Others are also expressing caution. "It takes a lot of natural gas to process oil sands, and much more will have to be allocated," says James Halloran, Wall Street analyst for National City Bank in Cleveland. Without the added natural gas, "technological improvements will have to be made to make up for the lack of it. At some point, the cost to the environment may limit production growth." Producers, meanwhile, are having trouble getting the needed resources to support increased development of oil sands.
If they have to import natural gas to get the oil out of the sand, that is a showstopper. As a general rule, an energy resource needs to use about 1/2 or less (preferably much less) of it's own energy to be viable. External energy inputs must be minimal.