裂缝性储层压降分析方法及其应用

Pressure Drowdown Analysis Method and Its Application in Fractured Reservoir

现有的压降分析解释技术只适合于低渗透均质油藏,而不能解释裂缝性储层的压裂裂缝参数。在总结Nolte经典G函数压降曲线分析方法的基础上,根据裂缝性地层存在微裂隙的特征,建立了裂缝性储层压裂压力降落分析模型。应用无因次压力函数图和叠加导数图,做出了压降特征曲线,可以判断天然裂缝的闭合压力;在此基础上,可以计算依赖于压力变化的滤失特征,以及天然裂缝对滤失的影响。实例计算表明该模型具有一定的可靠性和实用性,对裂缝性油藏压裂裂缝参数的解释以及运用获得的参数进行压裂施工效果评价和压裂设计指导具有重要的意义。

The existent pressure drawdown analysis technologies were only suitable for low permeability and isotropy reservoirs,not for interpreting fracture parameters of fractured reservoirs.By investigating and summarizing the classical Nolte G-function method and studying the special features of fractures in the fractured reservoirs,the pressure drawdown analysis model for the fractured reservoirs was established based on the features of micro-fractures in the fractural reservoirs.The closing pressure of naturally fractured can be obtained from the characteristic curves of pressure decline,which were achieved by using dimensionless pressure function and superposition derivative.On the basis stated above,the filtration features depending on pressure changes and the influence of the natural fracture on the filtration are obtained.The examples show that the model is reliable and adaptive,it is of great significance for natural fracture parameter interpreting and its operation effect evaluation.