鄂尔多斯盆地延长天然气探区山西组山2段成岩相及优质储层研究

鄂尔多斯盆地东南部延长天然气探区下二叠统山西组山2段成岩作用复杂，主要结合普通薄片、铸体薄片、扫描电镜等资料对山2段成岩作用进行系统研究，确定研究区储层经历了压实作用、胶结作用、交代作用和溶解作用等多种成岩作用。根据山2段填隙物的胶结类型、颗粒的接触性质、物性数据和成岩作用特征，在研究区划分出5种成岩相:Ⅰ类，弱压实-黏土薄膜-石英弱加大胶结溶蚀相；Ⅱ类，中压实-硅质胶结溶蚀相；Ⅲ类，中压实-黏土杂基充填微孔相；Ⅳ类，强压实-硅质胶结致密相；Ⅴ类，强压实黏土充填致密相。另外结合试气资料，确定Ⅰ类、Ⅱ类、Ⅲ类这3类成岩相为储集层发育的优势成岩相带。最后根据储层岩石学特征、物性特征、沉积相以及成岩相分析优质储层发育特征，以期为有利成藏区带预测提供依据。

Diagenetic Facies and High-quality Reservoir Study of Shanxi-2 Member in Jingbian Gas Field,Ordos Basin

Diagenesis of the Member 2 of lower Permian Shanxi Formation of Jingbian gas field in southeastern Ordos basin is complicated.Based on the thin sections,casting thin sections,scanning electron microscope and so on,systematic research on the diagenesis of the Member 2 of Shanxi Formation has been carried out.It showed that reservoirs in this study area have experienced diagenesis such as compaction, cementation,metasomatism and dissolution.According to the depositional-diagenetic environments and the various fabric characteristics of the diagenetic changes of the Member 2 of Shanxi Formation,this study area can be divided into five types of diagenetic facies:Ⅰ.weak compaction-clay membrane-quartz weak increase cement dissolution phase;Ⅱ.Compaction-siliceous cement dissolution:Ⅲ.compaction-clay matrix filling porous phase;Ⅳ.compaction-siliceous cement dense phase;Ⅴ.compacted clay filled dense phase.Combined with gas-test data,Ⅰ is the most favorable diagenetic facies zone,Ⅱ and Ⅲ are the second favorable diagenetic facies zones.Finally,the reservoir characteristics,physical features,sedimentary facies and diagenetic facies were applied to analyze the developmental characteristics of high quality reservoir,and it provides a sound basis for the prediction of favorable areas.