准噶尔盆地东部吉南凹陷二叠系油气地质条件与源下成藏特征  

Petroleum geology and sub-source hydrocarbon accumulation of Permian reservoirs in Jinan Sag,eastern Junggar Basin,NW China

作　　者：李建忠 陈旋 杨润泽 林潼[2] 杨帆 马强[1] 苟红光 卫延召 林霖[1] LI Jianzhong;CHEN Xuan;YANG Runze;LIN Tong;YANG Fan;MA Qiang;GOU Hongguang;WEI Yanzhao;LIN Lin(PetroChina Tuha Oilfield Company,Hami 839009,China;PetroChina Research Institute of Petroleum Exploration and Development,Beijing 100083,China)

机构地区：[1]中国石油吐哈油田公司,新疆哈密839009 [2]中国石油勘探开发研究院,北京100083

出　　处：《石油勘探与开发》2023年第3期491-503,共13页Petroleum Exploration and Development

基　　金：中国石油油气与新能源分公司前期项目“重点盆地油气综合地质研究与勘探潜力评价”(2022KT0405);中国石油前瞻性与基础性重大科技项目“不同类型大气田(区)成藏主控因素及领域评价”(2021DJ0605);中国石油科技管理部基础性、前瞻性科技攻关项目“岩性油气藏群富集规律及有利区带评价技术研究”(2021DJ0404)。

摘　　要：基于最新钻井资料,结合埋藏史、成烃史、成藏史剖析,明确源下成藏特征,构建准噶尔盆地吉南凹陷二叠系成藏模式。研究表明:(1)吉南凹陷二叠系芦草沟组厚层咸化湖盆相优质烃源岩主体达到成熟阶段,资源基础雄厚;井井子沟组、梧桐沟组和芦草沟组均发育规模储集体,且纵向上存在多套良好的区域盖层,生-储-盖配置良好,存在源下、源内、源上3种成藏组合。(2)溶蚀作用、烃类充注保孔作用及绿泥石膜的存在,有效增加了源下储集空间,原油先充注、储集层后致密的特征提高了成藏的有效性。(3)浮力和源-储压差共同构成源下成藏的充注动力,地层内部微小错断使其具有“源-储侧向对接”的优势,微裂缝在各成藏期均可成为原油高效渗流和持续充注的重要通道。(4)井井子沟组经历中晚二叠世、中晚侏罗世和新近纪晚期共3期成藏,具有“早期远距离运聚成藏-中期原油混注成藏-晚期近距离充注高点成藏”的特征。吉南凹陷二叠系油藏的勘探发现与理论认识揭示了冲断带具备形成大油田的优越条件,具有良好勘探前景。研究成果对该区及地质条件类似地区的油气勘探具有启示和借鉴意义。According to the latest drilling and the analysis of the burial history,source rock evolution history and hydrocarbon accumulation history,the sub-source hydrocarbon accumulation characteristics of the Permian reservoirs in the Jinan Sag,eastern Junggar Basin,are clarified,and the hydrocarbon accumulation model of these reservoirs is established.The results are obtained in four aspects.First,the main body of the thick salified lake basin source rocks in the Lucaogou Formation has reached the mature stage with abundant resource base.Large-scale reservoirs are developed in the Jingjingzigou,Wutonggou and Lucaogou formations.Vertically,there are multiple sets of good regional seals,the source-reservoir-caprock assemblage is good,and there are three reservoir-forming assemblages:sub-source,intra-source and above-source.Second,dissolution,hydrocarbon charging and pore-preserving effect,and presence of chlorite film effectively increase the sub-source pore space.Oil charging is earlier than the time when the reservoir becomes densified,which improves the efficiency of hydrocarbon accumulation.Third,buoyancy and source-reservoir pressure difference together constitute the driving force of oil charging,and the micro-faults within the formation give the advantage of“source-reservoir lateral docking”under the source rock.Microfractures can be critical channels for efficient seepage and continuous charging of oil in different periods.Fourth,the Jingjingzigou Formation experienced three periods of oil accumulation in the Middle–Late Permian,Middle–Late Jurassic and Late Neogene,with the characteristics of long-distance migration and accumulation in early stage,mixed charging and accumulation in middle stage and short-distance migration and high-position accumulation in late stage.The discovery and theoretical understanding of the Permian reservoirs in the Jinan Sag reveal that the thrust belt has good conditions for forming large reservoirs,and it is promising for exploration.The study results are of guidance and ref

关 键 词：准噶尔盆地 阜康断裂带 吉南凹陷 二叠系井井子沟组 成藏条件 源下成藏 

分 类 号：TE122[石油与天然气工程—油气勘探]