尼日尔三角洲盆地深水区油气成藏模式与有利区带预测  

Hydrocarbon accumulation model and favorable play prediction in deep water area,Niger Delta Basin

作　　者：陈经覃 康洪全 范洪耀 冯鑫 Chen Jingtan;Kang Hongquan;Fan Hongyao;Feng Xin(CNOOC International Limited)

机构地区：[1]中国海洋石油国际有限公司,100028

出　　处：《中国石油勘探》2020年第4期95-104,共10页China Petroleum Exploration

基　　金：国家科技重大专项“非洲重点区油气勘探潜力综合评价”(2017ZX05032-002)。

摘　　要：大西洋两岸深水区是当前热门的油气勘探领域,已发现的大中型油气田多为盐岩相关构造,而尼日尔三角洲盆地未沉积盐岩,发育泥底辟和泥火山等泥相关构造。为理清深水挤压构造区油气成藏规律,综合利用地震、钻井、测井、原油物性等资料,运用综合地质分析法,从尼日尔三角洲盆地深水区构造沉积演化入手,开展油气成藏模式研究。研究表明,尼日尔三角洲盆地深水区晚白垩世至今始终处于深海—半深海沉积环境,主力烃源岩为上白垩统—古新统海相烃源岩,于晚中新世进入生排烃高峰,随着尼日尔三角洲不断向海进积,中—下中新统以朵叶沉积为主,上中新统以水道复合体沉积为主,断层和裂缝是油气垂向运移的主要通道。在此基础上,建立了深水区“树形”近源油气成藏模式,指出汇烃面积是尼日尔三角洲盆地深水区油气富集的主控因素。深水区北部泥底辟构造区成藏条件好,未钻探的构造圈闭数量多,具有较大勘探潜力。Deep water area on both sides of the Atlantic Ocean is a hot fi eld of oil and gas exploration,and most of the discovered largemedium oil and gas fi elds are salt-related structures.In the Niger Delta Basin,there are no salt deposits,but mud diapirs,mud volcanoes and other mud-related structures.In order to clarify the rules of hydrocarbon accumulation in deep-water compressed zone,the study of oil and gas accumulation model is carried out based on seismic,well drilling,logging,crude oil physical properties and other data,starting from the tectonic and sedimentary evolution of the deep water area of the Niger Delta Basin through comprehensive geological analysis.The study shows that the deep-water area of the Niger Delta Basin has been in deep to semi-deep marine sedimentary environment since the Late Cretaceous.The main source rocks are the marine source rocks deposited from the Upper Cretaceous to the Paleocene,which entered the peak period of hydrocarbon generation and expulsion in the Late Miocene.As the Niger Delta continued to prograde towards the sea,the Middle and Lower Miocene were dominated by lobe deposits,while the Upper Miocene was dominated by channel complex deposits.Faults and fractures are the main pathways for vertical migration of oil and gas.On this basis,the"tree-shaped"near-source hydrocarbon accumulation model of the deep water area is established,which indicates that the fetch area is the main controlling factor of hydrocarbon enrichment in the deep water area of the Niger Delta Basin.The mud-diapir-structure area in the north of the deep water area has good hydrocarbon accumulation conditions with a large number of undrilled structural traps,and the exploration potential is promising.

关 键 词：尼日尔三角洲盆地 深水区 泥底辟 成藏模式 汇烃面积 

分 类 号：TE112.3[石油与天然气工程—油气勘探]