Numerical Simulation of Effect of Eccentricity on Annulus Pressure of Aerated Drilling
Bibliographic record
Abstract
Aerated drilling can effectively solve the mud leakage, reservoir pollution and the critical question of the effect of productivity. It also can protect, find and correctly evaluate oil and gas resources. The technology of aerated drilling is applied to detailed exploration and step-out well of oil and gas field of low pressure, this technology has wide applications. Based on the previous researches, the effect of drill string under the condition of eccentricity on annulus pressure is considered in this paper. After in-depth investigations, annulus pressure of concentric and eccentric conditions are analyzed through the CFD numerical simulation, the distribution law of pressure of eccentric annulus along well depth is expounded. The following conclusions can be showed through the CFD numerical simulation: the annulus pressure of aerated drilling follows curve, the pressure decreases gradually from the bottom to wellhead. The pressure does not vary abruptly in the position of changing area of annulus cross-section, the reason is that the gravitational pressure drop plays the leading position in the annulus pressure drop. Liquid is incompressible fluid, although the gas volume is changed, the density of gas is small relative to the density of liquid, so the density of drilling fluid changes little in the variable cross-section. Under the same conditions, the flow pressure drop of eccentric annulus is less than concentric annulus. Key words: Aerated drilling; Concentric annulus; Eccentric annulus; Annulus pressure; CFD numerical simulation
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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 | 0.002 |
| Meta-epidemiology (narrow) | 0.000 | 0.000 |
| Meta-epidemiology (broad) | 0.001 | 0.001 |
| Bibliometrics | 0.001 | 0.001 |
| Science and technology studies | 0.001 | 0.001 |
| Scholarly communication | 0.001 | 0.001 |
| Open science | 0.001 | 0.001 |
| 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".