Notice bibliographique
Résumé
This article, written by Assistant Technology Editor Karen Bybee, contains highlights of paper SPE 100615, "Prediction of Slug-to-Annular Flow-Pattern Transition (SAT) for Reducing the Risk of Gas Lift Instabilities and Effective Gas-Liquid Transport From Low-Pressure Reservoirs," by P. Toma, SPE, P.R. Toma Consulting Ltd., and E. Vargas and E. Kuru, SPE, U. of Alberta, prepared for the 2006 SPE Gas Technology Symposium, Calgary, 15–17 May. Slug-flow to annular-flow transition occurring during upward gas/liquid flow is a source of flow instabilities often experienced in conventional gas lift as well as in unloading water accumulated at the bottom of gas wells. In both situations, a significant decrease in tubing pressure from perforations to wellhead is associated with a significant increase in superficial gas velocity and may induce flow-pattern transitions. The full-length paper uses field data and laboratory measurements to suggest that flow-pattern transition can result in flow instabilities and should be avoided. Introduction Understanding and prediction of slug-flow to annular-flow transition are essential for designing effective gas lift or unloading strategies. Mechanistic modeling of gas/liquid-flow systems including descriptions of major flow patterns and transitions is essential to develop suitable production strategies in both depleted and large offshore gas/oil reservoirs. These include the ability to control the stability of a suitable gas/liquid-flow pattern from perforations to wellhead and achieve the designed production volumes. To minimize the pressure drop, large-liquid-volume gas lift primarily uses a slug flow pattern, while production of gas with relatively small amounts of condensate or water uses an annular flow pattern. Slug-to-annular flow-pattern transition including the intermediate churn condition is considered to be a potential source of instabilities. Fig. 1 shows flow patterns for upward vertical flow. Difficulties visually assessing the hydrodynamic evolution of this transition because of highly turbulent gas/liquid-flow reversals are a source of controversy, mainly related to the definition of churn as a standalone flow pattern or as a transition stage between slug and annular flow. Slug Flow Pattern. The slug flow pattern is characterized by a chain of bullet-shaped, rising Taylor bubbles. A relatively large amount of liquid and much smaller gas bubbles are contained in a slug found between two consecutive Taylor bubbles. The population of much smaller bubbles found in the slug subpattern is formed continuously through turbulent breaking of the trailing edge of large Taylor bubbles and disappears through coalescence (back into Taylor bubble). The slug-subpattern volume is essential to transport a large amount of liquid upward during conventional gas lift operations. A back-flowing liquid film (found between Taylor bubbles and the tubing) is an equally essential feature of any slug flow pattern and limits the depth from which liquid can be transported in a slug flow pattern from extremely low-pressure reservoirs.
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 distillée sur la base complète
Imitation des enseignantsNi prévalence calibrée, ni vérité terrain. Validation humaine à venir. Apprise à partir de 10 348 étiquettes directes de Codex et de 10 348 étiquettes directes de Gemma. Le mode candidate est l'union des têtes enseignantes seuillées; le consensus est leur intersection. Ces sorties portent le statut machine_predicted_unvalidated et ne sont ni des étiquettes humaines ni des étiquettes directes de modèles de pointe.
Scores Codex et Gemma par catégorie
| Catégorie | Codex | Gemma |
|---|---|---|
| Métarecherche | 0,001 | 0,000 |
| Méta-épidémiologie (sens strict) | 0,000 | 0,000 |
| Méta-épidémiologie (sens large) | 0,000 | 0,000 |
| Bibliométrie | 0,001 | 0,000 |
| Études des sciences et des technologies | 0,000 | 0,000 |
| Communication savante | 0,000 | 0,000 |
| Science ouverte | 0,000 | 0,000 |
| Intégrité de la recherche | 0,000 | 0,000 |
| Charge utile insuffisante (le modèle a refusé de juger) | 0,000 | 0,000 |
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 tête enseignante, 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 ».