弱氧化性酸液作用下页岩油储层应力敏感性研究与应用  

Research and application of stress sensitivity of shale oil reservoir under the action of weak oxidizing acid

作　　者：曹杰 欧阳传湘[1] 邱春霖 马力[1] CAO Jie;OUYANG Chuanxiang;QIU Chunlin;MA Li(School of Petroleum Engineering, Yangtze University, Wuhan 430100, China)

机构地区：[1]长江大学石油工程学院,武汉430100

出　　处：《中国科技论文》2020年第5期542-546,共5页China Sciencepaper

基　　金：国家自然科学基金资助项目(51804039)。

摘　　要：为了探究弱氧化性酸液对储层中金属矿物和黏土矿物的影响,观察储层应力敏感性变化,并获取微观机理证明,将选取的塔里木油田吐格尔明段储层岩心分别置入蒸馏水和质量分数为10%的弱氧化性酸液中充分浸泡24 h,然后对岩心进行数据分析和机理分析。结果显示:经浸泡后,4块岩心的渗透率均有提高,但经弱氧化性酸液浸泡岩心的渗透率是蒸馏水浸泡岩心的4.37~17.26倍;通过函数拟合发现4块岩心的临界压力分别为8.24、7.11、9.27、8.27 MPa,在低有效应力区域内递减斜率分别为0.145、0.160、0.129、0.136,对比发现经弱氧化性酸液浸泡的岩心渗透率损失较轻,有效弱化了岩心应力敏感性。扫面电镜图片和恒速压汞方法显示,弱氧化性酸液深入溶蚀裂缝,岩心中金属矿物和黏土矿物遭到溶蚀,起到了使裂缝延申、疏通堵塞孔喉、溶扩孔隙、增强储层连通性、降低应力敏感损伤等作用。In order to explore the influence of weak oxidizing acid solution on metal minerals and clay minerals in the reservoir,observe the change of stress sensitivity of the reservoir,and obtain the micro mechanism proof,the cores of Turgming reservoir in Tarim were put into distilled water and 10%weak oxidizing acid for twenty-four hours,and then the data and mechanism of the cores were analyzed.The results show that the permeability of the four cores is increased after soaking,but the permeability of the cores soaked in weak oxidizing acid solution is 4.37~17.26 times higher than that of the cores soaked in distilled water.After function fitting,it was found that the critical pressure of the four cores was 8.24,7.11,9.27 and 8.27 MPa respectively,and the decline slope in the low effective stress area was 0.145,0.160,0.129 and 0.136 respectively.By comparison,it was found that the permeability loss of the cores soaked in oxidation liquid was slow,effectively weakening the core stress sensitivity.Scanning electron micrographs and constant velocity mercury injection method show that weak oxidizing acid solution deeply dissolves the fracture,metal minerals and clay minerals in the rock core are eroded,which make the fracture extend,dredge and block the pore throat,dissolve and expand the pore to enhance the connectivity,reduce the stress sensitive damage and so on.

关 键 词：应力敏感性 氧化 酸化 渗透率 

分 类 号：TE348[石油与天然气工程—油气田开发工程]