Numerical Analysis of Cuttings Accumulation Tendency in Horizontal Annulus at Different Drilling Conditions
Bibliographic record
Abstract
Abstract The influence of rotational speed and eccentricity of the drill pipe as well as the effect of fluid flow rate on the accumulation of cuttings in the horizontal annulus are the focus of this study. Computational Fluid Dynamics (CFD) is utilized to model a horizontal annulus section which conveys solid-liquid two-phase flow at different drilling conditions. In this numerical study, the Eulerian multiphase flow model has been adopted for solidliquid characteristics analysis. Here the basic continuity and momentum equations have been considered, which have further been reduced to solve the conservation of mass and momentum equations with appropriate boundary and initial conditions. The study has considered the transient, turbulent model (k-epsilon) with no-slip conditions at pipe walls as well as velocity inlet and pressure outlet at the boundaries. The result indicates the clear impact of rotational speed on the cuttings removal process in the horizontal annulus section. As the rotational speed of the drill pipe increases, the cuttings concentration drops down significantly in the annulus section. Around 20% less accumulation is noticed if the drill pipe rotation is increased from 0 RPM to 120 RPM, which happens due to momentum created by the rotation that does not allow the particles to be accumulated. The eccentricity has a significant impact on solid accumulation as well. However, with increased flow rate and eccentricity, the pressure across the annulus section drops substantially. The difference in pressure drop is noticed as much as around 61 Pa/m with the flow rate change. Consequently, a higher pressure drop per length for the higher velocity of fluid implies higher pumping power consumption. The findings from this study may help to understand the optimum operating conditions for horizontal drilling. The effects of drilling conditions are identified and the complex multiphase flow in the annulus is modeled that could be extended to further related studies.
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 | 0.001 |
| Meta-epidemiology (narrow) | 0.000 | 0.000 |
| Meta-epidemiology (broad) | 0.000 | 0.000 |
| Bibliometrics | 0.001 | 0.000 |
| Science and technology studies | 0.000 | 0.000 |
| Scholarly communication | 0.001 | 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".