Practical Control of SAGD Wells With Dual-Tubing Strings
Bibliographic record
Abstract
Summary Practical methods of operating dual-/triple-tubing strings, on the basis of temperature monitoring that is currently available, to achieve uniform steam-chamber development and enhanced production in a steam-assisted-gravity-drainage (SAGD) process, are presented. The work is motivated by the fact that numerous operators use dual-tubing strings for designing and optimizing steam-chamber development. Flow in the region of the SAGD horizontal well pair is often irregular, and dual-tubing strings may help to even out and improve both injection and production. Problems that operators have with multiple tubing strings in wells include their control and design. In this work, the injector and the producer will have two tubing strings each: one landed at the toe and the other at the heel. Control points are applied on each injection tubular. Injection at these control points is regulated by a proportional- integral-derivative (PID) feedback controller monitoring temperature differences between injected and produced fluids. A brief examination and discussion of the performance of control points in the production tubulars are also included. The PID controller will attempt to accomplish two goals: (i) to achieve evenness in injection and production conformance along both wells and (ii) to enforce a specified temperature offset between the injector and producer in order to improve oil production and reduce steam production and injection. Sensitivity of the feedback controller will be examined for (a) heterogeneity where several synthetic permeability patterns will be tested to gauge the effectiveness of coping with reservoir complexity, (b) update frequency where a comparison will be made between instantaneous and periodic updating of the controller error terms, and (c) ability of the controller to cope with early temperature rises in produced fluids. Well monitoring is accomplished through the use of high-temperature fibre-optic temperature sensing that is currently available. Results and further discussion are offered on whether an additional tubular landed at the midpoint of both wells will benefit production from a heterogeneous reservoir.
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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 | 0.001 |
| 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 | 0.001 |
| Scholarly communication | 0.001 | 0.001 |
| Open science | 0.001 | 0.001 |
| 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".