Exploration Vignettes in the Rocky Mountain Region

Title: Exploration Vignettes in the Rocky Mountain Region
Author: John M. (Jack) Parker
Publication: The Outcrop, February 2002, p. 8

Editor’s Note: This essay on Adena field is the second in an “occasional series” of short essays gathered from the experiences of oil-finders in the Rockies. Author Jack Parker is a long-time RMAG member and past RMAG and AAPG president.

Adena Field, Denver Basin, Colorado: The Largest Oil Field in the Denver Basin

by John M. (Jack) Parker

One Man’s Dry Hole is Another’s Discovery

In 1933, it took a lot of selling to make a deal in the exploration business because of the Depression. To stimulate interest in eastern Colorado, Francis Van Tuyl and Ben Hutchinson Parker published three separate articles that year on oil possibilities in eastern Colorado. Francis Van Tuyl, Russell “Rut” Volk and Carl Heiland were all part of the Plains Exploration Company. Among the more creative uses for “previously owned” cars, Plains Exploration used a Cadillac hearse for a seismic field vehicle.

One of the early efforts by Plains Exploration Co. was a deal on a “structure” in Morgan County, Colorado. Plains made a deal with the Indian Territory Illuminating Oil Company (ITIO), which later became Cities Service, to drill a wildcat. In 1933, ITIO drilled into the J Sand, found no stain and plugged the well. In May 1953, Falcon-Seaboard Drilling Co. drilled a seismic anomaly in the same area as the ITIO dry hole and found a good J Sand (Cretaceous) gas well. In November 1953, Bill Tomberlin drilled a purported seismic high (which was actually a topographic high whose contours were traced from a topographic map onto a blank piece of paper and then sold as a seismic map) about two miles NW of the Falcon-Seaboard gas well. Tomberlin’s well was completed flowing 900 BOPD from the J Sand.

The ITIO hole had drilled into the gas cap of the Adena field. In those days, mud-gas detectors did not exist. Because the cuttings had no stain or odor, the ITIO well was plugged. At the Falcon-Seaboard gas well, no structural closure was present. Falcon-Seaboard didn’t realize that they were in the gas cap of one of the largest fields in the Denver Basin. Bill Tomberlin knew that he had a great well, but had no concept that it was at the western edge of the oil column of a large field. Adena field is a 77.3 MMBOE stratigraphic trap; no structural closure is present. It is the largest oil field in the Denver Basin.