Simulation Study of Surfactant Flooding for EOR Applied to Edvard Grieg Field
Abstract
The global average oil recovery does not exceed 45% as after the primary and secondary recovery, a large amount of oil is left behind in the reservoir. This oil needs to be recovered to meet ever-increasing oil demand and to do so, several Enhanced Oil Recovery (EOR) technologies have been developed. This thesis will focus on surfactant based enhanced oil recovery processes. Laboratory experiments and field projects have proved the efficiency of surfactant flooding in increasing the oil recovery. To ensure successful long-term reservoir recovery, engineers often use methods like numerical simulations and pilot studies. This thesis uses the Eclipse black oil simulation model (Eclipse 100) to simulate surfactant flooding. The purpose of this thesis work is to apply a numerical simulation of surfactant flooding in a sector model from Edvard Grieg Field model and to estimate EOR potential. The mechanisms of enhanced oil recovery by surfactant are discussed in this thesis, and different designs of surfactant flooding are studied to optimize the project profitability. The base case results show that adding surfactants to injection water can increase the oil recovery by 5.8 %. The combination of surfactant and polymer was also investigated, and sensitivity analyses were made to see how the changes in chemicals concentrations and slug sizes would affect the oil recovery.The Net Present Value (NPV) calculations were used to evaluate the economic efficiency of surfactant and surfactant-polymer projects.The study shows that, with the assumptions made, surfactant-polymer flood has increased the oil recovery of the selected reservoir by 9.8 % and provided an important financial return.