http://www.bloomberg.com/apps/news?pid= ... j1uo_gdNI4
le premier article que j' avais mis la : http://forums.oleocene.org/viewtopic.ph ... 23#p178623
Ce n'est pas une découverte nouvelle (connu depuis 50 ans) mais le type de formation dans lequel est ce pétrole ne permettait pas des couts bon marchés (c'est à dire compétitifs) d' exploitation.
Avec un pétrole à 100 $ le baril (depuis plus de 100 jours déjà), la situation change et il semble qu' on assiste à une ruée vers l' or noir dans le Dakota.
De grosses fortunes vont se faire. (le mythe états unien ....)
A suivre dans les années qui viennent.
Dakota Oil Fields of Saudi-Sized Reserves Make Farmers Drillers
June 3 (Bloomberg) -- John Bartelson, who smokes Marlboro Lights through fingers blackened with tractor grease, may look like an average wheat farmer. He isn't. He's one of North Dakota's new oil barons.
Every month, he gets a check for tens of thousands of dollars from a company in Houston called EOG Resources Inc., which drilled two oil wells on his land last year. He says the day his first royalty check arrived was one to remember.
``I smiled to beat hell, and I went to town and had a beer,'' Bartelson, 65, says.
His new wealth springs from the Bakken formation, a sprawling deposit of high-quality crude beneath the durum wheat fields of North Dakota, Montana and southern Saskatchewan and Manitoba. The Bakken may give the U.S. -- the world's biggest importer of oil -- a new domestic energy source at a time when demand from China and India is ratcheting up the global competition for supplies and propelling average U.S. gasoline prices to almost $4 a gallon.
And unlike the tar from Canada's oil sands, Bakken crude needs little refining. Swirl some of it in a Mason jar and it leaves a thin, honey-colored film along the sides. It's light - -almost like gasoline -- and sweet, meaning it's low in sulfur.
Best of all, the Bakken could be huge. The U.S. Geological Survey's Leigh Price, a Denver geochemist who died of a heart attack in 2000, estimated that the Bakken might hold a whopping 413 billion barrels. If so, it would dwarf Saudi Arabia's Ghawar, the world's biggest field, which has produced about 55 billion barrels.
The challenge is getting the oil out. Bakken crude is locked 2 miles (3.2 kilometers) underground in a layer of dolomite, a dense mineral that doesn't surrender oil the way more-porous limestone does. The dolomite band is narrow, too, averaging just 22 feet (7 meters) in North Dakota.
The USGS said in April that the Bakken holds as much as 4.3 billion barrels that can be recovered using today's engineering techniques. That's a fraction of the oil that Price said should be there, but it's still the largest accumulation of crude in the 48 contiguous U.S. states. North Dakota, where Bakken exploration is most intense now, won't become Saudi Arabia unless technology improves.
``The Bakken is the biggest thing in oil in the lower 48 right now,'' says Jim Jarrell, president of Ross Smith Energy Group Ltd., a research firm in Calgary. ``And among the least understood.''
For decades, the Bakken was the fool's gold of the oil industry. The name describes a geological formation that looks like an Oreo cookie: two layers of black shale that bleed oil into the middle layer of dolomite. It's named after Henry O. Bakken, the North Dakota farmer who owned the land where the first drilling rig revealed the shale layers in the 1950s.
All of the layers are thin -- about 150 feet altogether -- and none of them give up oil easily. In older, vertical wells, oil would often flow for a month and then fizzle.
Now, companies like Austin, Texas-based Brigham Exploration Co.; Denver-based Whiting Petroleum Corp.; and EOG are drilling horizontally. They go straight down 10,000 feet and then put a slight angle in the mud motor, a 30-foot piece of tubing that drives the bit, so they hit the Bakken sideways, making a horizontal tunnel 4,500 feet long through the dolomite.
That exposes more of the oil-bearing rock. Then they pump pressurized water and sand into the hole to fracture the dolomite, making cracks for oil to seep through.
It eventually winds up in a pipeline that runs east to Clearbrook, Minnesota, and then south to Chicago.