In:
Transactions of the AIME, Society of Petroleum Engineers (SPE), Vol. 213, No. 01 ( 1958-12-1), p. 228-235
Abstract:
Published in Petroleum Transactions, AIME, Volume 213, 1958, pages 228–235. Abstract Recent literature shows that pronounced increases in oil recovery can result from the use of miscible systems in recovery operations. This literature also points out certain problems associated with maintaining miscibility, e.g., compositional changes resulting from alterations in pressure and temperature or from zone dilution. The purpose of the work described in this paper was to study miscible zones for possible use in waterflooding operations and examine the manner in which these zones break down. The fluid system selected for study was oil - tertiary-butyl alcohol - water, which, because of its narrow range of miscibility, is ideally suited for investigation in short, linear systems. The laboratory-observed effects on oil recovery and zone stability of a number of variables are reported. Among the variables investigated were miscible zone size, viscosity ratio, length of travel, and interstitial water saturation. Results obtained with this system show that interstitial water adversely affects recoveries because of premature phase break. Salinity of the water further aggravates this situation. This effect, although pronounced for this system, would probably occur in any fluid system containing an alcohol. As expected, viscosity ratio has a decided influence on recovery efficiency and zone stability. The results also show that use of a sufficient zone size, even though the system has poor phase characteristics, yields higher oil recoveries than are obtained from straight water floods. Length-of-travel studies showed a square root relationship between zone growth and path length for favorable viscosity ratios. No such clear-cut dependence was observed under unfavorable viscosity conditions. Introduction As new oil reserves have become increasingly more difficult and expensive to find and develop, the oil industry has devoted more and more time and money to finding more efficient methods for exploiting known reserves. The increasing number of water floods is one manifestation of this attempt to improve oil recoveries from existing fields. Since considerable quantities of oil are by-passed by the waterflood process, it is only a partial answer to the problem. The search continues.
Type of Medium:
Online Resource
ISSN:
0081-1696
Language:
English
Publisher:
Society of Petroleum Engineers (SPE)
Publication Date:
1958
Permalink