Studies on the Stability of the Foamy Oil in Developing Heavy Oil Reservoirs Bashir Busahmin 1 *, Brij Maini 2 , Rama Rao Karri 1 and Maziyar Sabet 1 1 Department of Petroleum and Chemical Engineering Universiti Teknologi Brunei, Brunei Darussalam, BE 1410 2 Department of Chemical and Petroleum Engineering, Schulich School of Engineering, University of Calgary, Calgary, Canada *Corresponding author: bashir.abusahmin@utb.edu.bn Keywords: foamy oil, foam stability, experimental investigation, Hele-Shaw, aqueous foam Abstract. In the process of natural energy depletion, foamy oil is characterized of low production Gas Oil Ratio, high oil viscosity, high daily production rate and high primary recovery factor. The stability of the foam turns out to be the prevailing factor that governs the life of the ‘foamy oil’. To enumerate the main factors affecting the stability of the foam, a high-temperature–high-pressure visualized experiment model for foamy oil stability test was developed. A serial of experiments was conducted to evaluate the performance of the foam stability. The effects of oil viscosity, height of the oil column, dissolved gas content and dispersed gas were investigated and recorded. These experiments were conducted using a Hele-Shaw, a high pressure cell. The volume of foamy oil produced, either by a step reduction in pressure or by a gradual (linear) reduction in pressure, and its subsequent decay was observed, visually. The experimental results show that foamy oil stability increases with higher oil viscosity, higher oil column, higher dissolved gas content and higher pressure decline rate. Asphaltene content was not observed to increase the foamy oil stability significantly. The results also show that the foam quality of foamy oils is much lower than aqueous foams. Introduction Foamy oil flow occurs in primary production of heavy oil under solution gas drive. Many of heavy oil reservoirs under solution gas drive marked unusual good primary performance; high oil production rates, low produced gas oil ratio and high recovery [1-5]. Experiments were conducted by [6-11] in a high-pressure cell to investigate the stability of foam and the factors that affects it. The foamy oil was produced by gradual (linear) reduction in pressure and its subsequent decay was observed visually. The effect of oil viscosity, height of oil column, dissolved gas content and pressure decline rate were investigated. The oil is produced in the form of oil-continuous foam which has the appearance of chocolate mousse and contains a high volume fraction of gas. It has been suggested that the flow behavior of foam in porous media can be correlated with foam stability in just such a bulk vessel. Foam stability was measured in the lab for both mineral and crude oils by monitoring the decay of the foam height. It has been suggested that the flow behaviour of foams in porous media can be correlated with foam stability in just such a bulk vessel [12, 13]. Foamy oil flow behaviour is affected by the interfacial properties of the oil-gas system. It is believed that naturally occurring surface active chemicals play an important role in foamy oil flow; however, due to the extremely complex chemistry and the number of components in the system, it is impractical to determine the effect of each component. Therefore, it is desirable to have an indirect method of characterizing the surface chemistry of the system. One easily measurable parameter is the stability of foam in a bulk vessel. It has been suggested that the flow behaviour of foams in porous media can be correlated with foam stability in just such a bulk vessel. The results of experiments by Urgelli et. al.,[14], indicated that the nucleation of the gas bubbles to create a gas phase was a very slow process due to the high oil viscosity. The main objective of this paper was to compare the Stability of the Foamy oil using viscous mineral oil and crude oil systems under similar conditions. Defect and Diffusion Forum Online: 2017-02-23 ISSN: 1662-9507, Vol. 371, pp 111-116 doi:10.4028/www.scientific.net/DDF.371.111 © 2016 Trans Tech Publications, Switzerland All rights reserved. No part of contents of this paper may be reproduced or transmitted in any form or by any means without the written permission of Trans Tech Publications, www.ttp.net. (#75053228, Iowa State University, Ames, USA-23/02/17,16:59:59)