Reservoir Development Using Offset VSP Techniques in the Denver-Julesburg Basin

Abstract

Multioffset vertical seismic profiles (VSP's) have been used successfully to delineate and develop a Sand D field in the Denver-Julesburg basin. Sand D production in Wattenberg field was established by the Sierra Energy and Berge Exploration Well 34-3. Subsequently, three successive wells failed to find the Sand D channel. A stratigraphic model study suggested that offset VSP techniques could be used to determine the extent of the Sand D reservoir accurately and to identify potential offset drilling locations. On the basis of this study, a five-offset VSP was conducted in the discovery well. Interpretation of the data produced an accurate map of the reservoir limits and identified two additional drilling locations. The first of these locations was drilled and completed in Sand D. Subsequently, a VSP was run in this well to complete the delineation of the reservoir and to reconfirm the second offset location.