CN-121993189-A - Method, device, equipment and storage medium for evaluating limit for gas reservoir

CN121993189ACN 121993189 ACN121993189 ACN 121993189ACN-121993189-A

Abstract

The application provides a method, a device, equipment and a storage medium for evaluating limit for a gas reservoir. The method comprises the steps of calculating critical full life cycle accumulated gas yield of a gas well under preset yield based on current gas price, determining critical first-year gas yield and critical first-year average gas yield based on the critical full life cycle accumulated gas yield and the first-year gas yield ratio of the gas well in a high-water-content tight sandstone gas reservoir area, determining a linear relation between the first-year average gas yield and the water-gas ratio based on water production data and gas production data of a plurality of first-class gas wells, determining the critical water-gas ratio, performing reservoir calibration on a plurality of second-class gas wells based on the critical water-gas ratio and the critical first-year average gas yield, and determining the porosity, the permeability and the lower limit of the gas saturation of an effective reservoir of the high-water-content tight sandstone gas reservoir based on reservoir calibration results. In the method, the gas reservoir utilization limit is estimated by combining the gas-water relation between the economic factors and the gas reservoir, so that the accuracy of the utilization limit estimation is improved.

Inventors

Han Jiangchen
GUO ZHI
CAO ZHENGLIN
WANG GUOTING
MENG DEWEI
CHEN KEFEI

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 evaluating a reservoir use limit of a gas reservoir, comprising: Calculating critical full life cycle accumulated gas yield of the gas well under the preset yield rate based on the current gas price, and determining critical first-year gas yield and critical first-year daily gas yield based on the critical full life cycle accumulated gas yield and the first-year gas yield ratio of the gas well in the high-water-content compact sandstone gas reservoir area; Determining a linear relation between daily gas production and water gas ratio of the first year based on water production data and gas production data of a plurality of first gas wells in a high-water-content tight sandstone gas reservoir, wherein the production time of the first gas well is less than one year, and the ratio of the open time to the production time is greater than a preset ratio; determining a critical water-gas ratio based on the linear relationship and the critical first year daily gas production; performing reservoir calibration on a plurality of second-class gas wells in the high-water-content tight sandstone gas storage area based on the critical water-gas ratio and the critical first-year daily average gas production; And determining the lower limit of the porosity, permeability and gas saturation of the effective reservoir of the high-water-content compact sandstone gas reservoir based on the reservoir calibration result.
2. The method of claim 1, wherein reservoir calibration of a plurality of second type gas wells in the high water content tight sandstone gas reservoir based on the critical water gas ratio and the critical first year average daily gas production comprises: Determining a gas-to-water ratio of the second gas wells based on gas testing data of the second gas wells for each of the second gas wells, wherein the gas testing data comprises daily gas production and daily water production; Determining that the daily gas production of the gas test is greater than the daily average gas production of the critical first year, and the reservoir calibration result of the second-class gas well with the gas test water-gas ratio being smaller than the critical water-gas ratio is a benefit gas layer; determining that the daily gas production of the gas test is smaller than or equal to the average gas production of the critical first year and larger than the preset gas production, and the reservoir calibration result of the second-class gas well with the gas test water-gas ratio smaller than the critical water-gas ratio is a differential gas layer; Determining that the daily gas production of the gas test is smaller than or equal to the preset gas production, and the reservoir calibration result of the second-type gas well with the gas test water-gas ratio smaller than the critical water-gas ratio is a dry layer; And determining a reservoir calibration result of the second-class gas well with the gas-water ratio of the test gas being greater than or equal to the critical water-gas ratio as a water layer.
3. The method of claim 1, wherein determining the lower limits of porosity, permeability, and gas saturation of the high water tight sandstone gas reservoir effective reservoir based on the reservoir calibration results comprises: acquiring the porosity, the permeability and the gas saturation of each second gas well; and determining the lower limit of the porosity, the permeability and the gas saturation of the effective reservoir of the high-water-content tight sandstone gas reservoir based on reservoir calibration results of the plurality of second-class gas wells and the porosity, the permeability and the gas saturation of each second-class gas well.
4. The method of claim 3, wherein determining the lower limit for the porosity, permeability, and gas saturation of the high water tight sandstone reservoir effective reservoir based on the reservoir calibration results for the plurality of gas wells of the second type, and the porosity, permeability, and gas saturation of each of the gas wells of the second type, comprises: Determining a lower limit of porosity and permeability of the high-water-content tight sandstone gas reservoir effective reservoir based on the porosity and permeability of the second-gas wells of the dry layer in the reservoir calibration results of the plurality of second-gas wells; And determining the lower limit of the gas saturation of the effective reservoir of the high-water-content tight sandstone gas reservoir based on the gas saturation of the water layer in the reservoir calibration results of the plurality of second gas wells.
5. The method of claim 3, wherein determining the lower limit for the porosity, permeability, and gas saturation of the high water tight sandstone reservoir effective reservoir based on the reservoir calibration results for the plurality of second-type gas wells, and the porosity and permeability and gas saturation of each of the second-type gas wells, comprises: Drawing a first distribution map and a second distribution map based on the reservoir calibration results of the plurality of second gas wells and the porosity, permeability and gas saturation of each of the second gas wells, wherein the first distribution map is used for describing the distribution of the porosity and permeability of the second gas wells of various reservoir calibration results, and the second distribution map is used for describing the distribution of the gas saturation and the porosity of the second gas wells of various reservoir calibration results; determining a lower limit for porosity and permeability of the high water content tight sandstone reservoir effective reservoir based on the first profile; Based on the second profile, a lower limit of gas saturation of the high water content tight sandstone gas reservoir effective reservoir is determined.
6. The method according to any one of claims 1-5, further comprising: Acquiring total life cycle accumulated gas production and first-year gas production of a plurality of third-class gas wells; And determining the first-year gas yield ratio of the gas wells in the high-water-content tight sandstone gas reservoir based on the total life cycle accumulated gas yield and the first-year gas yield of each third-class gas well.
7. An apparatus for evaluating reservoir use boundaries of a gas reservoir, comprising: The critical value calculation module is used for calculating critical full life cycle accumulated gas yield of the gas well under the preset yield rate based on the current gas price, and determining critical first-year gas yield and critical first-year daily average gas yield based on the critical full life cycle accumulated gas yield and the first-year gas yield ratio of the gas well in the high-water-content tight sandstone gas reservoir; The first-year linear relation determining module is used for determining the linear relation between the average daily gas production rate and the water-gas ratio of the first year based on the water production data and the gas production data of a plurality of first-class gas wells in the high-water-content tight sandstone gas reservoir, wherein the production time of the first-class gas wells is less than one year, and the ratio of the well opening time to the production time is greater than a preset ratio; The critical water-gas ratio determining module is used for determining a critical water-gas ratio based on the linear relation and the critical first year average daily gas production; the reservoir calibration module is used for carrying out reservoir calibration on a plurality of second-class gas wells in the high-water-content compact sandstone gas storage area based on the critical water-gas ratio and the critical first-year daily average gas production; and the limit determination module is used for determining the lower limit of the porosity, the permeability and the gas saturation of the high-water-content tight sandstone gas reservoir effective reservoir based on the reservoir calibration result.
8. An electronic device includes 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 of claims 1 to 6.

