Experiments on Displacement of Viscoplastic Fluid in an Annulus With Wavy Inner Wall: Applications in Primary Cementing
Bibliographic record
Abstract
Abstract This study delves into the dynamics of displacement flow within an annulus characterized by sinusoidally varying gap widths, aiming to replicate the effects of borehole irregularities on flow behavior. The experimental setup mimics a scenario where a spacer fluid displaces the mud initially within the annular region of the well. Our experiments utilize miscible fluids with physical and rheological properties similar to those found in field fluids. Specifically, the displacing fluid, brine, emulates a wash, while the displaced fluid comprises a non-Newtonian Carbopol solution, representing drilling mud properties. The annulus was positioned vertically and the displacing fluid was injected from bottom to top. High-speed cameras were used to capture the instantaneous behavior of the displacement flow. Our investigation reveals that the presence of yield stress in the displaced fluid leads to residual viscoplastic fluid remaining within the wavy annulus, predominantly at locations where the gap width is at its maximum. Continuous injection of the displacing fluid is necessary to eliminate these residual layers effectively. The main purpose of this study is to broaden the industry’s perspective on designing effective cementing jobs, which are vital in the construction of oil and gas wells, by including some assessment of the effects of geometric irregularity in the annular geometry.
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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 | 0.000 | 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 | 0.000 | 0.001 |
| Scholarly communication | 0.000 | 0.000 |
| Open science | 0.000 | 0.000 |
| Research integrity | 0.001 | 0.000 |
| Insufficient payload (model declined to judge) | 0.001 | 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".