深层裂缝性致密砂岩气藏基质-裂缝气体流动机理

Mechanism of Gas Flow in Matrix-Fracture in Deep Fractured Tight Sandstone Gas Reservoirs

为了探明深层裂缝性致密气藏的气体流动规律,研发了基质–裂缝系统气体流动物理模拟装置,建立了高温高压基质–裂缝系统气体流动物理模拟方法,模拟了不同温度和压力条件下气体从基质到天然裂缝及人工裂缝的流动过程,以及基质与裂缝之间的传质过程;对比分析了不同温度和压力条件下气体流动的差异性,明确了高温高压作用下应力和流态对气体流动规律的综合影响。模拟结果显示,储层压力和应力显著影响气体流量和岩石渗透率,温度变化对气体流量和渗透率的影响相对较小,含天然裂缝岩心受应力敏感和气体滑脱效应的影响显著。研究结果为深层裂缝性致密气藏的高效开发提供了理论依据。

In order to investigate the gas flow law of deep fractured tight gas reservoirs,a gas flow physical simulation device for matrix-fracture system was developed.Moreover,a gas flow physical simulation method for hightemperature and high-pressure matrix-fracture system was established and was used to simulate the gas flow process from matrix to natural and artificial fractures,as well as the mass transfer process between matrix and fracture under different temperature and pressure conditions.The differences in gas flow behavior under different temperature and pressure conditions were compared,and the comprehensive influence of stress and flow pattern on gas flow law under high temperature and high pressure was clarified.The simulation results show that the gas flow and rock permeability are significantly affected by reservoir pressure and stress,while the temperature changes have a relatively minor impact on gas flow and permeability.In addition,cores with natural fractures are significantly affected by stress sensitivity and gas slippage effect.The findings of this study can provide a theoretical basis for the efficient development of deep fractured tight gas reservoirs.