U.S. Operator Optimizes Performance in Granite Wash Low Permeability, Light Oil/Gas Condensate Well
A U.S. independent operator retained Sproule to help determine the key drivers needed to optimize well performance in horizontal wells with multi-stage hydraulic fracture completions in the Granite Wash.
- Granite Wash contains complex mineralogy
- Depositional environments range from near shoreline to continental slope events to deep marine
- Reservoir property changes between fields and horizons are difficult to characterize
- The Granite Wash is a mature vertical well play extending across six counties in the Texas Panhandle and Western Oklahoma. The laterally and vertically extensive formations were developed with closely spaced vertical wells for several decades. More recently, almost all development has been horizontal.
- Unlike typical sandstone reservoirs, the Granite Wash has complex mineralogy, including quartz, potassium and sodium feldspars, illite, chlorite, dolomite and calcite.
- Depositional environments range from near shoreline to continental slope events to deep marine. Many of the targets consist of compartmentalized sub-marine fan deposition. Due to the high level of reservoir heterogeneity and GOR, it is difficult to characterize reservoir property changes between fields and horizons.
- Sproule constructed a three-dimensional sub-surface model of the reservoir with multiple stratigraphic benches. The team defined reservoir quality from petrophysical properties that affect the productivity of the wells, including but not limited to porosity, permeability, saturations and rock mineralogy.
- Sproule built property distribution models for each property across the study areas. They also investigated well completion and stimulation parameters, including lateral length, number of fracturing stages, spacing of frac stages and perforation clusters, and normalized fluid and proppant volumes.
- The team then correlated reservoir quality from the three-dimensional model and parameters from the stimulation database with well production to identify both stimulation and reservoir production drivers.
- The study resulted in improved conclusions and recommendations for completion and stimulation in specific geographic areas and stratigraphic benches – to ultimately optimize well performance.