Bakken Production: A Learning Curve

LeFever, Julie A. ¹ (1) North Dakota Geological Survey, Grand Forks, ND

The Bakken Formation is a well known source rock with estimates of 200 billion barrels of oil-in-place. Over the years, three major plays have attempted to produce a portion of this oil with varying degrees of success. Early production occurred in outstanding vertical wells in Antelope Field from the Bakken-Sanish section. Later vertical wells along the northern Nesson Anticline were less successful. Vertical wells drilled along the Bakken Fairway produced at only moderate rates, but encouraged the horizontal Bakken shale play of the 1990s. The horizontal shale play was characterized by significantly  higher production rates for the same cost as a vertical well. Horizontal wells with moderate production rates appear to be associated with higher EURs. Horizontal recoveries are generally 38% greater than vertical wells. Currently the average horizontal shale well has produced 10 years and has an average EUR of 167,000 bbls of oil.

The current play horizontally drills the middle member. Recovery rates of 8 to 16% in Montana will yield up to 640,000 bbls of oil/section. Based on the limited production history presently available, 77 wells are each expected to recover in excess of 200,000 bbls of oil. The play is moving into North Dakota and the early wells are showing varied success. Differences in lithologies, pressures, and temperatures require different drilling practices than in the Montana play. Current and past production in combination with additional pay section suggests a high probability for success as North Dakota moves down the learning curve.

AAPG Search and Discovery Article #90055©2006 AAPG Rocky Mountain Section Meeting, Billings, Montana