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

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 flow gully）。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。

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

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 ...