Time-Lapse Crosswell Tomography in the Atabaska Tar Sands Area

P205 TIME-LAPSE CROSSWELL TOMOGRAPHY IN THE ATABASKA TAR SANDS AREA Abstract Two crosswell seismic surveys were acquired in the Atabaska Tar Sands at Steepbank oil-sand reservoir before and after the start of the steam injection. The objective of the survey was to monitor the shape and the movement of the steam zone. Since seismic velocities decrease with increase of temperature any variations in compressional and shear wave velocities may indicate the advance of the steam zone. High resolution tomographic images have been derived from the crosswell data using direct P- and shear wave arrival times. The direct shear wave arrival