Montana’s Elm Coulee to top 200 million bbl

Sept. 24, 2009
Elm Coulee field, Montana’s primary Bakken shale oil producing field discovered in 2000, is a giant that is expected to recover more than 200 million bbl.

By OGJ editors
HOUSTON, Sept. 24
-- Elm Coulee field, Montana’s primary Bakken shale oil producing field discovered in 2000, is a giant that is expected to recover more than 200 million bbl.

The field has more than 600 wells that produce primarily from the middle Bakken, Stephen Sonnenberg and Aris Pramudito of the Colorado School of Mines wrote in the American Association of Petroleum Geologists Bulletin.

Elm Coulee has produced 78.4 million bbl of 42° gravity oil and 55.7 bcf of gas through December 2008. Oil in place is estimated at 5 million bbl/sq mile.

The Bakken total interval, consisting of an upper shale, middle silty dolostone, and lower siltstone, is 10-50 ft thick with 8-14 ft of vertical pay, and the field covers 450 sq miles in Richland County.

Initial production is 200-1,900 b/d at horizontal wells and generally less than 100 b/d at vertical wells. Formation depth is 8,500-10,500 ft.

“The Elm Coulee field illustrates that the Bakken petroleum system has enormous potential for future oil discoveries in the Williston basin,” the authors wrote.

Bakken oil production predated Elm Coulee at Antelope field in 1953 and Elkhorn Ranch field in 1961, both in North Dakota. Elkhorn Ranch field had the play’s first horizontal well, in the upper Bakken in 1987.