CN-116877049-B - Quantitative evaluation method for water invasion degree of gas reservoir type gas storage

CN116877049BCN 116877049 BCN116877049 BCN 116877049BCN-116877049-B

Abstract

The invention relates to a quantitative evaluation method for water invasion degree of a gas reservoir type gas storage, which comprises the steps of recognizing geological structure and physical property characteristics of the gas reservoir type gas storage, collecting a corresponding target reservoir outcrop sample, arranging a sensor for monitoring at a key point of a simulation sample, packaging a protective layer, simulating pre-burying an injection water shaft, prefabricating a gas reservoir injection well and a gas production well, analyzing formation water saturation in a servo pump injection system, setting true triaxial ground stress conditions to simulate gas injection and gas production under different working conditions, monitoring and collecting acoustic wave speed, acoustic emission information, wide area electromagnetic signals and the like in the gas injection and gas production process through the pre-buried sensor, and quantitatively evaluating the water invasion degree of the gas reservoir under the long-term dynamic injection and production alternating action of the gas injection and production well through the data. The method can be used for quantitatively evaluating the water invasion gas reservoir degree under the real alternating action of long-term dynamic injection and production of the gas reservoir, and provides technical support for optimizing the injection and production degree of the exhausted gas reservoir.

Inventors

ZHANG HONG
SU HAIBO
WANG JIAN
GUO HAITAO
YANG JIAKUN
FAN XUE
WANG HAIFENG
YANG XIAOPING
WANG DUOCAI
LI HONGLIE
FU YAPING
FAN LILIN
Huang Famu
ZHANG PING

Assignees

国家石油天然气管网集团有限公司

Dates

Publication Date: 20260505
Application Date: 20230630

Claims (6)

