镇原-泾川地区长9油层组成岩演化序列研究

Research on Diagenetic Evolutionary Sequences of the Chang 9 Oil-bearing Formation in Zhenyan-Jingchuan Area

运用沉积学理论,通过镜下观察和岩矿分析,研究镇原-泾川地区长9油层组的岩石学特征及成岩作用类型并建立成岩演化序列。研究表明长9油层组主要发育细、中粒的岩屑砂岩、长石岩屑砂岩,其成分成熟度较低,但结构成熟度较高;填隙物以胶结物为主,主要为碳酸盐胶结物,其次为硅质胶结物,杂基含量较少,主要为黏土杂基和灰泥杂基。通过显微镜鉴定开展储层成岩作用研究,主要的成岩作用包括压实作用、胶结和自生矿物的形成作用、溶蚀作用、交代和重结晶作用。分析了成岩作用对储层的改造作用,进一步总结并建立了研究区的4种成岩作用演化序列,为研究区该油层组下一步的油气勘探和开发提供重要的理论基础。

Sedimentology theory, research petrological characteristics, diagenesis types and establish its diagenet- ic evolutionary sequences about Chang 9 oil-bearing formation in Zhenyan-Jingchuan area by microscopic observation and analysis of rock and mineral are used. Research shows that Chang 9 oil-bearing formation mainly developed fine, medium lithic sandstone and feldspar lithic sandstone, its componential maturity is low, but have higher structural maturity. Interstitial material mainly base on cement that is mainly carbonate cement, followed by siliceous cement, lower content of matrix, matrix is mainly clay and lime mudstone. Carry out diagenesis research by microscopic identification, the main diagenesis includes compaction, cementation and the formation of authigenic minerals, dissolution, account and recrystallization. Analyse that diagenesis transform the reservoir, further summarize and establish four diagenetic evolutionary sequences, that provide important theoretical basis for next step oil-gas exploration and development about this oil-bearing formation in research area.