In-situ recovery process fluids
The heavy oils produced from the Alberta oil sands contain cyclic organic compounds together with sulphur and nitrogen. Upon thermal treatment they have the potential to form carcinogenic, mutagenic, and toxic compounds. Recovery of oil by in-situ combustion processes, such as the Combination of For...
| Main Authors: | , |
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| Format: | Other/Unknown Material |
| Language: | English |
| Published: |
1988
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| Subjects: | |
| Online Access: | https://doi.org/10.7939/R39J1J https://era.library.ualberta.ca/items/74fda59d-3d25-45bd-982a-009d4fcdd7d1 |
| Summary: | The heavy oils produced from the Alberta oil sands contain cyclic organic compounds together with sulphur and nitrogen. Upon thermal treatment they have the potential to form carcinogenic, mutagenic, and toxic compounds. Recovery of oil by in-situ combustion processes, such as the Combination of Forward Combustion and Waterflood (COFCAW) process, may result in the formation of such biologically active compounds with generation dependent upon operating conditions. The objective of the present research program is to evaluate produced oils and accompanying waters from in-situ combustion processes for possible biological activity. This evaluation is based on biological testing, using the Ames test for mutagenicity and the Microtox test for toxicity, and on the chemical analysis of oils and waters for the presence of known carcinogens. For comparison, oils produced by the less thermally rigorous steam injection process, as well as naturally occurring bitumen, and synthetic crude oil and other oils produced from the Athabasca and Peace River oil sands were examined. Analysis of oils produced by in-situ combustion showed the presence of many carcinogenic and mutagenic compounds, among them the well known carcinogen benzo(a)pyrene (BaP). The BaP content of a mixture of bitumen, cracked oil, and diesel fuel produced by the COFCAW process from the Gregoire Lake pilot project contained 14 µg/g BaP. This compares with 1.5 µg/g in unaltered bitumen and 1 to 3 µg/g in most crude oils. Samples obtained from the Suffield Heavy Oil project which had not undergone rigorous thermal treatment contained from 1.5 to 7.5 µg/g benzo(a)pyrene and emulsion produced by steam injection from the Peace River Pilot project. operated by Shell Canada Resources Limited, contained 2.7 µg/g. An oil produced by dry retorting of the Athabasca oil sands contained 16 µg/g BaP. Oils produced from combustion tube experiments with Athabasca oil sand had a similar BaP content, 2.6 and 4.2 µg/g. Some tars and pitches, especially coal tars, may contain 10 ... |
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