Merrick Johnston

Temperature and Frequency Dependence of Viscoelasticity in Bitumen: Lab Measurements on Heavy Oil and Bitumen Merrick Johnston

Bitumen is a viscoelastic material that has a nonzero shear modulus at low temperatures and/or high frequencies. This viscoelastic behavior results from its large, complex, molecular compounds that create dense, viscous hydrocarbons. Subsurface bitumen fields require secondary recovery processes to reduce viscosity and produce the hydrocarbons. Heat is one of the primary techniques. The change of velocity in the reservoir should be a function of the temperature and production of the bitumen. This thesis has two lines of investigation to aid in understanding the temperature and frequency dependency of viscoelasticity in bitumen and bitum-saturated rock, and from that, to assist others in interpretation of their time-lapse seismic data. Along the first line of investigation, this research made lab measurements to estimate velocities as a function of temperature and frequency of the Canadian Grosmont formation reservoir rocks. The thesis measurements focused on two sets of samples: a) homogeneous, dolomite core plug, which was grain-supported and b) smaller heterogeneous reservoir samples, which were bitumen- supported.