渤海辽东湾锦州25-1地区沙三段沉积体系演化及有利砂体分析

Evolution of the sedimentary system and favorable reservoir analysis of the 3^(rd) member of Shahejie formation in Jinzhou 25-1 area,Liaodong Bay,Bohai Sea

利用锆石测年法和重矿物特征法,结合区域沉积背景、钻井、测井及地震等资料,开展了渤海辽东湾锦州25–1地区沙三段物源、古地貌特征以及沉积特征分析,探讨了沙三段各层序时期(SQ1–SQ3)的沉积相类型及沉积体系演化规律。结果表明,锦州25–1地区沙三段为双物源沉积,物源主要来自于燕山褶皱带和辽西凸起带;发育扇三角洲、辫状河三角洲以及湖泊3种沉积相类型;古地貌对沉积体系及其展布有着重要的控制作用;结合沙三段沉积演化过程分析,明确了辽西1号断层高部位辫状河三角洲前缘水下分流河道砂体和高品质扇三角洲前缘砂体为锦州25–1地区沙三段的有利储集体。

Based on zircon dating and heavy mineral characteristics,combined with regional sedimentary background,drilling,logging and seismic data,the provenance,paleogeomorphology and sedimentary characteristics of the 3^(rd)member of Shahejie formation in Jinzhou 25-1 area are analyzed,and the sedimentary facies types and evolution rules of sedimentary system in each sequence period(SQ1-SQ3)of the third member of Shahejie formation are discussed.The results show that:the 3rd member of Shahejie formation in Jinzhou 25-1 area is a dual source deposit,which mainly comes from Yanshan fold belt and Liaoxi uplift belt;three sedimentary facies types,namely fan delta,braided river delta and lacustrine facies,are developed.Paleogeomorphology plays an important role in controlling sedimentary system and its distribution.Combined with the analysis of the sedimentary evolution process of the 3rd member of Shahejie formation,it is clear that the braided river delta front underwater distributary channel sandbody and high-quality fan delta front sandbody in the high part of Liaoxi 1 fault are the favorable reservoirs.