滨浅海泥流沟谷识别标志、类型及沉积模式——以莺歌海盆地东方1-1气田为例  

Mud Flow Gully Identification Mark,Type and Depositional Model in the Littoral and Neritic Marine:A case study of Dongfang1-1 gas field in Yinggehai Basin

作　　者：李胜利[1] 于兴河[1] 谢玉洪[2] 陈志宏[2] 刘力辉 

机构地区：[1]中国地质大学,北京100083 [2]中国海洋石油有限公司湛江分公司,广东湛江524057 [3]诺克斯达石油科技有限公司,北京100192

出　　处：《沉积学报》2010年第6期1076-1080,共5页Acta Sedimentologica Sinica

基　　金：国家科技重大专项(2008ZX05056-002-02-01);中国地质大学(北京)海相储层演化与油气富集机理教育部重点实验室开放基金项目资助(EEL2008-6)

摘　　要：在滨浅海沉积环境中有一类特殊的重力流水道沉积,名为泥流沟谷(mud flowg ully)。泥流沟谷以泥岩充填为主,呈正韵律,厚度中等,往往切割其下部的砂体。在垂向上表现为泥流沟谷之下多为临滨或滨外的砂坝与滩砂,其上多为滨外泥沉积。泥流沟谷主要形成于滨浅海地形转折之处,由于构造事件的影响,导致塑性的尚未固结成岩的泥质沉积产生滑动,形成一种形态上类似下切河道的沟谷,在地形平缓之处,这些泥流又发生汇聚形成前端连片分布的特征。按泥流冲沟切割砂体的规模,可细分为"深"、"中"、"浅"三种类型,其中"深沟谷"表现为"深而宽"的特征,发育在地形坡折带,下切程度强;而"浅沟谷"呈现"浅而窄"的特点,发育在地形上游平缓带,下切程度弱;"中沟谷"下切深度介于"深"、"浅"两种沟谷之间,下切程度中等。泥流沟谷是储集砂体的侧向渗流屏障,浅沟谷往往分布在砂体中心部位,深沟谷分布在砂体边缘,中沟谷处于二者之间。受泥流沟谷的影响,砂坝砂体呈孤立状分布,同时由于夹层的影响使得砂体横向及垂向连续性与连通性变差。In the littoral and neritic sedimentary environment,there is a special kind of gravity-flow deposition,known as mud flow gully.Mudflow gully filled with mudstone mainly positive rhythm,the thickness of the middle,often incised the sand body below it.Vertically,the mud flow gully was often underlain by shoreface or offshore sandbar and beach sand and overlain mostly by offshore mudstone deposition.Mud flow gully mainly formed at the topography transition area of shore and offshore,due to the tectonic events which resulted in slumping of plastic,low diagenetic consolidation fine-grained sediment and forming a gully shape similar to incised valley.Finally,in the gentle terrain,those mud flows began to afflux and generate contiguous cluster distribution characteristics.According to the size of incising sand body,mud flow gully can be classified into＂deep＂,＂middle＂and＂shallow＂three types.In which,deep gully＂performanced for the＂deep and wide＂,mainly developed in the terrain slope-break area and incised the sand body deeply;while＂shallow gully＂presented＂shallow and narrow＂,appeared mainly in the upper area of flat terrain with a lower level of a weak cut;meanwhile,＂middle gully＂cutting degree was between deep and shallow depth.Mud flow gully was the lateral seepage barrier for reservoir sand bodies,and usually,shallow gullies were often found in the center of sand body,deep gullies were located in the edge of the sand body and middle gullies were between such two.Influenced by the mud flow gullies,sand bars were isolated and at the same time,because of the impact of intercalation mudstone,sand body＇s lateral and vertical continuity and connectivity became worse.

关 键 词：滨浅海 泥流沟谷 临滨砂坝 沉积模式 

分 类 号：P512.2[天文地球—地质学]