Physical Simulation of Primary Production in Duvernay Shale – Impact of Thermal Maturity on Oil Production
Bibliographic record
Abstract
Abstract Most unconventional wells typically exhibit limited oil production during the primary production stage, primarily due to ultralow permeability of the rock matrix and immaturity of the organic matter. To understand the key factors responsible for this limitation and identify candidate sweet spots for drilling, we conduct physical simulations of the primary production stage in the laboratory. In this study, Duvernay shale samples undergo a single-cycle methane injection process to simulate the primary production stage. We utilize a visualization cell to explore oil-recovery mechanisms under representative reservoir conditions. We soak oil-saturated core plugs with methane at 4,150 psig and a reservoir temperature of 90°C to restore initial reservoir conditions. After equilibrium, we deplete the cell pressure at a controlled rate to simulate the primary production stage. Using two shale samples with different thermal maturity levels, our results demonstrate that methane diffuses into both cores during the soaking; however, it dissolves in oil only in the mature shale sample, resulting in a live oil with a solution gas-oil ratio of 932 standard ft3/stock tank barrel. During the primary production stage, we observe significant oil production under the solution-gas drive mechanism from the mature shale, while the immature shale exhibits negligible oil production. Natural fractures enhance gas penetration into the core, contributing to increased oil production in the primary production stage. Ultimately, the mature shale sample exhibits an oil recovery factor of 25.6% of original oil-in-place after the primary production stage, a remarkable contrast to 1.5% recovery observed in the immature shale. This difference is attributed to the immaturity of the organic matter, insufficient original oil-in-place, and absence of connected oil-wet pore network in the immature shale sample, confirmed by wettability evaluation and rock-eval pyrolysis data.
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 | 0.000 |
| Meta-epidemiology (narrow) | 0.000 | 0.000 |
| Meta-epidemiology (broad) | 0.000 | 0.000 |
| Bibliometrics | 0.000 | 0.000 |
| Science and technology studies | 0.000 | 0.000 |
| Scholarly communication | 0.000 | 0.000 |
| Open science | 0.000 | 0.000 |
| Research integrity | 0.001 | 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".