Characterization of the Microstructure of the Cement/Casing Interface Using ESEM and Micro-CT Scan Techniques
Notice bibliographique
Résumé
Summary Integrity of the cement/casing interface is an essential element of establishing an effective barrier system in cased and cemented wellbores. Failure to establish and maintain an effective barrier can result in negative environmental and economic impacts, such as leakage of formation fluids into the environment or loss of production and costly remediation. The main focus of this paper is defined as the characterization of the cement/casing interface microstructure, which is critical for better understanding of the requirements for establishing effective zonal isolation and the long-term integrity of cemented wellbore sections of active wells, as well as the integrity of the abandoned wells. The primary objectives of this study were: first, to confirm the most suitable methods for preparing cement/casing samples and characterize the microstructure of the cement/casing interface (i.e., quantify the size of the microchannel due to possible debonding (gap) at the cement/casing interface and its progression along the wellbore axis); and second, to understand how different test methods can affect the microstructure, and once we have a firm baseline, analyze the effect of different cement compositions on the performance. More specifically, we have investigated effects of the cement composition and preparation, environmental conditions [i.e., relative humidity (RH) of the storage and testing conditions], cement shrinkage, and the expansion additive on the integrity of the cement/casing interface at the micrometer scale by using environmental scanning electron microscope (ESEM, 0.05 µm resolution) and microcomputed tomography (μ-CT, 11.92 µm resolution) scanning techniques. Cemented casing samples were prepared by using Class G and special abandonment cement blends with and without expansion additives and stainless-steel pipes. Results showed that any significant change in the RH of the environment during the cement preparation, curing, and testing process significantly affects the size of the gap at the cement/casing interface in test samples. Analyses of the ESEM images have shown that the 2D nonuniform gap size between the cement and the casing is inversely proportional to the change in the RH of the environment. Results suggested that cement slurries set and cured under downhole conditions with relatively constant RH may not undergo significant shrinkage and yield only minimal debonding effect. The 3D gap model reconstructed from the µ-CT images confirmed that the gap between cement and casing mostly occurred at the cement polished surface and the gap didn’t show any significant connectivity below the cement polished surface, indicating that common sample preparation methods can significantly affect the near-surface interface. Cement blends prepared with expansion additives have shown smaller gap size. The use of expansion additives enhances the cement/casing interface integrity by effectively reducing the gap size at the cement/casing interface. We conclude that as long as the RH of the environment does not change significantly, the cement is expected to undergo a limited shrinkage, and the gap between the cement and the casing may not induce any significant leakage pathway because the gap is only locally distributed at the cement polished surface without showing any significant connectivity along the wellbore axis.
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 | 0,000 |
| 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 ».