Under the terms of Annex I of the U.S.-Canada Cooperative Agreement on Tar Sand and Heavy Oil the organizational and laboratory work leading to the development of a physical properties data base has been completed. The data base will be a vehicle for the transfer of information about tar sand and heavy oil between participants of the agreement and to the public.
Information required for complete geological and engineering descriptions of tar sand and heavy oil deposits has been identified. Geological descriptions of the Athabasca and Asphalt Ridge deposits have been prepared. However, little information about many of the engineering properties, such as magnitude and direction of minimum and maximum permeabilities, is available in the literature. The data base will, in its early stages, contain little engineering data.
A computerized data base, developed at the Alberta Research Council, includes information on the visual examination of whole oil sand and determination of physical and chemical properties of whole oil sand and bitumen. Data from cooperative studies sponsored by the Alberta Committee on Oil Sands Analysis and the Phillips Petroleum Company were used to estimate the precision of data in the open literature that woUld be eritered into the data base. These studies
showed that systematic errors during analysis (ie. lack of agreement between laboratories for properties o f a single. sample)lack of agreement between laboratories for properties o f a single. sample) will seriously diminish the significance of a single data point in the data base. ThIs type of data can best be used to estimate the typical properties of a deposit.
In an attempt to identify spme of the reasons for variations in analytical data and to resolve discrepancies, the Western, Research Institute and the Alberta Research Council exchanged samples of oil sand from the Asphalt Ridge and Athabasca deposits. They were able to provide equivalent data for most properties, the exceptions being elehlel1tal ,carbon, carbon residue, relative density (15°C/15°C), and C5 ashphaltenes. A difference in methods for extracting test samples of bitumen was identified as being a potential contributor to differences in the bitumen properties.
In. subsequent studies at the Alberta Research Council, failure to correct for entrained isolids and. residual solvent, which was related to sample preparation, was confirmed to be a major source of discrepancy between the two laboratories' data. In addition, the level of ashphaltenes was significantly affected by prolonged exposure to heat and selective adsorption on cellulose thimbles in the extraction apparatus.
A final exchange of bitumen samples prepared at the Alberta Research Council indicated that discrepancies changed with the capabilities of the laboratories. It appears that the systematic errors that contribute to these discrepancies can only be controlled or at least minimized through the use of secondary standards.