鄂尔多斯盆地东南缘晚石炭系-早二叠系海陆过渡层序及聚煤模式  

Marine-continental transitional sequence and coal accumulation model during Late Carboniferous to Early Permian in the southeast margin of Ordos Basin

作　　者：向英杰 娄林 孙静 XIANG Yingjie;LOU Lin;SUN Jing(Exploration Division,PetroChina Xinjiang Oilfield Company,Urumqi,Xinjiang 830011,China;Zhundong Oil Production Plant,PetroChina Xinjiang Oilfield Company,Fukang,Xinjiang 831511,China)

机构地区：[1]中国石油新疆油田分公司勘探事业部,新疆乌鲁木齐830011 [2]中国石油新疆油田分公司准东采油厂彩南作业区,新疆阜康831511

出　　处：《东北石油大学学报》2023年第2期104-116,I0007,I0008,共15页Journal of Northeast Petroleum University

基　　金：国家自然科学基金项目(41572090)。

摘　　要：综合岩心、钻测井及地化资料,研究鄂尔多斯盆地东南缘晚石炭系—早二叠系海陆过渡层序地层演化及其内部聚煤规律,建立海陆过渡层序下的聚煤模式。结果表明:研究区识别区域不整合面、河道下切侵蚀面、暴露面和洪泛面4类层序界面类型,划分SQ1、SQ2、SQ3和SQ44个四级层序,内部发育障壁—潮坪—潟湖、碳酸盐台地、曲流河三角洲和辫状河三角洲4类沉积序列类型。由晚石炭世到早二叠世,沉积环境经历由近海海相到陆相三角洲的完整海陆过渡演化过程。SQ1和SQ3层序是主要的聚煤阶段,潮坪—潟湖和三角洲水下分流间湾为成煤提供有利环境,分别形成区域分布的厚层连续煤和厚薄交互连续煤。SQ2和SQ4层序聚煤作用较弱,局部发育薄煤和炭质泥岩。层序可容纳空间差异和相对海平面变化控制海陆过渡层序地层格架内的聚煤规律,高可容空间下HST晚期聚煤、低可容纳空间下HST早期聚煤。该结果揭示海陆过渡含煤地层层序演化及其聚煤作用,有助于指导煤层气资源的勘探和开发。The core,drilling and logging data and geochemical data are integrated to study the stratigraphic evolution of the marine-continental transitional sequence during Late Carboniferous to Early Permian in southeast margin of Ordos Basin and its internal coal-accumulation law.The study identified four types of sequence boundary types of regional unconformity surface,channel down-cut erosion surface,exposure surface and flooding surface,and divided into four fourth-order sequences of SQ1,SQ2,SQ3 and SQ4,in which four types of sedimentary facies types of barrier-tidal flat-lagoon coast,carbonate platform,meandering river delta and braided river delta are developed.From the Late Carboniferous to the Early Permian,the sedimentary environment experienced a complete marine-continental transition from offshore marine to continental delta.SQ1 and SQ3 are the main coal-accumulating stages.The tidal flat-lagoon and delta underwater distributary bay provide a favorable environment for coal-forming,and form the regional distribution of thick continuous coal and thick and thin alternating continuous coal respectively.SQ2 and SQ4 have weak coal-accumulation and locally develop thin coal and carbonaceous mudstone.The difference in the accommodation space of the sequence itself and the change of relative sea level control the coal accumulation in the framework of the marine-continental transitional sequence stratigraphy,and summarize two modes of coal accumulation in the late HST under the high accommodation space and in the early HST under the low accommodation space.The study reveals the sequence evolution and coal-accumulation of coal-bearing strata in the sea-land transition,which is helpful to guide the exploration and development of coalbed methane resources in this area.

关 键 词：鄂尔多斯盆地 晚石炭系 早二叠系 海陆过渡 沉积层序 聚煤模式 

分 类 号：TE122.2[石油与天然气工程—油气勘探] P618.13[天文地球—矿床学]