Introduction to this Special Section: Heavy Oil

With giant reservoirs declining, few giant discoveries, and increased demand, it is clear that the world will rely, in the short term at least, on a readily available alternative to conventional oil—heavy oil. Most heavy-oil deposits are in Canada and Venezuela, both of which contain recoverable reserves comparable to those of Saudi Arabia. Other significant deposits are in the United States (California, Alaska, and Utah), Mexico, Russia, China and Oman (Figure 1).