CN-121995530-A - Method and system for spatially describing water invasion dominant channels of crack-pore type gas reservoir

CN121995530ACN 121995530 ACN121995530 ACN 121995530ACN-121995530-A

Abstract

The disclosure belongs to the technical field of gas reservoir exploration, and particularly relates to a method and a system for spatially describing a water invasion dominant channel of a crack-pore type gas reservoir. The method comprises the steps of establishing a dual-medium fine geological model, obtaining a matrix permeability model according to the matrix porosity model and a crack permeability model according to the discrete crack network model, meshing a matrix non-uniformity characterization parameter based on the matrix permeability model, and meshing a crack non-uniformity characterization parameter based on the crack permeability model. The method and the device can accurately judge the near-well water invasion channel or the seepage barrier, can predict the water invasion channel or the area to be water-immersed of the total gas reservoir, reduce the influence of human factors, and realize the prediction of the geometric form and the spatial configuration relation of the water invasion channel aiming at the fracture-pore type reservoir, which is visual and fine, high in calculation efficiency and comprehensive in evaluation parameter.

Inventors

Wen Guangyao
WANG YU
CHEN HUAILONG
ZHANG PEIJUN
GONG XINGLIN
WEI XIAODONG

Assignees

中国石油天然气集团有限公司
中国石油国际勘探开发有限公司
中石油阿姆河天然气勘探开发(北京)有限公司
中国石油集团东方地球物理勘探有限责任公司

Dates

Publication Date: 20260508
Application Date: 20241105

Claims (13)

