地震层速度精度分析及其在油气勘探中的应用

Analysis of seismic interval velocity accuracy and its application to hydrocarbon exploration,

地震层速度是地震资料定量解释的重要依据,它解决地质问题的能力取决于其精度和地质体的埋藏深度。一般来说,精度越高、埋藏深度越浅,利用层速度解决地质问题的能力越强。例如精度为5％的层速度、埋深1000m,可以识别26m厚的气层。利用层速度研究岩性,必须使其误差小于岩性变化所引起的速度变化。当层速度的误差大于因岩性变化所引起的速度变化时,由岩性引起的速度异常被淹没在误差之中了,这样的层速度不能用于岩性研究。

Seismic interval velocity is an important basis for quantitative seismic interpretation, and its contribution to solving geological problem depends on its accuracy and the depth of a geological target.Generally speaking, the higher the accuracy is, and the more shallow the geological tagert is,the higher the ability for us to solve geological problem using interval velocity is.If interval velocity accuracy is 5% and depth is 1000m, a gas reservoir 26m thick can be identified. To ascertain lithology using interval velocity, we must make interval velocity error smaller than velocity variation due to lithology variation.Interval velocity anomaly can be covered when the interval velocity error is higher than velocity variation due to lithology variation, so such an interval velocity can not be used in lithology research.