准噶尔盆地腹部及西南缘白垩系烃源岩地球化学特征及沉积环境分析  

Geochemical Characteristics and Sedimentary Environment Analysis of Cretaceous Source Rocks in Central and Southwestern Junggar Basin

作　　者：刘洪军[1] 段俊梅[2] 秦黎明[3] 张枝焕[4] 席伟军[4] 

机构地区：[1]西安石油大学油气资源学院,西安710065 [2]中国地质调查局西安地质调查中心,西安710054 [3]中国石化石油工程技术研究院,北京100101 [4]中国石油大学油气资源与探测国家重点实验室,北京102249

出　　处：《地质科技情报》2013年第4期25-30,共6页Geological Science and Technology Information

基　　金：国家重点基础研究发展计划973课题(2006CB202303);国家科技十一五重大专项专题项目(2008ZX05002-006)

摘　　要：近年来,准噶尔盆地南缘勘探实践表明,部分油气来源于白垩系烃源岩,勘探前景广阔。系统分析了白垩系烃源岩分布特征、生烃潜力及沉积环境。研究结果表明,准噶尔盆地腹部及西南缘白垩系烃源岩分布范围广、厚度大,最大厚度达500m,但烃源岩非均质性强,成烃贡献区域主要集中在山前断裂带东西两侧,自西部四棵树凹陷部分区域,至沙湾凹陷东部。准噶尔盆地腹部及西南缘白垩系烃源岩生烃潜力变化较大,非均值性强,在四棵树凹陷与沙湾凹陷均有优质层段出现,w(TOC)在1.0%以上,(S1+S2)在2mg/g以上,烃源岩较好,有机质类型为Ⅱ2型,部分为Ⅲ型,生烃组分为孢子体、角质体及部分壳屑体。四棵树凹陷与沙湾凹陷白垩系烃源岩的地球化学特征比较接近,白垩纪沉积时期,研究区气候干燥,沉积中心在沙湾凹陷南缘区域,主要发育滨浅湖相沉积,局部地区(如沙湾凹陷)发育半深湖相沉积,烃源岩主要形成于以藻类或其他低等水生生物与陆源高等植物输入为主的弱还原-还原沉积环境。Recently,from the exploration results in southern Junggar Basin,the partial crude oil is derived from the Cretaceous source rocks,which has extensive generation hydrocarbon potential.Based on the former research,the distribution,hydrocarbon potential and sedimentary environment of Cretaceous source rocks have been investigated.The results indicate that the Cretaceous source rock is characterized by extensive distribution,large thickness with the maximum thickness of 500 m.However,the Cretaceous source rocks have strong heterogeneity and the distribution of hydrocarbon generation area was focused on the east and west sides of the fault belts from western Sikeshu Depression to Shawan Depression.In research area,the hydrocarbon generation potential varied for high heterogeneity,but also there has high quality source rocks with the content of TOC more than 1.0% and the（S1＋S2） more than 2 mg/g.The kerogen type is Ⅱ2 and Ⅲ and hydrocarbon components include sporophyte,cutinite and exinite.Actually,the geochemical characteristics of the Cretaceous source rocks between Sikeshu Depression and Changji Depression is similar.During the Cretaceous sedimentation,the climate was dry and the sedimentary centre was in southern Shawan Depression.The sedimentary facies were shore shallow lake and partial area developed semi-deep lacustrine.Therefore,the source rocks were formed in the weak reduction-reduction environment with algae,other lower aquatic organisms and lacustrine high plants.

关 键 词：白垩系烃源岩 地球化学特征 沉积环境 准噶尔盆地腹部及西南缘 

分 类 号：TE121.31[石油与天然气工程—油气勘探]