滞留压裂液与页岩储层相互作用研究进展

Research Progress on Interaction Between Retained Fracturing Fluid and Shale Reservoir

回顾了近些年压裂液滞留研究进展,从页岩对压裂液滞影响和压裂液对页岩的作用两个方面,总结归纳了一系列前人的物理模拟方法和结论。研究压裂液滞留主要通过渗吸实验,其中渗吸瓶法简单方便,适合同一批样品横向对比自吸排驱能力大小;悬挂称量法可以得到较为精确的干样自吸曲线;岩心夹持器法可以更贴近实际的模拟压裂液从裂缝进入页岩基质这一实际过程。研究压裂液对页岩作用主要方式有:岩石表面性质变化、孔隙内流体分布变化、岩石力学性质变化。结合渗吸实验,润湿性和Zeta电位可以反映受压裂液作用岩石表面性质的变化;AFM可以观察岩石表面因矿物的结晶析出导致面粗糙度变化;NMR曲线能提供孔吼结构信息和流体分布信息;测定杨氏模量和泊松比可以研究岩石的力学性质变化。

This paper reviews the research progress of fracturing fluid retention in recent years,and summarizes a series of previous physical simulation methods and conclusions from two aspects:The influence of shale on fracturing fluid retention and the effect of fracturing fluid on shale.The retention of fracturing fluid is mainly studied by imbibition experiment,in which the imbibition bottle method is simple and convenient,which is suitable for the lateral comparison of self-imbibition drainage ability of the same batch of samples.The self-priming curve of dry sample can be obtained by suspension weighing method.The core gripper method can more closely simulate the actual process of fracturing fluid entering the shale matrix from the fracture.The main ways to study the effect of fracturing fluid on shale include:the change of rock surface properties,the change of fluid distribution in pores,and the change of rock mechanical properties.Combined with imbibition test,wettability and Zeta potential can reflect the change of rock surface properties under fracturing fluid action.AFM can observe the surface roughness changes due to the crystallization of minerals.NMR curves can provide pore structure information and fluid distribution information.Measurement of Young′s modulus and Poisson′s ratio can be used to study the mechanical properties of rock.