东营凹陷南斜坡东部地区沙四段储层成岩作用研究

东营凹陷南斜坡东部地区沙四段储层岩性主要有砂砾岩、砾状砂岩、砂岩和粉砂岩,砂岩类型以岩屑长石砂岩为主,长石砂岩和长石岩屑砂岩次之.成岩矿物类型主要有粘土矿物、石英、长石、碳酸盐、黄铁矿等,其中粘土矿物有高岭石、伊利石、绿泥石、伊-蒙混层.储层成岩演化阶段处于晚成岩A1亚期,油气注入时间为7.5～25 Ma前.砂岩储层成岩相划分为三种类型:压实成岩相、碳酸盐胶结成岩相和不稳定碎屑溶蚀成岩相.储层性质明显地受到成岩相的控制,水下辫状河道砂体是油气储集的主要场所.

Diagenesis of the Member 4 of the Shahejie Formation in the south slope of the Dongying depression, China

The sandbodies of the Member 4 of the Shahejie Formation (Es4) in the south slope of the Dongying depression are mainly conglomeratic sandstone, sandstone, and minor siltstone. The sandstones are mostly lithic arkose. The main diagenetic minerals of the sandstones include authigenetic clay minerals, quartz and feldspar overgrowth, late carbonate cement and sideropyrite. The authigenetic clay minerals include kaolinite, illite, chlorite and illite-montmorillonite. There are four diagenetic facies in the south slope of the Dongying depression. Obviously, the reservoir quality is controlled by diagenetic facies. In this area, braided-channel sandbodies are important locations for oil and gas storage. The reservoir diagenetic stages can be divided into A_1-substage of late diagenesis. The petroleum fillings of this reservoir occurred from about 7.5 Ma to 25 Ma.