Recognition and sources of secondary biogenic gases in the oil sand areas, Western Canada Sedimentary Basin
Bibliographic record
Abstract
Research Article| March 01, 2015 Recognition and sources of secondary biogenic gases in the oil sand areas, Western Canada Sedimentary Basin Haiping Huang Haiping Huang Department of Geoscience, University of Calgary, 2500 University Drive NW, Calgary, AB T2N 1N4 Canada and School of Energy Resource, China University of Geosciences, Beijing 100083, China Search for other works by this author on: GSW Google Scholar Author and Article Information Haiping Huang Department of Geoscience, University of Calgary, 2500 University Drive NW, Calgary, AB T2N 1N4 Canada and School of Energy Resource, China University of Geosciences, Beijing 100083, China Publisher: Canadian Society of Petroleum Geologists Received: 12 May 2014 Accepted: 10 Dec 2014 First Online: 27 Nov 2017 Online Issn: 2368-0261 Print Issn: 0007-4802 © the Society of Canadian Petroleum Geologists Bulletin of Canadian Petroleum Geology (2015) 63 (1): 20–32. https://doi.org/10.2113/gscpgbull.63.1.20 Article history Received: 12 May 2014 Accepted: 10 Dec 2014 First Online: 27 Nov 2017 Cite View This Citation Add to Citation Manager Share Icon Share Facebook Twitter LinkedIn MailTo Tools Icon Tools Get Permissions Search Site Citation Haiping Huang; Recognition and sources of secondary biogenic gases in the oil sand areas, Western Canada Sedimentary Basin. Bulletin of Canadian Petroleum Geology 2015;; 63 (1): 20–32. doi: https://doi.org/10.2113/gscpgbull.63.1.20 Download citation file: Ris (Zotero) Refmanager EasyBib Bookends Mendeley Papers EndNote RefWorks BibTex toolbar search Search Dropdown Menu toolbar search search input Search input auto suggest filter your search All ContentBy SocietyBulletin of Canadian Petroleum Geology Search Advanced Search Abstract Western Canada Sedimentary Basin oil sand deposits are derived from light oils generated in southwestern Alberta, which migrated to the north and east for more than 100 km. Biodegradation is the primary process that transformed the original light crude oil into heavy oil and bitumen, although other alteration mechanisms were present. Biodegradation levels increase from the southwest (non-biodegraded) to the northeast (extremely biodegraded) and are associated with decreasing reservoir paleo-temperature that plays the primary role in controlling the biodegradation regime. Compositional gradients and variable biodegradation within a single reservoir column indicate that water-leg size is a critical local control on vertical variations of biodegradation degree and oil physical properties.Secondary biogenic gas is a by-product of the formation of heavy oils and bitumens by anaerobic biodegradation, and "gas over bitumen" is a common feature of the bitumen accumulations. Observed 13C-depleted methane and 13C-enriched CO2 provides direct evidence for methanogenic biodegradation and biogenic methane generation. Supplemental evidence for anaerobic biodegradation is found in the geochemistry of associated formation water. The gases associated with anaerobic biodegradation are easily differentiated from primary biogenic gases using the isotopic signature of C2+ alkane components. Based on the observed crude oil biodegradation levels, the stoichiometry of methanogenic alkane biodegradation, and assuming a conversion rate of carbon dioxide to methane, approximately 141.3 × 1012 m3 (4991 Tcf) of secondary biogenic methane was generated accompanying the biodegradation of these petroleum accumulations. However, assessing how much secondary biogenic gas is preserved currently in the subsurface is difficult. Gas resource assessments performed prior to and independent of biodegradation studies suggests that McMurray Formation is expected to contain approximately 58.7 × 109 m3 natural gas in place and that all Mannville Group reservoirs associated with the oil sand regions (Athabasca and Lloydminster) are expected to contain approximately 608.5 × 109 m3 of raw gas in place. Even if the estimates of retained gas are conservative, it is apparent that the vast majority of the secondary biogenic methane generated during biodegradation is leaked into the overburden, dissolved in formation water, or escaped into the atmosphere. Abstract Les sables bitumineux du bassin sédimentaire de l'Ouest du Canada dérivent du pétrole léger ayant migré du sud-ouest de l'Alberta en direction nord et est sur plus de 100 km. La biodégradation constitue le principal procédé de transformation du pétrole brut léger