Sensitivity Analysis and Evaluation for Carbon Dioxide Storage Coefficient in the Process of Oil Displacement

Abstract

Achieving a permanent CO 2 storage in the process of CO 2 flooding in oil reservoir, which is the most realistic way to fulfill CO 2 emission reduction obligations for developing countries. It will provide reliable data for CO 2 reduction and enhanced oil recovery to evaluate correctly and research clearly the CO 2 storage and displacement efficiency. Through theoretical analysis and numerical simulation methods, the introduction of the concept of CO 2 storage coefficient, the CO 2 storage and displacement efficiency are analyzed and evaluated under CO 2 miscible and immiscible flooding. It focuses on the effects of the reservoir parameters, fluid parameters and CO 2 injection methods on CO 2 storage and flooding in the CO 2 miscible flooding with the different injection volume conditions. The results show that the CO 2 storage and displacement efficiency for miscible flooding is significantly higher than immiscible flooding. Moreover, with the increasing volume of CO 2 injected, CO 2 storage coefficient and oil recovery are increased. The vertical and horizontal permeability ratio, oil viscosity and the injection method have the important implications on the CO 2 storage coefficient. It can be drawn from the analysis and evaluation results, CO 2 miscible flooding is an effective way of storage and displacement, meanwhile, the CO 2 storage and oil recovery can be the best in a certain range of CO 2 injection volume. The conclusions and understanding achieved is technical reference for CO 2 storage in oil reservoir, and to provide a strong basis for CO 2 storage project implementation on site.