Many Minnelusa fields in the Powder River Basin have been successfully unitized and water-flooded. However, forming the Spirit (Minnelusa "A") Unit was more complicated than most. This Unit required the lawyers, geophysicists, landmen, and engineers to each solve a piece of the puzzle, which when fit together formed the Unit.

The main producing well in the Spirit field lies outside the boundary of the Lily (Minnelusa "A") Unit. Reservoir production and pressure response indicated it was draining a fairly large area and was not responding to nearby water-floods or supplied by a natural waterdrive. Drilling to the north, east and south failed to find commercial pay. Apparently, the Spirit (Minnelusa "A") field extended west into the Lily (Minnelusa "A") Unit. However, it was producing from a Minnelusa "A" accumulation which was not in hydraulic communication with the Lily reservoir.

This paper describes how the ownership problem was resolved, the field was defined, the injection and production responses forecasted and how the water-flood actually has responded to date.

You can access this article if you purchase or spend a download.