oa 3D Model-Based Time Gather Velocity Analysis

Highly accurate earth models are required before one can experience the benefits of depth imaging. As structure and prospect become increasingly complex and subtle, Dix-based methods become ineffective as velocity estimation tools. Model-based methods are more effective 'because they bring the interpreter's evolving understanding of structure to the velocity estimation process. We describe the use of two types of model-based methods employed in three dimensions; stacking value matching and coherency inversion. These methods are used to define interval velocities on a land 3D survey.