Maximizing recoverable reserves in tight reservoirs using geostatistical inversion from 3-D seismic: A case study from the Powder River Basin, USA

The application of horizontal drilling and multi-stage hydraulic fracturing has boosted economic recoveries from unconventional reservoirs. Applying this technology requires proper placement of horizontal wells combined with hydraulic stimulation to create fractures extending from the horizontal wellbore. The economics of unconventional plays can be improved if horizontal wellbores target facies with favorable reservoir and geomechanical properties. An integrated, multi-disciplinary approach has been developed in order to reduce economic risk, facilitate improved and faster decision making and enable more efficient and effective well placement. Subsurface volumes of lithofacies, reservoir rock properties and geomechanical properties, all of which honor data from multiple disciplines, provided the means to generate lithology and property maps, including Phi-H, together with associated measurements of uncertainty for selected facies and properties. This seismically-constrained geomodeling approach enabled optimum identification of sweet spots for reservoir development and well placement. The methodology demonstrates the value of incorporating stratigraphic, geological, petrophysical, engineering and geophysical data into an integrated subsurface reservoir model.