Non-linear Axial Vibrations of Composite Drill Strings Considering Interaction of Roller Cone Bit and Polycrystalline Diamond Compact Bit with Rock
Bibliographic record
Abstract
Due to the world increasing energy demands, optimizing the drilling system parameters such as the weight on bit (WOB), and the structure of drill string and bit, also vibrations and dynamic behavior of drill strings are of significant interest to researchers and energy industries. Specially, to overcome limitations of drilling operations in oil and gas industry, composite drill strings as high-tech devices are under development. In this research, the fully coupled non-linear axial vibrations of composite drill strings due to the interaction of two common bits namely; Roller Cone (RC) and Polycrystalline Diamond Compact (PDC) with rock, considering the major non-linear terms, the drill string-wellbore contact, the different weight on bit (WOB) and the different composite configurations using the finite element method (FEM) and the Lagrangian approach were studied. This study proved that the different configurations of composite drill strings showed specific dynamic behavior at different conditions. Therefore, composite drill string can be designed for particular purposes. Also, the results imply the remarkable effects of weight on bit (WOB) and type of bits on the axial vibrations of composite drill strings.
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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 | 0.000 |
| 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 | 0.000 |
| 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".