Reservoir Engineering in the 70's and 80's

Abstract

Most of the significant contributions to reservoir engineering were made by a handful of prodigious giants in the 1930's and 1940's. The most significant contribution we can make in the next 20 years will be to fully understand -- perhaps with the help of that latest prodigy, the computer - what those giants were driving at. Introduction Reservoir Engineering is a branch of engineering that derives its name from the phrase "petroleum reservoir". The derivation of the term "petroleum engineering" might be considered in somewhat the same fashion. In either case, it is the petroleum reservoir that is all-important because the authority of a petroleum engineer usually ends somewhere between petroleum engineer usually ends somewhere between the oil field and the refinery. Unfortunately, neither the term "petroleum engineering" nor the term "reservoir engineering" is adequately descriptive. These terms mean nothing to a layman, and only little more to other engineers. This problem has worried many members of the Society of Petroleum Engineers for some time. Although it is possible to coin names more descriptive of our function - Energy and Natural Resources Engineering, Geohydraulics Engineering - such names still miss the mark in many respects. So do definitions of either petroleum engineering or reservoir engineering. A frequently cited definition of reservoir engineering is "the application of scientific principles to the drainage problems arising during the principles to the drainage problems arising during the development and production of oil and gas reservoirs". This definition misses the mark, also, in that the essence of reservoir engineering is only hinted at in the word "problems". The reservoir engineer tries to optimize the drainage of a valuable fluid from a subterranean reservoir of generally unknown size and character. This is the problem; he is working with something he never sees. problem; he is working with something he never sees. As F. H. Allen has said, "Petroleum Engineering, certainly as it will be practiced even more so in the future, is a very indirect science. We cannot even get in direct contact with the oil and gas in their native reservoirs. We can only deal with indirect readings and conduct operations from the surface of the ground which we hope will have certain effects at depth". Indirect determination of some characteristic of an object is a well established method usually introduced in elementary general science courses. The mass of an object may be determined directly with a beam balance, or indirectly from the measured volume and density of the object. In reservoir engineering it appears that there is no hope of ever physically examining the object directly. It is not physically examining the object directly. It is not likely that we shall mine or exhume many reservoirs. Thus the responsibility of the reservoir engineer usually involves a two-step process: to make and interpret indirect measurements of the quantitative characteristics of the reservoir, and to employ this information and basic physical principles to forecast the behavior of the reservoir under any potentially useful production scheme. potentially useful production scheme. Although significant publications concerning reservoir engineering problems began to appear in the 1920's, this field of study began essentially only 35 years ago. Major subjects such as multiphase flow through porous media and the material balance for an oil reservoir have appeared during this period. JPT P. 33