Tomographic Reconstruction for Imaging EOR Processes in Hydrocarbon Reservoirs

Clastic reservoirs saturated with heavy oils have been observed to exhibit a marked relationship between velocity of propagation of acoustic waves and temperature of the oil saturated sediments. This observation forms the basis for a method of monitoring the changes which occur in the reservoir when thermal enhanced oil recovery (EOR) procedures are used. New developments in crossborehole tomographic imaging allow accurate images of the reservoir to be obtained, clearly delineating the zones affected by thermal EOR. Using both compressional and shear components of the wavefield (representing distinct coupled modes of propagation in an elastic medium), a variety of physical parameters such as incompressibility (bulk modulus), shear modulus, and Poisson ratio can be tomographically reconstructed.