Horizon Attributes and Fracture-Swarm Sweet Spots in Low-Permeability Gas Reservoirs

Abstract

TX 75083-3836, U.S.A., fax 01-972-952-9435. AbstractHorizon attributes, i.e., attributes that numerically describe geometric characteristics of interpreted horizons from conventional (i.e., p-wave) 3-D seismic volumes, hold considerable potential for identifying fracture-swarm sweet spots in low permeability reservoirs.

Curvature for visualization of seismic geomorphology

“…Throughout the basin, NE-SW striking fractures and cleats (in coal) are known or suspected to be present in Cretaceous reservoirs in the San Juan Basin based on outcrop mapping, seismic analyses and engineering analyses (e.g. Hart et al 2000Hart et al , 2002Marroquin & Hart 2004). These NE-SW trends, and other trends, are visible in curvature maps of Cretaceous horizons in the study area (Marroquin & Hart 2004).…”

“…Originally, these horizon attributes were employed to detect subtle structures such as faults or fractures that might have an impact on reservoir performance (e.g. Hesthammer & Fossen 1997;Townsend et al 1998;Dalley et al 1989;Hart et al 2000Hart et al , 2002Marroquin & Hart 2004). Current interest in identifying and understanding stratigraphic features, for lithology prediction, reconstructions of geologic history, geohazard prediction or other purposes, has led interpreters to examine the use of horizon attributes for examining stratigraphic features.…”