喀麦隆里奥—德雷盆地泥岩底辟构造与油气分布规律  

Mud shale diapir structure and hydrocarbon distribution in the Rio del Rey Basin of Cameroon

作　　者：袁井菊[1] 丁一萍[1] 苏玉山[1] 陈占坤[1] 哈里 YUAN Jingju;DING Yiping;SU Yushan;CHEN Zhankun;KHALID Abuganaya(SINOPEC Petroleum Exploration ＆ Production Research Institute,Beijing 100083,China)

机构地区：[1]中国石化石油勘探开发研究院,北京100083

出　　处：《石油实验地质》2018年第4期508-512,共5页Petroleum Geology & Experiment

基　　金：国家科技重大专项"重点盆地油气勘探目标评价与优选"(2016ZX05033-002)资助

摘　　要：里奥—德雷(Rio del Rey)盆地位于喀麦隆境内、尼日尔三角洲(Niger Delta)东北缘,油气资源十分丰富,已有30余年油气勘探开发历史。古新世以来发生的长期海退和三角洲沉积作用,形成了现今的里奥—德雷被动大陆边缘盆地,其主要发育3个地层单元,自下而上分别为阿卡塔(Akata)组、阿格巴达(Agbada)组和贝宁(Benin)组。在三角洲进积推进过程中,由于大陆边缘的重力作用和三角洲泥岩的塑性推覆作用,由陆向海、自北向南形成了3个构造区,即伸展构造区、泥岩底辟构造区和逆冲推覆构造区。其中,在泥岩底辟构造区形成了许多与泥岩底辟或泥岩脊相关的辟顶背斜、断背斜构造圈闭或辟边岩性遮挡圈闭,现今已发现的大型油气田主要与这些圈闭有关。同时,泥岩底辟的活动也形成了储集和运移方面的优势条件,促使油气在泥岩底辟构造区富集高产。因此,未来泥岩底辟构造区以及与泥岩底辟相关的圈闭仍然是里奥—德雷盆地进一步寻找勘探潜力的主要地区。The Rio del Rey Basin is located in Cameroon and the northeast of the Niger Delta. It is rich in oil and gas resources,and has more than 30 years of oil and gas exploration and development history. Long-term regression and delta sedimentation since the Eocene have formed the present Rio del Rey passive continental margin basin. Three stratigraphic units developed,including the Akata,Agbada and Benin formations respectively from bottom to top. In the process of delta progradation,the extensional,shale diapir and toe thrust tectonic zones were formed from north to south and also from onshore to offshore because of the gravity action of continental margin and the plastic over-thrusting of deltaic mudstone. In the mudstone diapir tectonic zone,many diapir anticlines or faulted-anticlines and lithologic traps related to mudstone diapirs or mudstone ridges have been formed. The large oil and gas fields that have been discovered to date are mainly related to these traps. At the same time,the activity of mudstone diapirs also provided superior conditions of reservoir and migration,which promoted the oil and gas enrichment and high yield in the diapir tectonic zone. Therefore,the mudstone diapir tectonic zone and the traps associated with mudstone diapirs are still the main targets for further exploration potential in the Rio del Rey Basin.

关 键 词：泥岩底辟 泥岩脊 构造圈闭 油气分布规律 里奥—德雷盆地 喀麦隆 

分 类 号：TE121.2[石油与天然气工程—油气勘探]