Abstract: In the exploration process of shale gas，the total energy dissipation of hydraulic fracturing is one of the significant indicators to evaluate whether it is worthy to be explored.The theoretical formula of the total energy consumption in the process of the hydraulic fracturing for the plane strain problem was deduced based on the principle of energy balance of Griffith，and the impact of crack development speed，water viscosity and crack shape on the whole energy consumption was analyzed.It was concluded that the brittle rocks tended to be more beneficial to the conservation of energy dissipation of hydraulic fracturing with the lower crack speed.Furthermore，the formula of energy dissipation per unit time with the equal water injection was obtained.With the growth of crack，the energy dissipation per unit time decreased gradually；accordingly，the power of the pressurized equipment mainly depended on the loading potential of the initial crack fracturing.The conclusion can be used for reference to evaluate and improve the hydraulic fracturing exploration of shale gas.

Key words: shale gas, hydraulic fracturing, energy dissipation, crack

摘要： 在页岩气开采中，水力劈裂总的能量耗散是评价页岩气是否具有可开采价值的一个重要指标。基于Griffith能量平衡原理，推导了平面应变问题水力劈裂过程中系统的总能耗的理论公 式。分析了裂纹扩展速度、水的黏滞性和裂纹面的形态对系统总能耗的影响，得出了高脆性岩石材料在较低裂纹扩展速度下有利于节省水力劈裂的总能耗。同时推导了在等流量注水时单位时 间的能量耗散表达式，随着裂纹的扩展，单位时间的能量耗散逐渐递减，因此，加压设备的功率主要取决于初始裂纹劈裂时的加载能力。该结论对于评估和改进水力劈裂开采页岩气有一定的 借鉴意义。

关键词: 页岩气, 水力劈裂, 能量耗散, 裂纹