页岩气储层水力压裂裂纹扩展数值模拟

A numerical simulation on rules of crack extension during hydraulic fracturing in shale gas reservoir

针对页岩气储层的层状结构致使其水力压裂裂纹扩展不同于常规油气储层问题,采用粘结单元模拟实际的层状储层界面特性的数值模拟方法,建立页岩气储层水力压裂力学模型和反映岩体层状界面的破坏开裂准则,进行层状岩体水力压裂三维数值模拟.得到了储层应力场、孔隙压、裂纹面的损伤和张开度分布以及裂纹扩展的时空变化规律.

Abstract： Shale gas is a huge unconventional gas resource. Industrial gas can be obtained only by hydraulic fracturing due to its low porosity and permeability. The rules of crack extension in shale differ from the conventional reservoir due to its layered structure. Cohesive element can truly simulate the interface characteristics of shale reservoir. The hydraulic fracturing mechanics model and interface crack criterion are established. A three-dimensional numerical simulation of hydraulic fracturing draws the distributions of stress, the pore pressure and the damage of cohesive element and the rules of crack extension, which will provide a reference value and significance for industrial exploitation of shale gas.