of the pore structure of the microcomputerized tomographic image to construct a first pore structured grid model comprises: Intercepting cube sub-images with different side lengths from the center of the microcosmic computed tomography image; Respectively calculating the porosity and the water saturation of each cubic sub-image; Determining a fluctuation trend of the porosity and the water saturation based on the porosity and the water saturation of each of the cubic sub-images; Determining the corresponding minimum cube sub-image as a representation unit model under the condition that the fluctuation trend of the porosity and the water saturation is smaller than a preset amplitude; Each image pixel of the characterization unit cell model is converted into a hexahedral mesh cell to construct the first pore structured mesh model.
4. A method according to claim 3, further comprising: Obtaining a multiphase surface grid model based on the characterization unit body model by utilizing a marching cube algorithm, wherein the multiphase surface grid model is used for characterizing the distribution of phase interfaces of hydrogen, water and rock solids; extracting each contact point on a three-phase contact line of rock, hydrogen and water from the multiphase surface grid model; calculating in-situ contact angles of contact points on the three-phase contact line, wherein the in-situ contact angle corresponding to any contact point is obtained by calculating an included angle between a normal vector of a hydrogen-water phase interface unit at the contact point and a normal vector of a water-rock solid phase interface unit; And in the space of the characterization unit body model, taking the average diameter of the pores as the size of a moving window, and counting the local average value of the in-situ contact angle to obtain the wettability distribution data.
5. The method of claim 1, wherein mapping the wettability distribution data to the first pore structured grid model by corresponding coordinate locations with reference to the coordinate system of the first pore structured grid model to obtain a second pore structured grid model comprises: Determining the center point coordinates of each wall surface grid cell in the first pore structured grid model, wherein the wall surface grid cells are grid cells of pores contacted under the condition of fluid flow; Determining a local average value of in-situ contact angles in the wettability distribution data corresponding to each center point coordinate; and assigning the local average value of the in-situ contact angle to a wall grid cell corresponding to the coordinate position in the first pore structured grid model to obtain the second pore structured grid model.
6. The method as recited in claim 1, further comprising: Setting boundary conditions of single-phase flow simulation on the first pore structured grid model, wherein the single-phase flow simulation simulates water injection to the first pore structured grid model to simulate the operation of flowing of water phase in the first pore structured grid model, the boundary conditions comprise that an inlet of the water injection operation is set to be used for injecting the water phase at fixed pressure, an outlet of the water injection operation is set to be at a zero pressure value, and the wall surfaces of the first pore structured grid model except the inlet and the outlet are set to be impermeable boundaries; Simulating the flow of the aqueous phase in the first pore structured grid model using a finite volume method under the boundary conditions; and calculating the absolute permeability of the first pore structured grid model by using Darcy's law under the condition that the simulation process reaches a convergence standard.
7. The method of claim 6, wherein performing a two-phase flow simulation operation of water-flooding hydrogen on the second pore structured grid model to obtain a hydrogen-water permeability curve of the hydrogen reservoir comprises: Setting reservoir temperature conditions and pressure conditions on the second pore structured grid model; determining the water phase density, water phase viscosity, hydrogen density, hydrogen viscosity and hydrogen-water interfacial tension coefficient under the reservoir temperature conditions and pressure conditions; Setting the hydrogen and water distribution represented by the microcomputerized tomography image as the initial fluid distribution of the two-phase flow simulation of the water-driven hydrogen; Setting boundary conditions of two-phase flow simulation operation of water-flooding hydrogen on the second pore structured grid model, wherein the boundary conditions comprise that an inlet of water injection operation is set to inject water phase at a constant speed, an outlet of water injection operation is set to be a zero pressure value, and the wall surfaces of the second pore structured grid model except the inlet and the outlet are set to be impermeable boundaries; Under the boundary condition, performing two-phase flow simulation of water-flooding hydrogen on the second pore structured grid model by using a fluid volume method to obtain the effective hydrogen permeability and the effective water phase permeability under different water saturation in the two-phase flow simulation process of the water-flooding hydrogen; Determining the relative permeability of hydrogen and the relative permeability of water phase at different water saturation based on the effective permeability of hydrogen, the effective permeability of water phase and the absolute permeability at different water saturation; And determining a hydrogen-water permeability curve of the hydrogen storage library based on the relative permeability of hydrogen and the relative permeability of water phase at the different water saturation levels.
