Notice bibliographique
Résumé
Technology Focus To cater to the seasonal highs and lows in demand throughout a year, natural gas is stored in underground storage facilities. The need for such facilities arose because increasing (or decreasing) gas production to mirror changes in demand is neither practical nor economical. Therefore, gas is produced and stored during low-demand times and retrieved to meet the highs during winters. This cyclic trend can be observed also in gas-storage inventories [as reported by the Energy Information Administration (EIA)]. The northeast US has the highest concentration of such storage facilities, close to the biggest market. Most of the underground gas-storage facilities are depleted reservoirs, but aquifers and leached salt caverns are also used. The US and Canada were the pioneers in realizing the potential of depleted reservoirs for gas storage and, hence, have several well-developed facilities. What makes depleted reservoirs attractive is the presence of existing wells used to produce the reservoir, plus the geologic and engineering knowledge acquired during the development of the field. All that information is leveraged when repurposing the field for gas storage. Depleted reservoirs also contain some amount of gas already in the reservoir, which decreases the requirement to inject gas as cushion gas. (Cushion gas is immobile gas that remains in the reservoir and allows the reservoir to be used for storage.) Depleted reservoirs are also the most abundant. I would be remiss not to touch upon the Aliso Canyon incident of 2015. Aliso Canyon was the second-largest storage facility in the US at the time. The industry learned a harsh lesson about the repercussions when containment is lost for such facilities. The loss of containment was because of the casing failure of one of the wells (along with having subsurface safety valves removed in the past). This led to 109,000 tonnes of methane emissions by some estimates. One measure that was proposed to reduce such risks is to use offshore reservoirs nearing abandonment for gas storage (instead of onshore ones that are close to populated urban areas). At the time of this writing, the week-to-week change in the natural gas storage inventory was –237 Bcf, and levels remained lower than the 5-year historical average, according to the EIA. This withdrawal from the inventory was less than most forecasts based on the extreme cold temperatures faced by the US. The Henry Hub natural gas prices reached highs of more than $4.5/million Btu in 2018 because of record gas demand. The price has since dipped to $2.57/million Btu because of abatement in the extreme weather leading to lower demand for heating. To learn more, visit the SPE Annual Technical Conference and Exhibition in Calgary, 30 September–2 October, and the Gastech Exhibition and Conference in Houston, 17–19 September. Recommended additional reading at OnePetro: www.onepetro.org. SPE 190838 Comprehensive Evaluation of the Dynamic Sealing Capacity of Clayey Caprocks in a Large Underground Gas Storage by Junchang Sun, PetroChina, et al. SPE 192961 Maintaining Flare-Tip Health by Venugopal Bakthavachsalam, ADNOC, et al. SPE 192783 Cutting-Edge Solutions for Sour-Gas Treatment: A Retrospective Study by Kuwait Oil Company by Fahad Al-Ghanem, Kuwait Oil Company, et al.
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 | 0,002 |
| Méta-épidémiologie (sens strict) | 0,001 | 0,000 |
| Méta-épidémiologie (sens large) | 0,000 | 0,000 |
| Bibliométrie | 0,001 | 0,001 |
| Études des sciences et des technologies | 0,001 | 0,000 |
| Communication savante | 0,004 | 0,003 |
| Science ouverte | 0,001 | 0,002 |
| Intégrité de la recherche | 0,003 | 0,002 |
| Charge utile insuffisante (le modèle a refusé de juger) | 0,425 | 0,281 |
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 ».