Pronghorn Sands Sub-Formation -- Introduction -- The Bakken, North Dakota, USA

Whiting Petroleum continues to post the most interesting / informative corporate presentations. Over time the corporate presentations change, and unfortunately some great slides gradually disappear. Take a look at slide 16 at Whiting's current corporate presentation.

A new pay zone is being targeted by Whiting: the Pronghorn Sand(s). This is my introductory blurb:

Sometime in 2011, Whiting started referring to a new prospect as the Pronghorn prospect, a bit southeast of their Lewis & Clark prospect in southwestern North Dakota. Over time, a bit more information trickled out, and now, based on a recent Whiting corporate presentation (same link as above) it appears there is a new formation at least in some parts of the Bakken: the Pronghorn Sand(s), an upper formation which is just below the Bakken. See slide 16 of Whiting's November, 2011, presentation (unfortunately those presentations will change over time, and this slide may be "lost." 

The graphic reveals that in Whiting's Tarpon prospect there is the well-understood middle Bakken, lower Bakken, and Three Forks formations. Whiting is presently drilling into both the middle Bakken and the Three Forks in their Tarpon prospect. 

In their Lewis & Clark prospect, the middle Bakken thins out to be almost negligible, but the Three Forks remains fairly thick (about the same as elsewhere in the Williston Basin). Interestingly enough, the Pronghorn Sand just begins to show up in the Lewis & Clark, and although not very thick, is thick enough to be drilled.

In the Pronghorn prospect, the middle Bakken becomes very thin. The Three Forks remains the same, but here the Pronghorn Sand is very thick and the target for Whiting drilling. 

On the sidebar at the right, I have added this new sub-formation to the Three Forks section.