高能气体压裂载荷计算模型与合理药量确定方法

针对高能气体压裂中合理火药质量范围难确定的问题,分别利用不同加载条件下的岩石动态损伤模拟试验和对强内压下射孔套管径向位移、周向应力的理论研究,建立既能确保压裂储层岩石又不会破坏套管的极限压力计算模型;结合已有火药爆燃加载模型和压挡液柱运动模型,组建极限装药量耦合动力学模型,进而推导耦合数值求解方法;在此基础上分别研究火药弹装药结构和压挡液柱高度对极限火药质量的影响。应用结果表明,11次现场高能气体压裂施工中无破坏套管井例,8次作业措施有效,达到预期效果。

Load calculation model and determination method of reasonable charge for high-energy gas fracturing

Due to the difficulty of determining the reasonable gunpowder range in high-energy gas fracturing(HEGF),a pressure limit calculation model was developed through the rock damage simulation test at different loading conditions and the fundermental study for perforated casing radial displacement and circumferential stress at forceful internal pressure.With the model,the reservoir rock can be fractured and the casing will not be damaged.Combined with the deflagration load model and the kinematics piezoresistive liquid column model,the coupling dynamics model was used to calculate the gunpowder limit and the numerical solution was developed.Based on these,the load constitution of the powder bomb and the influencing rule of piezoresistive liquid column for powder quality limit were studied.The results from 11 HEGF on-site operations show that no casing is destroyed and eight operations are effective,which reaches the expectation.