Mapping Prospective Channel Sands Using Full- Wave Seismic Interpretation

Roth, Murray¹, Ron Larson² (1) Transform Software and Services, Denver, CO (2) Apache Canada, Calgary, AB

Many of the practical applications of “Full-Wave” seismic technology has been directed to marine applications, particularly to view through obscuring “gas clouds”. In this instance, the propagation characteristics of seismic shear waves (S-waves) are used to achieve an imaging advantage over traditional primary wave (P-wave) seismic data. Recent advances in acquisition technology are redefining the fidelity and economics of Full-Wave seismic measurements. Consequently, these new techniques are being applied to a number of land-based E&P challenges including lithology and fluid identification.

We investigate the usefulness of full-wave seismic interpretation for mapping prospective channel sands in the Western Canadian Sedimentary Basin. While the fluvial systems of the Lower Cretaceous Rex formation are readily identified, thin sands and rapidly varying lithology makes well placement an ongoing challenge. We have found that a combined interpretation of full wave data, including a structural analysis of traditional P-wave and amplitude analysis of “mode-converted” PS-wave data provides a unique diagnostic tool for identifying prospective gas sands.

While full-wave seismic holds tremendous potential for well targeting, extra care is required during the seismic processing and interpretation stages, to ensure data quality supports E&P objectives. Pre-conditioning steps like phase matching and frequency enhancement are essential for preparing to register PS-wave data to match P-wave data events. A multi-attribute seismic approach was developed to facilitate a robust method to interactively match PS and P-wave seismic data. Seismic inversion and visual integration also proved to be valuable tools, highlighting anomalous locations that have been drilled, with initial promising results.

AAPG Search and Discovery Article #90055©2006 AAPG Rocky Mountain Section Meeting, Billings, Montana