This report summarizes data produced as part
of a U.S. Department of Energy (DOE) project to evaluate methods for improving
waterflood response in the Upper Cretaceous D sandstone of the Denver basin.
Historically poor performance of waterflooding in this widespread reservoir
has meant total recoveries averaging less than 20% of original oil in place
(OOIP), with considerable variation in local sweep efficiency. Detailed
reservoir characterization of the D sandstone in the Sooner unit, integrating
well-log, core, seismic, and engineering data, resulted in an updated reservoir
model that included delineation of multiple reservoir compartments. This
model was used as a basis for a field redevelopment plan whose initial
stage involved realigning existing injectors/producers and drilling several
infill locations to increase sweep efficiency on a compartment-by-compartment
basis. Results of implementation included a 100% increase in daily unit
production, an increase in proven reserves of 696,000 bbl oil equivalent
to more than 10% of OOIP. On the basis of these results, ultimate recovery
from the unit, with implementation of selective infill drilling, is projected
at 32.6% OOIP. Success of the project
©
Copyright 1997. The American Association of Petroleum 
Geologists
. All rights
reserved.
1Petroleum
Consultant, 1511 18th Avenue East, Seattle, Washington 98112.
Grateful
acknowledgment is expressed to Mark Sippel of Mark Sippel Engineering (Denver,
Colorado) for providing data and expertise essential to the writing of
this report. Appreciation is also extended to Floyd Bardsley for artwork.
Send reprint
requests to AAPG Publications Manager, P.O. Box 979, Tulsa, Oklahoma 74101-0979.
M = million,
G = billion.
