Ranking Production Potential Based on Key Geological Drivers - Bakken Case Study

Abstract

Abstract The Bakken Play is a lithologically complex, mixed carbonate-clastic and low porosity-permeability petroleum system comprised of juxtaposed source rocks and reservoir intervals. The play spans variable source maturity, reservoir pressure and temperature, and fluid type. The target reservoirs are thin (below seismic resolution), gently-dipping and variably affected by subtle structure, faults or natural fractures. As a continuous oil accumulation with an unconventional development model, numerous horizontal wells with multi-stage completions will be required to develop the Bakken Play. Ranking future drilling locations is a critical step in planning the development strategy and optimizing the economics of the play. Ranking methods are typically based on prior well performance; however, in the Bakken Play we recognize that numerous non-geological parameters associated with drilling, completions, and production operations contribute to well performance. In this paper we describe a methodology to assess the underlying productivity potential of the reservoirs based on key geological drivers. With an extensive well log database, petrophysical uncertainty can be addressed and stock-tank oil originally in place (STOOIP) calculated and mapped. Nevertheless, the relationship of STOOIP to production performance remains weak due to drilling, completion, and production variables. In this study we apply geological modifiers to the calculated in-place resource to better represent the productivity potential. Geological modifiers include source maturity and charge access, reservoir facies and properties, structure (trap and natural fractures), overpressure, and fluid properties.