John McCaslin
Exploration Editor
Most exploratory interest in the Denver basin province these days centers around recent Paleozoic discoveries and subsequent development action.
Petroleum Frontiers, a Petroleum Information publication, notes in its coverage of the western Nebraska panhandle region, that this play was long overdue. Wildcatting has been characterized by very high success ratios for a basin with thousands of wells and dry holes. Some discoverers have seen 70% success in this Paleozoic oil hunt.
DEEPER DENVER BASIN WORK
Today's Paleozoic work in the Denver basin centers around the Kimball, Nebraska townsite.
New London Oil Co. 1 Lukassen, SW NW B-15n-56w, Kimball County, was undergoing pump tests in January. Earlier reports gave the well 20-25 bbl per day on pump of the Permian upper Wolfcamp zone. Location is 6 miles northwest of town. The wellsite is near Cretaceous Dakota "J" sand oil production in Dill field and is also 6 miles north of Klenholz field, a 10 oil well Wolfcamp Exxon Corp. success.
There is also wildcat action in 29-15n-56w and field development work in SW SE 4-14n-56w, Kleinholz field. Recently, Exxon staked 1 Linn-Terrestrial in SW NE 29-15n-56w, central Kimball County. Goal was the Pennsylvanian to 9,000 ft. Kleinholz was opened in 1986 by Exxon.
OPENS NEW EPOCH
The Denver basin has always been tagged as one of great Cretaceous success.
Thousands of wells have been drilled to the Cretaceous "J" and "D" sands. But the number of Paleozoic penetrations in the two-state area of northeastern Colorado and southwestern Nebraska is slim by comparison. Paleozoic discoveries have been limited in Nebraska's part thus far to the Kimball and Cheyenne counties sector, To date as many as seven individuals productive zones have been called in the mid-late Pennsylvanian (Des Moinesian, Missourian, Virgilian, and Early Permian (Wolfcampian) units. There may be more to exploit in the future. Bird field has been one of the state's best oil producers since its birth in 1985, and it produces from but one sand.
Amazon field was the first pre-Cretaceous strike in the Nebraska portion of the Denver basin, some 80 miles northeast of similar pay on the basin's western flank near the Rocky Mountain Front. In 1980, the Diamond Shamrock 1 McMillen, NE NE 28-14n-52w, 16 miles west of Sidney, pumped 115 b/d of oil from the Virgil at 7,062-94 ft.
Current Paleozoic activity is not far from the discovery well at Gurley that opened the Denver basin many years ago.
About 18 miles southwest of Gurley, Celsius and Sun in 1985 completed two deep Pennsylvanian oil wells, opening Bird field. Prior to that strike, there were fewer than 12 deep tests within a 12 mile radius.
Although there remains very little well control in the Paleozoic sector, exploratory hopes are high for more small fields, primarily structurally defined. Drilling costs are relatively inexpensive. More wildcatting is necessary.
The outcome is far from decided.
Copyright 1990 Oil & Gas Journal. All Rights Reserved.
