鄂尔多斯盆地富县地区长8成岩相及其对储层类别的控制

富县地区延长组长8油层组是重要的产油层段之一,储层性能除了受沉积环境的影响之外,还受成岩作用、尤其是成岩相的控制.综合利用储层铸体薄片、压汞、扫描电镜和物性分析等资料对富县地区长8油层组碎屑组成、胶结物组分和储层孔隙结构、物性特征、成岩相及储层类别进行了详细研究,分析了储层成岩相分布规律及其对储层类别的控制作用.得出以下结论：研究区长8油层组主要发育5种成岩相：绿泥石薄膜胶结相、泥质胶结相、石英及长石胶结相、碳酸盐胶结相和长石溶蚀相.储层物性分布规律明显受成岩相控制,绿泥石薄膜胶结相和长石溶蚀相区储层物性最好,为Ⅱ类储层,为研究区最有利储集层发育的相带;泥质胶结相及石英、长石胶结相区储层物性稍差,为Ⅲ类储层;泥质胶结相及碳酸盐胶结相区储层物性最差,为Ⅳ类储层,即非储集岩.

Diagenetic facies and its control over reservoir types of Chang 8 in Fuxian Area of Ordos Basin

Chang 8 oil group of Yanchang formation is one ot the main oil producing zone in Fuxian are a, the reservoir performance of the study area not only is affected by the depositional environment, but al so affected by diagenesis, especially controlled by diagenetic facies. Based on the data of property analy sis,casting thin, scanning electron microscopy and mercury,the detrital component, cement composition,pore structure of reservoir, physical properties, diagenetic facies and reservoir category of Chang 8 oil group of Yanchang formation in Fuxian area are studied. The diagenetic facies distribution and its control action to reservoir category are analyzed also. Summarizing the following conclusions：Chang 8 oil group of the study area mainly developed five kinds of diagenetic facies ： chlorite film cementation, clay cemen tation, quartz and feldspar cementation, carbonate cementation and feldspar dissolution facies, the physi cal properties distribution of reservoir was significantly controlled by diagenetic facies, chlorite film ce mentation and feldspar dissolution phase region have the best reservoir properties, as type Ⅱ reservoir and it is the most favorable reservoir facies;the reservoir properties of argillaceous cementation and quartz, feldspar cementation zone is somewhat less, as type Ⅱ reservoir; the reservoir properties of argil laceous cementation and carbonate cementation cementation is the worst, as type IV reservoir, that is nonreservoir rocks.