1. A method for spatially characterizing a water-invaded dominant channel of a fracture-pore gas reservoir, the method comprising: Establishing a dual-medium fine geological model, wherein the dual-medium fine geological model comprises a matrix porosity model and a discrete fracture network model; obtaining a matrix permeability model according to the matrix porosity model, and obtaining a crack permeability model according to the discrete crack network model; Performing matrix non-uniformity characterization parameter gridding based on the matrix permeability model, and performing fracture non-uniformity characterization parameter gridding based on the fracture permeability model; Constructing a matrix water invasion channel geological feature parameter evaluation standard through matrix heterogeneity characterization parameter gridding, and constructing a crack water invasion channel geological feature parameter evaluation standard through crack heterogeneity characterization parameter gridding; Obtaining a matrix average probability attribute body based on matrix water invasion channel geological feature parameter evaluation criteria, and obtaining a crack average probability attribute body based on crack water invasion channel geological feature parameter evaluation criteria; Obtaining a water invasion channel distribution model according to the matrix average probability attribute body and the crack average probability attribute body, and carrying out spatial depiction on a water invasion dominant channel of a region to be tested through the water invasion channel distribution model to obtain a spatial depiction result.
2. The method for spatially characterizing a water-intrusion dominant channel of a fracture-void gas reservoir of claim 1, Obtaining a matrix permeability model from the matrix porosity model, comprising: Obtaining actual values of porosity and permeability of different deposition microphases of each small layer; obtaining a cross graph through the actual values of the porosity and the permeability, wherein the cross graph comprises a porosity-permeability relation curve; fitting a porosity and permeability relation curve to obtain a power function related to the porosity; obtaining predicted values of the permeability of each small layer under different deposition microphases by using a power function; and obtaining a matrix permeability model based on the predicted value of the permeability.
3. The method for spatially characterizing a water-intrusion dominant channel of a fracture-void gas reservoir of claim 1, Obtaining a fracture permeability model according to the discrete fracture network model, comprising: Acquiring the crack permeability; And obtaining a fracture permeability model by using an Oda method.
4. The method for spatially characterizing a water-intrusion dominant channel of a fracture-void gas reservoir of claim 1, After the matrix non-uniformity characterization parameter gridding based on the matrix permeability model and the fracture non-uniformity characterization parameter gridding based on the fracture permeability model, the method comprises the following steps: dimensionless conversion is carried out on characteristic parameters of the matrix and the crack; The characteristic parameters include at least a non-uniformity characterization parameter and a permeability.
5. The method for spatially characterizing a water-intrusion dominant channel of a fracture-void gas reservoir of claim 1, The water invasion channel geological feature parameter evaluation criteria comprise homogeneity, non-homogeneity and strong non-homogeneity.
6. The method for spatially characterizing a water-intrusion dominant channel of a fracture-void gas reservoir of claim 1, Obtaining a matrix average probability attribute body based on matrix water invasion channel geological feature parameter evaluation criteria, comprising: Correcting a single well discretized permeability log by using the core experimental permeability; Verifying the correlation coefficient of each heterogeneity parameter of the single well discretized permeability log and the matrix; setting the weight of each geological feature parameter of the related matrix according to the correlation coefficient; and obtaining a matrix average probability attribute body by using the weight and the permeability of each geological characteristic parameter related to the matrix.
7. The method for spatially characterizing a water-intrusion dominant channel of a fracture-void gas reservoir of claim 1, Obtaining a fracture average probability attribute body based on fracture water invasion channel geological feature parameter evaluation criteria, wherein the fracture average probability attribute body comprises the following components: Correcting a single well discretized fracture strength curve by using the core experimental permeability; verifying correlation coefficients of a single well discretized fracture strength curve and various heterogeneous parameters of the fracture; Setting the weight of each geological feature parameter of the related crack according to the correlation coefficient; and obtaining the average probability attribute body of the fracture by using the weight and the permeability of each geological characteristic parameter of the related fracture.
8. The method for spatially characterizing a water-intrusion dominant channel of a fracture-void gas reservoir of claim 1, Obtaining a water intrusion channel distribution model according to the matrix average probability attribute body and the crack average probability attribute body, wherein the water intrusion channel distribution model comprises the following steps: And obtaining a water invasion channel distribution model according to the matrix average probability attribute body, the crack average probability attribute body, the geological feature parameter weights of the related matrix and the geological feature parameter weights of the related crack.
9. A water-intrusion dominant channel space characterization system of a fracture-void gas reservoir, the system comprising: The establishing module is used for establishing a dual-medium fine geological model, wherein the dual-medium fine geological model comprises a matrix porosity model and a discrete fracture network model; The first acquisition module is used for obtaining a matrix permeability model according to the matrix porosity model and obtaining a crack permeability model according to the discrete crack network model; the meshing module is used for meshing the matrix non-uniformity characterization parameters based on the matrix permeability model and meshing the fracture non-uniformity characterization parameters based on the fracture permeability model; The evaluation standard module is used for constructing matrix water invasion channel geological feature parameter evaluation standards through matrix heterogeneity characterization parameter gridding and constructing crack water invasion channel geological feature parameter evaluation standards through crack heterogeneity characterization parameter gridding; The second acquisition module is used for obtaining a matrix average probability attribute body based on matrix water invasion channel geological feature parameter evaluation criteria and obtaining a crack average probability attribute body based on crack water invasion channel geological feature parameter evaluation criteria; and the depicting module is used for obtaining a water invasion channel distribution model according to the matrix average probability attribute body and the crack average probability attribute body, and spatially depicting the water invasion dominant channel of the region to be tested through the water invasion channel distribution model to obtain a spatial depicting result.
10. The water-intrusion dominant channel space characterization system of a fracture-void type gas reservoir according to claim 9, further comprising: The conversion module is used for carrying out dimensionless conversion on the characteristic parameters of the matrix and the crack; The characteristic parameters include at least a non-uniformity characterization parameter and a permeability.
11. The water-flooding dominant channel spatial characterization system of a fracture-void type gas reservoir of claim 9, wherein, The second obtaining module is used for obtaining a matrix average probability attribute body based on matrix water invasion channel geological feature parameter evaluation criteria, and comprises the following steps: the second acquisition module is used for correcting a single-well discretized permeability log by using the core experimental permeability; Verifying the correlation coefficient of each heterogeneity parameter of the single well discretized permeability log and the matrix; setting the weight of each geological feature parameter of the related matrix according to the correlation coefficient; and obtaining a matrix average probability attribute body by using the weight and the permeability of each geological characteristic parameter related to the matrix.
12. The water-flooding dominant channel spatial characterization system of a fracture-void type gas reservoir of claim 9, wherein, The second obtaining module is used for obtaining a fracture average probability attribute body based on fracture water invasion channel geological feature parameter evaluation criteria, and comprises the following steps: The second acquisition module is used for correcting a single well discretized fracture strength curve by using the core experimental permeability; verifying correlation coefficients of a single well discretized fracture strength curve and various heterogeneous parameters of the fracture; Setting the weight of each geological feature parameter of the related crack according to the correlation coefficient; and obtaining the average probability attribute body of the fracture by using the weight and the permeability of each geological characteristic parameter of the related fracture.
13. The water-flooding dominant channel spatial characterization system of a fracture-void type gas reservoir of claim 9, wherein, The characterization module is used for obtaining a water invasion channel distribution model according to the matrix average probability attribute body and the crack average probability attribute body, and comprises the following steps: The characterization module is used for obtaining a water invasion channel distribution model according to the matrix average probability attribute body, the crack average probability attribute body, each geological feature parameter weight of the related matrix and each geological feature parameter weight of the related crack.

