High-Temperature Downhole Motor Facilitates Cleanout of Obstructed Thermal Well, Saving Production Downtime
Bibliographic record
Abstract
Abstract Certain wells in the Peace River region of Alberta, Canada, produce heavy crude oil along with H2S and CO2. The heavy crude oil is normally recovered with enhanced production methods involving thermal wells whereby the crude is heated to very high temperatures to facilitate production. One such well became plugged by scale deposits and efforts were made to clean out the obstruction using coiled tubing (CT) intervention techniques. However attempts to do so with jetting tools and acidisation proved to be ineffective and the only alternative left was to run a mill with a downhole motor. A major problem was posed by the bottomhole temperature of 300° C (572°F) which precluded the use of standard motors. The operator was thus faced with the probability of having to make an extended shut down to allow the well temperature to decline to an operable temperature level where standard equipment could be used, or look to alternatives. In an attempt to avoid this extended downtime it was decided to run a non elastomeric high temperature downhole motor, which uses a positive displacement principle with a stainless steel stator and rotor system with no elastomers, which as a result is rated to 260°C (500°F). The 2-7/8″ OD motor was run with a 3-9/16″ OD mill on 2″ OD CT to try to mill out the obstruction in the 4-1/2″ slotted liner while circulating KCl fluid at the rate of 50 litres/min (13gallons/min) and Nitrogen at 30 standard cubic meters/min (1100 standard cubic feet/min). The obstruction was encountered at 820.6 meters (2,692ft) and successfully milled to 929m (3048ft) where the mill broke through and was run to bottom at 945m (3100ft) to circulate clean before pulling out. The whole operation took a total of 9 hours. In this paper the authors will review the well conditions and the motor design and explain the decision to run it at downhole temperatures in excess of its rating. They will go on to detail the milling operation which was successful in returning the well to production at a considerable saving in production downtime when compared to the available alternatives.
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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 | 0.001 | 0.000 |
| Research integrity | 0.000 | 0.000 |
| Insufficient payload (model declined to judge) | 0.007 | 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".