陇东地区延长组长6-长8油层组成岩相研究

Diagenetic facies study on Chang 6-8 oil formations of Triassic Yanchang Formation in Ordos basin, China

在对鄂尔多斯盆地陇东地区三叠系延长组长6-长8 油层组沉积相特征、岩相古地理演化研究的基础上,详细研究了区内长6-长8油层组成岩作用类型及特征,主要成岩作用类型有压实、胶结、溶蚀、重结晶等成岩作用;并深入研究了成岩相类型、特征,包括了泥岩压实相、压实—压溶相、残余原生粒间孔一次生溶孔相、次生溶孔相和微裂缝相等5类;根据储集砂岩中充填物组合类型分出10种亚成岩相,进而阐述了不同成岩相的平面分布。为进一步研究成岩相对储层的形成与发育的影响提供了重要的基础资料。

In this paper, the authors study in detail the diagenetic types and characteristics of Chang 6-Chang 8 oil formations in the region on the basis of studying the character of sedimentary facies and paleogeographic evolution of the Chang 6-Chang 8 oil formations. The main diagenetic types include compaction, cementation, erosion, recrystallization and so on. The authors further study the types and characteristics of the diagenetic facies. There are five types which include mudstone compaction facies, compaction-pressolution facies, residual protozoal intergranular-secondary dissolution facies, secondary dissolution facies, and micro-fractures facies. Through further studying on the types of fillings in reservoir sandstone, ten sub-diagenetic facies are clssified. The authors describe the plane distribution of diversity diagenetic facies and distribute important basic information for further studying the influence of diagenetic facies on the formation and development of reservoirs.