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Permian Stacked-Pay Potential Assessment Using Multi-Disciplinary Analytics


Nearly 100 years after the original discovery wells, the Permian Basin continues to challenge “conventional thinking” and provide opportunities for new understandings and economic opportunities. In this current phase of unconventional Permian development (i.e. hydraulically fractured horizontal wells), a significant case-in-point is the Alpine High focus upon deeper Pennsylvanian, Woodford and Barnett reservoirs. A comprehensive understanding of the Permian Basin: spanning the Delaware, Central Platform and Midland Sub-basins specifically; requires an evolving understanding of the interplay of thousands of feet and hundreds of million years of deposition. Accessing regional interpretations of over 100,000 vertical wells, a time-equivalent framework of major Paleozoic sequence depths and thicknesses is introduced. Using a database of well over 10,000 horizontal wells: drilling, completions and production data are used in tandem with geologic framework data to develop analytic models to isolate regional trends of major reservoirs. Engineering variations in well lengths (and paths), proppant intensity, frac type, and more, are modeled from statistically significant sampling of horizontal wells using multi-variate analytics techniques. Practically, this workflow “normalizes” the impact of different engineering decisions to isolate the impact of geology on well performance. What is clear is the significance of hydrocarbon maturity and depth (i.e. reservoir pressures) in the understanding of oil and gas prospects across the Permian. While the core of the Delaware or Midland sub-basins may have 10 or more distinct landing zone targets (spanning the Bone Springs/Wolfcamp and Spraberry/Wolfcamp benches respectively); the Permian Basin fringes may offer a half dozen or more targets (spanning Wolfcamp/Pennsylvanian/Woodford/Barnett). What is clearly illustrated is that thousands of feet of potential play exists across very large extents of the Permian, requiring increasingly more in-depth understanding of depositional patterns, lithology, mineralogy, geomechanics, and more. Using basic drilling and completions cost estimates, “penalty weightings” are estimated to better understand the relative economic viability of multi-zone development across the play. As the “modern Permian” moves into more mature stages of unconventional field development, it is critical to deploy optimized pad drilling and lateral/vertical spacing strategies, driven by grounded geologic input.