AN IMPROVED METHOD FOR MIGRATING SEISMIC DATA

摘要

A method for properly migrating seismic data which has been elevation-static corrected. The method is comprised of assigning a zero (or very small) migration velocity for data located below a datum, yet above the original recording surface elevation. A best estimated earth velocity is input into the migration algorithm to represent the earth below the original recording surface. For seismic data collected in water-covered environments where the water bottom is irregular, the method contemplates that the data lying above the water bottom are migrated using the migration velocity of water. The data lying at or below the water bottom are migrated with a migration velocity of zero. In a second step, are elevation-static corrected and migration is performed where the velocity is zero between the datum and the original surface. Data below the surface is migrated using the estimated earth velocity.