Numerical Analysis of Enhanced Heavy Oil Recovery (EHOR) by Chemical Injection

Date
2016
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Abstract
Chemical flooding has been proved to be technically feasible and economically affordable to increase oil recovery in western Canada heavy oil reservoirs. Numerical studies of experimental results are carried out to improve the understanding of EOR mechanism of chemical flooding of heavy oil. Polymer flooding of heavy oil on the lab scale shows appreciable incremental oil recovery. However, when it is extended to field scale, the high recovery efficiency usually cannot be achieved. Scaling-up analysis of polymer flooding of heavy oil is conducted in this research. Twenty-eight dimensionless scaling groups are derived using inspectional analysis and validated by numerical simulation. The effect of each scaling group on oil recovery is examined by sensitivity analysis. Nine scaling groups dominating the process are identified. These dominant scaling groups can be used to design scaled experiments to predict field-scale oil recovery by polymer flooding in heavy oil reservoirs. A fast and effective method to examine the potential of enhanced heavy oil recovery by polymer flooding is developed in this study. Experimental results of sand-pack polymer flooding tests, for heavy oil samples with different viscosities, are analyzed. For each heavy oil sample, the polymer viscosity-sensitive range, within which the incremental recovery increases dramatically with increasing polymer viscosity, is different. To facilitate the evaluation of polymer flooding potential for heavy oils with various viscosities, the oil-water mobility ratio at the end of waterflooding is chosen as a normalization factor. Using normalization, an identical oil-water mobility ratio-sensitive range can be obtained for heavy oils with different viscosities. Based on the normalized relationship, the potential of enhanced heavy oil recovery by polymer injection can be quickly and effectively evaluated. Experimental results of chemical flooding of heavy oil suggested that lower interfacial tension resulted in lower heavy oil recovery. Theoretical analysis is conducted to give a reasonable explanation to the detrimental effect of interfacial tension reduction on heavy oil displacement. The effect of interfacial tension reduction induced by surfactant during heavy oil displacement is further studied by carrying out linear stability analysis, tube bundle calculation and numerical simulations.
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Keywords
Engineering--Petroleum
Citation
GUO, ZIQIANG. (2016). Numerical Analysis of Enhanced Heavy Oil Recovery (EHOR) by Chemical Injection (Doctoral thesis, University of Calgary, Calgary, Canada). Retrieved from https://prism.ucalgary.ca. doi:10.11575/PRISM/27140