Reserves and Resources¹

¹ Based on independent reserves and resources estimates by GLJ Petroleum Consultants Ltd. as of December 31, 2008. See reserves and resources cautionary advisory in Canadian Oil Sands’   Annual Information Form dated March 13, 2009 and the definitions below.
² The Trust, through its operating subsidiary, holds a 36.74% interest in the Syncrude Project. 

Proved Reserves that can be estimated with a high degree of certainty to be recoverable. NI 51-101 further identifies the certainty level for proved reserves as “at least a 90% probability that the quantities actually recovered will equal or exceed the estimated proved reserves”.

Proved plus Probable Reserves  Additional reserves that are less certain to be recovered than proved reserves. NI 51-101 defines the certainty level as “at least a 50% probability that the quantities actually recovered will equal or exceed the sum of the estimated proved plus probable reserves.” Therefore, under NI 51-101, the proved plus probable reserves represent a “best estimate” or “expected reserves”.

Contingent Resources  Quantities of petroleum estimated, as of a given date, to be potentially recoverable from known accumulations using established technology or technology under development, but which are not currently considered to be commercially recoverable due to one or more contingencies.

Prospective Resources  Quantities of petroleum estimated, as of a given date, to be potentially recoverable from undiscovered accumulations by application of future development projects. Prospective resources have both an associated chance of discovery and a chance of development.

Best Estimate  Term used to describe an uncertainty category for resources estimates referring to the best estimate of the quantity that will actually be recovered. It is equally likely that the actual remaining quantities recovered will be greater or less than the “best estimate”. The best estimate of Contingent and Prospective Resources is prepared independent of the risks associated with achieving commercial production.

See the "Reserve Data and Other Information" section of Canadian Oil Sands' Annual Information Form  for additional information on reserves and resources.