辽河油田西部凹陷东营组四级层序下沉积体系特征  

CHARACTERISTICS OF THE SEDIMENTARY SYSTEM FOR THE FOURTH-ORDER SEQUENCES IN DONGYING FORMATION OF WEST SAG IN LIAOHE OILFIELD

作　　者：曹宇森 CAO Yusen(Research Institute of Exploration and Development,PetroChina Liaohe Oilfield Branch Company,Panjin 124010,China)

机构地区：[1]中国石油辽河油田分公司勘探开发研究院,辽宁盘锦124010

出　　处：《大庆石油地质与开发》2018年第5期8-15,共8页Petroleum Geology & Oilfield Development in Daqing

基　　金：中国石油天然气股份有限公司科研项目"富油气凹陷的形成与前景预测"(2013D-0708)

摘　　要：辽河油田西部凹陷东营组成藏条件优越,但传统东营组地质分层难以提高勘探精度,同时东营组沉积条件复杂、沉积类型多样造成储层预测困难,制约了东营组油气藏的勘探发现。依据层序地层学和沉积学研究方法,对西部凹陷东营组四级层序地层格架内的沉积体系的特征、空间展布和演化规律进行了分析。研究表明:东营组为陆相—湖相复合沉积环境,古地貌、古物源和古环境控制了东营组沉积类型和展布;东营组可识别出冲积扇、河流、三角洲、湖泊4大类沉积体系和冲积扇、曲流河、辫状河、曲流河三角洲、辫状河三角洲、扇三角洲、滨浅湖滩坝7类沉积相;东营组可划分为4个四级层序,在四级层序等时格架下,东营组沉积体系展布呈现"南北分区,东西分带"的特点,整体形成冲积扇—河流—三角洲沉积体系组合,沉积体系演化具有纵向上由多样转换为单一、横向上由分化转换为统一的特点。Although the accumulating conditions of Dongying Formation reservoir are favorable in West Sag of Liaohe Oilfield,the traditional geological stratification of Dongying Formation is difficult to improve the exploration precision. At the same time,the complicated sedimentary conditions and various sedimentary types of Dongying Formation make the reservoir prediction difficult,thus the exploration and discovery of Dongying Formation oil and gas reservoir are restricted. With the help of the methods of the sequence stratigraphy and sedimentology,the characteristics,spatial distribution and evolutionary laws of the sedimentary system in the fourth-order sequence stratigraphic framework of Dongying Formation in West Sag are analyzed. The researches show that Dongying Formation belongs to continental-lacustrine sedimentary combined environments,and the paleogeomorphology,palaeo-source/antiquities and paleoenvironment control the sedimentary type and distribution of Dongying Formation; Four types of thesedimentary system,including the alluvial fan,river,delta and lake,can be identified in Dongying Formation,and moreover there exist seven types of the sedimentary facies i. e. the alluvial fan,meandering river,braided river,meandering river delta,braided river delta,fan delta and shore-shallow lake beach dam; Dongying Formation can be divided into four fourth-order sequences,under the fourth-order sequence isochronous frame,the sedimentary system of Dongying Formation presents the characteristics of ＂ North-south subdivision,east-west zonation＂ and forms the alluvial fan-fluvial-delta sedimentary system assemblage as a whole,the evolution of the sedimentary system is characterized by the vertical transformation from diversity to singleness and horizontal transformation from differentiation to unification.

关 键 词：西部凹陷 东营组 四级层序 沉积体系 演化模式 

分 类 号：TE121.3[石油与天然气工程—油气勘探]