库车坳陷盐下构造畸变特征分析和校正  

Analysis and Correction of Distorted Subsalt Structure in Kuqa Depression, Tarim Basin

作　　者：梁顺军 吴超[2] 唐怡 雷刚林[2] 冯磊[2] 李乐 徐振平[2] 高怀军 

机构地区：[1]川庆地球物探勘探公司,成都610213 [2]中国石油塔里木油田分公司勘探开发研究院,新疆库尔勒841000

出　　处：《新疆石油地质》2009年第5期571-575,共5页Xinjiang Petroleum Geology

摘　　要：库车坳陷盐下构造形态在时间剖面上常发生畸变,这是造成该区钻探失利的重要因素。根据地震波传播的动力学特征,可将盐下构造畸变分为两类,即绕射性和反射性畸变。在此基础上,通过模型正演,分析了影响盐下畸变程度的2个重要因素(盐上构造形态和层速度结构),引入盐下构造水平参考线(Lsh)和平均速度变化趋势线(va)v的概念。分析vav、Lsh的形态和变化趋势,即可判定盐下构造在时间剖面的真伪和畸变程度。采用叠前深度偏移和时深转换方法,可有效校正盐下构造畸变现象,预测高点偏移方向和偏离距离,为油气勘探提供可靠的圈闭和井位。The oil-gas exploration of subsalt structure in Kuqa depression indicates that the structural styles appear to be seriously distorted in time section for being influenced by the structural styles and velocity structures of overlying strata, resulting in partly big differentiation from real configuration. This paper analyzes the key factors affecting the distorted degree of subsah structure by forward modeling, classifies the distorted subsah structure into two types of distorted ones, one is affected by wave diffraction, the other is by wave reflection, based on dynamic feature of seismic wave propagation, and introduces two concepts： the subsalt structure＇s horizontal level line （Lsh） and the average velocity change trend line （vav）, which can be used to distinguish the true or false and distorted degree of subsalts in time section. It is concluded that the prestack migration and time-depth conversion method can be applied to effective correction of such a distorted phenomenon and prediction of the migration direction and distance of highs, hence providing more reliable traps and well locations for petroleum exploration.

关 键 词：塔里木盆地 库车坳陷 盐下构造 时间剖面 叠前深度偏移 时深转换 校正 

分 类 号：P631.443.91[天文地球—地质矿产勘探]