Publications

Data in complex geological environments such as layered, fold–thrust, anticlinal and faulted structures often show strong lateral velocity heterogeneity and seismic anisotropy. The assumptions used in time imaging or isotropic depth imaging workflows are often not adequate to correct for the errors introduced by the complex wave-propagation in such geological media. For these reasons, tilted transverse isotropy (TTI) anisotropic model building and depth migration must be considered to address these issues in order to produce an optimum seismic image with better amplitude response and more accurate event positioning. Such a situation is evident in the Karama survey in the Eastern Makassar Strait. A TTI depth imaging workflow was designed to handle the challenges in Karama’s complex foldthrust structures. With no well information in this new exploration area we had to incorporate knowledge and experience from an adjacent survey within the same basin to derive the Thomsen parameters. The tilt parameters for the anisotropy symmetry axis were estimated from the seismic dip field on the assumption that the tilt direction is normal to the structural dip. (Audebert et al, 2006). Application of the above TTI anisotropic model building and depth imaging workflow for the Karama survey demonstrated significant improvements in the final seismic image quality.