塔里木盆地哈得逊地区巴楚组地层序列及成因机理

Strata sequence and its mechanisms of the Bachu Formation in the Hudson area,Tarim Basin

通过研究确定塔里木盆地哈得逊地区巴楚组地层序列类型及其成因机理,解决地层演化和沉积历史的相关争议。通过岩心、测井资料的分析及区域地层对比,确定哈得逊地区巴楚组东河砂岩段之上存在下泥岩段和生屑灰岩段。哈得逊地区东河砂岩段、下泥岩段、生屑灰岩段在石炭系早期依次沉积,此沉积序列为该区巴楚组标准沉积序列,该标准序列与塔里木盆地其他地区的东河砂岩段—下泥岩段—生屑灰岩段沉积序列一致。由于在沉积之后即受构造抬升、不均匀剥蚀及混积作用影响,该区大部分巴楚组标准地层序列不再完整,并形成角砾岩段,形成5种地层序列类型(自下而上):Ⅰ东河砂岩—下泥岩—生屑灰岩;Ⅱ东河砂岩—下泥岩—角砾岩;Ⅲ东河砂岩—下泥岩;Ⅳ东河砂岩—角砾岩;Ⅴ东河砂岩,此种地层序列在东河砂岩油藏区具有明显的分区性。对哈得逊地区巴楚组地层序列的正确认识对该区沉积环境和沉积层序、东河砂岩钙质来源和成岩作用、地震资料应用以及油气勘探等研究具有重要意义。

The aim of this article is to confirm the strata sequence and the mechanisms of the Bachu Formation of the Hudson area,Tarim Basin and to settle the related debates of the stratigraphic evolution and sedimentary history.Based on the specific analysis on cores,well-logging and regional stratigraphic correlation,it has been proved that the lower mudstone member and bioclastic limestone member exist above the Donghe sandstone member of the Bachu Formation in Hudson.Donghe sandstone member,lower mudstone member,bioclastic limestone member in Hudson were deposited successively during the Early Carboniferous,which constituted the standard sedimentary sequence of the Bachu Formation in the area.This standard sedimentary sequence is identical with those in other areas in the Trim Basin.Because of the later tectonic uplift,differential denudation and mixed deposition,the strata sequence of the Bachu Formation was no longer intact.The Breccia member was generated and five types of strata sequence were formed（from bottom to top）：Ⅰ Donghe sandstone member-lower mudstone member-bioclastic limestone member,Ⅱ Donghe sandstone member-bioclastic limestone member-breccia member,Ⅲ Donghe sandstone member-lower mudstone member,Ⅳ Donghe sandstone member-breccia member andⅤ Donghe sandstone member.Each type of strata sequence lies in its own unique area within the Donghe sandstone reservoir area.The recognition of the Bachu Formation in Hudson influences the study of sedimentary environment and sequence,the source of the calcium of the calcareous interlayers and diagenesis in the Donghe sandstone,the application of the seismic data and the petroleum exploration of the area.