The Structure Parameters Optimization of Variable Direction Joint During Extracting Casing in High-Inclination Directional Well
Bibliographic record
Abstract
During extracting casing in high-inclination directional well, the existence of variable direction joint (VDJ) can enhance the build-up ability of washover string. And it can increase the compatibility between washover head and casing to some extent. However, too large or too small bending angle of VDJ will result in that the washover head cuts the upper and bottom parts of casing. Therefore, it is necessary to design reasonable bending angles for casing damage wells with different borehole curvature. In this paper, through the geometrical and mechanical analysis on the washover string with VDJ, a build-up rate calculation model and an axial force calculation model are established respectively. Moreover, through establishing the finite element model of washover tubing-ball-casing combination, the contact stress distribution is obtained. Under the critical condition of casing breaking when the contact stress exceeds the yield stress, the reasonable bending angle of VDJ matching with different casing damage well is designed. We can conclude that the research results play an important significance for in assuring the safe extracting casing. Key words: Variable direction joint; Safe extracting; Parameters optimization; Casing damage well
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How this classification was reachedexpand
Full frame distilled prediction
Teacher imitationNot calibrated prevalence, not ground truth. Human validation pending. Learned from the 10,348 direct Codex labels and 10,348 direct Gemma labels. Candidate is the union of thresholded teacher heads; consensus is their intersection. These outputs are machine_predicted_unvalidated and are not human labels or direct frontier model labels.
Codex and Gemma teacher scores by category
| Category | Codex | Gemma |
|---|---|---|
| Metaresearch | 0.000 | 0.000 |
| 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 | 0.000 |
| Scholarly communication | 0.000 | 0.001 |
| Open science | 0.000 | 0.000 |
| Research integrity | 0.000 | 0.000 |
| Insufficient payload (model declined to judge) | 0.000 | 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 teacher head, 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".