Consecutive Experimental Determination of Stress‐Dependent Fluid Flow Properties of Berea Sandstone and Implications for Two‐Phase Flow Modeling
Bibliographic record
Abstract
Abstract In this study, changes in the hydrodynamic properties of Berea sandstone at a constant temperature of 40 °C are reported as effective confining stress is increased to 30 MPa. Through a novel consecutive approach, porosity, absolute permeability, drainage relative permeability, and drainage capillary pressure were shown to systematically change with effective stress. The relative permeability measurements were taken using a steady‐state method for the N2/water fluid pair. A second method, in which a saturated core with the wetting phase was flushed with the non‐wetting phase at an increasing flow rate, was used to determine the drainage capillary pressure. Core saturation was determined using a gas separation unit and mass‐balance considerations. This study revealed a decrease in porosity and absolute permeability, from 13.16% and 58 mD to 12.24% and 36 mD, respectively, with the increase in effective confining stress. In terms of relative permeability curves, this study showed a systematic decrease in irreducible wetting phase saturation from 0.44 to 0.24 as effective stress increased; this could be interpreted in core‐scale as a progressive tendency of the initially water‐wet Berea sandstone to the gas phase. The capillary pressure curve also presented an upward shift in response to increased effective stress. These changes in the hydrodynamic rock properties with stress suggest that scaling flow parameters of porous media under effective stress conditions may be required to accurately predict flow behavior under conditions of changing stress.
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 | 0.001 |
| Scholarly communication | 0.000 | 0.000 |
| Open science | 0.000 | 0.000 |
| Research integrity | 0.000 | 0.000 |
| Insufficient payload (model declined to judge) | 0.001 | 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".