鄂尔多斯盆地东南部晚古生代陆表海层序演化过程与其控制下的聚煤模式  

Stratigraphic Sequence Evolution in Southeastern Ordos Basin and Coal Accumulation Pattern in an Epicontinental Sea Basin

作　　者：付超 于兴河[2] 李顺利[2] 李树新[3] 何发岐 彭子霄 FU Chao;YU XingHe;LI ShunLi;LI ShuXin;HE FaQi;PENG ZiXiao(CNOOC Research Institute Ltd.,Beijing 100028,China;Energy School,China University of Geosciences(Beijing),Beijing 100083,China;PetroChina Coalbed Methane Branch,Beijing 100028,China;SINOPEC North China Oil and Gas Branch,Zhengzhou 450006,China)

机构地区：[1]中海油研究总院有限责任公司,北京100028 [2]中国地质大学(北京)能源学院,北京100083 [3]中石油煤层气分公司,北京100028 [4]中石化华北油气分公司,郑州450006

出　　处：《沉积学报》2023年第5期1598-1608,共11页Acta Sedimentologica Sinica

基　　金：国家自然科学基金项目(421721112);中国博士后面上基金项目(2022M723532)。

摘　　要：鄂尔多斯盆地东南部作为我国重要的煤炭和煤层气产地,其较为复杂的沉积环境演化过程为陆表海背景下聚煤环境研究提供了良好的研究对象。以鄂尔多斯东部晚古生代沉积为例,建立统一标准的层序地层格架,并且提出对应的层序叠置样式;在此基础上结合陆表海聚煤规律,揭示不同层系间聚煤范围的差异,厘清垂向上的层序叠加样式和平面含煤沉积体展布规律之间的关系。从井—震精细解释出发,定量刻画出不同平面范围内沉积物供给量(S)与可容纳空间变化量(A)。最终归纳出三种短期层序的叠加演化样式:持续进积型层序,持续暴露型层序,沉积转化型层序。其中,持续进积型层序主要发育中厚煤层,受地形影响较大;持续暴露型层序发育煤层较薄,分布范围有限;沉积转化型层序,沉积供给方向不断变化,导致泥炭局部聚集为厚煤层,但是平面发育范围有限。针对上述三种层序样式,结合成煤环境确定对应主控因素,提出持续进积型层序与持续暴露型层序主要受控于可容纳空间变化,而沉积转化型层序受控于沉积供给速率影响。The Southeastern Ordos Basin is one of the most critical production sources of coal and coalbed methane in China.Its complex sedimentary evolution provides a case for studying the stratigraphic sequences forming a gentle slope and their coal accumulation patterns.The focus of this study was the sedimentary process that took place during the Late Paleozoic.After establishing the stratigraphic sequence of a gently sloping region,the sequence stratigraphic stack pattern was reconstructed.The regional differences in coal accumulation settings in this epicontinental sea basin and their relationships within the various layers and the coal-bearing sediments was clarified by a quantitative analy⁃sis of integrated well-logs and seismic data and relating it to sediment supply(S)and accumulation space(A).The sequence stratigraphy was classified into three patterns:aggressive-dominated(AD)pattern,exposed-dominated(ED)pattern,and transfer(Tf)pattern.In AD-type coal accumulation,a medium-thickness coal seam tended to develop,dominated by the paleotopography.ED coal accumulation mostly developed thin coal seams of limited distri⁃bution.A change in sediment supply formed the Tf coal accumulation,resulting in the thickest coal layers,but of lim⁃ited areal distribution.From consideration of the accumulation patterns and their main influences,it was inferred that AD and ED patterns were determined by the accumulation space(A),whereas the Tf pattern resulted from the sedi⁃ment supply rate.

关 键 词：鄂尔多斯盆地 晚古生代 可容纳空间 沉积物供给 聚煤响应 

分 类 号：P512.2[天文地球—地质学]