Velocity model updating in prestack Kirchhoff time migration for PS converted waves: Part Ⅱ - Application

摘要

We have developed a practical approach for updating the velocity of PS converted waves based on the inverse normal-moveout common-image-point gather obtained from prestack Kirchhoff time migration. We have integrated all the steps involved in updating the migration velocity model into an interactive tool and have applied this approach to a real seismic data set from the Alba Field in the North Sea. Based on experience in handling the real data, we discuss various practical aspects of updating the velocity model, including: what kind of initial velocity model should be used; which parameters in the velocity model should be updated; and how to update them. Application of prestack Kirchhoff time migration to the data set using the updated velocity model produces an improved image of the Alba Field.