Growth rate of CO2 hydrate film on water–oil and water–gaseous CO2 interface

Abstract

It is known that injection of carbon dioxide into the petroleum reservoir (CO 2 flooding) is one of the effective methods for enhanced oil recovery. CO 2 flooding may be complicated by formation of CO 2 hydrate plugs. It makes topical investigation of CO 2 hydrate formation in the system gaseous CO 2 –oil–water. In this work, the growth rates of carbon dioxide hydrate films at the water–oil as well as the water–gas interface are studied in the pressure range of 2.30–3.04 MPa and at temperatures between –5.4 and +5.0 °C. It is found that the growth rate for the water–oil interface is 3.5 times lower than that for the water–gas interface with carbon dioxide. It is hypothesised that the observed decrease in the growth rate is related to the mechanical resistance of the oil components adsorbed on the interface to the growth of the hydrate film. The growth rate of the film has been shown to depend on the experimental procedure, most likely due to the different initial concentrations of carbon dioxide in the aqueous solutions.