Seismic and geomechanical physical properties of bitumen saturated carbonates: application in the development of the Grosmont formation of Alberta

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The carbonate Grosmont formation in NE Alberta holds upwards of 25% of Canada's bitumen resources. To date this resource remains essentially untapped. Production is held back by the unknown risks associated with producing such high viscosity fluids from a rock that is quite different from the more conventional oil sands. One way to reduce this risk is to carry out 'time lapse' seismic surveys over the area in question. Such surveys can help to map out disturbances of the underground c conditions. However, the full value of these expensive seismic surveys cannot be realized without corresponding information on the in situ physical properties of the rocks in the earth. In order to properly interpret this seismic data, one must also have knowledge of how the density and the seismic wave speeds of the rock will change with variations in pressure, temperature, and fluid content. This study seeks to address this problem through a three year collaboration with Laricina Energy Ltd., operator of the joint venture Saleski field pilot project, and its partner OSUM Oil Sands Ltd. We will measure the physical properties of bitumen saturated core materials as they are subject to the conditions of pressure and temperature that are encountered in the earth during stimulation. Seed funding from an ENGAGE grant has allowed us to construct a new pressure-temperature control system; this proposal will now work with this equipment to measure the physical properties of a wide variety of core samples. The initial work will be carried out using ultrasonic transducers at very high frequencies of 1 MHz. However, an important component to this research program is the construction of a novel system that allows us to measure the same properties at low frequencies that are more comparable to the actual seismic field measurements. This is very important for such materials as the wave speeds and attenuations can be quite different between the ultrasonic and the seismic frequency bands. The work will also include a third complementary component that takes advantage of the unique and world class core and log data set obtained by our industrial partner. This allows us to look at in situ fractures and interpret stress adding to our knowledge of the factors influencing seismic responses.