1. The quantitative evaluation method for the water invasion degree of the gas reservoir is characterized by comprising the following steps of: collecting physical characteristic parameters according to the actual condition of a water-immersed gas reservoir type gas storage, and acquiring a sample from underground according to the physical characteristic parameters; digging holes in the circumferential direction of the position of the water invasion front edge of the sample according to a point array mode, respectively arranging different types of sensors in each hole, and marking leads of each sensor on the sample; The method comprises the steps of carrying out packaging treatment on a sample marked by a lead wire, reserving the lead wire of each sensor outside during the packaging treatment, and pre-burying a plurality of shafts on the sample subjected to the packaging treatment, wherein the shafts comprise a water injection shaft, a gas storage injection shaft and a gas production shaft, and each shaft is provided with a connecting wire joint for sealing; Performing outer cladding manufacturing on the sample to obtain a prefabricated sample, sealing connecting line joints on an injection shaft of the gas storage and the gas production shaft through sealing joints, connecting leads of each sensor with a preset servo pumping system, injecting simulated stratum water into a sandstone layer of the prefabricated sample through the injection shaft, transmitting data monitored by each sensor to the servo pumping system for analysis of stratum water saturation, obtaining information of water layer distribution diffusion trend and position, and disconnecting the leads of each sensor from the servo pumping system; Performing environment simulation on gas injection and gas production environments through a preset test system to obtain test data, reconnecting each sensor with the servo pumping system in the environment simulation process, transmitting data monitored by each sensor to the servo pumping system in the set environment, performing quantitative assessment on water edges, and determining whether a fingering phenomenon occurs according to assessment information; taking the test data and the evaluation information as quantitative information for evaluating the water invasion degree of the gas reservoir under the long-term dynamic injection-production alternating action of the injection-production well; The method comprises the steps of carrying out packaging treatment on a sample marked by a lead, reserving the lead of each sensor outside during the packaging treatment, and embedding a plurality of wellbores on the sample after the packaging treatment, wherein the steps are as follows: Packaging by adopting colorless transparent epoxy resin material as protective layer coating agent, and reserving leads of each sensor outside during packaging; Drilling holes in the pre-buried samples by using a diamond drill bit, filling soluble salt in the lower part of the drilled holes, separating the filled salt by using plasticine on the upper part of the filled salt, and pre-burying a water injection shaft, a gas storage injection shaft and a gas production shaft of the packaged samples, wherein epoxy resin is adopted to seal the annular space between each shaft and the drilling annulus of the samples; after the epoxy resin is solidified, the rubber clay is punctured by a needle cylinder, and clear water is repeatedly injected to erode and discharge the lower salt, so that an open hole section is formed; And carrying out outer cladding preparation on the sample to obtain a prefabricated sample, wherein the prefabricated sample comprises the following concrete steps: Manufacturing a cube mould with a set side length, wherein the set side length is larger than the side length of the sample, adopting cement mortar as a sealing material of the sample, mixing and stirring according to a set proportion, and pouring cement slurry material into the cube mould; The method comprises the steps of slowly placing a sample into a cube mould by adopting a crane, placing the sample in the middle, placing the end face containing a shaft upwards, leading out a water injection shaft, a connecting wire joint reserved by a gas injection shaft and a gas production shaft and leads of each sensor to the outside, pouring cement mortar around the sample, vibrating, and sealing the upper end face of the sample by adopting the cement mortar to obtain a prefabricated sample.
2. The quantitative evaluation method for the water invasion degree of the gas reservoir type gas storage according to claim 1, wherein physical characteristic parameters are collected according to the actual condition of the water invasion type gas reservoir type gas storage, and a sample is obtained from underground according to the physical characteristic parameters, specifically: Collecting physical characteristic parameters from underground according to the actual condition of a water invasion gas reservoir, determining a target horizon according to the physical characteristic parameters, acquiring a target horizon characteristic parameter in the target horizon, and determining a representative object model sample according to the target horizon characteristic parameter; and determining an outcrop sampling horizon in the object model sample, and acquiring a sample from the outcrop sampling horizon according to a set size.
3. The quantitative evaluation method for the water invasion degree of the gas reservoir type gas storage according to claim 2, wherein the physical characteristic parameters comprise a downhole core histogram, continuous logging data and imaging logging and well drilling data; the target horizon characteristic parameters include porosity, permeability, sonic velocity, and fracture development data.
4. The quantitative evaluation method for water invasion degree of gas reservoir type gas storage according to claim 2, wherein the determining of the outcrop sampling horizon in the object model sample is specifically: And testing the core sample in the object model sample, comparing test data with known sampling reference data, and determining an outcrop sampling horizon, wherein the comparison data of the test data and the sampling reference data comprises compression resistance, tensile strength, elastic modulus, poisson ratio, porosity and permeability parameters.
5. The quantitative evaluation method for the water invasion degree of the gas reservoir according to claim 1, wherein the environmental simulation of the gas injection and gas production environment is performed by a preset test system, specifically: Placing the prefabricated sample in a preset true triaxial physical model testing machine, starting a preset testing system, reconnecting leads of each sensor with the servo pumping system, synchronously collecting information through each sensor, loading a required ground stress value by the true triaxial physical model testing machine, keeping constant, setting a constant pressure value by the servo pumping system according to reservoir pore water pressure parameters, and monitoring the total returned liquid quantity through a sensor for collecting liquid flow data under the action of gas driving water in the gas injection and production process, wherein water can flow back into the servo pumping system by a simulated reservoir; And performing environment simulation under different injection and production rates and different injection and production periods according to the set injection and production simulation working conditions.
6. The quantitative evaluation method for water invasion level of gas reservoir according to any one of claims 1 to 5, wherein the environmental simulation is performed on gas injection and gas production environments by a preset test system, in the environmental simulation process, each sensor is reconnected with the servo pumping system, data monitored by each sensor is transmitted to the servo pumping system in the set environment, quantitative evaluation is performed on water edges, and whether a fingering phenomenon occurs is determined according to evaluation information, which is specifically as follows: In the environment simulation process of gas injection, synchronously starting a sound wave speed and sound emission testing system and a wide area electromagnetic resistance testing system, when the saturated water of the rock in the simulated geologic body is influenced by gas drive, the corresponding penetrating sound wave speed and waveform are different, and analyzing the testing information of water saturation or gas saturation in the simulated reservoir by a wavelet transformation mode; Testing the resistivity change of the penetrating body by a wide area electromagnetic method to obtain test information simulating the water content and gas content characteristics in the reservoir; Monitoring the damage degree of the prefabricated sample in the process of multi-displacement by using an acoustic emission probe to obtain the test information of the damage of the prefabricated sample; Reconnecting each sensor with the servo pumping system, transmitting data monitored by each sensor to the servo pumping system, obtaining the water discharge in the gas injection process through the servo pumping system, quantitatively and reversely calculating the range value reached by the gas through the water discharge, quantitatively evaluating the water edge according to the range value and each test information, and determining whether the fingering phenomenon occurs according to the evaluation information.

