Borehole Seismic Modeling Using Curvilinear Boundary-Conforming Meshes

The accurate interpretation of borehole seismic data and high-quality acoustic imaging of oil well heterogeneities is greatly affected by geometric borehole irregularities: washouts, non-circular cross-sections (elliptic and keyhole sections), fractures, etc. Unfortunately, the numerical models for studying field data cannot model non-ideal geometric effects when classical circular or rectangular grid systems are used. More natural curvilinear grids, which adjust to the borehole shape under consideration, are needed for modeling accuracy. Therefore, this project will develop algorithms that generate special ¿boundary-conforming, curvilinear grids,¿ which ¿fit the irregular three-dimensional borehole like a glove.¿ Phase I will design the software infrastructure: the basic three-dimensional grid generators, the color display algorithms, and the seismic solvers. Ultimately, several acoustic-seismic formulations will be solved on these grids and their ability to accurately simulate geometric details (e.g., reflections, energy radiation) will be assessed. Commercial Applications and Other Benefits as described by the awardee: The gridding techniques developed in this research should be useful in other areas of geophysical wave propagation, including earthquake analysis in laterally varying media, borehole crack propagation in massive hydraulic fracturing, etc. The same grids also should be applicable to Darcy flow and well test (pressure transient) calculations, thus providing a uniform and consistent basis for evaluating a given reservoir