Notice bibliographique
Résumé
This article, written by Assistant Technology Editor Karen Bybee, contains highlights of paper SPE 107014, "Sour- Well Serviceability of Higher-Strength Coiled Tubing," by H.B. Luft, T. Padron, and E. Kee, BJ Services Co. Canada Ltd., and E. Szklarz, Shell Canada Ltd., prepared for the 2007 SPE/ICoTA Coiled Tubing and Well Intervention Conference and Exhibition, The Woodlands, Texas, 20–21 March. A joint-industry project (JIP) was initiated approximately 2 years ago to extend the research conducted into the serviceability of coiled tubing (CT) for underbalanced sour-well drilling and workover operations to higher-strength [90- to 110-ksi specified-minimum-yield-stress (SMYS)] grades. A significantly different and unique laboratory testing protocol is used in the present JIP research. The methodology calls for full-body tubing specimens that have been immersed in a sour solution of varying severity followed by testing in a bend-fatigue machine (BFM) to determine the low-cycle fatigue performance of high-strength CT materials degraded by exposure to a sour environment. Introduction Over many years, sour-well interventions have been performed with CT with relatively few failures. This success likely is the result of a variety of factors including time of exposure to sour conditions, adequate corrosion-protection programs, inherent resistance to hydrogen sulfide (H2S) damage by different CT materials, continuing research into the response of CT materials to sour conditions, and generally good CT-management procedures to minimize the risk of failure. A better understanding of the response of CT materials while exposed to sour downhole conditions has been the focus of research for several years. The testing used both coupon and full-body CT test specimens. The testing protocol included standard and custom-designed fixtures comprising slow-strain-rate testing (SSRT), axial low-cycle corrosion fatigue (LCCF), double-cantilever beam (DCB), Natl. Assn. of Corrosion Engineers (NACE) hydro-gen-induced cracking (HIC) and proof-ring tests, acoustic-emission (AE) measurements of crack-incubation times, constant-load tests (CLTs) on full-body specimens for sulfide stress cracking (SSC), BFM tests on CT sour-fatigue specimens, and a custom-designed hydrogen-diffusion vacuum cell for full-body CT specimens. Extensive metallographic examinations were performed to investigate failure mechanisms, fracture characteristics, and relationships to CT material properties and environmental severity. The initial JIP considered only CT-strength grades of 70 and 80 ksi and concluded with a recommendation that sour-service CT strings be limited to a maximum strength of 80-ksi yield. This was based on SSRT strain-to-fracture limitations for CT of higher strength using conventional A606/607 modified materials. Bend-fatigue lives of CT materials were estimated on the basis of LCCF measurements by assuming that the ratio of axial- to bend-fatigue life in sweet environments applied equally to sour conditions. The 80-grade sour CT limit served the JIP companies well but imposed an undesirable limitation on sour-well interventions for which higher-strength CT strings were required. The purpose of the full-length paper is to share the major interim findings of the second JIP, involving tests conducted over the last 1 1/2 years on higher-strength CT90, CT100, and CT110 grades. The majority of these data involves actual low-cycle fatigue tests on 7-ft-long CT specimens that were submerged in a sour solution for 4 days before fatigue loading to failure.
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 | 0,001 |
| Méta-épidémiologie (sens strict) | 0,000 | 0,000 |
| Méta-épidémiologie (sens large) | 0,000 | 0,000 |
| Bibliométrie | 0,001 | 0,000 |
| Études des sciences et des technologies | 0,000 | 0,000 |
| Communication savante | 0,001 | 0,001 |
| Science ouverte | 0,000 | 0,000 |
| Intégrité de la recherche | 0,000 | 0,000 |
| Charge utile insuffisante (le modèle a refusé de juger) | 0,002 | 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 ».