Abstract

Tar sands (also known as oil sands and bituminous sands) are sand deposits impregnated with the dense, viscous petroleum-like material called bitumen and are widely distributed throughout the world. Commercial methods for the recovery of bitumen from tar sand involve mining and nonmining operations. The Athabasca deposit is mineable within concepts of the economics and technology of open-pit mining. Nonmining (in situ) recovery techniques using steam have not had the same degree of success for bitumen recovery but have had notable success in heavy oil reservoir operations.

The hot-water process is the only successful commercial process in the 1990s to be applied to bitumen recovery from mined tar sand. Various process options have been tested.

The API gravity of tar sand bitumen varies greatly depending on the deposit; viscosity is very high and volatility low. The bitumen is upgraded by a combination of carbon rejection (coking) and product hydrotreating. Bitumen is converted commercially by delayed coking and fluid coking to distillate oils, coke, and light gases. The coker distillate is a partially upgraded material and is a suitable feed for hydrodesulfurization to produce a low sulfur synthetic crude oil.