TY - CONF
T1 - A new way of compositional simulation without phase labeling
AU - Khorsandi, Saeid
AU - Li, Liwei
AU - Johns, Russell T.
N1 - Funding Information:
The authors thank the member companies of the Enhanced Oil Recovery JIP in the EMS Energy Institute at The Pennsylvania State University at University Park, PA for their financial support. Dr. Russell T. Johns holds the George E. Trimble Chair in Earth and Mineral Sciences and the Energi Simulation Chair in Fluid Behavior and Rock Interactions at Penn State.
Publisher Copyright:
© 2018, Society of Petroleum Engineers.
PY - 2018
Y1 - 2018
N2 - Current relative permeability models rely on phase labeling, and cannot accurately capture the effect of compositional variations on relative permeabilities and capillary pressures in enhanced oil recovery (EOR) processes. Discontinuities in flux calculations not only cause serious convergence and stability, but also affects the estimated recovery factor. We developed a fully compositional simulation model using an equation of state (EoS) for relative permeabilities to eliminate the unphysical discontinuities in flux functions caused by phase labeling. In addition, we extended our relative permeability EoS to three phases. The model can capture complex hysteresis effects on three-phase relative permeability. The tuned model is used for simulation of multi-cycle WAG injection. The approach allows for a new search scheme to improve initial estimates for flash calculation. The results show increased robustness of high-resolution compositional simulation for both front calculations (recovery estimates) and convergence of flash algorithms. This paper provides a novel way forward to develop a fully compositional reservoir simulation based solely on continuous and robust equation-of-state relative permeabilities. In addition, this paper provides a detailed analysis of the effects of discontinuous phase labeling on simulation performance and accuracy for 1-D and 2-D water-alternating-gas flooding and three-hydrocarbon-phase flow. The results demonstrate the significant benefits of using an EoS for relative permeabilities.
AB - Current relative permeability models rely on phase labeling, and cannot accurately capture the effect of compositional variations on relative permeabilities and capillary pressures in enhanced oil recovery (EOR) processes. Discontinuities in flux calculations not only cause serious convergence and stability, but also affects the estimated recovery factor. We developed a fully compositional simulation model using an equation of state (EoS) for relative permeabilities to eliminate the unphysical discontinuities in flux functions caused by phase labeling. In addition, we extended our relative permeability EoS to three phases. The model can capture complex hysteresis effects on three-phase relative permeability. The tuned model is used for simulation of multi-cycle WAG injection. The approach allows for a new search scheme to improve initial estimates for flash calculation. The results show increased robustness of high-resolution compositional simulation for both front calculations (recovery estimates) and convergence of flash algorithms. This paper provides a novel way forward to develop a fully compositional reservoir simulation based solely on continuous and robust equation-of-state relative permeabilities. In addition, this paper provides a detailed analysis of the effects of discontinuous phase labeling on simulation performance and accuracy for 1-D and 2-D water-alternating-gas flooding and three-hydrocarbon-phase flow. The results demonstrate the significant benefits of using an EoS for relative permeabilities.
UR - http://www.scopus.com/inward/record.url?scp=85050478358&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=85050478358&partnerID=8YFLogxK
U2 - 10.2118/190269-ms
DO - 10.2118/190269-ms
M3 - Paper
AN - SCOPUS:85050478358
T2 - SPE Improved Oil Recovery Conference 2018
Y2 - 14 April 2018 through 18 April 2018
ER -