SPE Reservoir Evaluation & Engineering
Volume 14, Number 5, October 2011, pp. 634-643

SPE-141207-PA

Near-Well-Subdomain Simulations for Accurate Inflow-Performance-Relationship Calculation To Improve Stability of Reservoir/Network Coupling

View full textPDF ( 624 KB )

DOI  More information 10.2118/141207-PA http://dx.doi.org/10.2118/141207-PA

Citation

  • Gűyagűler,B., Zapata, V.J., Cao, H., Stamati, H.F., and Holmes, J.A. 2011. Near-Well-Subdomain Simulations for Accurate Inflow-Performance-Relationship Calculation To Improve Stability of Reservoir/Network Coupling. SPE Res Eval & Eng 14 (5): 634-643. SPE-141207-PA. http://dx.doi.org/10.2118/141207-PA.

Discipline Categories

  • 6.5 Reservoir Simulation

Keywords

  • reservoir-surface network coupling, subdomain simulation, coupling oscillations, balancing errors

Summary

Externally coupled workflows that rely on exchanging inflow-performance relationships (IPRs) at the coupling points, such as those between reservoir and surface-network simulators, may exhibit oscillations because of the IPR calculated at the beginning of a timestep not being representative of the IPR at the end of the timestep. One solution is to have an implicitly coupled reservoir/surface system. This is often impractical because the reservoir and the surface network may be modeled using different applications, or the resulting coupled system may become too large and too complex to solve implicitly because of processing time and convergence issues. We propose the calculation of multipoint IPRs obtained by solving near-well subdomains for the subsequent timestep. A flexible reservoir-simulation architecture enables the dynamic creation and simulation of near-well subdomains at run time. Subdomains are created automatically within the vicinity of the well or may be defined dynamically from the pressure gradient. These near-well-subdomain simulations are embedded within the full-field simulation and extract all the required model properties (pressure/volume/temperature, rock) from the full-field model. The most recent fluxes from the global solution are used as boundary conditions for the near-well subdomains. In this paper, the subdomain IPRs are used within reservoir/network coupling workflows for which traditionally calculated IPRs result in oscillations and high errors. Sensitivity analysis is carried out on the extent of the subdomains and the size of the coupling timestep. A real field case is used to show that subdomain IPRs result in smooth pressure/rate profiles as opposed to the oscillatory profiles obtained from explicitly calculated IPRs and that they also help reduce balancing errors between reservoir and surface models.

© 2011. Society of Petroleum Engineers

View full textPDF ( 624 KB )

History

  • Original manuscript received: 22 January 2011
  • Meeting paper published: 20 October 2010
  • Revised manuscript received: 19 April 2011
  • Manuscript approved: 1 July 2011
  • Published online: 3 October 2011
  • Version of record: 13 October 2011