西峰油田LM井区长7储层微观孔隙结构特征

采用薄片、扫描电镜、高压压汞等多种技术手段,对西峰油田LM井区长7储层孔隙结构进行系统分析和深入研究,结果表明:长7储层属于特低孔超低渗储层,成岩作用强,次生溶孔较为发育,长石、岩屑及碳酸盐胶结物等易溶矿物的溶蚀是形成次生孔隙的重要原因,中孔及大孔是主要储集空间,细喉及微喉是基本渗流通道,微裂缝极大改善了储层渗流能力.研究区长7储层具有复杂的孔隙结构,微观的孔隙结构特征是造成油井产能差异的重要因素.

Microscopic pore structure characteristics of the Chang 7 reservoir in LM wellblock of Xifeng Oilfield

Pore structure determines the seepage characteristics of reservoir fluid and directly influences the development effect of water flooding.The pore structure of Chang 7 reservoir in the studied area is analyzed and studied by using many technical means such as thin sections,scanning electron microscopy,high pressure mercury intrusion,etc.it is shown that the Chang 7 reservoir is of ultra-low porosity,super low permeability and strong diagenesis,in which secondary solution pores are relatively developed.The dissolution of flspar,rock debris and carbonate cements is the important reason for the formation of the secondary pores.Most of the reservoir space is medium and large pores;fine and micro throats are the basic seepage channels.Micro-fracture greatly improves the seepage ability of the reservoir.The Chang 7 reservoir is of complex pore throat characteristic,and the microscopic pore structure characteristic is the important factor caused the difference in the productivity of oil wells.