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

It is known that injection of carbon dioxide into the petroleum reservoir (CO2 flooding) is one of the effec-tive methods for enhanced oil recovery. CO2 flooding may be complicated by formation of CO2 hydrate plugs. It makes topical investigation of CO2 hydrate formation in the system gaseous CO2-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 degrees 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.(c) 2022 The Chemical Industry and Engineering Society of China, and Chemical Industry Press Co., Ltd. All rights reserved.