CAJ | 학술논문

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(L_(sh))和平均速度变化趋势线(υ_(av))的概念.分析υ_(av)、L_(sh)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.
고차요함염하구조형태재시간부면상상발생기변,저시조성해구찬탐실리적중요인소.근거지진파전파적동역학특정,가장염하구조기변분위량류,즉요사성화반사성기변.재차기출상,통과모형정연,분석료영향염하기변정도적2개중요인소(염상구조형태화층속도결구),인입염하구조수평삼고선(L_(sh))화평균속도변화추세선(υ_(av))적개념.분석υ_(av)、L_(sh)적형태화변화추세,즉가판정염하구조재시간부면적진위화기변정도.채용첩전심도편이화시심전환방법,가유효교정염하구조기변현상,예측고점편이방향화편리거리,위유기감탐제공가고적권폐화정위.
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 subsalt 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 (L_(sh)) and the average velocity change trend hne (υ_(av)),which can be used to distinguish the true or false and distorted degree of subsahs 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.