CN-121995499-A - Method, device, equipment, medium and product for determining water saturation of fractured reservoir

CN121995499ACN 121995499 ACN121995499 ACN 121995499ACN-121995499-A

Abstract

The application provides a method, a device, equipment, a medium and a product for determining water saturation of a fractured reservoir, and relates to the technical field of oil and gas development. The method comprises the steps of obtaining fracture porosity of a target fracture-containing reservoir, obtaining a first corresponding relation between a first parameter and the fracture porosity based on the fracture porosity of the target fracture-containing reservoir, wherein the first corresponding relation is determined according to a second corresponding relation between the resistivity increase rate and the water saturation under different fracture porosities, the first parameter is a parameter reflecting the electrical influence of the fracture porosity, determining a parameter of a water saturation calculation model according to the first corresponding relation and the fracture porosity of the target fracture-containing reservoir so as to obtain a target water saturation calculation model, and determining the water saturation of the target fracture-containing reservoir according to the target water saturation calculation model. The method improves the accuracy of the water saturation calculation result, and is closer to the core analysis result.

Inventors

XIN YI
FENG JIAMING
YANG XIANZHANG
CAO JUNTAO
WANG KEWEN
QI XINZHONG
FENG ZHOU
HAN CHUANG
WU DACHENG
ZHAO XINJIAN

Assignees

中国石油天然气股份有限公司

Dates

Publication Date: 20260508
Application Date: 20241108

Claims (10)

1. A method of determining water saturation of a fractured reservoir, the method comprising: Acquiring fracture porosity of a target fracture-containing reservoir; Acquiring a first corresponding relation between a first parameter and fracture porosity based on the fracture porosity of the target fracture-containing reservoir, wherein the first corresponding relation is determined according to a second corresponding relation between the resistivity increase rate and the water saturation under different fracture porosities, and the first parameter is a parameter reflecting the electrical influence of the fracture porosity; Determining parameters of a water saturation calculation model according to the first corresponding relation and the fracture porosity of the target fracture-containing reservoir so as to obtain a target water saturation calculation model; And determining the water saturation of the target fractured reservoir according to the target water saturation calculation model.
2. The method of claim 1, wherein determining the first correspondence from a second correspondence between resistivity increase and water saturation at different fracture porosities comprises: Constructing a plurality of digital core models, wherein each digital core model has corresponding crack porosity; performing numerical simulation on each digital core model to obtain a second corresponding relation under each crack porosity; Inputting the second corresponding relation into a formula corresponding to a preset water saturation calculation model to determine first parameters corresponding to the porosities of all cracks; And performing linear fitting based on the porosity of each crack and the corresponding first parameter to obtain a first corresponding relation.
3. The method of claim 2, wherein performing numerical simulation on each of the digital core models to obtain a second correspondence at each fracture porosity comprises: the following operations are performed for each of the digital core models: Acquiring a plurality of preset water saturation levels, and simulating corresponding resistivity according to each preset water saturation level; and calculating a corresponding resistivity increase rate based on each resistivity to obtain a second corresponding relationship.
4. The method of claim 2, wherein the first correspondence corresponds to the formula: wherein p 2 is a first parameter; The porosity of the crack, and a, b and c are constants.
5. The method of claim 2, wherein the determining a target water saturation calculation model from the first correspondence and the fracture porosity of the target fractured reservoir comprises: determining a saturation index of the target fractured reservoir; Determining a first parameter and a second parameter corresponding to the fracture porosity of the target fracture-containing reservoir based on the first corresponding relation, wherein the sum of the addition of the second parameter and the first parameter is equal to one; And inputting the saturation index, the first parameter and the second parameter corresponding to the fracture porosity of the target fracture-containing reservoir into a formula corresponding to the preset water saturation calculation model to obtain a target water saturation calculation model.
6. The method of claim 5, wherein the determining the saturation index of the target fractured reservoir comprises: acquiring different water saturation of the target rock core and corresponding resistivity of the target rock core; calculating a resistivity increase rate based on the resistivity; and drawing a relation curve according to the different water saturation and the resistivity increase rate, and determining the absolute value of the corresponding slope of the relation curve as a saturation index.
7. A water saturation determination apparatus for a fractured reservoir, comprising: the acquisition module is used for acquiring the fracture porosity of the target fracture-containing reservoir; The acquisition module is further configured to acquire a first correspondence between a first parameter and fracture porosity based on the fracture porosity of the target fracture-containing reservoir, where the first correspondence is determined according to a second correspondence between a resistivity increase rate and water saturation at different fracture porosities, and the first parameter is a parameter reflecting an electrical effect of the fracture porosity; The determining module is used for determining parameters of the water saturation computing model according to the first corresponding relation and the fracture porosity of the target fracture-containing reservoir so as to obtain a target water saturation computing model; The determination module is further configured to determine the water saturation of the target fractured reservoir according to the target water saturation calculation model.
8. An apparatus for determining water saturation of a fractured reservoir comprising a processor and a memory communicatively coupled to the processor; The memory stores computer-executable instructions; The processor executes computer-executable instructions stored in the memory to implement the method of any one of claims 1 to 6.
9. A computer readable storage medium having stored therein computer executable instructions which when executed by a processor are adapted to carry out the method of any one of claims 1 to 6.
10. A computer program product comprising a computer program which, when executed by a processor, implements the method of any one of claims 1 to 6.

