Evaluation Method of CO2 Sequestration and Enhanced Oil Recovery in an Oil Reservoir, as Applied to the Changqing Oilfields, China

Abstract

Injecting CO2 into oil reservoirs was proven to have a great CO2 sequestration capacity to reduce greenhouse gas emission and economic potentials via enhanced oil recovery (EOR). This paper proposes a CO2 sequestration estimation method based on the material balance method, which considered the CO2 displacement efficiency, CO2 sweep efficiency, CO2 dissolution, and some reservoir and fluid properties. The CO2 EOR estimation method is also proposed and refers to the traditional petroleum engineering method. In the evaluation method of CO2 sequestration and EOR potential, the sequestration coefficient and recovery factor are two important parameters. In this study, the stream tube simulation method is introduced to determine them. The evaluation method is applied to estimate the CO2 sequestration capacity and EOR potential in the Changqing oilfield of China. The Changqing oilfield province lies in the Ordos Basin of western China. Published data indicate that the Changqing oilfield includes about 22 oilfiel...