TY - GEN
T1 - Comparison of Upscaling methods in a heterogeneous carbonate model (SPE 154499)
AU - Pickup, G. E.
AU - Corbett, P. W.M.
AU - Kazemi, A.
AU - Shaikhina, D. S.
PY - 2012
Y1 - 2012
N2 - Carbonate reservoirs are of great importance, due to their large hydrocarbon reserves. However, their complex structure makes them challenging targets to develop. In order to predict reservoir performance, we need to be able to model the effects of heterogeneity at a variety of scales. In this study, we have constructed a detailed geological model using published data for an outcrop of the San Andres Formation. The resolution of the model is 1.2 m x 0.6 m, much finer than a conventional reservoir simulation model. The aim of this work was to determine if we could develop a feasible approach to upscale the model. A number of single-phase upscaling methods were tested, including averaging (arithmetic/harmonic), and flow-based upscaling with local and extended boundary conditions. In addition the Well Drive Upscaling (WDU) method, a relatively new method, was applied. In this method a single-phase global simulation is performed with appropriate boundary conditions: high pressure at injection wells, low pressure at producers. The flows are then summed and the pressures averaged in order to calculate the effective transmissibilities between the coarse cells. The upscaling methods were tested by simulating a waterflood. Cases with single and multiple relative permeabilities were examined. The upscaling factor in each case was 65 by 5. In general, the coarse-scale models gave late breakthrough, and overestimated the recovery. The WDU method was consistently better than the other methods, because it was able to preserve the correct flow between coarse cells. On the contrary, the conventional flow-based methods with local boundary conditions gave poor results, sometimes worse than averaging. These results show that upscaling in a complex carbonate reservoir is feasible, providing a suitable method, such as the WDU method, is applied.
AB - Carbonate reservoirs are of great importance, due to their large hydrocarbon reserves. However, their complex structure makes them challenging targets to develop. In order to predict reservoir performance, we need to be able to model the effects of heterogeneity at a variety of scales. In this study, we have constructed a detailed geological model using published data for an outcrop of the San Andres Formation. The resolution of the model is 1.2 m x 0.6 m, much finer than a conventional reservoir simulation model. The aim of this work was to determine if we could develop a feasible approach to upscale the model. A number of single-phase upscaling methods were tested, including averaging (arithmetic/harmonic), and flow-based upscaling with local and extended boundary conditions. In addition the Well Drive Upscaling (WDU) method, a relatively new method, was applied. In this method a single-phase global simulation is performed with appropriate boundary conditions: high pressure at injection wells, low pressure at producers. The flows are then summed and the pressures averaged in order to calculate the effective transmissibilities between the coarse cells. The upscaling methods were tested by simulating a waterflood. Cases with single and multiple relative permeabilities were examined. The upscaling factor in each case was 65 by 5. In general, the coarse-scale models gave late breakthrough, and overestimated the recovery. The WDU method was consistently better than the other methods, because it was able to preserve the correct flow between coarse cells. On the contrary, the conventional flow-based methods with local boundary conditions gave poor results, sometimes worse than averaging. These results show that upscaling in a complex carbonate reservoir is feasible, providing a suitable method, such as the WDU method, is applied.
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M3 - Conference contribution
AN - SCOPUS:84928185150
T3 - 74th European Association of Geoscientists and Engineers Conference and Exhibition 2012 Incorporating SPE EUROPEC 2012: Responsibly Securing Natural Resources
SP - 1317
EP - 1326
BT - 74th European Association of Geoscientists and Engineers Conference and Exhibition 2012 Incorporating SPE EUROPEC 2012
PB - European Association of Geoscientists and Engineers, EAGE
T2 - 74th European Association of Geoscientists and Engineers Conference and Exhibition 2012 Incorporating SPE EUROPEC 2012: Responsibly Securing Natural Resources
Y2 - 4 June 2012 through 7 June 2012
ER -