【摘要】 随着油气藏压裂技术的发展和应用 ,压裂后压力递减分析方法受到广泛重视。文章针对压裂停泵后的压力测试数据 ,考虑裂缝中流体压缩性的影响 ,根据裂缝内的流体质量平衡原理 ,首次研究了裂缝闭合前、后的压力变化规律 ,即裂缝闭合前、后的压力测试数据均与时间函数成线性关系 ,提出了一种新的确定支撑裂缝闭合点的精确化分析方法 ,并给出了确定裂缝闭合压力、裂缝闭合时间及其它压裂评价参数的计算方法。该方法考虑了支撑剂的影响 ,既适用于测试压裂又适用于加砂压裂的压后压力资料分析 ,不仅可以获得压裂液滤失系数、裂缝长度、裂缝宽度、压裂液效率等评价参数 ,还可以获得传统压降分析方法不能获得的裂缝闭合压力和闭合时间、支撑裂缝闭合压力和闭合时间、支撑裂缝宽度等评价参数。最后 ,通过计算实例说明了方法的适用性和可靠性。更多还原

【Abstract】 As hydraulic fracturing techniques are developed and applied,the more and more attention has been paid to the analyzing method of pressure decline after fracturing.According to the pressure testing data after the pumps stop,considering the effect of fluid compressibility in the fractures,and based on the principle of fluid mass equilibrium,the pressure variation law is first investigated before and after fracturing.It is found that the function of pressure vs.time appears linear relationship before and after fractures closure.A new accurately analyzing method is developed to determine the closure points of propping fractures.And the calculating method is provided to determine the closure pressure and time of the fractures, and other parameters for fracturing evaluation.Considering the influence of the proppant,the method can be used to analyze the pressure data of fracturing test and the pressure data after fracturing with sand.With the method,the evaluation parameters,such as fracturing fluid loss coefficients,fracture length,fracture width,and fracturing fluid efficiency,etc.,can be achieved.Also,the evaluation parameters,such as the fractures closure pressure and time,the closure pressure and time of the propped fractures,and the width of the propped fractures,etc.,which can’t be determined by traditional analyzing method of pressure drop,can be achieved.The applicability and reliability of the method is demonstrated by calculation with real cases.更多还原