Monthly Archives: February 2018

Fayetteville Shale v. Moorefield Shale

The Fayetteville Shale v. Moorefield Shale

The Moorefield Shale is between the Boone Formation and the Fayetteville and rapidly thickens to the southeast. Some geologists believe the lower Fayetteville is actually Moorefield age. The Fayetteville transitions to a deep water facies called the Stanley in the Ouachita Basin.  Beds are predominately level with a northeast-southwest trend of linears indicating major faults and an east-west series of faults stair-stepping into the Ouachita Basin to the south. As the formations deepen rapidly to the south, the beds become deformed into synclines and anticlines.  The Stanley appears to encompass the Fayetteville – Moorefield – Upper Boone Formations and is not differentiated in the Ouachita from the Shales of the Fayetteville-Moorefield Formations.

On the surface the Batesville Sand and Ruddell Shales are between the Fayetteville and Moorefield, but many geologists believe the Ruddell is an upper Moorefield unit and the Batesville appears to pinch out to the south.  The Moorefield thickens to the southeast and, as shale, is indistinguishable except by electric log signatures.  Nevertheless there is no clear distinction between the two, except that Southwestern Energy has adopted a nomenclature that rests upon the notion that the two formations are distinct and separated by a thin Batesville (?) Sand unit.  The Upper Fayetteville is conventionally treated as less productive but the middle and Lower Fayetteville is the primary target for production. There is only the shortest of distances between the Lower Fayetteville Shales and the Moorefield.

If the lateral extent of fracking in the Fayetteville is 600’ in width, what real barrier prevents the frack from traversing up or down 300’?  Since the entire thickness of the Fayetteville – Moorefield section is 350’ or less, what prevents communication between the Fayetteville (and the 20% royalties paid to mineral owners) and the Moorefield (where mineral owners are paid only 12½% royalty before post-production expenses?)  Does anyone believe that the Moorefield formation won’t be communicating with the upper beds for a substantial way and thus almost certainly in most cases be extracting gas from the Fayetteville Shale?

This communication will be obvious once the decline curves for nearby Fayetteville wells are compared to new production in the Moorefield. I predict a sharp change in the decline of these Fayetteville wells where communication exists and many, if not most will communicate if sited within a few hundred feet of an existing Fayetteville Well.

So the question is has the Arkansas Oil and Gas Commission considered this potential? And the solution is to require all Moorefield wells to replicate the royalties paid for the zones above so that it doesn’t make any difference if vertical communication exists.