Continuously Updating a SAGD Reservoir Model Through the AHM Process

Wisam Shaker, PhD Candidate
Supervisors: Dr. Zhangxing(John) Chen,
Dr. Greg Walker, RE Lead , Talisman


Rate measurements in the well pair and pressure and temperature readings in the observation wells are uncorrelated. The global objective function that included the rate measurements in the well pair and pressure and temperature in two observation wells succeeded to generate a range of models close to the truth case with an acceptable noise through the AHM process. The intersection area on a Venn diagram for the rate, temperature and pressure surveillance should contain the truth model. The  measurements in observation Well 5 are redundant for the current depletion plan that was implemented in the field. The surveillance testing workflow  is able to remove the dangerous models from reservoir portfolio, reduce the uncertainty range of a SAGD reservoir in future outcomes and design  an effective surveillance plan. The rate measurements in well pairs are of high importance in the first period of the history matching. The structure on the PDF of the future reservoir outcomes is a guide that the future surveillance probably adds value to the AHM.  The computational cost of EnKF is fairly low; it can easily be implemented in parallel. Automation is desired but we still need to achieve an integration with the EnKF workflow. The suggested objective functions workflow helps identify the best history matched models in the ensemble.