Shallow horizontal drilling in heavy oil reservoirs is a mature technology. However, the differences in regional deposit depths combined with unique oil and rock properties can make for a completely new set of drilling challenges. The in-situ development of the Athabasca Oil Sands (McMurray Formation) characterized by extremely high bitumen concentration and negligible inter granular rock strength definitely provides this type of unique environment.
The phenomena of bitumen accretion along with borehole stability, sand control, and zonal isolation in extreme production temperature environments are the areas where key adaptations have been made from conventional heavy oil developments. Handling drilling waste and designing casing and liners which maintain their mechanical integrity during SAGD production provided further challenges accepted by all the major In-situ Oil Sands developers which include AEC, Suncor, CNRL, Conoco (Gulf), PetroCanada and PanCanadian.