Evaluating Wettability and Imbibition Oil Recovery of the Core Plugs and Crushed Rock Samples from the Duvernay Formation
Notice bibliographique
Résumé
Unconventional sources have become the leading sources of hydrocarbons in North America. These unconventional resources with low porosity and ultra-low permeability can produce hydrocarbon at profitable rates from a hydraulically fractured horizontal well. However, rock-fluid properties need to be characterized to obtain an efficient hydrocarbon recovery. Therefore, a detailed understanding of rock properties especially wettability is crucial as it has an effect on both waterflooding and enhanced oil recovery (EOR) techniques. The primary objective of this research is to determine the wettability characteristics of shale by conducting contact angle and imbibition experiments. We investigate the functional dependence of wettability on the mineralogy, petrophysical properties, and the geochemical properties that are associated with source rock. Moreover, we present the potential driving factor of imbibition by using the spontaneous imbibition and co-current imbibition data of shale samples. We also characterize the mechanisms controlling oil recovery from shales by soaking process. In this study, we evaluate the wettability of organic shale samples drilled in the Duvernay Formation, which is a source rock located in the Western Canadian Sedimentary Basin (WCSB). We characterize the shale samples by measuring pressure-decay permeability, effective porosity, initial oil and water saturation, mineralogy, total organic carbon (TOC) content. We also conduct thin section analysis and Scanning Electron Microscope (SEM) and energy-dispersive X-ray spectroscopy (EDS) analyses on shale samples to characterize the location, type, and size of pores. We use reservoir oil and brine to conduct air-liquid contact angle and air-liquid spontaneous imbibition tests for wettability measurements of both intact core plugs and crushed shale packs (CSP) prepared from drilling cuttings. We also conduct co-current imbibition to calculate the capillary pressure ratio. After evaluation of wettability, we conduct soaking experiments. First, we measure liquid-liquid contact angles of soaking fluids and reservoir oil equilibrated on the surface of the oil saturated core plugs. Then, we conduct the soaking test by immersing the oil-saturated plugs and CSP samples in soaking fluids with different compositions and physical properties and record oil volume produced due to spontaneous imbibition of the soaking fluids. The soaking fluids are characterized by measuring surface tension, interfacial tension (IFT), viscosity, and pH. We analyze the results of soaking tests performed on core plugs and CSPs and investigating the controlling parameters affecting capillary pressure and imbibition oil recovery factor (RF). The results of wettability measurements demonstrate that the Duvernay samples have a stronger wetting affinity to oil compared to brine. The positive correlations of TOC content with both effective porosity and pressure-decay permeability suggest that the majority of connected pores are present within the organic matter which can also be supported by the SEM/EDS analysis. Organic porosity may explain the strong oil-wetness of the shale samples. The results of liquid-liquid contact angle tests show that the soaking fluid with lower IFT shows a stronger wetting affinity towards the shale samples. Similarly, the results of soaking tests conducted on the core plugs and CSPs show that oil RF is higher for the soaking fluids with lower IFT, which may be due to wettability alteration towards less oil-wet conditions. In addition, comparing the results of air-brine imbibition with those of the soaking tests indicates that adding the non-ionic surfactant to the soaking fluid may alter the wettability of organic pores towards less oil-wet conditions, leading to the displacement of oil from hydrophobic organic pores. The results also show that the presence of water film in shale samples may increase their wetting affinity towards the soaking fluids, leading to higher oil RF in the samples with higher initial water saturation.
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 | 0,000 | 0,000 |
| Méta-épidémiologie (sens strict) | 0,000 | 0,000 |
| Méta-épidémiologie (sens large) | 0,000 | 0,000 |
| Bibliométrie | 0,001 | 0,001 |
| 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) | 0,001 | 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 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 ».