高分辨率层序格架内煤层发育特征及聚煤规律研究

Characteristics of Coal Mines of High Resolution Sequence Stratigraphy and Coal Accumulation Law

以鱼卡煤田150余口钻井为研究对象,在层序界面识别基础上,对研究区侏罗系含煤地层进行了高分辨率层序地层划分,共划分出6个长期旋回(LSC1~LSC6)和12个中期旋回(MSC1~MSC12)。侏罗系含煤地层主要发育A型、C1型、C2型和C3型4种层序结构类型。层序结构中,以C1型中期旋回聚煤能力最好,煤层厚,次为C2型和A2型中期旋回,发育较厚煤层;该类层序结构的主要聚煤时期为每一中期旋回的上升半旋回的湖平面上升阶段,以厚煤层发育为特征,下降半旋回聚煤作用较弱,以薄煤层叠置发育为特征。

Taking more than 150 wells as the research object, base on the recognition of sequential interface, the Jurassic coal-bearing stratas in the study area were high-resolution divided, and this study area is divided into 5 long term cycle and 12 middle term cycle. Analysis of sequence structure of middle term cycle show that Jurassic coal-bearing stratas main development types of sequence structure are Type A, Type C1, Type C2 and Type C3. Through detailed research of each coal accumulation characteristic, the type of best coal accumulation ability is Type C1 middle term cycle, the great thickness of coalbed, secondly for the Type C2 and Type A2. Increasing semi-cycles of every medium cycle in Type C1 is mainly for coal accumulating with thick coal layers, while decreasing semicycles in weak for coal accumulating with thin coal layers.