Currently, almost no Bakken production contains oil extracted directly from the organic-rich shale members of the Bakken petroleum system. Rather it comes from tight, conventional reservoirs close to the shale/source rock zones; the largest producer being a dolomitic sandstone reservoir called the Middle Bakken.
Anywhere else in the world that would make the Bakken system a tight oil play, not a shale play.
But that ship has sailed. ‘Bakken shale’ has become almost a household phrase in North America and beyond.
And soon it could also be technically correct, thanks largely to the efforts of Slawson Exploration.
Slawson, the third company to drill a horizontal well in the Bakken formation, is successfully producing “some oil” from the Upper Shale Bakken member in three fields — the South West Big Sky project in Montana’s Richland county; the Lambert project in Montana’s Richland and Dawson counties; and the Squaw Gap field in North Dakota’s McKenzie County.
The Montana wells were drilled in 2010-11.
Don’t bother checking the North Dakota Department of Minerals website for the list of Bakken Horizontal Wells by Producing Zone (www.dmr.nd.gov/oilgas/bakkenwells.asp) because it’s missing three of Slawson’s four Upper Bakken horizontal wells in — we assume (Slawson wouldn’t confirm) — the Squaw Gap field, all drilled and or completed in 2007-08.
But if you check recent permits issued for new wells, you’ll see six new Squaw Gap wells on April 16.
Squaw Gap dates back to the 1980s, possibly earlier, when vertical wells were the norm, but at that point Shell Oil was the operator; prior to Slawson taking over in 2003, it was Headington Oil.
Company Vice President Craig Slawson was the first person to respond to a plea in Petroleum News Bakken’s first edition, April 15, 2012, asking for a geology lesson that would explain why the Bakken was referred to as a shale play.
“You are correct that the vast majority of wells target the middle Bakken,” he wrote in an email.
In a follow-up interview, he said, “Nobody in their right mind would target, would drill into, the upper or lower Bakken shale,” noting, “we aren’t right-minded.”
Technically savvy Slawson Exploration is “the only company” that has targeted the Upper Bakken using horizontal wells, he said.
And Craig Slawson is almost ready to talk publicly about what Slawson Exploration, a privately held family firm founded by his father, has been doing to entice the Upper Bakken shale to produce oil.
Stay tuned.
—Kay Cashman
