Coiled Tubing Drilling: Case Study, New Zealand
Bibliographic record
Abstract
Abstract While the oil and gas market continues to fluctuate, operators are forced to reduce drilling costs and increase efficiency to remain profitable; therefore, the focus on well reentry, sidetracks, and multilaterals from existing wellbores is growing in popularity, particularly within Australasia. Coiled tubing drilling (CTD) technology has been explored in New Zealand; however, successfully executed operations have so far been limited. After evaluating economic benefits and finding a suitable candidate trial well, a Canadian-based operator attempted a CTD operation in New Zealand that was technically successful. This case history outlines the two-phase project and discusses well intervention to isolate existing perforations and the sidetrack from the primary motherbore to drill to the base of the new reservoir. The objectives were to convert the suspended well from an oil producer to a water injector, enhance oil recovery within the field, and prolong oil production by reviving an underused asset. This paper discusses the engineering and technology used as well as regulatory obstacles and challenges encountered that were overcome to reach the operator’s objective. A 2 7/8-in. coiled tubing (CT) string was used for both phases of the operation, spanning intervention and drilling to perform all scheduled operations as efficiently as possible. The resulting completion, post-sidetrack, was to incorporate the CT workstring with approximately 100 m of a perforated 2 7/8-in. jointed pipe to maintain openhole stability across the injection zone.
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How this classification was reachedexpand
Full frame distilled prediction
Teacher imitationNot calibrated prevalence, not ground truth. Human validation pending. Learned from the 10,348 direct Codex labels and 10,348 direct Gemma labels. Candidate is the union of thresholded teacher heads; consensus is their intersection. These outputs are machine_predicted_unvalidated and are not human labels or direct frontier model labels.
Codex and Gemma teacher scores by category
| 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) | 0.000 | 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 teacher head, 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".