Are Field Polymer Enhanced Oil Recovery Projects Reaping the Benefits of Residual Oil Saturation Reduction Due to Polymer Viscoelasticity?
Notice bibliographique
Résumé
Summary For polymer solutions used in enhanced oil recovery (EOR), viscoelasticity is a rheological phenomenon that has a strong flux dependency and has been tied to significant reductions in residual oil saturation (Sor) during laboratory corefloods at high flux conditions. However, an unanswered question is whether the polymer’s viscoelastic effects reduce Sor over a significant portion of a polymer-flooded reservoir. In this paper, two methodologies are used to answer this question for polymer-flood projects across nine countries (Argentina, Austria, Canada, China, India, Oman, Russia, Suriname, and USA). In Method 1, the average Darcy velocity in each field is compared with the corresponding predicted velocity for the onset of shear thickening. Then, the effects of variables on Darcy velocity are examined, such as radial distance from the wellbore, well-spacing, horizontal well length, and thickness. In Method 2, the Sor reduction potential of the field polymer solutions used is evaluated by analyzing relevant coreflood experiments conducted in various laboratories. The observations from the laboratory results are considered in view of the fluid velocity, oil viscosity, permeability, mode of flooding, and pressure gradient of the various field projects. For most polymer floods with horizontal injectors, the highest possible Darcy velocity for various combinations of thickness, injection rate, horizontal well length, and well spacing is too low (in the range of ~0.01–0.2 ft/D) and unlikely to reach the onset velocity for viscoelastic behavior (i.e., >1 ft/D for most field conditions). For most vertical polymer injectors, less than 1% of the reservoir will experience fluid velocities high enough for viscoelasticity to potentially be important. Less-permeable reservoirs (<200 md) could experience the onset of shear thickening viscoelasticity at low rates (e.g., ~0.17 ft/D), but even so, a very small fraction of the reservoir is expected to achieve this onset flux. At a very short well spacing of 100 ft in the Pelican Lake polymer flood, the average velocity is ~1.7 ft/D. For an extreme case of a low thickness (10 ft), short horizontal well length (1,210 ft), and a small well spacing of 656 ft, an average velocity of ~1.2 ft/D and a pressure gradient of ~7.7 psi/ft were estimated for the Matzen field polymer flood. Although the average velocity is higher than the average onset flux rate, Sor reduction appears unlikely based on the macroscopic pressure gradients. This paper conveys the improbability of shear-thickening induced-viscoelasticity causing Sor reduction in field applications. It also discusses the potential role of other effects for Sor reduction in existing polymer floods, including wettability alteration by the polymer and secondary-vs.-tertiary polymer-flooding effects. EOR researchers are advised to use realistic field-relevant fluxes during laboratory assessments while studying Sor reduction.
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 | 0,000 | 0,000 |
| Méta-épidémiologie (sens strict) | 0,000 | 0,000 |
| Méta-épidémiologie (sens large) | 0,000 | 0,000 |
| Bibliométrie | 0,000 | 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 | 0,001 |
| 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 ».