Survey of Energy Resources 2007
Natural Bitumen - Summary and Implications
Occurrences of natural bitumen and extra-heavy oil are widespread; the volume of oil in place appears to be of at least the same order of magnitude as the volume of original oil in place at known conventional oil accumulations. The Alberta bitumen deposits are the only bitumen projects that are currently produced and upgraded to refinery feedstock or SCO. The commercially successful Orinoco Oil Belt and Alberta oil sands extraction and upgrading technologies will probably be applied to other deposits listed in Tables 4-1 and 4-2. These projects have demonstrated, at least for the Orinoco Oil Belt and the Canadian oil sands, that these resources can be extracted and upgraded at rates that make an important contribution to each country's petroleum supply and at costs that are currently competitive with conventional non-Opec resources.
Estimates of supply costs per barrel for natural bitumen are higher than for many sources of conventional crude oil supply.
Moreover, market prices of raw bitumen/diluent blend are discounted by refiners relative to conventional oil prices. As a response to the risk in the volatility of bitumen and heavy oil prices, operators of new projects will either vertically integrate extraction with upgrader/refinery facilities or develop alliances for upgrading/refining their extracted product.
Venezuela has agreements with several national oil companies to evaluate areas of the Orinoco Oil Belt outside of the current project areas for expansion of its extra-heavy oil production base. In Canada the large number of proposed projects that would expand bitumen production has raised some concern about the adequacy of natural gas, diluents, and fresh water supplies. The technologies known as VAPEX (Vapor-Assisted Petroleum Extraction) and THAI (Toe-to-Heel Air Injection) are designed to address the water and gas inadequacy concerns. These are in the field testing stages. In the VAPEX process, a mixture of light hydrocarbon liquids is injected into the reservoir to enhance the reduction in bitumen viscosity induced by steam injection. The enhancement of viscosity reduction brought about by the VAPEX process reduces the steam (water and natural gas) requirements for SAGD projects. The THAI process entails igniting oxygen through a vertical air injection well to lower the viscosity of the bitumen and then recovering the bitumen through a horizontal production well, thus eliminating the need for gas and water for steam injection.
Richard F. Meyer
US Geological Survey