东尼日尔盆地群上白垩统Donga组沉积体系及勘探潜力  

The Sedimentary System and Hydrocarbon Potential of Upper Cretaceous Donga Formation, East Niger Basin Group

作　　者：袁圣强[1] 姜虹[1] 汤戈[2] 肖坤叶[1] 刘邦[1,3] 潘春浮 王海荣 毛凤军[1] 郭郁[3] 周川闽 Yuan Shengqiang;Jiang Hong;Tang Ge;Xiao Kunye;Liu Bang;Pan Chunfu;Wang Hairong;Mao Fengjun;Guo Yu;Zhou Chuanmin(Research Institute of Petroleum Exploration&Development,PetroChina,Beijing 100083,China;Research Institute of Petroleum Exploration and Development of Dagang Oilfield,PetroChina,Tianjin 300280,China;China National Oil and Gas Exploration and Development Corporation,Beijing 100034,China;School of Energy Resources,China University of Geosciences,Beijing 100083,China)

机构地区：[1]中国石油勘探开发研究院,北京100083 [2]中国石油大港油田分公司勘探开发研究院,天津300280 [3]中国石油国际勘探开发有限公司,北京100034 [4]中国地质大学能源学院,北京100083

出　　处：《地球科学》2023年第2期705-718,共14页Earth Science

基　　金：中国石油股份有限公司科学研究与技术开发项目“海外复杂裂谷盆地精细勘探关键技术研究”(No.2021DJ3103)。

摘　　要：东尼日尔盆地群属于西非裂谷系.基于地震、钻井、井壁取心和地球化学分析数据等资料,针对下组合新层系Donga组,从沉积体系分析入手,探讨其成藏组合和勘探潜力.Donga组为晚白垩世海侵背景下发育的一套正旋回沉积层序,下粗-中上部细,顶部发育薄层碳酸盐岩.该层序在东尼日尔盆地群跨多个盆地广泛发育和连续沉积,预示着晚白垩世盆地群形成了暂时统一盆地.海侵事件显著影响了晚白垩世的沉积体系,控制了其含油气系统发育和油气成藏.Donga组广泛沉积的泥岩为有效烃源岩和盖层.Donga组主要发育侧向对接供烃“上生下储”和“自生自储”成藏模式.储层是Donga组成藏主控因素,盆地群埋藏适中、近物源的北部和东南部边缘相带储层发育,具备较好勘探潜力.The East Niger basin group belongs to the West African Rift System. Based on seismic, drilling, side wall core, and geochemical analysis data of Donga formation, this paper analyses its depositional system, play and exploration potential. Donga formation is a normal cycle sequence formed in late Cretaceous transgression, and the top is developed with thin carbonate rocks.This sequence is widely developed in the Upper Cretaceous of the East Niger Basin Group, which indicates that seawater flooded these basins during the Late Cretaceous and forms a temporarily unified basin. The transgression event significantly affected the sedimentary system of the Late Cretaceous basin and controlled its petroleum system and hydrocarbon accumulation. The widely deposited mudstone can be a good hydrocarbon source rock and cap rock. There are two plays in Donga formation, upper generation and lower reservoir, supply hydrocarbon laterally, and self-generated and self-stored. Reservoir is the control factor of Donga formation hydrocarbon accumulation, the moderate buried and near provenance area in the north and southeast margin could develop good reservoir and has good exploration potential.

关 键 词：东尼日尔 Termit盆地 上白垩统 沉积体系 油气潜力 Donga组 石油地质 

分 类 号：TE121[石油与天然气工程—油气勘探]