Using carbon dioxide to develop highly viscous oil fields in carbonate reservoirs. Global experience analysis

Abstract

The problem of involving the enormous resources of highly viscous oil in the more active development is becoming increasingly urgent, which requires the implementation of modern technologies from oil and gas companies. The use of traditional methods of oil production for the extraction of highly viscous oil does not allow reaching the oil recovery coefficient above 15-20%. Thus, the key issue in solving this problem is the selection and implementation of effective technologies for the extraction of such hydrocarbon resources. Currently, there are a number of technologies based on the use of carbon dioxide as an treatment agent, which are successfully used in high-viscosity oil fields around the world. This article is devoted to the review and analysis of the effectiveness of projects for the carbon dioxide injection in high viscosity fields in carbonate reservoirs. Information is provided on the results of the implementation of projects for the injection of carbon dioxide in domestic and foreign fields. To analyze the effectiveness of the projects, indicators such as the ratio of the injected gas volume to the oil recovered volume, the oil recovery coefficient increase and the oil recovery rate per well were selected. The analysis showed that the ratio of the injected carbon dioxide volume to the oil recovered volume could vary greatly depending on the geological and physical characteristics of the deposits. At the same time, during cyclic injection of CO2, a smaller amount was required in comparison with the areal injection. The increase in the oil recovery coefficient can reached 9.14% with an increase in high viscosity oil recovery rate on average up to 3.8 m3/day/well.