拟垂直地震剖面法

在当代石油勘探中,声测井、垂直地震剖面(VSP)以及地震勘探的联合应用与综合解释正变得日益重要。为实现综合解释,曾经在上述三种方法之间发展了若干种变换技术。然而目前还欠缺一种变换—从地面地震资料换算成VSP,即所谓的拟VSP法。本文提出了一种实现该方法的方案,它是基于在频率—波数域以递推方式将上、下行波向下延拓,并且使它们在穿越界面时互相耦合,从而求得拟VSP。用理论模型对本法进行了检验。予期用此法能够参照地震测井或声测井的层速度,把地面地震记录转化为拟垂直地震剖面。拟垂直地震剖面可能有助于资料解释,从而老井资料的潜力也将得到发挥。

A METHOD OF PSEUDO VSP

The integrated application and interpretation among sonic log, vertical seismic profile (VSP) and seismic survey are becoming more and more important for oil and gas exploration. Many techniques of the data transformation among these methods mentioned above were developed to accommodate the requirement of integrated interpretation. But there remains a transformation to be developed, which converts the surface seismic data into VSP. This is the pseudo VSP method. In this paper a variant of pseudo VSP is suggested, which is based on the recursively downward continuating both the upgoing and downgoing waves and coupling them on interfacies. All processes are carried out in frequency-wave number domain. This method was tested by theoretical models. "We hope the potential of the old wells would be exhausted by means of supplying interval velocities via the seismic log or sonic log, when one makes a pseudo VSP. It is expected also that the pseudo VSP would help us to improve the data interpretation.