Anisotropic tomography of the Glenn Pool crosswell data

Abstract

The Glenn Pool oil field is located on the North Eastern Platform of Oklahoma, extending into Tulsa and Creek Counties. Crosswell seismic tomography is used as a geophysical method for reservoir imaging and description. Initial processing of the crosswell data indicated the presence of seismic anisotropy (Vertical Transverse Isotropy, VTI). The anisotropy is characterized through Thomsen’s Epsilon and Delta parameters. An anisotropic ray tracing scheme is developed to compute travel times honoring these parameters. A systematic velocity inversion procedure is developed based on the weighted residual back projection technique and a common domain vertical velocity is obtained. The results are very encouraging and are in excellent agreement with the geologic description from well log, core, and outcrop studies.