An analog to existing Devonian

Western Montana Bakken in Play

A significant new Bakken Shale oil play has finally warmed up in northwest Montana.

After a brutal winter that all but stopped move-in and exploration activities, operators have gone back to work completing their initial test programs.

The potential play area includes Glacier, Toole, Pondera and Teton counties in Montana and extends across the border into Canada, where the Bakken equivalent is known as the Exshaw.

Across the state from the North Dakota-Montana Bakken play in the Williston Basin, the new Alberta Basin exploration area is seen as an analog to existing Devonian shale oil production.

Play depths range from 4,000 to 7,500 feet in the most active exploration region, stretching from the western thrustbelt to the Sweetgrass Arch on the east.

Estimates of the total resource in place vary from 10 to 15 million barrels of oil equivalent per square mile.

Rosetta Resources Inc., Newfield Exploration Co. and Anschutz Exploration Co. dominated early leasing, but more than a dozen smaller U.S. independents and Canadian junior oils have taken neighboring positions.

Tom Richmond
Tom Richmond

“Most of the activity is on the Blackfeet Indian Reservation, which makes it a little bit difficult” to get information, said Tom Richmond, division administrator for the Montana Board of Oil and Gas in Billings.

Almost all drilling so far has been vertical, light, and very tight in terms of disclosure, Richmond noted. He said companies have six months from completion before they must begin releasing well results.

Both Newfield and Anschutz have drilled horizontal wells on the Montana side of the Southern Alberta Basin, Richmond said. He described the Anschutz well as something of an offset to a much earlier discovery.

“There’s a Greenhorn Shale well that’s been producing just outside of Glacier National Park for 35 years,” he said.“It’s our only Greenhorn well.”

Testing Continues

Like its eastern counterpart, the Alberta Basin Bakken has attractive shale oil features. It also offers multiple prospective zones, including the Nisku, Bakken-Three Forks and Lodgepole formations, as well as other secondary targets.

Good pipeline transportation exists in the area, thanks in part to the presence of the once prolific Cut Bank oil and gas field in addition to Canadian production.

Operators plan to evaluate the western Bakken play based on their vertical test or pilot programs. No meaningful production picture will emerge until more wells have been horizontally drilled and fractured.

Rosetta Resources has a 300,000-acre lease position in northwest Montana, where it had two rigs under contract and was completing an 11-well vertical drilling program.

At the beginning of April, the company had drilled eight vertical delineation wells with operations under way on its ninth and tenth vertical wells. An additional vertical well was planned for the second quarter of 2011.

Based on encouraging results, Rosetta said it also will spud the first of three planned horizontal wells in the second quarter.

Newfield Exploration had drilled seven vertical wells and completed and placed on production two horizontal wells. It announced that all of its Alberta Bakken wells to date encountered oil.

Newfield has 280,000 net acres in the play in Glacier County.

“We recently completed our second horizontal well and are preparing to drill our eighth vertical well. We continue to test multiple perspective horizons across our acreage,” said Lee Boothby, Newfield president.

“As we have said time and again, we’re executing on our assessment plans, testing multiple formations,” he added,“and do not plan to discuss results until we have a better understanding of our acreage and its potential.”

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