Wattenberg Field Area: A Near Miss and Lessons Learned after 35 Years of Development History

Stephen A. Sonnenberg, Thomas L. Birmingham, and Guonong Hu
Kerr-McGee Rocky Mountain Corporation, Denver, CO

The most important mineral resource activity in Colorado during the last thirty five years has been the discovery and development of the Wattenberg and adjacent petroleum fields. Located north of Denver across the axis of the Denver basin, the Wattenberg Field Area has produced over 4.6 TCFGE from the J (Muddy), Codell, Terry (Sussex), and Hygiene (Shannon) sandstones and Niobrara chalks and shales. The majority of the production comes from the J, followed by the Codell, Terry, Niobrara, and Hygiene. The producing area is a classic multiple pay accumulation in a basin center which is associated with a geothermal anomaly.

The preliminary prospect map shows an area of no water recovery from possible bypassed J Sandstone wells corresponding in a general way to Wattenberg field.

All petroleum accumulations in the Wattenberg area are regarded as stratigraphic traps, although unconformities and paleostructure have played a subtle but detectable role. Variation in thickness and reservoir quality is related to original environmental facies and paleostructure that locally influenced unconformities, fracturing, and diagenesis.

The lessons learned from this field include: a potential basin-center field may be defined by dry holes (by-passed producers), technology is key to unlocking tight reservoirs, well spacing in tight gas sands is smaller than initially anticipated because of reservoir heterogeneity, LRLC pay may be present, geothermal anomalies are an important, and extensive vertical migration is possible.