鲁西隆起区奥陶系碳酸盐岩成岩环境演化

根据野外剖面观察和室内薄片鉴定,鲁西隆起区岩石类型主要为碳酸盐岩,包括白云岩、石灰岩及其过渡类型,其次为蒸发岩和膏溶角砾岩。研究区经历了多期次、多类型的成岩作用。储层储集空间主要包括晶间孔、粒间和粒内溶孔、残余粒内孔和粒间孔、铸模孔、溶洞和裂缝。结合研究区地质背景、岩石学特征和成岩作用分析,将该区成岩环境划分为海水成岩环境、表生成岩环境和埋藏成岩环境。其中:表生成岩环境中发育的溶蚀作用是优质储层形成的关键;海水成岩环境和中埋藏成岩环境中发育的白云石化作用对储层也起到了积极作用;而埋藏成岩环境中发育的胶结作用是造成储层物性变差的主要原因。

Evolution of Diagenetic Environment for Ordovician Carbonate in the West Shandong Rise

A study was made on the field section and thin section of rocks in the West Shandong Rise. The results show that the principal type of rocks in this area is primarily carbonate including dolomite, limestone and their transi- tion type,then followed by evaporation rocks and gypsum breccia. The given area has experienced a multi-phased and multi-typed diagenesis. The dominant reservoir space consists of intracrystal porosity, intraparticle and dissolution porosity,moldic,vugs and fractures. The diagenetic environments can be divided into such types as marine,exodia- genesis and burial diagenetic environment according to the geological background,petrologic characteristics and diagenesis of the area. The dissolution occurred in the exodiagenesis environment has played a key role in the formation of high quality reservoir. The dolomitization developed in the marine and burial diagenetic environment has also helped the formation of reservoir. The cementation developed in burial diagenetic environment has remained the main cause for poor properties of reservoir