Notice bibliographique
Résumé
Abstract Chemical potential related borehole (in)stabilities in the field are predominantly time-dependent. With the intention of developing a real-time wellbore (in)stability modelling capability, experimental work was undertaken to investigate the role of the chemical potential of drilling fluids on transient pore pressure and time-dependent rock property alterations of shale formations. The current work presents the concept, and discusses the results of these undertakings. The experiments using a Pore Pressure Transmission Test (PPT) apparatus expose formation (shale) cores under simulated downhole conditions to various salt solutions and drilling fluids. The uniqueness of this study comes from the fact that timedependent alteration in the pore pressure, acoustic and rock properties of formations subjected to compressive tri-axial stress are recorded during the PPT experiments. This eliminates the anisotropy-associated differences obtained when different samples are used to determine the relationship between these characteristic parameters of shale formations. The main objective of this effort is to translate the results of the PPT tests to actual drilling conditions. At that point, the formation- drilling fluid chemical potential borehole instability model would be validated and updated in real-time to predict borehole (in)stabilities. Introduction Borehole instability in shales is a continuing problem that results in a substantial annual expenditure by the petroleum industry ($700 million according to conservative estimates). In the past, oil-based muds (OBM) have been the system of choice for difficult drilling. As environmental concerns restrict the use of oil-based muds, the petroleum service industry must provide innovative means to obtain OBM performance without negatively impacting the environment. Water-based muds (WBM) are attractive replacements from a direct cost viewpoint. However, conventional WBM systems have failed to meet key performance measures met with OBMs, especially while drilling high-angle, extended-reach well trajectories going through water-sensitive shale formations. Historically, wellbore (in)stability problems have been approached on a trial-and-error basis, going through a costly multiwell learning curve before arriving at reasonable solutions for optimized operations and systems. Recent studies(1, 2) of fluidshale interactions have produced fresh insights into the underlying causes of borehole (in)stability, and these studies suggest new and innovative approaches to the design of water-based drilling fluids. Since the identification of chemical-potential related instabilities in shales, a chemical-potential borehole stability analytical model has been proposed to describe the physio-chemical interaction(1, 3). Advances in technology are providing new downhole sensors and tools that are increasingly able to collect and transmit information to the surface in real time, thus enabling field personnel to make faster and more informed decisions. There are increasing economic demands on reducing rig downtimes associated with borehole instability problems. Thus, the anticipation and resolution of instabilities in the field using MWD/LWD data in conjunction with prior geophysical and shale/fluid interaction knowledge is becoming more critical. In this study, transient pore pressure, compressional and shear wave velocities, and the deformation of shale cores under geostatic stress are measured.
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 | 0,008 | 0,012 |
| Méta-épidémiologie (sens strict) | 0,002 | 0,001 |
| Méta-épidémiologie (sens large) | 0,001 | 0,002 |
| Bibliométrie | 0,005 | 0,004 |
| Études des sciences et des technologies | 0,001 | 0,002 |
| Communication savante | 0,013 | 0,009 |
| Science ouverte | 0,005 | 0,006 |
| Intégrité de la recherche | 0,004 | 0,003 |
| Charge utile insuffisante (le modèle a refusé de juger) | 0,041 | 0,034 |
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 ».