Abstract
Two-and three-dimensional simulation studies have been carried out to evaluate waterflood oil recovery in a 40-acre 5-spot pattern using horizontal and vertical well systems. The three-dimensional simulation results indicate that the parameters considered, i.e. vertical permeability-horizontal permeability ratio, injection and production rates, and reservoir thickness have little effect on waterflood oil recovery for a particular water-oil mobility ratio. For both vertical and horizontal well systems, oil recovery decreases with increasing water-oil mobility ratio. It is concluded that the water-oil mobility ratio is the dominant parameter affecting waterflood oil recovery, in line with the experimental results of Craig-Geffen-Morse for conventional waterflood. Waterflood oil recovery using a horizontal well system is shown to be higher than that based on a vertical well system. In addition, maximum oil recovery is obtained using a horizontal well with maximum horizontal section open to flow. A correlation has been developed which expresses volumetric sweep efficiency in a 5-spot pattern as a function of water-oil mobility ratio. This correlation would be useful for estimating waterflood oil recovery for the range of reservoir parameters considered.
Ferreira, Horacio (1995). Simulation studies of waterflood performance with horizontal wells. Master's thesis, Texas A&M University. Available electronically from
https : / /hdl .handle .net /1969 .1 /ETD -TAMU -1995 -THESIS -F475.