Three-dimensional multicomponent imaging of reservoir heterogeneity, Silo Field, Wyoming : Geophysics V56, N12, Dec 1991, P2048–2056

Abstract

The Reservoir Characterization Project at Colorado School of Mines acquired a three‐dimensional (3-D) multicomponent survey over Silo field in southeastern Wyoming with the objective of imaging reservoir heterogeneity. A 3-D shear‐wave survey resolved spatial variations in the fracture distribution of Niobrara chalks by detecting small percentages of anisotropy induced by fractures in chalks of the Niobrara reservoir. In addition, the compressional‐wave survey imaged structural drape over a zone of deeper salt dissolution, which fractured the brittle chalks. Rotation analysis of the shear‐wave survey took advantage of its 3-D nature to identify an azimuthal pattern of anisotropy associated with vertical fractures, known as extensive dilatancy anisotropy (EDA). The shear‐wave data were sorted by shot‐to‐geophone azimuth to search for the orthorhombic pattern of anisotropy that might be expected from the combined effects of sedimentary layering and vertical fractures, but it was not found at Silo Field. Alt...