塔中地区下奥陶统鹰山组热液白云岩内幕型储层形成机制及其分布特征  

The Forming Mechanism and Its Distribution Characters of Hydrothermal Dolomite Reservoirs in Tazhong Area

作　　者：王振宇[1] 王二伟[1] 杨薇[2] 林新[1] 孙超[3] 郭靖[4] 

机构地区：[1]西南石油大学资源与环境学院,四川成都610500 [2]中石化江汉油田分公司江汉采油厂,湖北潜江433301 [3]中石油青海油田分公司测试公司资料解释中心,青海海西州816400 [4]中石油吉林油田分公司乾安采油厂,吉林松原131400

出　　处：《石油天然气学报》2011年第12期41-45,171,共5页Journal of Oil and Gas Technology

基　　金：国家科技重大专项(2008ZX05049)

摘　　要：塔中地区鹰山组白云岩储层逐渐成为该地区油气主力产层,对该区热液白云岩的岩石特征、成因模式及其分布特征的研究对下一步的勘探开发具有重要的指导意义。通过碳氧同位素、微量元素、阴极发光、岩心及薄片等特征综合识别发现,塔中地区奥陶系热液白云岩储层主要分布在下奥陶统鹰山组中下部和蓬莱坝组;其形成机理主要为埋藏期富含Mg2+的地层卤水沿断裂、裂缝及先期存在的孔洞层上升进入到缝洞体系中,在热液作用下发生白云岩化作用。白云岩化作用引起晶间孔发育,后期受酸性地层水溶蚀发育蜂窝状、串珠状溶蚀孔洞体系,形成白云岩内幕型储层。The dolomite reservoirs of Yingshan Formation in Tazhong Area became the principal pay-zone of oil and gas,it was of great significance to study the,genetic patterns,and distribution characteristics of the hydrothermal dolomite reservoirs for the nest oil exploration.By the comprehensive study of carbon-oxygen isotope,determination of trace elements,cathode-luminescence emission analysis and rock core and thin section analyses,it was discovered that the hydrothermal dolomite reservoirs are distributed mainly in the mid-lower parts of Yingshan Formation and Penglaiba Formation of lower Ordovician in Tazhong Area.The genesis mechanism is that the brine water is enriched in Mg2+ of burial formation moved upward into the fracture-pore system through faults and fractures,dolomization would was induced by the hydrothermal fluid,in which inter-crystal pore was always developed and dissolved by acid-formed water into cellular,paternoster pore system,and the dolomite inside reservoirs are formed.

关 键 词：塔中地区 鹰山组 热液白云岩 成因模式 白云岩内幕型储层 

分 类 号：P618.13[天文地球—矿床学]