History Matching of a Heavy-Oil Combustion Pilot in Romania

Abstract

Abstract Many papers have been published in recent years on the numerical modeling of in-situ combustion. They have mainly dealt with numerical formulations, but very few have been devoted to field history-match, especially concerning heavy-oil. Among the fields exploited by in-situ combustion, Suplacu de Barcau in Romania, with its very high-viscosity oil (2000 mPa.s at reservoir conditions), offers an interesting case for bringing out the main difficulties encountered during history-matching with a 3D in-situ combustion simulator. This paper describes the different phases of the numerical study made on the initial 5-spot pattern using a compositional thermal model. An effort was made to simulate the reaction aspects in radial geometry (ignition phase and propagation of the combustion front) and then to perform 3D match of production data. The different choices concerning the description of the reservoir, the definition of the kinematic parameters related to the laboratory tests performed and the numerical parameters are described. In spite of various uncertainties as to the pilot test data and the reservoir description, it was possible to: (1) obtain very good agreement for the propagation of the combustion front and the temperature distribution; and (2) reproduce the oil and gas production curves and the injection pressure.