地震速度场建立与变速构造成图的一种方法

A method for building of seismic velocity field and structure mapping by variation in velocity

马海珍 ,雍学善 ,杨午阳 ,鲁烈琴 ,王小卫 .地震速度场建立与变速构造成图的一种方法 .石油地球物理勘探 ,2 0 0 2 ,37(1) :5 3～ 5 9本文剖析了地震速度场建立与变速构造成图传统方法中影响成图精度的主要因素 ,指出了传统方法中造成误差较大、准确性较低的原因。从解决传统方法中存在的问题入手 ,提出了相应的速度场建立与变速构造成图方法 ,指出了在浮动基准面地震工区中使用本方法的条件和要求 ,并将其扩展为适合于深度偏移的层速度建模方法。本方法采用层位反偏移技术、沿层横向叠加速度谱剖面技术、三维空间射线追踪层速度相干反演技术和图形偏移构造成图技术 ,对各反射目的层位进行单层速度场建立与构造成图 ,解决了传统方法中影响速度场和构造图精度的主要问题。实际应用表明 ,该方法提高了速度场建立与构造成图的精度 ,是一套技术先进。

The paper analyzed the primary factors that have influence on mapping precision in traditional methods for building of seismic velocity field and structure mapping by variation in velocity and pointed out the reasons of big errors and poor accuracy in conventional methods.Starting from solving problems existing in traditional methods,the paper presented correspondently a new method for building of seismic velocity field and structure mapping by variation in velocity ,pointed out the application conditions and demands of the method in a seismic working area with floating datum and expanded it in method of model-building in interval velocity suitable for depth migration.The techniques of horizon de-migration,lateral velocity spectrum section along horizon,3-D ray-tracing coherence inversion for traicing interval velocity,map migration for depth structure and building of velocity field and structure mapping in single horizon for separate reflected targets are adopted in the new method.All these measures can resolve the principal problems having influence on precision of velocity field and structure map in conventional method.The attached examples and practical applications in 10 working areas show that the method improved the precision of building of velocity field and structure mapping,which is a technique-advanced,time-efficient and practical method for velocity model-building and structure mapping.