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Williston Three Forks/Sanish interval tapped

By OGJ editors
HOUSTON, July 10 -- Two North Dakota wells 23 miles apart have flowed at promising rates from the Devonian Three Forks/Sanish formation, providing evidence that the zone might be separate from most of the Middle Bakken shale oil completions in the Williston basin, said Continental Resources Inc., Enid, Okla.

The more recent completion, Mathistad 1-35H well in Mackenzie County, went on production July 4 and has averaged 1,095 b/d of oil equivalent, 90% oil and 10% gas. Continental has a 40% working interest in the well.

Harold Hamm, Continental chairman and chief executive officer, said, "This is a second positive data point in our effort to determine whether the Three Forks/Sanish formation is a separate oil-producing reservoir not drained by a horizontal well completion in the Middle Bakken zone above it. If the Three Forks/Sanish proves to be a separate reservoir, it would add significant incremental reserves to the Bakken play."

The company's first Three Forks/Sanish well, Bice 1-29H, averaged 693 boed in its first week on production (OGJ, June 2, 2008, Newsletter). It is in Dunn County 23 miles south-southeast of the Mathistad well.

At Mathistad, the top of the Three Forks/Sanish formation is 75 ft beneath the base of the Upper Bakken shale. Before the Bice and Mathistad wells, Continental typically completed its North Dakota Middle Bakken wells with a well bore 8 ft below the base of the Upper Bakken shale.

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