original en pétrole lourd et en bitume, bien que d'autres mécanismes d'altération entrent en jeu. Les niveaux de biodégradation augmentent du sud-ouest (zones sans biodégradation) au nord-est (biodégradation intense) et sont liés à la paléo-température décroissante du gisement laquelle régit principalement le régime de biodégradation. Les gradients compositionnels et la biodégradation variable d'un gisement donné indique que la dimension de la couche d'eau est un facteur local crucial régissant les variations verticales du degré de biodégradation et des propriétés physiques du pétrole.Le gaz biogénique secondaire est un sous-produit de la formation du pétrole lourd et du bitume par biodégradation anaérobique et le gaz au-dessus du bitume est un facteur courant en termes d'accumulations bitumineuses. Le méthane appauvri en C13 et le CO2 enrichi en C13 nous confirment directement la biodégradation méthanique et la production de méthane biogénique. Des preuves supplémentaires de biodégradation anaérobique se trouvent dans la géochimie de l'eau associée à la formation. Il est facile de distinguer les gaz liés à la biodégradation anaérobique des gaz biogéniques primaires par l'emploi de la signature isotopique des composants alkaniques C2+. D'après les niveaux de biodégradation du pétrole brut observés et la stoechiométrie de la biodégration alkane méthanique, en plus de supposer un taux de conversion du dioxide de carbone en méthane, environ 141.3 × 1012 m3 (4 991 Tpi3) de méthane biogénique secondaire a été produit durant le processus de biodégradation de ces accumulations pétrolifères. Cependant, il s'avère plus difficile d'estimer la quantité de gaz biogénique secondaire préservée dans la subsurface à ce moment. L'estimation des ressources gazières réalisée avant les études sur la biodégradation et celle indépendante à celles-ci nous laissent penser que la Formation de McMurray est prévue contenir environ 58,7 × 109 m3 de gaz naturel en place, et que tous les gisements du groupe de Mannville liés aux sables bitumineux de la région (Athabasca et Lloydminster) sont prévus contenir environ 608,5 × 109 m 3 de gaz brut en place. Même si les estimations sur la rétention gazière se révèlent prudentes, il est apparent que la vaste majorité du méthane biogénique secondaire produit durant la biodégradation s'est écoulée dans le recouvrement, dissoute dans l'eau de la formation ou échappée dans l'atmosphère.Michel Ory You do not have access to this content, please speak to your institutional administrator if you feel you should have access.
Fetched live from OpenAlex and de-inverted. Abstracts are not stored in this database: the inverted indexes are 8.6 GB of the frame’s 9.3 GB of text, and the host has 13 GB free.
How this classification was reachedexpand
Full frame machine prediction
Teacher imitationNot calibrated prevalence, not ground truth. Human validation pending. The Gemma side is a direct model label for every work in the frame, read from the title-only record. The Codex side is a classifier learned from the 10,348 direct Codex labels and calibrated to design-weighted sample rates; fields without enough sample support carry no Codex call. Candidate is the union of the two sides; consensus is their intersection. These outputs are machine_predicted_unvalidated and are not human labels.
Distilled classifier scores by category (both heads)
| Category | Codex | Gemma |
|---|---|---|
| Metaresearch | 0.000 | 0.001 |
| Meta-epidemiology (narrow) | 0.000 | 0.000 |
| Meta-epidemiology (broad) | 0.000 | 0.000 |
| Bibliometrics | 0.004 | 0.006 |
| Science and technology studies | 0.001 | 0.001 |
| Scholarly communication | 0.001 | 0.000 |
| Open science | 0.000 | 0.001 |
| Research integrity | 0.000 | 0.000 |
| Insufficient payload (model declined to judge) | 0.002 | 0.000 |
Machine scores (provisional)
The two teacher heads of the student model, read on this work. A score orders the frame for review; it never asserts a category, and the validation status ships verbatim with every row.
Baseline scores from an immature model (maturity gate not passed, 7 training rounds). Scores rank; they never assert a category.
score_only:v0-immature-baseline · verbatim from the scoring run: score_only means the number may rank works, and no category label ships from itClassification
machine, unvalidatedMachine predicted; a candidate call from one source (direct Gemma or distilled Codex), not a consensus.
How this classification was reached, model by model and score by score, is at the end of the page under "How this classification was reached".