突泉盆地中侏罗统万宝组沉积环境与烃源岩特征

Sedimentary environment and characteristics of hydrocarbon source rock
of Middle Jurassic Wanbao Formation in Tuquan Basin

 王辉 朱占平 宋土顺 李昌晓

吉林大学地球科学学院，吉林 长春 130061 华北理工大学矿业工程学院，河北 唐山 063009）

College of Earth Sciences, Jilin University, Changchun 130061, China College of Mining Engineering, North China University of Science and Technology, Tangshan 063009, China)

 由于内蒙古突泉盆地侏罗系沉积环境及烃源岩研究较为薄弱，文中利用野外地质调查与剖面实测、岩相学、烃源岩分析等方法，结合钻井和地震资料，系统研究盆地侏罗系万宝组地层，查明了万宝组沉积环境及烃源岩特征。结果表明：万宝组为扇三角洲￣湖泊沉积环境，具有良好的勘探前景。利用地震资料识别出滨湖、浅湖、扇三角洲平原、扇三角洲前缘及火山岩等5种地震相类型，并编制了主要沉积相带的平面分布图。分布于盆地中部的万宝组暗色泥岩较发育，有机质类型为Ⅲ型，热演化程度处于高成熟—过成熟阶段，相关地球化学指标表明突泉盆地万宝组暗色泥岩为较好烃源岩。

 Based on the weak study of sedimentary environment and hydrocarbon source rocks in the Tuquan Basin of Inner Mongolia, this paper systematically studies the Jurassic Wanbao Formation in the basin and identifies the sedimentary environment and characteristics of hydrocarbon source rock of Wanbao Formation by applying field geological survey, measured profiles, petrography, the analysis of hydrocarbon source rock, and the drilling and seismic data. The results show there is a fan delta-lake sedimentary environment of Wanbao Formation, and it has a good prospect for exploration. The application of seismic data identified five kinds of seismic facies, including shore lacustrine, shallow lacustrine, fan delta plain, fan delta front and volcanic facies, and the map of the main plane distribution of the sedimentary facies is compiled. In the central part of the basin relatively developed the dark mudstones of the Wanbao Formation, of which the organic matter type is typeⅢ and thermal evolution is from high matured stage to over matured stage; those comprehensive geochemical indexes indicate that the dark mudstones are good hydrocarbon source rock.

10.6056/dkyqt201906002