Description

Method and system for spatially describing water invasion dominant channels of crack-pore type gas reservoir Technical Field The disclosure belongs to the technical field of gas reservoir exploration, and particularly relates to a method and a system for spatially describing a water invasion dominant channel of a crack-pore type gas reservoir. Background The biggest challenge faced in the development of the water-containing gas reservoir is that the water logging of the gas well not only causes the increase of the ground water treatment cost, but also shortens the stable production time of the gas reservoir, accelerates the decrease of the productivity and reduces the recovery ratio of the gas reservoir, thereby bringing huge resource waste and economic loss. The intuitive and fine gas reservoir water invasion channel prediction method can enable technicians to timely and accurately take targeted water prevention and control countermeasures, and plays a vital role in long-term stable production and efficient development of gas reservoirs. The conventional identification methods of the gas reservoir water invasion channel comprise a tracer method, a logging data identification method, a well testing data identification method, an analytic hierarchy process and a geological modeling method, and all the methods have respective technical limitations. The tracer method is an engineering method for achieving the purpose of monitoring the connectivity between wells by injecting a gas tracer into a gas well. The method has the advantages that the communication condition between the production wells can be known qualitatively, but the reservoir communication details of the wells and the far well zone cannot be described. The logging data identification method is a method for judging the communication relationship between wells by comprehensively explaining logging curves to obtain physical parameters of single-well reservoirs. The method can quantitatively describe the permeability change of different intervals on the well, can realize finer description on a water invasion channel between two wells with smaller well spacing, and can not be identified in a region without well control. The well test data identification method is a method for judging whether a water invasion dominant channel or a seepage barrier exists between wells or not by interpreting reservoir characteristic parameters through stratum pressure data obtained by methods such as pressure recovery well test and interference well test. The method can accurately describe the reservoir change condition in the well control range, but can not judge the area without well control. The analytic hierarchy process is to decompose the factors related to the water intrusion channel identification into a plurality of layers according to different attributes by establishing a hierarchical structure model, and obtain a final decision result through the processes of paired comparison matrixes, consistency inspection and the like. The method has the advantages of simplicity, convenience and rapidness, but has great influence on human factors, and can only be used as an auxiliary method for qualitative description. The conventional geological modeling method is to comprehensively apply dynamic and static information of a gas reservoir to build a three-dimensional geological model, and describe the plane spreading and spatial configuration relation of a water invasion channel by using permeability distribution as a discrimination basis. The method can achieve the aim of intuitively and finely describing the water invasion dominant channel to a certain extent, but the common research object is a single medium reservoir, and the water invasion dominant channel of the crack-pore type reservoir is not accurately described by only using the permeability as a discrimination basis, so that the comprehensive evaluation parameters can not be achieved. Disclosure of Invention In view of the foregoing, the present disclosure provides a method for spatially characterizing a water-invaded dominant channel of a fracture-pore gas reservoir, the method comprising: Establishing a dual-medium fine geological model, wherein the dual-medium fine geological model comprises a matrix porosity model and a discrete fracture network model; obtaining a matrix permeability model according to the matrix porosity model, and obtaining a crack permeability model according to the discrete crack network model; Performing matrix non-uniformity characterization parameter gridding based on the matrix permeability model, and performing fracture non-uniformity characterization parameter gridding based on the fracture permeability model; Constructing a matrix water invasion channel geological feature parameter evaluation standard through matrix heterogeneity characterization parameter gridding, and constructing a crack water invasion channel geological feature parameter evaluation standard through crack heter