Using Polymer Alternating Gas to Enhance Oil Recovery in Heavy Oil

3rd International Conference on Advances in Energy Resources and Environment Engineering

能源学;生态环境科学

Yang, Yongzhi^1 ; Li, Weirong^2 ; Zhou, Tiyao^1 ; Dong, Zhenzhen^3

State Key Laboratory of Enhanced Oil Recovery, Petrochina, Beijing

100083, China^1

BIC-ESAT, Peking University, Beijing

100193, China^2

Petroleum Engineeting Department, Xi'An Shiyou University, Xi'an

710065, China^3

关键词: Economic performance;    Enhance oil recoveries;    Heavy oil reservoirs;    Heterogeneous reservoirs;    Polymer flooding;    Reservoir modeling;    Sweep efficiency;    Water alternating gas;   

Others  :  https://iopscience.iop.org/article/10.1088/1755-1315/113/1/012182/pdf
DOI  :  10.1088/1755-1315/113/1/012182

学科分类：环境科学（综合）

来源: IOP

【 摘 要 】

CO2has been used to recover oil for more than 40 years. Currently, about 43% of EOR production in U.S. is from CO2flooding. CO2flooding is a well-established EOR technique, but its density and viscosity nature are challenges for CO2projects. Low density (0.5 to 0.8 g/cm3) causes gas to rise upward in reservoirs and bypass many lower portions of the reservoir. Low viscosity (0.02 to 0.08 cp) leads to poor volumetric sweep efficiency. So water-alternating-gas (WAG) method was used to control the mobility of CO2and improve sweep efficiency. However, WAG process has some other problems in heavy oil reservoir, such as poor mobility ratio and gravity overriding. To examine the applicability of carbon dioxide to recover viscous oil from highly heterogeneous reservoirs, this study suggests a new EOR method - polymer-alternating gas (PAG) process. The process involves a combination of polymer flooding and CO2injection. To confirm the effectiveness of PAG process in heavy oils, a reservoir model from Liaohe Oilfield is used to compare the technical and economic performance among PAG, WAG and polymer flooding. Simulation results show that PAG method would increase oil recovery over 10% compared with other EOR methods and PAG would be economically success based on assumption in this study. This study is the first to apply PAG to enhance oil recovery in heavy oil reservoir with highly heterogeneous. Besides, this paper provides detailed discussions and comparison about PAG with other EOR methods in this heavy oil reservoir.