8. The utility model provides a hydrogen and water phase infiltration curve determining means of underground hydrogen storage storehouse which characterized in that still includes: the acquisition unit is used for acquiring a microcomputerized tomographic image of a rock sample in the hydrogen flooding process, wherein the rock sample is a detection sample acquired from a hydrogen storage library in nature; A construction unit for performing characterization unit body analysis on the pore structure of the microscopic computer tomography image to construct a first pore structured grid model, wherein the first pore structured grid model is used for characterizing the pore structure of the rock sample, the first pore structured grid model is a geometric structure model, and the first pore structured grid model comprises a coordinate system of the pore structure; The mapping unit is used for mapping wettability distribution data to the first pore structured grid model through corresponding coordinate positions by taking a coordinate system of the first pore structured grid model as a reference so as to obtain a second pore structured grid model, wherein the wettability distribution data is calculated along three-phase contact lines of rock, hydrogen and water extracted from the microcosmic computer tomography image; And the operation unit is used for performing two-phase flow simulation operation of water-flooding hydrogen on the second pore structured grid model to obtain a hydrogen and water permeability curve of the hydrogen storage library, wherein the two-phase flow simulation operation of water-flooding hydrogen is a simulation operation of displacing a hydrogen gas phase in the second pore structured grid model with a water phase.
9. A computer readable storage medium, characterized in that the computer readable storage medium comprises a stored program, wherein the steps of the method for determining the hydrogen-water permeability curve of an underground hydrogen reservoir according to any one of claims 1 to 7 are implemented when the program is executed by a processor.
10. An electronic device comprising at least one processor and at least one memory coupled to the processor, wherein the processor is configured to invoke program instructions in the memory to perform the steps of the method for determining a hydrogen and water permeability curve of a subsurface hydrogen reservoir as claimed in any one of claims 1 to 7.

Description

Method and related equipment for determining hydrogen and water permeability curve of underground hydrogen storage Technical Field The invention relates to the field of underground space engineering, in particular to a method and related equipment for determining a hydrogen and water permeability curve of an underground hydrogen storage. Background The hydrogen energy is used as a clean energy carrier, great potential is shown in the aspects of energy transformation and climate change response, but the large-scale application of the hydrogen energy is in urgent need of economic and efficient storage technical support, underground hydrogen storage utilizes underground porous reservoirs such as depleted oil and gas reservoirs, water-bearing layers and the like, and by virtue of the characteristics of wide distribution, large capacity, good sealing performance and the like, the hydrogen energy is a feasible scheme for solving energy supply and demand fluctuation, however, the accurate prediction of the hydrogen storage capacity and the recovery efficiency of the porous reservoirs, the core basis of an optimized injection and production scheme is that the permeability curve of hydrogen and water two-phase flow in rock is accurately obtained, and the obtaining of the curve mainly depends on two types of methods, namely, the traditional indoor core displacement experiment is direct but has the limitation that equipment requirements are strict, the experiment cost is long, the period is long, and the complex conditions such as the temperature and pressure of the real reservoirs are difficult to be widely covered, and the like, and more critical is that the flammable and explosive hydrogen is greatly used in the experimental process, the obvious safety hidden danger is brought by the fact that the numerical simulation is realized, the cost and time is saved, the research is allowed in a wider parameter range, the hydrogen permeability curve is optimized, and the optimal injection and production scheme is based on the accurate obtaining of the permeability curve of the two-phase flow, and the real phase flow is difficult to calculate the condition of the real phase flow, and the real phase flow is not the real and the real phase flow condition, and the in the condition is not the complicated condition of the in the simulation of the rock in the condition of the simulation of the rock phase simulation, and the condition, and the in the phase simulation of the condition of the phase simulation. Therefore, the hydrogen and water permeation curve with higher accuracy is difficult to obtain in the prior art. Disclosure of Invention In view of the above problems, the invention provides a method for determining a hydrogen-water permeation curve of an underground hydrogen storage reservoir and related equipment, and mainly aims to solve the problem that the hydrogen-water permeation curve with higher accuracy is difficult to obtain in the prior art. To solve at least one of the above technical problems, in a first aspect, the present invention provides a method for determining a hydrogen-water permeability curve of an underground hydrogen storage, the method comprising: acquiring a microcosmic computer tomography image of a rock sample in a hydrogen flooding process, wherein the rock sample is a detection sample acquired from a hydrogen storage library in nature; Performing characterization unit body analysis on the pore structure of the microscopic computer tomography image to construct a first pore structured grid model, wherein the first pore structured grid model is used for characterizing the pore structure of the rock sample, the first pore structured grid model is a geometric structure model, and the first pore structured grid model comprises a coordinate system of the pore structure; Mapping wettability distribution data to the first pore structured grid model through corresponding coordinate positions by taking a coordinate system of the first pore structured grid model as a reference to obtain a second pore structured grid model, wherein the wettability distribution data is obtained by calculation along three-phase contact lines of rock, hydrogen and water extracted from the microcomputerized tomography image; And performing two-phase flow simulation operation of water-driven hydrogen on the second pore structured grid model to obtain a hydrogen and water permeability curve of the hydrogen storage library, wherein the two-phase flow simulation operation of water-driven hydrogen is a simulation operation of displacing a hydrogen gas phase in the second pore structured grid model with a water phase. Optionally, the acquiring a microcomputerized tomographic image of the rock sample during the hydrogen flooding process includes: Acquiring a microcomputerized tomography image under the simulation operation of hydrogen flooding on the rock sample, wherein the simulation operation of hydrogen flooding is used for simulat