滨里海盆地科尔占地区石炭系沉积相

Carboniferous sedimentary facies of Kolzhan area in Pre-Caspian Basin

余海洋 柳忠泉 王大华 徐佑德 车燕 陈云锋 姜颖

Yu Haiyang Liu Zhongquan Wang Dahua Xu Youde Che Yan Chen Yunfeng Jiang Ying

中国石油化工股份有限公司胜利油田分公司地质科学研究院, 山东东营 257015

Geological Scientific Research Institute, SINOPEC Shengli Oilfield Company, Dongying 257015

科尔占地区位于滨里海盆地阿斯特拉罕-阿克纠宾斯克隆起带东南部的比伊克扎尔次级隆起上, 该地区广泛发育下二叠统孔谷组盐岩, 以盐岩沉积为界, 它将整个剖面划分为盐上层系(以碎屑岩为主的含油气层系)和盐下层系(以碳酸盐岩为主的含油气层系)两个大的含油气层系, 石炭系为盐下层系中主要的含油气层系之一。通过对研究区唯一的盐下井K井岩屑及其薄片的详细观察, 并结合该井测井资料, 分析了石炭系的沉积特征, 并对其沉积相进行了划分与描述。K井石炭系主要发育3种类型沉积相, 分别为深水浊积扇相、斜坡相和台地相, 其中深水浊积扇相可进一步划分为内扇、中扇和外扇3个亚相, 台地相划分为滩间洼地和台内滩2个亚相。利用K井钻探结果, 结合区域资料, 初步预测出科尔占地区早石炭世和中石炭世末期沉积相带的平面分布特征。

Kolzhan area is located in Biykzhol relief, southeast of Astrakhan-Aktyubinsk uplift in PreCaspian Basin, and Kungurian salt of Lower Permian is developed widely here. The whole profile is divided into 2 hydrocarbon-bearing series by salt sediments, one is dominated by clastic rocks and another is dominated by carbonate rocks. Carboniferous formation is one of the main hydrocarbon-bearing formations beneath the salt sediments. According to the analysis of cuttings well K as well as the logging data, Carboniferous sedimentary characteristics are analyzed and sedimentary facies are classified and described. Three types of sedimentary facies are developed in Carboniferous formation of well K, including deep-water turbidite fan, slope and platform facies. Deep-water turbidite fan is further divided into inner, middle and outer fan, and platform facies is divided into interbank sag and platform shoal. Using drilling results of well K and regional data, early and late Carboniferous sedimentary facies distribution is predicted initially in Kolzhan area.