涠西南凹陷11-7区块流沙港组沉积体系构成及演化特征  

Sedimentary System and Evolution of Liushagang Formation,11-7 Block of Weixinan Depression

作　　者：姜平[1] 张建光 姚光庆[1,3] 李茂 

机构地区：[1]中国地质大学资源学院,武汉430074 [2]中海石油(中国)有限公司湛江分公司,广东湛江524034 [3]中国地质大学构造与油气资源教育部重点实验室,武汉430074 [4]中国石油大学(华东)石油工程学院,青岛266580

出　　处：《地质科技情报》2013年第2期97-104,共8页Geological Science and Technology Information

基　　金：中海石油(中国)有限公司湛江分公司课题(2006026157)

摘　　要：基于岩心、测井、录井和化验分析资料对研究区流沙港组储层的沉积体系进行了分析。研究结果表明,流三段岩性发育砂砾岩、含砾砂岩,分选、磨圆较差,同时,氧化色的泥岩发育显示滨浅湖的环境,沉积构造和粒度资料均显示发育碎屑流沉积,反映出近源快速堆积的扇三角洲沉积特征;流二段发育厚层泥岩,为半深湖-深湖环境;流一段以辫状河三角洲沉积为主体,岩性粒度较流三段稍偏细,前缘水下分流河道水动力较强,发育板状交错层理、槽状交错层理和平行层理以及波状层理等牵引流沉积构造,同时前缘地带沉积物中发育丰富的重力流、浊流沉积物。流沙港组的湖盆沉积体系经历了一个扩张、鼎盛到萎缩的过程。流三段沉积期为湖盆早期的扩张时期,流二段的巨厚层状的泥岩沉积时期为湖盆扩张的鼎盛时期,随后湖盆又开始逐渐萎缩进入流一段沉积时期,在此过程中,沉积体系主体从扇三角洲演变至半深湖、深湖和辫状河三角洲。The deposition system of Liushagang formation is various.The study of its composition,configuration and evolution characteristics can provide guidance for deep exploration and development.Based on the core,well logging,logging and the testing data,we analyze the distribution of sedimentary systems of Liushagang formation in weizhou 11-7 area.The lithology of L3 member is coarse granularity including sandy conglomerate and pebbly sandstone,with bad sorting and rounding.Mudstone with oxide color shows shallow lake sedimentary environment and sedimentary structure and granularity material all showed the existance of debris flow deposition.All the characteristics indicate fan delta sedimentary system developes with rapid deposition.The lithology of L2 member composes a set of thick mud which reflects fairly deep-deep lake sedimentary environment.The major sedimentary system of L1 member is braided river delta and the lithology of L1 member is slightly better than that of L3 member.The hydrodynamic force of underwater distributary channel of delta front is strong and there are tractive current sedimentary structures,such as tabular cross-bedding,trough cross bedding,parallel bedding and wave bedding.Morever,there is more gravity flow and turbidity current in the area between delta front and deep lake.During the sedimentary period of Liushagang formation,the lake basin experienced a process of expansion and prosperity to shrink.The sedimentary stage of L3 member is the expansion period of lake basin.The heyday of lake basin is L2 member sedimentary stage,and deposit a set of thick mudstone.After the L2 member sedimentary stage,the lake basin begins to shrink and.During the evolution process,the sedimentary system gradually evolved from fan delta to fairly deep lake and braided river delta.

关 键 词：涠西南凹陷 流沙港组 沉积体系 沉积演化 

分 类 号：P512.2[天文地球—地质学]