地震沉积学在识别重力流沉积体系中的应用

探讨地震沉积学方法在识别陆相断陷盆地重力流沉积体系的研究思路。以歧口凹陷歧南斜坡沙一段的深水厚层砂岩为研究对象, 在现代沉积学和地震沉积学理论和方法的指导下、分频解释和时频分析技术建立高频等时格架的基础上, 通过岩芯相精细描述确定沙一段主要发育重力流水道沉积体系。形成了以古地貌和地震属性约束物源方向, 预测重力流水道的宏观展布;地层切片、反演与三维可视化相结合刻画砂体空间展布形态的断陷湖盆沟道型重力流地震沉积学识别方法和技术。应用该方法对歧南斜坡重力流水道砂体进行了精细刻画, 为在歧口凹陷广泛发育的湖相泥岩中寻找岩性油气藏开辟新的勘探领域, 并在歧口凹陷油气勘探中取得了良好的应用效果, 同时也丰富和发展了断陷盆地重力流沉积体系的地震沉积学研究成果。

Mapping Gravity Flow Depositional Systems using Seismic Sedimentology

This paper discusses the research idea of mapping gravity flow depositional systems based on seismic sedimentology method. Case study on the thick layer sandstone of the first member of Shahejie Formation in Qinan slope, according to the theory and method of seismic sedimentology, this paper puts forward a program of seismic sedimentology suitable for China's continental fault basins with gravity flow depositional systems:first, the high frequency sequence stratigraphic framework are performed through time-frequency analysis and frequency decomposing technology; then application of seismic geomorphology and macroscopic attribute constraint source direction; Combining with core calibration to determine sedimentary facies types; and lastly, stratal slicing, seismic inversion and 3D visualization showing the spatial and temporal distribution of the gravity flow channel, application of this method and techniques to seismic sedimentology study, gravity flow channel sand body is clearly characterized. This study provides favorable exploration areas for finding hydrocarbon reservoirs in lacustrine mudstones in Qikou sag, good results have been produced and enriched fundamental research of seismic sedimentology.