The following general summarizing statements may be made from the results presented in this study.
1. Total water-drive reservoirs have in general an initial transientpressure decline which may be extremely steep at first, followed by a steady-state straight line portion has a slope of zero for the “infinite” aquifer used here. The transient period may be of longduration in tight formations with the pressure becoming more dependent on fluid expansion within the oil reservoir.
2. “Infinite” or large aquifers may easily produce all of the oil from a field whichis possible by the water encroachment process without resort to pressure maintenance. However, it may be necessary to return the produced water, especially when the water-oil ratios become high towardthe end of the life of the field.
3. A greater total water influx can be obtained from a limited aquifer without pressure maintenance when the producing rates are low at abandonment.
4. When apressure maintenance program is started, the lower the value of the pressure being maintained the greater will be the energy received from the natural aquifer.
5. When water injection is used toaid the natural water influx, the injection wells should be placed as near the oil-water contact as possible and still maintain a fairly uniform blood front.
6. If the permeability of fairly largeor “infinite” aquifer is quite low, such as 100 md for the one considered here, only a comparatively small part will be effective toward producing oil at economic rates.
Theauthor is indebted to Morris Muskat of the Gulf Oil Corp. for suggesting this problem and to H. G. Botset of the University of Pitttsburgh under whose direction the work was conducted in partialfulfillment of the requirements for the degree of Master of Science. The author also wishes to express his appreciation to Blaine B. Wescott, executive vice-president of the Gulf Research & Development Co....