Integrated Reservoir Characterization of Mississippian-age Mid-Continent Carbonates

Michael Grammer, Darwin Boardman, James Puckette, Jay Gregg, Priyank Jaiswal, Miranda Childress, Buddy Price, Beth Vanden Berg, and Stephanie LeBlanc

Carbonate reservoirs are characterized by significant heterogeneity at a number of scales, ranging from exploration to production and enhanced production scale. An understanding of how primary depositional facies, diagenesis, and the sequence stratigraphic framework control the development of pores in carbonate rocks, and how the variation in pore architecture influences reservoir permeability is a fundamental process in the accurate characterization of carbonate reservoirs. In addition, with the ubiquitous use of geostatistical models to define and predict 3-D reservoir architecture in the subsurface, it has become increasingly important to accurately define the probable geometric distribution of potential reservoirs and seals at multiple scales to provide geologically-based, three dimensional reservoir models that can be used to develop dynamic reservoir simulation and flow models. To effectively do this, the challenge is to integrate data on the primary depositional environment (facies, probable geometry, and susceptibility to diagenetic modification), the sequence stratigraphic framework, and the petrophysical characteristics of carbonates at multiple scales utilizing a combination of core, wireline logs, 3D seismic and the incorporation of both modern and ancient analogs. Mississippian carbonates of the Mid-Continent have been highly productive for several decades but with a move towards horizontal rather than vertical drilling, the internal heterogeneity of the unit has become even more apparent. A combination of outcrop and core work illustrates a distinct hierarchy in shallowing upward packages within most Mississippian reservoir units, with cycles ranging from a few meters thick, to 10's of meters, and larger. Understanding the sequence stratigraphic framework at the meter and tens of meter scale will aid the producer in identifying key producing intervals and also enhance the prediction of internal flow units and seals. 

AAPG Search and Discovery Article #90176©AAPG Mid-Continent Meeting, Wichita, Kansas, October 12-15, 2013