CN-121994673-A - Method, device, equipment, medium and product for determining pore structure of oil reservoir

CN121994673ACN 121994673 ACN121994673 ACN 121994673ACN-121994673-A

Abstract

The invention discloses a method, a device, equipment, a medium and a product for determining an oil reservoir pore structure. The method comprises the steps of carrying out two-dimensional scanning imaging on an oil reservoir core by utilizing high-resolution X-ray CT, constructing an initial pore network model according to a CT tomographic image of the obtained oil reservoir core, adopting at least two microscopic pore characterization experiments to process the oil reservoir core to obtain at least two pieces of nano pore statistical information, generating newly-increased pore nodes according to the at least two pieces of nano pore experimental data information and the initial pore network model, fusing the newly-increased pore nodes with the initial pore network model to obtain a target pore network model, and determining a pore structure diagram of the oil reservoir core according to the target pore network model. According to the invention, the initial pore network model is optimized through the multi-source nano pore data obtained through experiments, the nano-scale pores which are not identified by CT are subjected to complementary modeling, the accuracy of the target pore network model is improved, and the multi-scale unification of the pore structure is realized.

Inventors

LI HAIBO
YANG ZHENGMING
ZHOU TIYAO
YU JINBO
CHEN XINLIANG
Dou Zhuoying
ZHANG YU
Yang Lvshuai
ZHAO XINYI

Assignees

中国石油天然气股份有限公司

Dates

Publication Date: 20260508
Application Date: 20260212

Claims (11)

1. A method of determining a pore structure of a reservoir, the method comprising: Performing two-dimensional scanning imaging on the oil reservoir core by utilizing high-resolution X-ray CT, and constructing an initial pore network model according to the obtained CT tomographic image of the oil reservoir core; Processing the oil reservoir core by adopting at least two microscopic pore characterization experiments to obtain at least two types of nanopore statistical information, wherein the at least two types of nanopore statistical information at least comprise nanopore distribution information and total porosity; Generating a newly added pore node according to the at least two types of nanopore experimental data information and the initial pore network model, and fusing the newly added pore node with the initial pore network model to obtain a target pore network model; and determining the pore structure diagram of the oil reservoir core according to the target pore network model.
2. The method of claim 1, wherein generating new pore nodes from the at least two nanopore experimental data information and the initial pore network model comprises: determining initial model porosity according to the initial pore network model, and determining pore information to be supplemented according to the total porosity and the initial model porosity; and generating corresponding nanoscale pore nodes at the solid matrix position of the initial pore network model according to the nanopore distribution information and the pore information to be supplemented, and taking the corresponding nanoscale pore nodes as newly added pore nodes.
3. The method of claim 2, wherein the at least two microscopic pore characterization experiments comprise a high resolution scanning electron microscope analysis experiment, a low temperature nitrogen adsorption experiment, and a high pressure pump experiment; Processing the reservoir core by adopting at least two microscopic pore characterization experiments to obtain at least two types of nano pore statistical information, wherein the method comprises the following steps: Processing the oil reservoir core by adopting the high-resolution scanning electron microscope analysis experiment to obtain a nanopore distribution characteristic; The low-temperature nitrogen adsorption experiment is used for processing the oil reservoir core to obtain specific surface area, pore volume and pore diameter distribution information of the nano-pores; And the high-pressure pump experiment is used for processing the oil reservoir core to obtain the pore size distribution information, connectivity index and total porosity of the nano-pores.
4. A method according to claim 3, wherein generating corresponding nanoscale pore nodes at solid matrix locations of the initial pore network model from the nanopore profile information and the pore information to be supplemented comprises: Generating a corresponding number of nanoscale pore nodes according to the pore size distribution information obtained by the low-temperature nitrogen adsorption experiment and the high-pressure pump experiment; And determining the corresponding position information of the nanoscale pore nodes in the solid matrix of the initial pore network model according to the nanopore distribution characteristics obtained by the high-resolution scanning electron microscope analysis experiment.
5. A method according to claim 3, wherein fusing the newly added pore nodes with the initial pore network model comprises: based on connectivity indexes and nano pore distribution characteristics obtained by the at least two micro pore characterization experiments, a connection relationship between the newly added pore nodes and an original pore network in the initial pore network model is established by adding a trans-scale pore throat.
6. The method of claim 5, wherein establishing the connection relationship of the newly added pore node and the original pore network in the initial pore network model by adding a trans-scale pore throat comprises: And establishing the connection relation between the newly added pore node and the original pore network by adopting a random simulation or statistical reconstruction algorithm.
7. The method of claim 1, further comprising, after fusing the newly added pore nodes with the initial pore network model: calculating the model rock physical characteristics of the fused pore network model by adopting a digital core simulation technology; determining a comparison result of the model petrophysical characteristics and the experimental petrophysical characteristics of the reservoir core; If the two pore network models are consistent, determining the fused pore network model as the target pore network model; If the parameters are inconsistent, repeating iterative comparison is carried out by adjusting the parameters or the connection mode of the newly added pore nodes until the target pore network model is determined.
8. A device for determining the pore structure of a reservoir, the device comprising: the initial pore network model module is used for carrying out two-dimensional scanning imaging on the oil reservoir core by utilizing high-resolution X-ray CT, and constructing an initial pore network model according to the obtained CT tomographic image of the oil reservoir core; the device comprises a micro-pore information determining module, a micro-pore information analyzing module and a micro-pore analysis module, wherein the micro-pore information determining module is used for processing the oil reservoir core by adopting at least two micro-pore characterization experiments to obtain at least two types of nano-pore statistical information, and the at least two types of nano-pore statistical information at least comprise nano-pore distribution information and total porosity; the pore fusion module is used for generating newly-increased pore nodes according to the at least two types of nano pore experimental data information and the initial pore network model, and fusing the newly-increased pore nodes with the initial pore network model to obtain a target pore network model; And the pore structure diagram determining module is used for determining the pore structure diagram of the oil reservoir core according to the target pore network model.
9. An electronic device, the electronic device comprising: At least one processor, and A memory communicatively coupled to the at least one processor, wherein, The memory stores a computer program executable by the at least one processor to enable the at least one processor to perform the method of determining the reservoir pore structure of any one of claims 1-7.
10. A computer readable storage medium storing computer instructions for causing a processor to perform the method of determining the reservoir pore structure of any one of claims 1-7.
11. A computer program product, characterized in that it comprises a computer program which, when executed by a processor, implements the method of determining the pore structure of a reservoir according to any one of claims 1-7.

