evaporation.
The estimated volume of technically recoverable heavy oil (434 billion barrels) and natural bitumen (651 billion barrels) in known accumulations is about equal to the Earth's remaining conventional (light) oil reserves (table 1, fig. 1).
Table 1. Regional distribution of estimated technically recoverable
heavy oil and natural bitumen in billions of barrels (BBO).
|
Region |
Heavy oil
|
Natural bitumen
|
Recovery
factor* |
Technically
recoverable BBO |
Recovery
factor* |
Technically
recoverable BBO |
|
North America |
0.19 |
35.3 |
0.32 |
530.9 |
South America |
0.13 |
265.7 |
0.09 |
0.1 |
W. Hemisphere |
0.13 |
301.0 |
0.32 |
531.0 |
Africa |
0.18 |
7.2 |
0.10 |
43.0 |
Europe |
0.15 |
4.9 |
0.14 |
0.2 |
Middle East |
0.12 |
78.2 |
0.10 |
0.0 |
Asia |
0.14 |
29.6 |
0.16 |
42.8 |
Russia |
0.13 |
13.4 |
0.13 |
33.7** |
E. Hemisphere |
0.13 |
133.3 |
0.13 |
119.7 |
World |
|
434.3 |
|
650.7 |
www.bitumen.loxblog.com |
*Recovery factors were based on published estimates of technically
recoverable and in-place oil or bitumen by accumulation. Where
unavailable, recovery factors of 10 percent and 5 percent of heavy oil
or bitumen in place were assumed for sandstone and carbonate
accumulations, respectively.
**In addition, 212.4 billion barrels of natural bitumen in place is located in
Russia but is either in small deposits or in remote areas in eastern Siberia.
|
|
Figure 1. Distribution of the world's known recoverable oil resources and reserves by type. Technically recoverable oil in known heavy oil and natural bitumen accumulations is about equal to reserves of light oil (API gravity greater than 22°) in known conventional accumulations. BBO, billion barrels of oil. |
In spite of an immense resource base, heavy oil and natural bitumen accounted for only about 3 billion barrels of the 25 billion barrels of crude oil produced in 2000. Compared to light oil, these resources are generally more costly to produce and transport. Also, extra-heavy oil and natural bitumen must usually be upgraded by reducing their carbon content or adding hydrogen before they can be used as feedstock for a conventional refinery. The extra production, transportation, and upgrading costs explain why development and production of extra-heavy oil and bitumen are still limited. Their abundance, strategic geographic distribution, quality, and costs will shape their role in the future oil supply.