Geological controls on oil composition and viscosity in Alberta bitumen reservoirs : assessing vertical reservoir continuity
Bibliographic record
Abstract
Petroleum biodegradation in reservoirs produces large vertical and horizontal variations in oil composition and viscosity. This study reviewed fluid property gradients in Alberta oil sands reservoirs in relation to geological controls on intra-reservoir fluid communication and biodegradation. A single vertical oil sands profile was used to provide the molecular hydrocarbon geochemistry of biodegraded oils as well as the systematic vertical concentration gradients of individual compound classes. The study showed that the gradients developed over geological time as influxes of more buoyant oil rose to the top of the reservoir. Variations in specific hydrocarbon concentrations are a function of molecular structure, size, and shape. Rates of diffusion combined with enzyme-controlled biodegradation susceptibility of the component. Concentrations were more sensitive than bulk fluid properties to geological controls such as aquifer size, and reservoir permeability. The study demonstrated that molecular hydrocarbon concentrations can be used to delineate thin barriers to vertical fluid flow on geological timescales. A numerical study of the impact of semi-permeable baffles on fluid in oil sand reservoirs was also presented.
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 | 0.001 | 0.001 |
| Science and technology studies | 0.000 | 0.000 |
| Scholarly communication | 0.000 | 0.000 |
| Open science | 0.000 | 0.000 |
| Research integrity | 0.000 | 0.000 |
| Insufficient payload (model declined to judge) | 0.000 | 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".