Description

Method, device, equipment, medium and product for determining pore structure of oil reservoir Technical Field The invention relates to the technical field of oil reservoir development, in particular to a method, a device, equipment, a medium and a product for determining an oil reservoir pore structure. Background Reservoir rocks (particularly low permeability sandstone and shale unconventional reservoirs) have multi-scale pore structures, with pore sizes ranging from micron to nanoscale. Acquisition of the three-dimensional pore structure of the core by X-ray CT scanning is an important means of digital core modeling. CT imaging distinguishes pores and matrixes by threshold segmentation of gray values, and can intuitively present the three-dimensional morphology of larger pores in the rock. However, due to the imaging resolution of CT, micro CT is generally only able to resolve pores of larger size, making it difficult to capture nano-scale micro-pores. For low permeability-dense oil reservoir rock containing a large number of micro-nanopores, a digital core model reconstructed by only relying on micro-CT cannot contain nanopores, so that the porosity and permeability of the built model are obviously lower than the true values, statistical information is difficult to be effectively mapped into the producible chip geometry, and the chip manufacturing engineering floor of 'true topology + physical property consistency + producible' cannot be met. Disclosure of Invention The invention provides a method, a device, equipment, a medium and a product for determining an oil reservoir pore structure, which are used for solving the problem of low accuracy of a pore structure constructed according to CT imaging. According to an aspect of the present invention, there is provided a method for determining a pore structure of an oil reservoir, comprising: Performing two-dimensional scanning imaging on the oil reservoir core by utilizing high-resolution X-ray CT, and constructing an initial pore network model according to the obtained CT tomographic image of the oil reservoir core; Processing the oil reservoir core by adopting at least two microscopic pore characterization experiments to obtain at least two types of nanopore statistical information, wherein the at least two types of nanopore statistical information at least comprise nanopore distribution information and total porosity; Generating a newly added pore node according to the at least two types of nanopore experimental data information and the initial pore network model, and fusing the newly added pore node with the initial pore network model to obtain a target pore network model; and determining the pore structure diagram of the oil reservoir core according to the target pore network model. According to another aspect of the present invention, there is provided a device for determining the pore structure of an oil reservoir, comprising: the initial pore network model module is used for carrying out two-dimensional scanning imaging on the oil reservoir core by utilizing high-resolution X-ray CT, and constructing an initial pore network model according to the obtained CT tomographic image of the oil reservoir core; the device comprises a micro-pore information determining module, a micro-pore information analyzing module and a micro-pore analysis module, wherein the micro-pore information determining module is used for processing the oil reservoir core by adopting at least two micro-pore characterization experiments to obtain at least two types of nano-pore statistical information, and the at least two types of nano-pore statistical information at least comprise nano-pore distribution information and total porosity; the pore fusion module is used for generating newly-increased pore nodes according to the at least two types of nano pore experimental data information and the initial pore network model, and fusing the newly-increased pore nodes with the initial pore network model to obtain a target pore network model; And the pore structure diagram determining module is used for determining the pore structure diagram of the oil reservoir core according to the target pore network model. According to another aspect of the present invention, there is provided an electronic apparatus including: At least one processor, and A memory communicatively coupled to the at least one processor, wherein, The memory stores a computer program executable by the at least one processor to enable the at least one processor to perform the method of determining reservoir pore structure according to any of the embodiments of the present invention. According to another aspect of the present invention, there is provided a computer readable storage medium storing computer instructions for causing a processor to perform the method for determining a reservoir pore structure according to any of the embodiments of the present invention. According to another aspect of the application, there is pr