Ground Deformation Monitoring by Radar Interferometry and Subsurface Modeling of Oil Sands

Date
2014-09-05
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Abstract
The monitoring of surface displacements at Canadian oil sands sites, where carbon dioxide enhanced oil recovery (CO2-EOR) and cyclic steam stimulation (CSS) methods have been utilized, is conducted by applying radar interferometry. It is determined from differential interferometric synthetic aperture radar (DInSAR) results that surface elevation at the CO2-EOR site remains unchanged from January 2002 to September 2004, whereas noticeable surface deformation occurs between July 2007 and March 2011 at the CSS site. Additional investigation into surface displacements at the CSS site using the small baseline subset (SBAS) algorithm is performed to retrieve time-series maps of the cumulative surface deformation, which accounts for temporal evolutions of the changes in surface elevation. The temporal analysis confirms that the ground surface at the CSS site experiences non-linear time-varying deformations that either return to its initial level or stay unrecovered. The surface subsidence and heave during 3.7 years, reaching up to -33 cm and +72 cm, are observed from the SBAS-derived cumulative surface deformation maps. Subsurface modeling using cumulative surface displacements is performed to infer fractional volumetric changes at the reservoir level for the CSS site. By applying the geomechanical inversion with the Tikhonov regularization technique using reservoir-related parameters and InSAR-derived surface displacements, the fractional volumetric changes in the subsurface are estimated over time. The fractional volumetric changes at the reservoir level range from -1.8 % to +3.9 % for the 3.7 year period. InSAR-driven surface displacements are interpreted with information on CSS operations. The surface deformations coincide with the steam injection and show a time lag of 0 to 6 months between the peak steaming rate and maximum surface heave. The linear regression result indicates that the linear relationship between the fluid volume changes, which are caused by the steam injection and bitumen/water production, and the surface/subsurface deformations is positive with the square of correlation coefficients (R2) greater than 0.5 for all cases. Overall, it is concluded from this study that the surface deformation monitored by radar interferometry conforms well to oil recovery activities at the CSS site.
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Remote Sensing
Citation
Baek, J. (2014). Ground Deformation Monitoring by Radar Interferometry and Subsurface Modeling of Oil Sands (Doctoral thesis, University of Calgary, Calgary, Canada). Retrieved from https://prism.ucalgary.ca. doi:10.11575/PRISM/26326