Subsurface complexities related to the formation of Peripheral Foreland Basins (PFBs) can have significant impacts on unconventional resource development within their respective basin. In the Arkoma Basin of Southeast Oklahoma, a PFB formed during the Marathon Orogeny, the onset of thrusting and tectonic loading induced a complex series of dip-slip and strike-slip faults during basin formation. Existing interpretation of these subsurface hazards are thought to have substantial effect on rock quality, water intrusion, and parent-child interactions during development (among others).
Foundation Energy Management (FEM) employed a series of technologies to increase their understanding of the reservoir and its hazards. These technologies include geochemical liquids analysis from wellbore cuttings via Rock Volatiles Stratigraphy (RVStrat), passive acoustic imaging sensors (known as Measuring while Fracing or MWF), and precision injection of proppant, water, and gas tracers during the stimulation treatment. These technologies were applied to a pair of infill development wells in an existing unit. The goals of the project were meant to increase understanding of the following parameters: reservoir characterization, landing zone selection, completion optimization, fracture-driven interactions (FDIs), and subsurface hazards.
The multi-disciplinary study successfully met the objectives/goals of the Operator. The technologies employed assisted with quantifying and answering a series of questions related to the reservoir, its subsurface hazards, and provided economic implications into future development plans and strategy.
The Upper Devonian to Lower Mississippian Woodford Shale (and its age-equivalents) are one of the most prolific and important, continent-wide source rocks in North America (Coleman Jr. 2004). The Woodford is primarily a Type II kerogen source rock, albeit portions of the Woodford within the Arkoma are influenced by terrigenous Type III kerogen sources (Coleman Jr. 2004). Total Organic Carbon (TOC) can range from ∼2% to >10%, and the formation is typically classified as either siliceous mudstone or cherty siltstone (as supported by numerous geochemical studies, basin modeling studies, and core analysis). It is one of three facies targeted for unconventional resource play development within the Arkoma Basin (see Figure 1), and it is the primary target of Operators. Variable thermal maturity across the basin places the Woodford in both the wet gas and dry gas phase windows (moving west to east across the basin, as shown in Figure 2.)
