A stand of drillpipe at Eagle's horizontal Reed 1H-10 in Woods County
Tank battery at the Lohmann 1H-20 in Woods County
Founder and CEO, Steve Antry (right) and Operations manager Ladd Sullins stand atop a sand hopper at the frac of the Avard 1H-31 in Alfalfa County
Mississippian Geologic Overview
The Mississippian Limestone of northern Oklahoma and southern Kansas is comprised of four basic depositional environments. These are the Mississippi “Chat”, Chester, Meramec and Osage.
The Mississippi “Chat” is the uppermost member at the unconformity between the Pennsylvanian and Mississippian aged rocks and is considered to be a very good hydrocarbon reservoir. These “Chat” reservoirs are very wide spread, vary in gross thickness from a few feet to 80’ thick and are heterogeneous in nature. Net porosity thicknesses greater than 5% range from a few feet to greater than 40 feet. This is caused in part through uplift, alteration, erosion and deposition of the original limestone commonly referred to as Mississippi Lime. The “Chat” is comprised of varying amounts of weathered chert, limestone and dolomite. Porosities range from 3 to 35%. The resistivities are generally low due to the amount of weathered chert and appear to be wet on logs by conventional petrophysical analysis. These reservoirs are in fact not wet but do produce some water associated with the production of hydrocarbons. Water rates vary between wells depending on the actual mineral composition of the formation being completed.
The Mississippi Lime underlies the “Chat” and is comprised of the Mississippi Chester, Manning, Meramec and Osage. It is a deep water to shallow marine limestone sequence with interbedded dolomite facies enhancing porosity and permeability. This zone is also productive in the prospect area in addition to the Chat. Porosities range from 5 to 15% with water saturations ranging from 25 to 60%. Net porosity thickness greater than 5% range from 10 to 100’ with an average of 30 to 50’.
Due to the heterogenic porosity development within the Mississippian formations it is advantageous to drill horizontal wells to interconnect a larger percentage of porosity with one well bore. Fracture treatment of the formation during completion in addition to the horizontal placement of the well bore will add significant conduits for production of hydrocarbons adding significant recoverable reserves. These reserves would not be recovered with a conventional vertical well.