An experimental study of two multi-fluid flows of interest to the oilfield cementing industry
Bibliographic record
Abstract
In this work two multi-fluid flows are studied. In the first project, displacement flows in an eccentric annulus were studied experimentally. Displacement flows occur in the oil and gas industry during well construction when drilling mud is displaced by a cement slurry. To remove mud effectively, it is important to design the fluid rheology so that a steady displacement front can be achieved when displacing along an eccentric annulus. In our research, we have investigated the effects of viscosity, density and eccentricity of inner pipe on the interface dynamics. An experimental matrix is devised in a manner to capture the boundary between steady and unsteady displacements for specific pairs of fluids, and to compare against previously published models. Reasonable qualitative agreement was achieved however a systematic discrepancy was observed due to the presence of secondary flows and dispersion in the experiments. These effects have not been studied carefully so far and more sophisticated models are needed to predict this type of flow. In the second project, slumping flows of two non-Newtonian fluids in horizontal closed pipes were studied. This type of flow occurs during the abandonment of horizontal oil and gas wells, when sealing the well through the setting of cement plugs. We have studied the effects of changes in density difference and of small deviations from a perfectly horizontal inclination. The effects of these parameters on the slump length versus time were analyzed. Comparison of numerical and experimental results shows broadly similar trends, but with some qualitative differences also observed, possibly due to interfacial effects
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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 | 0.001 | 0.001 |
| Meta-epidemiology (narrow) | 0.000 | 0.000 |
| Meta-epidemiology (broad) | 0.000 | 0.000 |
| Bibliometrics | 0.000 | 0.000 |
| Science and technology studies | 0.001 | 0.001 |
| Scholarly communication | 0.000 | 0.001 |
| Open science | 0.000 | 0.000 |
| Research integrity | 0.001 | 0.001 |
| 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".