高能气体压裂瞬态压力耦合分析

高能气体压裂的瞬态压力分析是压裂设计、优化和控制的基础.本文提出了一个高能气体压裂瞬态压力分析模型,包括火药燃烧、压井液体运动、井筒流体通过射孔孔眼的泄流和裂缝中流体流动等分析内容.由于高能气体压裂工作介质的气——液混合流体的可压缩性,以上各项分析严重耦合.采用合适的数值计算模式,可以计算出瞬态压力的每一过程.计算实例结果表明.与实测结果吻合较好.根据这个压力分析模型,综合考虑装药参数、射孔参数、地层参数、压井参数等对施工结果的影响,能预测高能气体压裂的压力变化过程和裂缝范围,实现对高能气体压裂的优化和控制.

AN ANALYSIS OF COUPLED TRANSIENT PRESSURE DURING HIGH ENERGY GAS FRACTURING(HEGF)

Analysis of transient pressure is the basis of HEGF design,control and optimization.This paper presents a model for transient pressure analysis,which includes the analysis of propellant burning,stemming liquid motion,fluid drainage through perforation,and fluid flow in fractures.Because of the compressibility of working fluid used in HEGF,the above-mentioned analysis are coupled together.The pressure history is calculated step by step with a properly organized method.The example shows that the predicted results coincides with the measured ones to a satisfactory extent.With the use of the model,it is possible to examine the effects of the parameters of propellant loading,well perforation,formation as well as stemming fluid on the HEGF treatment results,to predict the pressure history and fracture extent,and to realize control and optimization of HEGF.