Rapid SAGD Simulation Considering Geomechanics for Closed Loop Reservoir Optimization

• Author / Creator

  Azad, Ali

• While numerical modeling and coupling techniques have been continuously studied, analytical solution or proxy modeling for geomechanical coupling of the steam assisted gravity drainage (SAGD) has not been clearly addressed in the literature. Simulations aside, there is no particular study on the use of geomechanics in closed loop reservoir optimization.
  This research has been carried out to cover two major objectives; providing a low order model to work with real-time data, and also investigating high-resolution geomechanical-flow simulation to work with data assimilation algorithms for history matching and reservoir characterization.
  As the first step, a physics-based semi-analytical model was proposed based on the original Butler/Reis SAGD theory. The model was proposed for linear steam chamber geometry by modifying the variation of oil saturation in advance of the steam chamber. The model was then verified with the past experimental lab test results and numerical simulation results. Geomechanics was incorporated using the classical limit equilibrium theory. The linear geometry model was then replaced by circular geometry model to better simulate the rising and depletion stages of SAGD process. For the circular geometry model, a multiplier coefficient was defined to consider geomechanics called the geomechanical impact factor (GIF). The final version of the proposed model was used for history matching two SAGD projects, UTF phases A and B.
  The application of analytical models in automated history matching and reservoir characterization was further investigated using the extended Kalman filter (EKF). For this case, Butler/Reis theory and the GIF concept were combined with the EKF for history matching the heterogeneous reservoirs with uncertainty. Using synthetic data and stochastic reservoir realizations, it was shown how analytical models are helpful in reservoir characterization.
  While the analytical solution is placed at the centre of the optimization process, the second objective of this research was explored by applying the ensemble Kalman filter (EnKF) to link monitoring data to the simulator(s). For this reason, an iterative geomechanical-flow coupling code was developed and assembled with the EnKF. Through numerical simulations using synthetically generated data, the significance of considering geomechanical monitoring data in reservoir surveillance was examined.

• Subjects / Keywords

  • Coupled Simulation
  • Analytical Solution
  • SAGD
  • Reservoir Characterization
  • Geomechanics
  • Kalman Filter
  • Thermal Recovery
  • Proxy Modeling

• Graduation date

  Spring 2012

• Type of Item

  Thesis

• Degree

  Doctor of Philosophy

• DOI

  https://doi.org/10.7939/R3TK9K

• License

  This thesis is made available by the University of Alberta Libraries with permission of the copyright owner solely for non-commercial purposes. This thesis, or any portion thereof, may not otherwise be copied or reproduced without the written consent of the copyright owner, except to the extent permitted by Canadian copyright law.