Oil Recovery Performance Of Pattern Gas Or Water Injection Operations From Model Tests

Abstract

Published in Petroleum Transactions, AIME, Vol. 204, 1955, pages 7–15. Paper presented at Petroleum Branch Fall Meeting in San Antonio, Oct. 17–20, 1954. Abstract A series of both water and gas pattern floods was made in the laboratory to study the oil recovery performances of such operations. These tests were conducted on consolidated sandstone models, using oil, water, and gas. The model floods were scaled to reproduce field performance under gas and water five-spot injection, X-ray shadowgraphs permitted observation of the gross fluid movement within the models. A method was developed for applying the mobility ratio concept to water flooding and dispersed gas drives in a five-spot well pattern. The areal sweep efficiency at breakthrough for dispersed gas drives is much higher than previously expected, lying in the range of 50 to 100 per cent. A method is presented for predicting the water-oil ratio performance of five-spot pattern water floods in uniform sands. This method is verified experimentally for the condition of no free gas initially present and for values of gas saturation normally encountered in fields following depletion operations. Production performance for pattern gas injection is also predictable by this method.