In an environment of low oil prices and low economic returns for heavy oil operations, SAGD and VAPEX processes appear very promising from a technical point of view. The purpose of this paper is to present guidelines for screening heavy oil reservoirs for exploitation by Steam Assisted Gravity Drainage (SAGD) and VAPEX processes.
Viability in the field would be strongly governed by factors such as net pay thickness, oil viscosity, presence of gas cap or bottom water, barriers to vertical flow, containment of the steam or vapour chamber within the target area, lateral and vertical extent of steam/vapour chambers, number of new horizontal/vertical wells to be drilled, solvent recovery, facilities requirements, etc.
Exploitation viability of heavy oil reservoirs is evaluated under different reservoir settings using a combination of reservoir/geological analyses and numerical simulation. This evaluation helps provide guidelines for screening reservoir prospects for the application of SAGD/VAPEX processes. The viability of these processes is sensitive to the reservoir characteristics of the specific target areas.