Horizontal Drilling with Dual Channel Drill Pipe
Bibliographic record
Abstract
Abstract Drilling of long horizontal wells is subjected to challenges, such as hole cleaning, drill string torque and drag, and challenges related to the Equivalent Circulating Density (ECD). Where the window for the downhole pressure is small, the length of the open hole section is limited by the dynamic ECD. The result is that several liners or casing strings may be required to reach the target depth. The Reelwell Drilling Method provides a new solution for above mentioned challenges, incorporating a dual drill string, with a separate channel for the return fluid from the well. This arrangement enables Managed Gradient Drilling, i.e. to drill with a constant downhole pressure gradient that can be controlled to be nearly independent of the flow rate. The solution is similar to Managed Pressure Drilling, however, differs in that the downhole pressure gradient is managed instead of the pressure at one depth in the well. In addition, this new method of ECD control provides efficient hole cleaning at low flow rates, and enables torque and drag reduction due to buoyancy of the drill string. A shallow horizontal trial well was drilled onshore Alberta, Canada, March 2016, to verify the new technology. New drilling equipment, including a newly designed aluminum dual drill string was used. New drilling procedures were employed, including the new Heavy Over Light drilling fluid solution. The equipment and procedures successfully verified the key benefits of the technology: –Managed Gradient Drilling with ECD eliminated by near static well annulus fluid.–Torque and drag reduction resulting from the drill string buoyancy effect.–Efficient hole cleaning at low flow rate, due to return flow inside the dual drill string. In the following sections, we describe the technology, how the field trial was organized and present drilling data from the shallow horizontal drilling operation that confirmed the capabilities of the system.
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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 | 0.000 |
| Scholarly communication | 0.000 | 0.000 |
| Open science | 0.001 | 0.001 |
| Research integrity | 0.000 | 0.000 |
| Insufficient payload (model declined to judge) | 0.003 | 0.001 |
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".