Link: PETROLEUM GEOLOGY OF THE NORTH DAKOTA WILLISTON BASIN

Very well-written article on the petroleum geology of the North Dakota Williston Basin.

• Major producing unit: the Madison Group of the Mississippi Formation.
  
• Limestone reservoir.
  
• Simple anticline structures.
  
• Paraffinic base oil, with API ranging from 19 to 55.
  
• Recovery factor: 15-20%.

The State's oil production peaked in mid 1980s at near 150,000 bbl/d. In year 2000, it was down to 90,000 bbl/d.

Right: Producing Counties/Wells