OBJECTS vs. LAYERS:

THE DIAGNOSTIC 3-D SEISMIC PROCESS (D3DSP)

Earths Seismic Duality and a New Process for Imaging, Measuring, and Evaluating Subterranean "Common-Impedance Objects" (e.g., Petroleum Reservoirs)

 

Louis E. Willhoit, Jr.

VTV, Incorporated (Denver, Co)

www.vtvinc.com

Energy Partners, Ltd. (New Orleans, La)

4/07/04

 

ABSTRACT

Studies in Quantum Mechanics have taught that various aspects of Nature possess a Wave-Particle, or Energy-Matter, duality. Theoretical models that ignore either side of Nature's dual personality, would deny the existence of many of today's most useful (and devastating) devices: Computers, cellular phones, televisions, lasers, and nuclear bombs. Current 3D seismic methodology is based on the "layered side" of what I call the earth's acoustic "Object-Layer" duality. I believe that, by acquiring, processing, and interpreting modern 3D seismic data using an "object-filled earth" model, rather than the conventional "layered earth" model, many subtle reservoirs can be imaged, measured, and evaluated for the first time. The "Diagnostic 3D Seismic Process" (D3DSP) requires accurately known seismic source and detector locations, and the use of available non-seismic information, to construct a D3D-Impedance Time Cube (Tube). Using the D3DSP recipe, I QCed the reprocessing of two relative acoustic impedance volumes, that contained high-resolution D3D-Impedance voxels. D3D-voxels are seismic samples (volume pixels) whose amplitude values are the relative natural logarithm of the acoustic impedance (density-multiplied-by-vertical-velocity) of the local rock volume. It is clear that good porosity filled with oil or (especially) gas, lowers the acoustic impedance of rocks, and I saw D3D-voxels containing 1/2 acre-foot of rock and fluid (55 feet x 55 feet x 2ms, or 10 feet) in a 10,500-foot deep gas-filled reservoir. At South Timbalier Block 26 and Eugene Island Block 27, I compared vertical, map, and volumetric images of D3D-Impedance data with twin conventional post-stack-migrated data, and saw both drilled and undrilled reservoirs more clearly. I found that the D3DSP produced 3D-renderings of buried, opaque reservoir objects that were more geologically identifiable and volumetrically quantifiable, than anything produced by conventional seismic (layer-based) methods. A D3D-Impedance Tube, with wells, in a volume visualization workstation, is the way to appreciate and profit from the "object side" of the earth's Object-Layer duality.