鄂尔多斯盆地中部长6和长8储层特征及酸敏机理  

Reservoir characteristics and acid sensitivity mechanism of Chang 6 and Chang 8 reservoirs in the central of Ordos Basin

作　　者：柳娜[1] 南珺祥[1] 刘伟[2] 

机构地区：[1]中国石油长庆油田勘探开发研究院,陕西西安710021 [2]川庆钻探工程公司长庆油田工程技术研究院,陕西西安710021

出　　处：《石油学报》2008年第4期588-591,共4页Acta Petrolei Sinica

基　　金：国家重点基础研究发展规划(973)项目(2003CB214607)资助

摘　　要：运用铸体薄片、X衍射、扫描电镜、能谱、等离子发射光谱仪等分析测试技术,对鄂尔多斯盆地中生界延长组湖盆中部长6和长8储层酸敏特征及机理进行分析的结果表明,长6和长8储层的敏感性为改善—弱酸敏性。绿泥石膜的溶蚀作用是造成改善型储层的主要原因;绿泥石与盐酸的反应过程中,反应残余的绿泥石晶片堵塞喉道,这是形成弱酸敏型储层的主要原因。对酸敏残液分析结果表明,在一定时间内不可能形成Fe(OH)3沉淀及堵塞喉道。因而,在储层酸化过程中应注入足量的酸化液,使残余物发生完全反应。但酸化液不宜在地层中滞留时间太长,否则易形成沉淀,从而降低渗透率。The reservoir characteristics and acid sensitivity mechanism of Chang 6 and Chang 8 reservoirs in the Mesozoic Yanchang Formation of Ordos Basin were analyzed by using some methods such as casting body slice image analysis,XRD, SEM, EEDS and ICP-AES. The results showed that there was amendatory weak damage resulted from acid sensitivity in Chang 6 and Chang 8 reser- voirs. The corrosion of chlorite membrane resulted in the evident improvement of microscopic pore structures. In the reaction process of chlorite with hydrochloric acid, remnant chlorite fell off from the wall of pores and jammed the throat, which is the main reason for weak sensitivity of the reservoirs in these regions. The sensitivity test showed that the remnant chlorite was impossible to form Fe（OH）3 precipitation in the simulative system. In the fracturing process, the adequate standard acidizing fluids should be injected into fractured wells in order to ensure the complete reaction of chlorite. The standard acidizing fluids only stay short time to avoid increment of acid value of fluid and forming precipitation.

关 键 词：鄂尔多斯盆地 储层特征 酸敏机理 绿泥石 酸化工艺 酸化液 

分 类 号：TE122.2[石油与天然气工程—油气勘探]