Experimental Investigation of the Influence of PDC Bit With Stinger on Drilling Performance Under Different Hole Cleaning Efficiencies
Bibliographic record
Abstract
Abstract The original design of the hole opener was a stinger without a bit and was meant to guide the hole along a previously drilling pilot hole and to keep drill cuttings from falling back into the pilot hole and efficiently transport them to the surface. Later hole opener designs included and end-of-stinger bit, initially a roller cone bit and later a PDC bit. Previous research conducted at the Drilling Technology Laboratory (DTL) involved using a PDC bit at the end of the stinger for drilling experiments in both field and lab settings. These experiments revealed improved drilling performance compared to using a flat base or a passive end-of-stinger bit. Building on this research, our study focuses on drilling with a PDC bit at the stinger, but at varying distances from the base. Our aim is to examine how the distance between the stinger bit and the base bit affects drilling performance and to establish correlations that can help optimize the length of the end-of-stinger bit for optimal drilling performance. We conducted experiments drilling various types of rocks under different Weight on Bit (WOB) and Revolution Per Minute (RPM) conditions. Experimental results indicated that drilling with and without the stinger had similar drilling performance in terms of ROP and drilling torque at low WOB. However, as WOB increased the founder point for drilling with the stinger was pushed to higher WOB and the drilling performance using the stinger was improved compared to drilling without the stinger. Drilling performance for all stinger lengths used were similar with no specific configuration performing better than the others.
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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 | 0.001 | 0.003 |
| Meta-epidemiology (narrow) | 0.001 | 0.000 |
| Meta-epidemiology (broad) | 0.001 | 0.000 |
| Bibliometrics | 0.001 | 0.001 |
| Science and technology studies | 0.000 | 0.000 |
| Scholarly communication | 0.001 | 0.001 |
| Open science | 0.001 | 0.001 |
| Research integrity | 0.001 | 0.001 |
| Insufficient payload (model declined to judge) | 0.003 | 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".