ConocoPhillips built its position in the D-J Basin Niobrara play between 2010 and 2012 with current leasehold of approximately 130,000 net acres south east of Denver. Envisaged as a new play extension to Wattenberg Field, based on a thermal anomaly in Arapahoe County, early production expectations were based on the aggregate of Niobrara horizontal wells across the basin. Production results from early COP horizontal wells were difficult to compare with aggregate D-J basin production, and demanded a more granular approach to analogue selection. With the goal of identifying geologically comparable well groups, ConocoPhillips' Niobrara Exploration team assembled a database of 800+ horizontal wells and 1500+ vertical producers, paring down potential analogues by thermal maturity, API gravity, fractured reservoir, petrophysical properties, lateral length and completion type. Petrophysical parameters were mapped across the basin in > 3000 wells, and extrapolated to all horizontal producers to enable cross-plotting with production rates, EUR estimates from decline curve analysis and fluid properties. Sensitivity analysis revealed meaningful trends in well orientation, API gravity, proppant volumes, target horizon and the relevance of oil in place, which helps focus the appraisal program and identify critical uncertainties to test. Selecting analogue wells based on reservoir properties and comparable well design was critical to calibrate reservoir simulation models to better forecast production from horizontal wells in the area of interest.
