Abstract:

Based on the interpretation of seismic profiles，slices and attributes，lateral accretion packages(LAPs) were found in Dongfang 1-1 area of the Yinggehai Basin in northern South China Sea. According to their sinuosity，LAPs can be categorized into high or low sinuous types，which are both characterized by a series of shingled reflections on seismic profiles. However，in the plan view，the high sinuous type is represented by a scrollbar pattern while the low sinuous type is ribbonlike.The LAPs are suggested to be formed by multiple stages of “cut-fill” as well as the subsequent lateral migration. The lower part of LAPs are consisted of coarsegrained reservoir resulting from the amalgamation of channel axis bottom deposits，which have good lateral connectivity and reservoir potential.However，it turns upwards into the combination of sandstones interbeded with mudstones，leading to a low lateral connectivity and quality.The discovery of the LAPs is significant to understand the nature of the deepwater gravityflow systems and also provides potential targets for the hydrocarbon exploration in the study area.

Key words: South China Sea, Yinggehai Basin, lateral accretion packages, gravity flow channel, shingled reflection

摘要：

基于三维地震数据的剖面、切片和属性解释,在南海北部莺歌海盆地东方1-1地区发现一种特殊类型的沉积体。按照侧积复合体弯曲度大小可分为高弯度型和低弯度型两类,在地震剖面上均以叠瓦状强振幅反射为主要识别标志,不同之处是前者在平面上通常呈一组同心半环,后者则表现为带状展布。侧积复合体可能为重力流水道多期“下切—充填”并发生连续横向迁移而成,其下部由互相切叠的水道底部沉积组成,一般粒度较粗且横向连续性好,可作为良好的油气储集层;而向上变为砂泥间互的岩性组合,连通性减弱、储集性能降低。侧积复合体的发现对深水重力流沉积体系研究具有重要意义,且可为研究区的油气勘探提供新的远景目标。

关键词: 南海, 莺歌海盆地, 侧积复合体, 重力流水道, 叠瓦状反射

CLC Number: 

• P512.2