Minnelusa Bracken Unit, Campbell County, Wyoming: Static and Quantitative Modeling with Analysis of Production Efficiency

Anthony Walton

The Minnelusa Bracken Unit is a successful waterflood and chemical flood that produces from an eolian sandstone reservoir in the B sandstone of the Pennsylvanian-Permian Minnelusa Formation in Campbell County, Wyoming. The combined geology-petroleum engineering design class at the University of Kansas studied this production unit, plus one additional well that produces from the same reservoir. The reservoir has produced over 1,480,000 bbls of oil from an estimated 3.5 million bbls OOIP. Data available included resistivity, gamma, and sonic logs for all wells and neutron-density logs for some; well production of oil, gas, and water; water injection volumes; well histories, drill-stem tests on two wells; and a core report. It was necessary to use Archie constants from nearby fields to calculate fluid saturations. After developing a full geological, petrophysical, and engineering static model of the reservoir, the class simulated the 3-year period of primary production (January 1983-February 1986) to develop a quantitative history match of the field. This process allowed the students to use geological and engineering insight to adjust the initial reservoir model. Subsequently, the class developed history matches for a 6-month period of waterflooding. A period of chemical flooding followed the initial waterflood (1986-1997) followed by waterflood that continues to the present. The final stage of the class project was to evaluate possible alternatives to the secondary and tertiary oil recovery operations in the field to explore alternative possibilities for optimization. Most data for this study were provided by Osborn Heirs Company of San Antonio, whose contribution is gratefully acknowledged. The speaker presents the best efforts of the entire combined class.

AAPG Search and Discovery Article #90176©AAPG Mid-Continent Meeting, Wichita, Kansas, October 12-15, 2013