Physical Properties of Carbonated Oils

Abstract

Abstract The growing interest in the use of CO2 in crude oil recovery increases the need for data on the effect of CO2 on hydrocarbon physical properties. Data are presented on the solubility of CO2 in various dead oils, the swelling changes in CO2 -oil solutions and the effect of CO2 on dead oil viscosity. This later property shows the most pronounced effect, with viscosity reductions up to 98 per cent of the uncarbonated viscosities. An empirical method of estimating the viscosity of carbonated oils is presented. The apparatus and procedures used are described in sufficient detail to allow others to make similar studies. Introduction The effect of dissolved carbon dioxide on the swelling and viscosity reduction of specific hydrocarbon oils has been observed and recorded by a number of investigators. The object of this paper is to offer a means of predicting these effects for crude oils free from natural gas, using the dead state viscosity and gravity of the crude oils. The CO. solubility and swelling of numerous crude oils were determined in a visual cell at various pressure levels. The viscosity of the oils carbonated to various pressure levels was then determined by measuring the pressure drop across a capillary tube. From these data, the physical properties were correlated empirically. The resulting correlations allow the prediction of CO solubility, swelling and viscosity reduction if the dead state gravity and viscosity of the oils are known.