| The Steam-Assisted Gravity Drainage (SAGD) process is a promising method for the efficient recovery of heavy oils and bitumen. In this thesis, new experiments are described which simulate heterogeneous reservoirs.;The results show that a short horizontal barrier does not affect the general performance greatly. A long horizontal barrier decreases the production rate but, in some configurations, not nearly as much as might be expected. For a reservoir containing a long horizontal barrier with bottom steam injection, conductive heat transfer through the barrier raises the temperature of the bitumen above. In some cases, the heated bitumen above the barrier may not flow, even though it is hot, because of the steam pressure holding up the oil at bottlenecks to the flow. This situation resembles a flooded distillation column with a clogged downcomer. Changing the steam injection location from bottom to top of the reservoir can overcome the "flooding" condition by pushing the heated oil to a lower, suitably placed, production well. The effects of horizontal barriers or tilted barriers can be overcome through proper arrangement of the injection and production locations. It is also observed that faster production is found when a higher permeability layer is above a lower permeability layer than when the conditions are reversed. (Abstract shortened by UMI.). |
