The MER (maximum efficient rate) is defined in terms of well known physicalconcepts, and an analytical solution correctly describing them is presented.The differences of opinion regarding its definition and application as an engineering concept are briefly reviewed. The relationship of the basic theoryof water-drive reservoirs and the evolvement of the MER from theseconsiderations is discussed. The primary objective of the study is to reviewprevious work and to present a new analytical technique which is based on theapplication of two different (but acceptable) methods of solution to a partialwater-drive reservoir. The widely divergent results indicate that care must beexercised in choosing a calculation method, and that the acceptability ofresults is dependent upon the accuracy with which the analytical methodcorrectly describes the physical behaviour of the reservoir fluids. The "Fluid Inventory" method, which is a computerized technique adopted as one of theexamples used in this paper, is reviewed in detail and is shown to be the mostacceptable of the investigated methods. This technique, as well as all other MER calculations, results in solutions that require reconciliation withindividual well phenomena and as such they cannot be applied in discriminately.
The term MER (maximum efficient rate), as it is currently understood by theoil industry and regulatory bodies, has undergone considerable evolution in thepast 20 years and even today there exists a controversy as to its ramificationsand final utilization. In 1947, Kraus (1) reviewed in detail the history of the MER concept and its useful engineering application as known at that time.Initially, the engineering usefulness of the MER was reflected in devising means of controlling excessive production from prolific oil pools in Texas, Oklahoma and California. It has been believed that prorationing of oilproduction and the resultant decrease in rates in many of the big pools wouldhave a favourable effect on their expected ultimate recoveries. After passingthrough a considerable number of API technical committee reviews, the industryfinally conceived an idea that there must exist an optimum rate for eachreservoir (i.e., a single and unique production rate), which would by itselfinsure optimum conservation of energy and thus result in maximum ultimaterecovery.