Description

Method, device, equipment and storage medium for evaluating limit for gas reservoir Technical Field The present application relates to the field of gas reservoir development and evaluation technologies, and in particular, to a method, an apparatus, a device, and a storage medium for evaluating a limit for a gas reservoir. Background Compact sandstone gas reservoirs are important gas reservoir types in China, and have higher natural gas reserves and exploitation potential. With continuous and deep development, the residual reserve body of the tight sandstone gas reservoir gradually changes to an aqueous zone, and the production capacity of the gas well is severely restricted due to the water production of the gas well, so that the development difficulty is high, and the exploration and development of the tight sandstone gas reservoir with water needs to be further developed. Defining the reservoir use limits of a tight sandstone reservoir containing water is critical to improving the exploration and development of this type of reservoir. At present, an evaluation method of the limit for the tight sandstone gas reservoir is mainly aimed at medium-low water tight sandstone gas reservoirs, mainly comprises a core analysis and test method, a gas test experience method and a productivity formula method, and aims at low accuracy of the high water tight sandstone gas reservoirs under the condition of complex geological features of the edge of a basin, so that logging interpretation accuracy is low, and development of the high water tight sandstone gas reservoirs is severely restricted. Therefore, it is highly desirable to provide an evaluation method capable of accurately evaluating the limit of the reservoir of a high-water-content tight sandstone reservoir, so as to achieve the purpose of developing the high-water-content tight gas reservoir with high efficiency. Disclosure of Invention The application provides a method, a device, equipment and a storage medium for evaluating limit for a gas reservoir, which are used for solving the problems that the limit for the gas reservoir of a high-water-content compact sandstone is fuzzy, is difficult to evaluate accurately and causes low logging interpretation accuracy. In a first aspect, the application provides a method of evaluating a reservoir use limit for a gas reservoir, comprising: calculating critical full life cycle accumulated gas yield of the gas well under the preset yield rate based on the current gas price, and determining critical first-year gas yield and critical first-year daily gas yield based on the critical full life cycle accumulated gas yield and the first-year gas yield ratio of the gas well in the high-water-content compact sandstone gas reservoir area; Determining a linear relation between daily average gas production and water-gas ratio in the first year based on water production data and gas production data of a plurality of first gas wells in a high-water-content tight sandstone gas reservoir, wherein the production time of the first gas wells is less than one year, and the ratio of the open time to the production time is greater than a preset ratio; Determining a critical water-gas ratio based on the linear relation and critical average gas production amount from the first year to the second year; Performing reservoir calibration on a plurality of second-class gas wells in a high-water-content compact sandstone gas reservoir based on the critical water-gas ratio and the critical average daily gas production; And determining the lower limit of the porosity, permeability and gas saturation of the effective reservoir of the high-water-content tight sandstone gas reservoir based on the reservoir calibration result. Optionally, performing reservoir calibration for a plurality of second type gas wells with production time greater than one year in a high water content tight sandstone gas storage area based on a critical water-gas ratio and a critical first year daily gas production rate, including: Determining the gas-water ratio of the second gas wells based on the gas test data of the second gas wells aiming at each second gas well, wherein the gas test data comprise daily gas production and daily water production of the gas test; Determining that the daily gas production of the gas test is greater than the average gas production of the first year, and the reservoir calibration result of the second-class gas well with the gas test water-gas ratio smaller than the critical water-gas ratio is a benefit gas layer; determining that the daily gas production of the gas test is smaller than or equal to the average gas production of the first year of the critical period and is larger than the preset gas production, and the reservoir calibration result of the second-class gas well with the gas test water-gas ratio smaller than the critical water-gas ratio is a differential gas layer; Determining that the daily gas production of the gas test is smaller than