储层改造三维物理模拟实验研究与应用

Study and Application of 3D Physical Modeling Experiment of Reservoir Stimulation

储层改造的影响因素分析,一直以来多以经验和理论为主,偶有开展的小尺寸岩样实验,结果亦不能反映储层改造的真实情况。为揭示施工参数对储层改造的影响规律,参照顺北油田典型高应力储层岩石力学参数制作了大尺度实验样品,采用水力压裂物理模拟系统开展了三维水力压裂实验,研究了泵注排量、液体黏度对水力压裂的影响,以及声音发射振幅与泵注压力的关系。结果表明:随着初期泵注排量的增加,储层改造所需的破裂压力逐渐增加,达到一定数值后排量对破裂压力影响较小;泵注排量对破裂瞬间裂缝尺度大小有影响,但对整个压裂过程的影响很小;施工初期采用低黏滑溜水可明显降低破裂净压力,有利于降低施工压力;声发射振幅与泵注净压力正相关,破裂净压力越大振幅越大。研究成果可为高应力超深井压裂施工参数优化设计提供参考。

The analysis on the influencing factors of reservoir stimulation has always made reference to experience and theory.Although there were some small-scale rock sample experiments occasionally conducted,the results obtained cannot reflect the actual conditions of reservoir stimulation.In order to discover the influence law of construction parameters on the reservoir stimulation,large-sized experimental samples were prepared with reference to the rock mechanics parameters of typical high-stress reservoirs in Shunbei Oilfield,three-dimensional hydraulic fracturing experiments were conducted with a hydraulic fracturing physical modeling system,and the effects of pumping displacement and liquid viscosity on hydraulic fracturing and the relationship between acoustic emission amplitude and pumping pressure were studied.The results showed that with the increase in initial pumping displacement,the fracture pressure required for reservoir stimulation was gradually increased;after reaching a certain value,the displacement had little effect on the fracture pressure;the pumping displacement had an effect on the fracture size at the moment of fracturing,but had little effect on the entire fracturing process;the application of low-viscosity slick water at the beginning of stimulation could significantly reduce the net fracture pressure,in favor of reducing the construction pressure;the amplitude of acoustic emission was positively correlated with the net pumping pressure,and the greater the net pressure at the moment of fracturing,the greater the amplitude.The study results provide a reference for the design of fracturing construction parameters optimization for ultra deep well fracturing under high stress.