页岩气藏三孔双渗模型的渗流机理

为了掌握页岩气储层气体复杂流动的规律，从而高效开发页岩气藏，对页岩气渗流机理进行了研究。借鉴适用于非常规煤层气藏双重孔隙介质模型和考虑溶洞情况的三重孔隙介质模型，基于页岩气储层特征和成藏机理，提出了页岩气藏三孔双渗介质模型；研究了页岩气解析扩散渗流规律，提出考虑储层流体重力和毛细管力影响的渗流微分方程；并利用数值模拟软件对页岩气产能进行了预测。结果表明：基质渗透率和裂缝导流能力是页岩气开采的主控因素，只有对储层进行大规模压裂改造，形成连通性较强的裂缝网络后才能获得理想的页岩气产量和采收率。

Seepage mechanism of a triple-porosity/dual-permeability model for shale gas reservoirs

This paper studies the seepage mechanism and productivity predication of shale gas reservoirs in order to acquire a better understanding of complex air flow patterns and thereby know how to get a high shale gas productivity.According to the existing dual-porosity medium model applicable to unconventional coalbed methane reservoirs and triple-porosity medium model considering the cave conditions,a triple-porosity/dual-permeability media model for shale gas reservoirs is proposed based on the characteristics and formation mechanism of shale gas reservoirs.Through the analysis of diffusion and seepage patterns for shale gas,this paper presents a seepage differential equation with the impact of the fluid gravity and capillary force taken into consideration.In addition,the shale gas productivity is forecasted by the numerical simulation software.The result shows that the matrix permeability rate and the fracture conductivity capacity are the main controlling factors of the production of shale gas reservoirs;it is effective to perform large-scale fracturing treatment on the reformation of shale gas reservoirs so as to form a fracture network with stronger connectivity for ideal shale gas recovery.