裂缝-孔隙型双重介质气藏开发影响分析

为了研究裂缝孔隙型双重介质气藏开发特征，建立了考虑应力敏感、气体滑脱效应和高速非达西流的裂缝孔隙型双重介质气藏渗流模型，通过数值模拟分析了不同渗流效应对气井生产的影响。结果表明，当窜流系数大于等于10^-6时，双重介质气藏与等效均质气藏的生产特征基本一致，此时可以运用分析均质气藏的方法和理论来研究双重介质气藏。气井生产早期，应力敏感对井底压降和稳产期的变化规律影响不大；气井生产中后期，应力敏感作用增强；窜流系数越小，应力敏感对井底压降的影响越早表现出来，对稳产期的影响也就越大。气井生产初期，高速非达西渗流对井底压降影响很小，气井生产中后期，高速非达西渗流对井底压降的影响增大；窜流系数越小，高速非达西渗流效应影响越早显现出来，对井底压降和稳产期的影响也就越大。裂缝孔隙型双重介质气藏虽然存在气体滑脱效应，但由于储层及井底压力相对较高，气体滑脱效应对裂缝孔隙型双重介质气藏气井生产的影响很小。

Analysis of the Influence of the Development of Fracture-porosity-type Volcanic Gas Reservoir

This study involved building a seepage model of a gas reservoir under the presumption of stress sensitivity, gas slippage effect, and high-speed non-Darcy flow to study the development characteristics of the fracture-porosity-type dual media gas reservoir. The influence of different seepage effects on the gas well was analyzed through numerical simulation methods. The results indicated that the production features of the dual media gas reservoir were basically in line with those of the equivalent homogeneous gas reservoir when the interporosity flow coefficient greater than or equal to 10^-6, Consequently, the theories and methods of analyzing the equivalent homogeneous gas reservoir can be applied to study the dual media gas reservoir. At the early stage of gas well production, the stress sensitivity had little influence on the pressure drop of the pit bottom and variation in the production plateau. The effect of the stress sensitivity is enhanced at the mid-late stage. Theoretically, the influence of the stress sensitivity on the pressure drop of the pit bottom was observed earlier with the decrease in the interporosity flow coefficient, and its effect on the production plateau became greater. The high-speed non-Darcy flow had little influence on the pressure drop of the pit bottom at the early stage of the gas well production, and the influence increased at the mid-late stage. Theoretically, the influence of the high-speed non-Darcy flow on the pressure drop of the pit bottom was observed earlier with the decrease in the interporosity flow coefficient. Its effect on the production plateau also became greater. The slippage gas effect existed in the fracture-porosity-type dual media gas reservoir, but was only slight because of the reservoir and the bottom hole pressure that was comparatively higher.