塔河油田盐下地区奥陶系成岩作用与孔隙演化

在55口井岩心、300片薄片观察的基础上,结合地球化学分析资料,系统研究了塔河油田南部盐下地区碳酸盐岩储层的成岩作用类型。研究表明:研究区存在胶结作用、溶蚀(或岩溶)作用、压溶作用、硅化作用、破裂作用、白云化作用和重结晶作用等多种成岩作用类型。溶蚀作用(或岩溶)分为4期,依次为同生期大气水溶蚀、加里东中期大气水岩溶、海西早期大气水岩溶以及海西晚期埋藏热液溶蚀作用,其中加里东中期大气水岩溶作用及海西早期大气水岩溶作用对改善区内碳酸盐岩储层物性具有重要意义。在此基础上,进一步分析了研究区成岩作用序列及孔隙演化。

Diagenesis and porosity evolution of the Ordovician in sub-salt area,Tahe Oilfields

Based on the observation of 55 cores and 300 thin sections and combined with the geochemical data, the diagenesis and porosity evolution of the study area were analyzed systematically.The types of diagenesis include cementation,karstification, pressolution, silicatization, cataclasis, dolomitisation, recrystallization. The karstification can be divided into four stages:Syngenetic stage,Middle Caledonian stage,Early Hercynian and Late Hercynian.And the karstification of Middle Caledonian stage and Early Hercynian are vital to the reservoir development.On the above results,the diagenesis and porosity evolution were analyzed.