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

Abstract

The problem of intensifying the development of vast highly viscous oil resources is becoming increasingly important, urging oil and gas producers to implement state-of-the-art technologies. The conventional methods used in highly viscous oil production cannot provide a recovery factor better than 15–20 %. Therefore, the key challenge in solving this problem is to select and implement effective technologies enabling the production of such hydrocarbon resources. Some of the current technologies are based on using carbon dioxide as a stimulation agent. These technologies are successfully applied in highly viscous oil fields around the world. This paper reviews and analyses the performance of projects for carbon dioxide injection at highly viscous oil deposits in carbonate reservoirs. It provides information concerning the results of the implementation of the projects for carbon dioxide injection in the domestic and foreign fields. The project performance analysis was based on such indicators as the ratio of injected gas to produced oil volume, the increment of oil recovery factor and the oil production rate per one well. The analysis shows that the ratio of injected carbon dioxide to produced oil volume can vastly vary depending on the geological and physical characteristics of the deposits. Along with that, cyclic СО2 injection requires lesser quantities of the gas compared to dispersed injection. An increment of the oil recovery factor can reach 9.14 % at highly viscous oil production rate growth up to 3.8 m3/day/well on average.

Keywords

• highly viscous oil
• carbonate reservoir
• enhanced oil recovery
• carbon dioxide
• permo-carboniferous deposit of usinskoe field
• immiscible displacement
• simulation technology