新疆三塘湖盆地芦草沟组混积岩型致密油形成条件与富集因素  

Geological conditions and enrichment factors of the Lucaogou Formation diamictite tight oil in Santanghu Basin,Xinjiang

作　　者：方向[1] 郝翠果[1] 刘俊田 宋微[1] FANG Xiang;HAO Cuiguo;LIU Juntian;SONG Wei(PetroChina Research Institute of Petroleum Exploration&Development,Beijing 100083,China;Research Institute of Exploration and Development,Tuha Oil Field Company,PetroChina,Hami 839009,Xinjiang,China)

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

出　　处：《地质通报》2023年第2期397-410,共14页Geological Bulletin of China

基　　金：“十四五”中国石油前瞻性基础性技术攻关课题《致密油甜点区评价与新区新领域优选研究》(编号:2021DJ2205)。

摘　　要：新疆三塘湖盆地芦草沟组发育一套火山碎屑岩、云质岩及泥质岩混杂沉积的湖相沉积建造,为典型的混积岩系沉积,具有独特的致密油形成条件,明确其富集团素对研究致密油分布、厘定有利探区具有重要意义。对芦草沟组形成条件与关键成藏条件进行分析,研究表明,芦草沟组形成于咸水—半咸水水体环境,主体为浅湖—半深湖环境,暗色细粒沉积物发育,具有优越的生油条件,其中有机质丰度大于2%、厚度大于100 m的优质烃源岩分布面积超过1200 km^(2)。受火山活动、裂缝、溶蚀作用等因素控制,有利储层较发育。芦草沟组源储互层、紧密接触,为规模致密油的形成奠定了良好的基础,油气富集主要受烃源岩品质、储层品质、源储配置、异常压力等因素的控制。The Lucaogou Formation in Santanghu Basin of Xinjiang is a set of lacustrine deposit,which is typical diamictite,mainly composed of detrital material of terrigenous origin,dust fall,carbonate rock in variable roportions.It has special geological formation conditions for tight oil,and unravelling its enrichment factors is critical for the further evaluation of the tight oil distribution and the favorable exploration area.In order to find out its enrichment factors,we make a comprehensive analysis of its geological background and main controlling factors in reservoir forming.The results indicate that deposited in saline sedimentation background,the deposits in the Lucaogou Formation in Santanghu Basin are dominated by shallow-semi-deep lacustrine facies,with dark fine-grained depostions.It has excellent oil-generating conditions.The distribution area of high-quality source rocks with organic matter abundance greater than 2%and thickness greater than 100 m exceeds 1200 km^(2).Under the influence of volcanism,fault-crack and dissolution,favorable reservoir is widely developed.The condition of source rock-reservoir integration and intimate contaction in the Lucaogou Formation provides a good foundation for massive tight oil accumulation.The enrichment of tight oil in the Lucaogou Formation is mainly controlled by the quality of source rock,the quality of reservoir,source-reservoir assemblage and overpressure.

关 键 词：三塘湖盆地 芦草沟组 混积岩 致密油 富集控制因素 新疆 

分 类 号：P618.130.2[天文地球—矿床学]