柴达木盆地深层油气成矿(藏)条件及有利区带  

Petroleum accumulation conditions and favorable exploration plays of deeply buried strata in Qaidam Basin

作　　者：石亚军[1,2] 杨少勇 郭佳佳 马新民 孙秀建[1] 徐丽[1] 邹开真[3] 田光荣 SHI Yajun;YANG Shaoyong;GUO Jiajia;MA Xinmin;SUN Xiujian;XU Li;ZOU Kaizhen;TIAN Guangrong(Research Insisitute of Petroleum Exploration&Development Northwect(NWGI),Lanzhou,Gansu 730020,China;Key Lab of Reservoir Description of CNPC,Lanzhou,Gansu 730020,China;PetroChina Qinghai Oilfield Company,Dunhuang,Gansu 736200,China)

机构地区：[1]中国石油勘探开发研究院西北分院,甘肃兰州730020 [2]中国石油集团油藏描述重点实验室,甘肃兰州730020 [3]中国石油青海油田分公司,甘肃敦煌736200

出　　处：《中国矿业大学学报》2020年第3期506-522,共17页Journal of China University of Mining & Technology

基　　金：国家科技专项(2016ZX05003-006);中国石油天然气股份有限公司重大科技专项(2016E-01)。

摘　　要：柴达木盆地深层油气勘探一直存有争议,且勘探程度低.目前,随着油气勘探程度的提高和不断深入,深层(4000 m以下)已逐渐成为重要的油气资源战略接替区,也成为油田可持续发展的关键.本文聚焦深层能否发育有效储层和改造型盆地深层油气能否规模聚集两大科学问题,创新储层的成储机制判识和油气的生成、运移、聚集等信息判定方法,构建了深层储层成储模式和油气成藏模式,进而优选出英西-英中-英东构造带、南翼山构造带、大风山构造带、碱山构造带、鄂博梁构造带、冷湖构造带、鸭湖构造带等未来深层勘探的7个有利区带.研究发现:1)柴达木盆地4000 m以下碳酸盐岩具有三元成储机理,形成纳米至毫米级储集空间,孔隙度介于6%~15%,碎屑岩和基岩具有多因素保孔的成储机理,碎屑岩6000 m以下孔隙度介于9%~15%,甚至超15%,基岩储层孔隙度普遍处在2%~8%之间,揭示了深埋条件具备一定的油气储集能力;2)受烃源岩生排烃和晚期构造运动控制,柴达木盆地深层普遍具有近源早成优保的成藏特征,其中西部坳陷区普遍为盐下源内源储一体大面积成藏、阿尔金斜坡带凹中隆为侧接式多层系成藏、北缘块断带晚期构造深层则为早成早聚原生成藏,晚期构造改造下深层仍整体具备形成大中规模油气藏的条件.Since the development and increasing degree of oil and gas exploration,deeply buried oil and gas reservoirs(>4000 m)with continuous controversies and low exploration degree have gradually become an important strategic area,and it is key to sustainable development for oil and gas exploration in Qaidam Basin.Focusing on the two major scientific issues including whether effective reservoirs could develop and hydrocarbon could accumulate in deep strata in reformed basin,innovations which involve in identification of reservoir-forming mechanism and judgment methods for hydrocarbon generation,migration and accumulation are proposed,and models of reservoir-forming and oil-gas accumulation are also constructed in this paper.Furthermore,seven favorable plays for future hydrocarbon exploration in deeply buried strata are figured out,including Yingxi-Yingzhong-Yingdong,Nanyishan,Dafengshan,Jianshan,Eboliang,Lenghu and Yahu structural belts in Qaidam Basin.The results showed that:1)the reservoir-forming mechanism of carbonate rocks in deeply buried strata(>4000 m)is named ternary controlling effect,and the reservoir space is in nanometer to millimeter scale with porosity up to 6%-15%.However,reservoir-forming mechanisms of clastic rock and bedrock are mainly pore preservation effects controlled by multiple factors.The porosity of clastic rock reservoir(>6000 m)could still reach 9%-15%,and that of bedrock reservoir is generally between 2%and 8%,which indicates that deep buried strata still have certain storage capacity for hydrocarbons;2)the deeply buried reservoirs in Qaidam Basin generally have the hydrocarbon accumulation conditions including source-nearing,early maturation and good preservation,which are under the controls of hydrocarbon generation and expulsion and late tectonic movement.There is large-scale source-reservoir integrated petroleum accumulation in the subsalt source rock in the western depression,multilayer lateral connecting reservoirs in the uplift of sag in the Altun slope belt.Primary reservoirs are cha

关 键 词：柴达木盆地 深层油气成藏 成储机理 成藏模式 有利区带 

分 类 号：TE122.14[石油与天然气工程—油气勘探]