Fluid Movement in the SAGD Process A Review of the Dover Project
Notice bibliographique
Résumé
Abstract The fundamentals of Steam Assisted Gravity Drainage (SAGD) steam chamber development are now well understood through Butler's analytical models, and extensive field and laboratory testing. However as industry continues to extend SAGD to new reservoirs and looks towards SAGD wind down at the end life of the projects, it is important that we recognize the value of not only understanding the steam chamber but also of the movement of fluid in the reservoir. The Dover SAGD Pilot is the most mature pilot of its kind in the world. A study of this Pilot has been undertaken in an attempt to understand the behavior of the fluid within and in front of the steam chamber. The economics of SAGD are significantly impacted by the cost of generating steam. At roughly 1mcf/bbl of bitumen produced for an SOR in the range of 2.3–2.5 m3/m3, natural gas is the single largest operating cost in a SAGD project. Water movement within the reservoir can impact the natural gas consumption wherein warm steam condensate not recovered must be replaced in the process by colder make-up water, decreasing the heat efficiency of the steam generation. Further, where water loss to the reservoir is high, the steam-oil ratio (SOR) may be negatively impacted. As we approach the 20th anniversary of the initiation of the Dover Pilot, the cold water injection test performed prior to any thermal operations taking place is revisited here. Understanding the transmissibility of water in the reservoir is key to choosing the optimal operating pressures and maximizing the value of a project. It has been widely published1,2 that the injection of non-condensable gas (NCG) into SAGD chambers will result in the accumulation of the NCG at the top of the chamber, cooling the chamber. The lower temperatures within the chamber cause the viscosity of the bitumen to increase thereby reducing the bitumen production rate. This has been suggested as a method of winding down steam chambers as they reach their economic producing limits3,4,5. From April 1998 to May 2002 NGC was injected with steam at the Dover Pilot. The gas volume injected at reservoir conditions was triple the volume of the produced bitumen over that time. The SAGD chambers did not behave as predicted. The bitumen production rate did not fall off any more than would be expected from a mature steam chamber and live steam was still detectable through the thermocouples within the steam chamber. Further, an increased overall recovery was observed, most likely from the gas assistance in the production of previously inaccessible reserves. The simulation model developed to describe, as well as further observations regarding the behavior of NCG in the reservoir, are discussed. Introduction Geographically located in northeast Alberta, the Athabasca Oil Sands deposit forms part of the western Canadian oil sands. With an estimated 1.7 trillion barrels of oil in place, it is arguably the single largest oil deposit in the world. SAGD, developed by Butler6 in the early 1980's, is to date, the most successful in-situ method of exploiting this resource.
Récupéré en direct depuis OpenAlex et désinversé. Les résumés ne sont pas conservés dans cette base de données : les index inversés représentent 8,6 Go des 9,3 Go de texte de la base, et le serveur dispose de 13 Go libres.
Comment cette classification a été obtenuedéplier
Prédiction machine sur la base complète
Imitation des enseignantsNi prévalence calibrée, ni vérité terrain. Validation humaine à venir. Le volet Gemma est une étiquette directe du modèle pour chaque travail de la base, lue sur la notice réduite au titre. Le volet Codex est un classifieur appris des 10 348 étiquettes directes de Codex et calibré sur les taux pondérés de l'échantillon; les champs sans appui suffisant ne portent aucun appel Codex. Le mode candidate est l'union des deux volets; le consensus est leur intersection. Ces sorties portent le statut machine_predicted_unvalidated et ne sont pas des étiquettes humaines.
Scores du classifieur distillé par catégorie (deux têtes)
| Catégorie | Codex | Gemma |
|---|---|---|
| Métarecherche | 0,004 | 0,005 |
| Méta-épidémiologie (sens strict) | 0,001 | 0,001 |
| Méta-épidémiologie (sens large) | 0,001 | 0,001 |
| Bibliométrie | 0,004 | 0,004 |
| Études des sciences et des technologies | 0,001 | 0,001 |
| Communication savante | 0,003 | 0,003 |
| Science ouverte | 0,001 | 0,001 |
| Intégrité de la recherche | 0,002 | 0,002 |
| Charge utile insuffisante (le modèle a refusé de juger) | 0,003 | 0,002 |
Scores machine (provisoires)
Les deux têtes enseignantes du modèle étudiant, lues sur ce travail. Un score ordonne la base pour la relecture; il n'affirme jamais une catégorie, et le statut de validation accompagne chaque rangée tel quel.
Scores de référence d'un modèle non mature (critères de maturité non atteints, 7 itérations). Un score ordonne; il n'affirme jamais une catégorie.
score_only:v0-immature-baseline · tel quel depuis la passe de notation : score_only signifie que le nombre peut ordonner les travaux, et qu'aucune étiquette de catégorie n'en découleClassification
machine, non validéePrédiction automatique; un appel candidat d’une seule source (Gemma direct ou Codex distillé), pas un consensus.
Le détail, modèle par modèle et score par score, se trouve en fin de page sous « Comment cette classification a été obtenue ».