Description

Quantitative evaluation method for water invasion degree of gas reservoir type gas storage Technical Field The invention relates to the technical field of underground gas storage safety detection, in particular to a quantitative evaluation method for water invasion degree of a gas reservoir type gas storage. Background The underground gas storage is one of important projects for energy safety and civil security in China, and the gas storage is a main body type of the underground gas storage and is in a development accelerating period. The gas reservoir type gas storage is basically formed by rebuilding a depleted gas reservoir, the stratum pressure is low in the initial period of production, side bottom water invades the inside of a reservoir, gas and water are distributed in a staggered mode, and stratum seepage conditions are complex. The method comprises the steps of providing a water invasion type gas storage multi-period injection and production capacity prediction model aiming at gas injection loss caused by gas-water mutual flooding, establishing a injection allocation determination method based on a material balance principle and taking a critical flow rate of stable migration of a gas-water interface as a constraint for determining the injection allocation of the initial production of the water invasion type gas storage, establishing a single well yield increase potential model of the gas storage based on effective permeability based on a binomial productivity equation, and developing a physical simulation experimental device of the water invasion type gas storage by utilizing a sucking-displacement phase-permeability evaluation technology and a multi-injection and production cycle nuclear magnetic resonance technology, thereby revealing a micro mechanism of gas-water migration in the multi-period water invasion process. However, the existing gas reservoir type gas storage water invasion degree evaluation method mainly comprises a reservoir numerical simulation method and core scale displacement simulation, and lacks technical means and methods for quantitatively evaluating real water invasion in a gas storage stress environment. Disclosure of Invention The invention aims to solve the technical problem of providing a quantitative evaluation method for the water invasion degree of a gas reservoir type gas storage aiming at the defects of the prior art. The technical scheme for solving the technical problems is as follows, the quantitative evaluation method for the water invasion degree of the gas reservoir type gas storage comprises the following steps: collecting physical characteristic parameters according to the actual condition of a water-immersed gas reservoir type gas storage, and acquiring a sample from underground according to the physical characteristic parameters; digging holes in the circumferential direction of the position of the water invasion front edge of the sample according to a point array mode, respectively arranging different types of sensors in each hole, and marking leads of each sensor on the sample; The method comprises the steps of carrying out packaging treatment on a sample marked by a lead wire, reserving the lead wire of each sensor outside during the packaging treatment, and pre-burying a plurality of shafts on the sample subjected to the packaging treatment, wherein the shafts comprise a water injection shaft, a gas storage injection shaft and a gas production shaft, and each shaft is provided with a connecting wire joint for sealing; Performing outer cladding manufacturing on the sample to obtain a prefabricated sample, sealing connecting line joints on an injection shaft of the gas storage and the gas production shaft through sealing joints, connecting leads of each sensor with a preset servo pumping system, injecting simulated stratum water into a sandstone layer of the prefabricated sample through the injection shaft, transmitting data monitored by each sensor to the servo pumping system for analysis of stratum water saturation, obtaining information of water layer distribution diffusion trend and position, and disconnecting the leads of each sensor from the servo pumping system; Performing environment simulation on gas injection and gas production environments through a preset test system to obtain test data, reconnecting each sensor with the servo pumping system in the environment simulation process, transmitting data monitored by each sensor to the servo pumping system in the set environment, performing quantitative assessment on water edges, and determining whether a fingering phenomenon occurs according to assessment information; and taking the test data and the evaluation information as quantitative information for evaluating the water invasion degree of the gas reservoir under the long-term dynamic injection-production alternating action of the injection-production well. The method has the beneficial effects that a sample is obtained, different types of sen