SBIR Phase II: A Novel Three-Dimensional Seismic Imaging Method by Migration to Common-Offset in Varible Velocity Media

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9531316 Popovici This Small Business Innovation Research Phase II project will develop and test computational software that offers the same accuracy as full 3-D prestack migration at a much lower cost. Applying prestack depth migration to 3-D seismic information is the main computational challenge facing the oil industry today. Cheaper and faster 3-D prestack imaging methods could open up new exploration venues in extremely complicated geological conditions such as those that exist in the overthrust region of the Western United States and below layers of salt in the Gulf of Mexico. The novel imaging algorithm migrates seismic data to a common offset in a laterally-variable velocity earth, and can simplify 3-D prestack depth migration, reduce the number of calculations, and overcome the problems associated with manipulating very large prestack data volumes. The end result of this research effort is a migration to common-offset (MCO) algorithm that can be used to process the two main types of seismic data: marine and land. For marine datasets, MCO coherently stacks data along several azimuths, and is followed by common-azimuth migration for final imaging. For land datasets, MCO coherently stacks data for a predetermined number of vector offsets (fixed azimuth and offset length) and is followed by 3-D Kirchhoff migration for imaging the reduced size dataset. The new MCO algorithm is of interest to oil companies and oil-field contractors. The proposed method better delineates the oil field structure and is used in oil exploration and reservoir monitoring and characterization. Both the oil companies that process seismic data in-house and the dataprocessing contractors would benefit from such a method because it allows sophisticated detailed processing at a much lower cost and over a shorter time frame.