东营凹陷南斜坡孔店组冲积体系碎屑岩储层特征及评价

Characteristics and evaluation of the clastic reservoirs in Kongdian Member in the southern slope belt of Dongying Sag

孔店组储层为冲积扇、河流、泛滥平原等冲积沉积体系砂岩 ,砂岩类型以岩屑砂岩、岩屑长石砂岩为主 .储层物性较好 ,随深度加大 ,储层物性逐渐变差 ;沉积相、碳酸盐、泥质胶结、溶蚀作用是影响砂岩物性的主要因素 .碳酸盐胶结及压实作用是本区储层物性变差的主要影响因素 ,分为浅埋期碳酸盐和晚期埋藏碳酸盐 (与有机酸脱羧作用有关 )胶结 2种 .泥质基质及黏土薄膜有利于砂岩原生孔隙的保存 ;溶蚀作用有利于储集层物性变好 .根据K/Φ等物性参数将储层划分为 3类 ,孔店组三段主要为Ⅱ类和Ⅲ类 ,孔店组一、二段 3类储集层均有分布 ,有利储层为Ⅰ类河流相的河道砂体 .

The clastic reservoirs are formed in allvial fan, river and flood plain. The types of main sandstone are debris sandstone and debris arkose. The physical properties of the reservoirs are better, and the greater the depth of the reservoirs, the worse the physical properties of them. Sedimentary facies, carbonate cementing, shale cementing and corrosion are the main factors of influencing the physical properties of the sandstones. Carbonate cementing and compaction are the main factors of making the physical properties of the reservoirs in the studied area worse. There are two types of carbonate cementing: shallowly buried carbonate cementing and late carbonate cementing. Shale matrix and clay cutan are favorable to the conservation of the primary pores in the sandstones. Corrosion can make the physical properties of the reservoirs better. The reservoirs are classified into three types according to their physical property parameters such as permeability, porosity and so on. The third formation of Kongdian Member is mainly the reservoirs of the second type and the third type, and there are the reservoirs of all three types in the first formation and the second formation. The favorable reservoir is the river channel sandstone of the reservoir of the first type.