Oxidation Studies of Light Hydrocarbons For Underbalanced Drilling Safety
Notice bibliographique
Résumé
Abstract Economic development of many of the world's oil and gas reserves will require application of improved drilling methods such as underbalanced drilling (UBD), a technique used to minimize formation damage in hydrocarbon reservoirs. In UBD operations, deoxygenated air is often injected along with an oil-based drilling fluid. This de-oxygenated air may contain up to 5% oxygen which can react with oil and/or an oil-based drilling fluid during the drilling process to form potentially hazardous oxidized hydrocarbons, leading to the presence of potentially flammable or explosive mixtures in the surface piping and/or drill string. Discussion of the oxidation behaviour of light oils and oil based drilling fluids in the literature is limited, particularly regarding the effects of long term exposure to oxygen. This paper characterizes the oxidation behaviour of two light oils and an oil-based drilling fluid using thermogravimetry (TG) and differential scanning calorimetry at 89 and 9,811 kPa (1,410 psig). The effects of core, pressure, and pre-exposure to oxygen on subsequent oxidation behaviour were studied. The results show that the addition of core enhanced the oxidation reactions of the oil samples and delayed exothermic activity of the drilling fluid. Elevated pressure accelerated the oxidation reactions. Pre-exposure to oxygen was shown to increase the reactivity of the oils and drilling fluid during subsequent oxidation. The results show that under certain conditions, oxidation processes could begin at significantly reduced temperatures, possibly leading to ignition of the hydrocarbon mixtures. Introduction Underbalanced drilling is a technique used to minimize formation damage caused by drilling fluid invasion in hydrocarbon reservoirs. In order to achieve this, the hydrostatic head of liquid in the hole must be decreased, which can be accomplished by co-injecting nitrogen, natural gas, flue gas, vitiated air (air mixed with nitrogen), or de-oxygenated air (air with some of the oxygen removed). The oxygen containing gases are the least expensive but the possibility of flammable or explosive mixtures is an important safety consideration. De-oxygenated air is normally obtained using portable membrane separation systems. However, this deoxygenated air often contains up to 5% oxygen, by volume. During the drilling process, this oxygen can react with produced hydrocarbons or the oil-based drilling fluid to form peroxides and other oxidized hydrocarbons. These oxidized hydrocarbons could pose a safety hazard. While the oxygen concentrations under consideration are relatively small, the pressures and temperatures in the reservoir and along the drill string are significant. Added to this is the effect of prolonged exposure to oxygen. Drilling fluid is re-circulated throughout the drilling operation and may be used in multiple operations. It may also be exposed to oxygen while in the drilling mud tanks at the surface (during the drilling operation) and storage tanks. Over time the fluid may be gradually oxidized, posing an increased risk of combustion or even explosion. Due to the serious ramifications of undesired oxidation processes, it is necessary to establish fundamental information on the oxidation behaviour of the hydrocarbons involved in these processes. A significant amount of research has been done in understanding the oxidation processes involved in air injection processes and in investigating the safety of underbalanced drilling applications.
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 | 0,000 | 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) | 0,001 | 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 ».