Collapse Strength Study for the Solid Expandable Tubular
Bibliographic record
Abstract
Abstract The paper summarized an experimental and theoretical study of the collapse resistant ability of solid expandable tubular (SET)after expansion, and the formula used to calculate the collapse strength of casing was modified to make it adaptable to the expandable tubular. One key limiting factor of the expandable tubular in its application in the open hole well to replace the casing is its post-expanded mechanical properties. The collapse strength of the expandable tubular after expansion was significantly compromised as the result of the comprehensive influence by the change of factors like the ovality, eccentricity and residual stress. In view of these problems, firstly full-scale expansion experiments were performed to examine all the impact of those factors; secondly the formula was modified based on the experimental data; thirdly the collapse experiments were carried out to test the strength of post-expanded tubulars as well as the accuracy of the modified formula. The results demonstrated that after large-scale plastic deformation, the dimension of the tubular changed dramatically as represented by the increase of eccentricity and ovality, the residual stress also appeared on both inside and outside surface of the tubular, the starting point of the collapse occurred at the position with the least wall thickness. The calculation results which reflected the average collapse strength of the tubular were larger than the actual experimental outcome but the error was kept well within 15%. We expect the research will contribute to the better understanding of the collapse resistant ability of post-expanded tubular and form the necessary technical basis for it future broad use.
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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 | 0.001 | 0.000 |
| Science and technology studies | 0.000 | 0.001 |
| Scholarly communication | 0.000 | 0.001 |
| Open science | 0.001 | 0.000 |
| Research integrity | 0.000 | 0.000 |
| Insufficient payload (model declined to judge) | 0.003 | 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".