The Energy and Geoscience Institute (EGI) in alliance with the Center for Scientific Computing and Imaging (SCI) at the University of Utah are using the world's first visual supercomputing center to apply interactive isosurfacing for the interpretation of seismic volumes. Seminal imaging technologies developed for application in the medical sciences are extended to the geosciences for evaluating three-dimensional volumes.

State-of-the-art seismic applications are based on tracking peak, trough or zero crossings for identifying boundaries and mapping interfaces. Isosurfacing is an operation that focuses on finding isosurfaces made of voxels of a constant value. Application of isosurfacing to seismic interpretation offers a powerful technique for automatic identification of discontinuities, reservoir geometry and fluid distribution. SCI's efficient sequential and parallel algorithms for isosurfacing technology extraction allow interactive selection and contouring of selected isovalues on the seismic waveform to be tracked and visualized in three-dimensional space.

Examples from Cenozoic siliciclastic high frequency sequences in the onshore Gulf Coast and Paleozoic carbonate sequences from the Mid-continent demonstrate the versatility of this technique. Visualizations include rotation above and flying-through, fluvial channels identified using isosurfacing applied to reflection amplitude, reflection strength and instantaneous frequency volumes. In carbonate terrain areas of reflection incoherence are diagnostic of karsted zones and isosurfacing provides a robust means of quickly identifying the lateral boundaries and vertical extent of these features.

Isosurfacing 3-D seismic data offers new methods for horizon generation, automatic fault surface generation, and spatial differentiation of seismic incoherence that will help in the identification of karsted zones, salt and shale boundaries, gas chimneys, identification of flat spots, dim-outs, bright spots, and delineation of stratigraphic pinchouts.

AAPG Search and Discovery Article #90937©1998 AAPG Annual Convention and Exhibition, Salt Lake City, Utah