Primary cementing flows: Accurate computation of multi-fluid displacement sequences
Bibliographic record
Abstract
A successful primary cementing operation is critical to maintaining the integrity of oil and gas wells. This operation includes injecting multi-fluid sequences into a narrow eccentric annulus, i.e., displacing the drilling mud first with a wash, followed by a spacer fluid, and finally, one or more cement slurries. We modify the two-dimensional gap averaged and the dispersive two-dimensional gap averaged models for multi-fluid displacement sequences. In particular, we implement a monotone numerical scheme, namely, the local Lax–Friedrichs scheme, for the evolution of the concentrations to ensure that individual fluid concentration bounds between 0≤c¯≤1, and the fluid concentrations sum to 1. The strong conservative properties of the numerical scheme are validated by achieving negligible relative errors (on the order of ∼10−15) for five distinct scenarios. The outcomes of this study can bring a significant improvement in designing the primary cementing operation, where an exact evaluation of fluid volumes is essential.
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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 | 0.003 |
| Meta-epidemiology (narrow) | 0.001 | 0.000 |
| Meta-epidemiology (broad) | 0.001 | 0.000 |
| Bibliometrics | 0.001 | 0.000 |
| Science and technology studies | 0.001 | 0.001 |
| Scholarly communication | 0.001 | 0.001 |
| Open science | 0.002 | 0.001 |
| Research integrity | 0.002 | 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".