Application of New Tomography Algorithms to Increase the Accuracy of Psdm Velocity Models

Reflection tomography is an industry-standard tool for PSDM velocity model building. It allows to create detailed velocity models for large 3D surveys meeting the tight deadlines of a typical seismic processing project. Tomography is widely used for updating both velocities and anisotropy parameters.

The main success factors of reflection tomography include quality of the initial velocity model and quality of the seismic data, used for the automatic Common Image Gather (CIG) picking. An inaccurate initial velocity model may result in finding a locally optimal solution and insufficient signal to noise ratio may reduce the efficiency of the automatic CIG picking algorithms. Acquisition geometry can also have a negative effect on tomography (e.g. lack of far offsets).

Well data, first break data and local dips in different offset ranges can be used to constrain the tomography algorithm thus overcoming these limitations