东营凹陷古近系深部碎屑岩储层中的黏土矿物

Clay minerals in clastic rock reservoir of deep formation in Paleogene of Dongying sag

通过钻井岩心观察、薄片鉴定、扫描电镜观察、X射线衍射、岩心物性分析等手段对东营凹陷古近系深部碎屑岩储层中的黏土矿物和储层物性进行研究。结果表明:研究区古近系深部碎屑岩储层黏土矿物以伊利石和伊/蒙混层为主,绿泥石次之,高岭石含量比较低;净砂岩中的黏土矿物主要由长石和岩屑溶解形成,储层物性表现为高孔高渗,杂砂岩中的黏土矿物主要是沉积黏土矿物及其转化产物,易损害储层物性;黏土矿物含量小于15%的储层勘探方向是寻找与油气充注匹配的次生孔隙,黏土矿物含量大于15%的储层勘探方向是寻找裂缝发育带及裂缝发育带附近的淋滤带。

The characteristics of clay minerals and reservoir physical properties in clastic reservoir of deep formation in Paleogene of Dongying sag were studied through cores observation, rock slices identification, scanning electron observation and physical properties analysis. The results show that illite and I/S are main clay minerals, chlorite takes the second place, and the content of kaolinite is low. The clay minerals of pure sandstone are mainly formed by feldspar and debris dissolution, and the reservoir property belongs to high porosity and high permeability. The clay minerals of greywacke are mainly depositional clay minerals and their transferred products, which tend to damage the reservoir properties. The exploration direction of the reservoirs with clay mineral content being less than 15% is to search the secondary pores with matching oil and gas injected, and the exploration direction of the reservoirs with clay mineral content being more than 15% is to search the fissure zones and leached zones near the fissure zones.