固相侵入对裂缝性碳酸盐岩应力敏感性的影响  

Impact of Solids Invasion on Stress Sensitivity in Fractured Carbonate Reservoirs

作　　者：康毅力[1] 郑德壮[1] 刘修善[2] 杜春朝[3] 

机构地区：[1]西南石油大学油气藏地质及开发工程国家重点实验室,成都610500 [2]中国石化工程技术研究院,北京100101 [3]中国石化西北油田分公司,乌鲁木齐830013

出　　处：《新疆石油地质》2012年第3期366-369,共4页Xinjiang Petroleum Geology

基　　金：国家973项目(2010CB226705);国家科技重大专项(2008ZX05005-006-08HZ)

摘　　要：以往裂缝性碳酸盐岩储集层应力敏感性研究多关注于基块和无固相侵入裂缝的情况,而对固相侵入后的裂缝应力敏感性鲜有研究。钻遇裂缝性储集层时易发生固相侵入损害,注入水悬浮固相亦不可避免会进入裂缝。固相颗粒在裂缝壁面形成的滤饼将影响应力作用下的裂缝闭合。制备致密裂缝碳酸盐岩露头岩样,开展工作液动态损害后的应力敏感性评价实验,研究了无固相侵入裂缝和固相侵入裂缝应力敏感性,用扫描电镜分析了裂缝壁面及固相侵入带的微观结构。结果表明,无固相侵入裂缝岩样应力敏感性系数平均值仅为0.21,固相侵入裂缝岩样应力敏感性系数平均为0.52,应力敏感程度显著增强。固相侵入使裂缝渗透率恢复率更低,导致储集层永久性损害。The previous studies about stress sensitivity of fractured carbonate reservoir mostly focused on that of matrix block and solid- free invaded fracture, while less attention was paid to that of fractures with solids invasion. It is a fact that damage of leakage solid invasion on fractured reservoirs readily occurs when drilling, and suspended solids invading into fractures is inevitable during waterflooding. The in- ternal and external cakes formed by solid particles on both sides of fracture wall are able to impact the fracture closure behavior under stress. This paper prepared the samples of carbonate rocks outcrop with tight fractures, carried out the stress sensitivity evaluation experi- ment after working fluid dynamic damage, made a comparison of stress sensitivity between solid-free invading fractured sample and solid in- vaded ones, and analyzed the microstructures of the fracture walls and the solid-invaded zones by means of SEM. The results show that the average stress sensitivity coefficient of solid-free invading fracture samples is 0.21, while that of solid invading fracture ones is 0.52, the lat- ter＇ s sensitivity is remarkably increased. Hence solid invasion may cause much lower fracture return permeability ratio than solid-free inva- sion, resulting in permanent damage of rock permeability.

关 键 词：裂缝性油气藏 碳酸盐岩 储集层 固相 应力敏感 渗透率 水质 

分 类 号：TE112.221[石油与天然气工程—油气勘探]