Description

Method, device, equipment, medium and product for determining water saturation of fractured reservoir Technical Field The application relates to the technical field of oil and gas development, in particular to a method, a device, equipment, a medium and a product for determining water saturation of a fractured reservoir. Background The water saturation is an important geological parameter reflecting the relation between the amount of water actually present in the rock or soil pores and the pore volume. In oil and gas development and reservoir evaluation, reserves and producibility of oil and gas reservoirs can be evaluated by measuring water saturation, and are used for resource evaluation and production optimization in oil and gas exploration and development. As hydrocarbon exploration progresses, heterogeneous anisotropic complex reservoirs become increasingly important for exploration, these reservoirs tend to develop fractures, and water saturation calculations face significant challenges. A learner derives a general relationship between resistivity and water saturation based on the non-uniform anisotropic formation model and determines the form of the saturation model based on the pore type of the reservoir. However, although the problem of the structural form of the saturation equation of the fractured reservoir is solved by the saturation model, an effective method for determining the model parameters is not provided, and the water saturation of the fractured pore reservoir is usually calculated by determining a uniform parameter in the use at the present stage, but the accuracy of the water saturation calculated by adopting the water saturation calculation model containing the uniform parameter is lower, and the difference from the core analysis result is larger. Disclosure of Invention The application provides a method, a device, equipment, a medium and a product for determining water saturation of a fractured reservoir, which are used for solving the technical problems that the accuracy of the water saturation calculated by adopting a water saturation calculation model containing uniform parameters is low and the difference between the water saturation calculated by adopting the water saturation calculation model and a rock core analysis result is large. In a first aspect, the present application provides a method of determining water saturation of a fractured reservoir comprising: Acquiring fracture porosity of a target fracture-containing reservoir; Acquiring a first corresponding relation between a first parameter and fracture porosity based on the fracture porosity of the target fracture-containing reservoir, wherein the first corresponding relation is determined according to a second corresponding relation between the resistivity increase rate and the water saturation under different fracture porosities, and the first parameter is a parameter reflecting the electrical influence of the fracture porosity; Determining parameters of a water saturation calculation model according to the first corresponding relation and the fracture porosity of the target fracture-containing reservoir so as to obtain a target water saturation calculation model; And determining the water saturation of the target fractured reservoir according to the target water saturation calculation model. In one possible design, determining the first correspondence from the second correspondence between resistivity increase and water saturation at different fracture porosities includes: Constructing a plurality of digital core models, wherein each digital core model has corresponding crack porosity; performing numerical simulation on each digital core model to obtain a second corresponding relation under each crack porosity; Inputting the second corresponding relation into a formula corresponding to a preset water saturation calculation model to determine first parameters corresponding to the porosities of all cracks; And performing linear fitting based on the porosity of each crack and the corresponding first parameter to obtain a first corresponding relation. In one possible design, performing numerical simulation on each digital core model to obtain a second correspondence at each fracture porosity includes: the following operations are performed for each of the digital core models: Acquiring a plurality of preset water saturation levels, and simulating corresponding resistivity according to each preset water saturation level; and calculating a corresponding resistivity increase rate based on each resistivity to obtain a second corresponding relationship. In one possible design, the first correspondence corresponds to the formula: wherein p 2 is a first parameter; The porosity of the crack, and a, b and c are constants. In one possible design, determining a target water saturation calculation model from the first correspondence and the fracture porosity of the target fractured reservoir includes: Determining a saturation index