Notice bibliographique
Résumé
Abstract Conventional Capillary Number theory predicts that residual oil will not be mobilized until a critical capillary number (2E-05) is exceeded. This theory was tested to determine residual oil saturation mobilization after the forced water imbibition. In the literature, high residual oil saturation was firstly established from water flooding at a certain pressure. Then gradually increasing pressure was applied for water injection until residual oil production was observed. At this research, firstly, it is confirmed that this critical capillary number (2E-5) is applicable when the initial residual oil saturation was estimated from a spontaneous water imbibition tests. Then the same type of experiments by building up the initial residual gas saturation from spontaneous oil or water imbibition tests were applied to the same samples. The entire procedures, which include spontaneous imbibition tests followed by a forced imbibition tests, were monitored by an online NMR system. Through analyses of experimental results, the critical capillary number for mobilizing residual gas from water imbibition and oil imbibition tests were estimated. It was found that the critical capillary number for gas- liquid system is very different from that of an oil-water system and the same rock. Berea sandstone plugs were used in all the experiments. The reason for using Berea sandstone plugs is due to their relative homogeneous pore structure. Additional Western Canada sandstone plugs were used for testing gas-water systems to confirm the results obtained from the Berea Sandstone plugs. Understanding the different mechanisms of producing discontinuous residual oil or residual gas is important today. Hopefully this research could show some new insight for recovering additional gas from gas reservoirs with active aquifers. Introduction Increasing the capillary number has long been investigatedas a strategy for improving oil recovery. Many methodologies either tested in the laboratory or applied in the field evolved around increasing the capillary number. Capillary number is defined as the ratio of viscous forces to capillary forces. Evaluation of the capillary number can be used to describe the relative importance of viscous forces to capillary forces during immiscible displacements. There are various forms of the capillary number. The most common versions of capillary number are those of Shaffman and Taylor1: Equation(1) (Available in full paper) Equation(2) (Available in full paper) When the non- wetting phase is trapped in the porous media, the pressure gradient required to move it through a capillary tube is much higher than what would be predicted by the pipe flow equation, due to the pressure discontinuity at the wetting/non-wetting interface. Because of the contact angle hysteresis, this discontinuity is not of the same magnitude on the both sides of the discontinuous non-wetting phase. For example, in a water-wet medium, on oil droplet represents the discontinuous non-wetting phase. As the oil droplet is pushed through a pore throat, its downstream end gets squeezed into a much narrower segment, making its radius of curvature much smaller than the upstream part. When analyzing the possibility of mobilizing such residual phase droplets, the interfacial curvatures play a most important role in predicting mobilization
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 | 0,001 | 0,005 |
| Méta-épidémiologie (sens strict) | 0,000 | 0,000 |
| Méta-épidémiologie (sens large) | 0,000 | 0,000 |
| Bibliométrie | 0,002 | 0,001 |
| Études des sciences et des technologies | 0,000 | 0,001 |
| Communication savante | 0,001 | 0,002 |
| Science ouverte | 0,001 | 0,000 |
| Intégrité de la recherche | 0,001 | 0,001 |
| Charge utile insuffisante (le modèle a refusé de juger) | 0,004 | 0,001 |
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 ».