Oil Field Deformation Monitoring with RADARSAT-2

Staples, Gordon¹; Lehrbass, Brad; and Henschel, Michael
¹[email protected]

The focus of this study was to use InSAR to monitor surface deformation that occurs when bitumen is extracted using a process termed Cyclic Steam Stimulation (CSS). CSS results in significant volumetric strain of the reservoir, so deformation is of interest. The surface deformation can provide insight into the recovery process effectiveness, casing, and surface facility integrity.

The approach entailed the installation of corner reflectors on pipeline-pilings which respond to the surface deformation induced by the CSS process. RADARSAT-2 UltraFine data were acquired every 24 days. MDA-developed InSAR algorithms were applied to the data to estimate millimeter-scale surface deformation. A reservoir dilation model was used to calculate the amount of surface heave and the model results were compared with the InSAR measurements. The model had a number of variable parameters of which the initial pore pressure, the failure pore pressure, and the dilation between the initial and the final pore pressures are the most significant.

There was good agreement between the InSAR and model with respect to surface heave or subsidence, but not with the magnitude of the deformation. To better understand why the magnitude differed, two wells were analyzed. For study well F07, using the standard parameters for the dilation calculation, the heave model only predicted ~30 mm of heave versus ~120 mm of InSAR-measured heave. Good agreement between the model and InSAR was obtained if the dilation prior to fill-up was increased to account for the larger depleted zone of a late-cycle CSS well. For study well U, the heave model predicted over 110 mm of heave versus ~80 mm from InSAR. Good agreement was obtained if the dilation at fill-up was eliminated since the steam was injected into a new reservoir.

A geomechanical heave model is a valuable predictive tool for enhanced oil recovery operations; however each well has different steam chamber and overburden structure and responds differently to steaming. InSAR deformation measurements can be used to improve a heave model using physically meaningful calibration parameters and to monitor the surface deformation over time to verify the heave model’s predictive accuracy.

AAPG Search and Discovery Article #90166©2013 AAPG International Conference & Exhibition, Cartagena, Colombia, 8-11 September 2013