Bibliographic record
Abstract
To safely store carbon dioxide in enhanced oil recovery/ CO2 sequestration projects it is important to ensure the integrity of the caprock during and after production and injection. A change in fluid pressure and temperature within a porous reservoir will generally induce stress changes within the reservoir and the rocks that surround it. Amongst the potential hazards resulting from these induced stress changes is the reactivation of existing faults or fractures and inducing new fractures, which may breach the hydraulic integrity of the caprock that bounds the reservoir. The theories of inclusions and inhomogeneities have been used in this research to derive semi-analytical and closed-form solutions for induced stress change during pore pressure change within a reservoir and in the surrounding rock, under plane strain and axisymmetric conditions. Methods have been developed to assess fault reactivation and induced fracturing during injection or production within a reservoir. The failure stress change concept for a Coulomb failure criterion has been used to study the likelihood of fault reactivation and induced fracturing within the reservoir. Formulations have been adopted to calculate the critical pressure change for fault reactivation and induced fracturing within the reservoir and in the surrounding rock during injection and production. Sensitivity analysis has been performed to study the effects of different parameters such as initial in-situ stress, reservoir geometry, reservoir depth, reservoir “tilt” or dip , material property contrast between the reservoir and surrounding rock, fault geometry, fault strength, and intact rock strength. General patterns of induced stress change, in-situ stress evolution, fault reactivation, and induced fracturing have been identified. The developed methodologies have been applied to six different case studies: fault reactivation analysis in the entire field for a synthetic case study; induced fracturing analysis in the entire field in a synthetic case study; fault reactivation and induced stress change analysis within the Ekofisk oil reservoir in North Sea; fault reactivation analysis in the Lacq gas reservoir in France; the Weyburn-Midale EOR/CO2 Storage project in southeast Saskatchewan; and acid gas injection in Zama oil field, Alberta. The results of these case studies show good consistency with field observation, and physical and numerical models. The generality, simplicity, and straightforwardness of the developed methodologies, along with their flexibility to model different plausible scenarios and their ease of implementation for systematic sensitivity analyses makes them suitable for decision-making and uncertainty management, specifically in early stages of reservoir development or site assessment for geological sequestration of carbon dioxide.
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 | 0.001 | 0.000 |
| Open science | 0.001 | 0.000 |
| Research integrity | 0.001 | 0.000 |
| Insufficient payload (model declined to judge) | 0.003 | 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".