Dimensional-model Studies of Oil-field Behavior

Abstract

This paper states the theory underlying the design of two kinds ofdimensionally scaled models of parts of idealized oil fields. One of thesesimulates an oil well and its surrounding sand for a distance of 16 ft.radially from the well. The other model simulates linear flow through layeredsands. Construction and operation of the models are described and typical dataare given. The unique features in the design of the models are:thetreatment of the permeability-viscosity quotient as a single variable andthe use of previously reported experimentally developed relations betweenrelative permeability and saturation and capillary pressure, saturation, porosity, permeability and interfacial tension. The models at present simulateflow of oil and water only, through unconsolidated sands. They are superior tounscaled models, which may give rise to erroneous conclusions. The models aredesigned to study the desirability of various methods of well completion andthe effects of various factors on recovery of oil from layered sands. Introduction Recent work on the fundamental behavior of flowing mixtures of fluids insands has resulted in the development of some new theory in this field, much ofwhich has been presented in previous papers. However, the application of thistheory to the behavior of oil wells or oil fields has proved too complicatedfor ordinary mathematical techniques, except in very highly simplified cases. Apractical solution to this problem appears, therefore, to lie in the use ofdimensionally scaled models of elements of oil fields. The object of this paper is, first, to present the theoretical andexperimental basis of the design of such models, and, second, to describe theirconstruction and operation. Experiments now under way on the models alreadybuilt will yield material for other reports, which will be devoted tointerpretation of the results in terms of oil-field behavior. So far, simple dimensional models of two kinds have been built and are beingoperated. These models represent different parts of an idealized oil field butobey the same underlying theory. The only fluids represented are oil and water, since certain questionable approximations are necessary for gas-liquidsystems. T.P. 1413