Abstract: Integration of Surface Geochemical and Seismic Methods in Exploring for D and J Sands in the Denver Basin
ZINKE, SALLY G.
The historical exploration approach in the Denver Basin has been geologic mapping of the D and J sands and generation of prospects based on wells with either sample or log shows. This approach has occasionally found a new field or field extension. Utilizing strictly a subsurface mapping approach generally precludes finding new, more significant areas of productive channels, crevasse splays, bars, or delta mouth bars. Adding unconventional surface geochemical methods and seismic to the exploration package allows the definition of new areas of D and J sand development.
An integrated exploration effort begins with an investigation area defined based on regional geologic mapping. This is preferably an area that has limited well penetration and therefore, has significant development potential. A regional surface geochemical survey is acquired on quarter mile or fifth of a mile spacing to define areas of microseepage. This regional survey if followed by detailed sampling of areas indicating microseepage on a tenth of a mile spaced grid. The surface geochemical surveys are followed by purchase and reprocessing of existing seismic and acquisition of new 2-D and 2-D swath seismic data. From the seismic data, a target area is defined for leasing and subsequent drilling. This approach can and does significantly lower the number of dry holes and increases the number of successful wells. Recent examples will be presented from the Denver Basin demonstrating this approach and comparison of success rates.
AAPG Search and Discovery Article #90946©1997 AAPG Rocky Mountain Section Meeting, Denver, Colorado