Reservoir Characterization of the Mississippian Meramec and Osage Series of Canadian, Kingfisher, and Blaine Counties (STACK Trend), Oklahoma: Relating Reservoir Characteristics to Productivity

Abstract

Mississippian reservoirs of the STACK (Sooner Trend in the Anadarko Basin of Canadian and Kingfisher) play in central Oklahoma are made up of heterogeneous mixed siliciclastic and carbonate reservoirs. Lithofacies in the Meramec consist of primarily of calcareous and argillaceous siltstones with some silty mudstones, packstones, and grainstones. Osagean facies exhibit significantly higher calcite abundance with facies consisting of silty or argillaceous mudstones and wackestones and more heavily bioturbated packstones and grainstones.

Lithofacies and abundance of calcite/silica in cored wells were identified and related to well-log responses to create electrofacies in non-cored wells using an Artificial Neural Network (ANN) and k-means classification methods. Facies logs, well-log data, core, thin sections, thin section photomicrographs, and XRD data were used to establish a stratigraphic framework that is characterized by a hierarchical stratigraphy of shoaling upward sequences ranging from a few feet to 100s of feet thick. These parasequences and their associated flooding surfaces were interpreted and correlated across the study area, resulting in NE-SW trending clinoforms that are prograding to the southeast.

The stratigraphic surfaces were used to construct a fine-scale 3-D grid for facies and petrophysical models that are constrained to electrofacies logs, vertical facies trends, porosity logs, and variogram parameters. Attributes from the 3-D reservoir models such as stratigraphic thickness, net to gross ratio, silica/calcite percent, and porosity, were compared to cumulative oil production, gas-oil ratio, (GOR), and fluid characteristics using multivariate analysis to illustrate relationships between reservoir properties and production.

AAPG Datapages/Search and Discovery Article #90323 ©2018 AAPG Annual Convention and Exhibition, Salt Lake City, Utah, May 20-23, 2018