塔中北斜坡奥陶系鹰山组岩溶作用与储层分布

Karstification and reservoir distribution of Ordovician Yingshan Formation in the northern slope of Tazhong

谢欣睿 毛健 王振宇

西南石油大学资源与环境学院，四川 成都 610500

College of Resources and Environment Engineering, Southwest Petroleum University, Chengdu 610500, China

塔中北斜坡奥陶系碳酸盐岩储层在很大程度上受岩溶作用的控制，深入总结古岩溶作用与储层分布的相关性对油气勘探开发具有重要意义。通过对岩心、薄片、阴极发光、测井及地化分析等资料综合研究，识别出在鹰山组顶部不整合面剥蚀残留地层中存在风化壳岩溶和埋藏岩溶2种类型的古岩溶作用。风化壳岩溶作用是形成优质储层的关键因素，受其控制的储层在垂向上主要局限在不整合面以下150 m深度范围内的表层岩溶带和径流岩溶带，平面上主要发育于岩溶斜坡区，又以岩溶残丘为最有利微地貌单元；埋藏岩溶与酸性流体、温度、地层压力、热液及断裂构造有关，是储层优化改造的关键因素，为碳酸盐岩盆地深部的油气勘探开拓了新领域。

Ordovician carbonate reservoirs of the northern slope of Tazhong are controlled by development of karstification to a great extent. It has a great meaning for oil and gas exploration to conclude the correlation of paleokarstification and reservoir distribution. Through comprehensive studying of geological data, such as core, thin slice, cathodoluminescence,well logging, geochemical analysis, weathering crust karst and burial karst along the unconformity erosion formation of the top part of Ordovician Yingshan Formation can be identified. The weathering crust karst is a key factor of forming high-quality reservoir. The controlled reservoirs are vertically limited in surface karst zone and flowthrough karst zone within 150 m below the unconformity surface. They mainly develop in karst slope area in plane. Karst hammock is most favourable microtopography unit. The burial karstification is related with acid fluid, temperature, formation pressure, thermal fluid and faulted structure. It is the key factor to optimize and reform the reservoirs, developing a foreground for exploration activity in the deep part of carbonate basin.

10.6056/dkyqt201303013