API

3 cases · 58 images for “corrosion”

Crevice Corrosion in a Subsea System — Aspect Before Analysis

API — sub-branches

Aspect of a transverse section of the 4" pipe showing the barnacles adhered to the internal pipe surface, and the leakage position (in the top of the figure).  It is possible to see that the deposits are attached all throught the internal pipe perimeter but the damage is localized.  The damage morphology suggests it is a crack, or a welding defect, but the microstructural analysis indicated that the damage is a galvanic effect at the autogenous seam weld.
1135
ML00140 / May.2019
Preferential Corrosion of Pipe Seam Weld
M - Low Carbon SteelP - Longitudinal Seam Welded PipeAp - ShipCd - Preferential Dissolution
Cm - Longitudinal Section AspectDf - Localized Corrosion
Aspect of the washout in the 5" drill pipe, in the pipe body, before cleaning the surface.
683
ML00068 / Sep.2020
Corrosion Fatigue of a 5" Drill Pipe
M - Low Alloy Medium Carbon QTP - Seamless PipeAp - O&G Well DrillingCd - Corrosion Fatigue
Cm - Aspect Before AnalysisDf - At the Surface
Fracture position at the pipe body, about 1 meter from the tool joint end.  The fracture presented two main aspects, a flat fracture transverse to the pipe axis, that propagated by fatigue through almost 50% of the pipe perimeter, and a final fracture by shear overloading.
560
ML00169 / Nov.2020
Drill Pipe Fracture in the Pipe Body
M - Low Alloy Medium Carbon QTP - Drill PipeAp - O&G Well DrillingCd - Corrosion Fatigue
Cm - Aspect Before AnalysisDf - General View

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ML00140 — Preferential Corrosion of Pipe Seam WeldM - Low Carbon SteelP - Longitudinal Seam Welded PipeAp - ShipCd - Preferential Dissolution
Micrography of the pipe transverse section presenting a granular microstructure.
147
ML00140 / May.2019
Preferential Corrosion of Pipe Seam Weld
M - Low Carbon SteelP - Longitudinal Seam Welded PipeAp - ShipCd - Preferential Dissolution
Cm - Nital Etched Micrography by OMDf - Transverse Section
Micrography of the pipe transverse section presenting a predominatly ferritic-perlitic microstructure.
132
ML00140 / May.2019
Preferential Corrosion of Pipe Seam Weld
M - Low Carbon SteelP - Longitudinal Seam Welded PipeAp - ShipCd - Preferential Dissolution
Cm - Nital Etched Micrography by OMDf - Ferrite and Pearlite
ML00140 / May.2019
Preferential Corrosion of Pipe Seam Weld
M - Low Carbon SteelP - Longitudinal Seam Welded PipeAp - ShipCd - Preferential Dissolution
Cm - Nital Etched Micrography by OMDf - Ferrite and Pearlite
Aspect of the 4" pipe that was in seawater service for 8 years and leaked in a longitudinal line that corresponds to the seam weld. The internal surface presented thick deposits. Although the pipe was cut with a thermal process, the analysis was conducted after mechanical cutting.
100
ML00140 / May.2019
Preferential Corrosion of Pipe Seam Weld
M - Low Carbon SteelP - Longitudinal Seam Welded PipeAp - ShipCd - Preferential Dissolution
Cm - Aspect Before AnalysisDf - General View
Detail of the transverse section of the 4" pipe at the longitudinal seam weld evidencing the leakage position.  The damage appears as a through wall opening.  The pipe thickness is 8 mm and there are no evidences of general corrosion (the SCH 80 corresponds to 8.6 mm) or pitting at the internal surface.
100
ML00140 / May.2019
Preferential Corrosion of Pipe Seam Weld
M - Low Carbon SteelP - Longitudinal Seam Welded PipeAp - ShipCd - Preferential Dissolution
Cm - Transverse Section AspectDf - Leakage

+19 more from this case →

ML00068 — Corrosion Fatigue of a 5" Drill PipeM - Low Alloy Medium Carbon QTP - Seamless PipeAp - O&G Well DrillingCd - Corrosion Fatigue
Aspect of the washout in the 5" drill pipe, in the pipe body, after cleaning the surface.  The surface presents several parallel tool marks that are not typical in the pipe since the torque is applied in the tool joint.
195
ML00068 / Sep.2020
Corrosion Fatigue of a 5" Drill Pipe
M - Low Alloy Medium Carbon QTP - Seamless PipeAp - O&G Well DrillingCd - Corrosion Fatigue
Cm - Surface AspectDf - At the Surface
The longitudinal section of the 1/2" thick pipe close to the washout position shows that the external tool marks are like notches that are corroded and cracks are iniciating from the corroded regions.  The top of the figure presents the external pipe surface and the bottom of the figure presents the internal pipe surface, with a green coating and the rusted washout.
154
ML00068 / Sep.2020
Corrosion Fatigue of a 5" Drill Pipe
M - Low Alloy Medium Carbon QTP - Seamless PipeAp - O&G Well DrillingCd - Corrosion Fatigue
Cm - NItal Etched MacroDf - Longitudinal Section
Macrography of the longitudinal section of the pipe presenting multiple cracks from the tool marks.
122
ML00068 / Sep.2020
Corrosion Fatigue of a 5" Drill Pipe
M - Low Alloy Medium Carbon QTP - Seamless PipeAp - O&G Well DrillingCd - Corrosion Fatigue
Cm - NItal Etched MacroDf - Cracks Transverse to the Surface
The microstructure of the pipe, presented in a longitudinal section, is an uniform tempered martensite.
105
ML00068 / Sep.2020
Corrosion Fatigue of a 5" Drill Pipe
M - Low Alloy Medium Carbon QTP - Seamless PipeAp - O&G Well DrillingCd - Corrosion Fatigue
Cm - Nital Etched Micrography by OMDf - Martensite
The micrography in the as polished condition of the longitudinal section of the pipe close to the washout, shows that at the tool mark tip (notch from the external surface) a fatigue crack already started from a corroded region (pitting).
187
ML00068 / Sep.2020
Corrosion Fatigue of a 5" Drill Pipe
M - Low Alloy Medium Carbon QTP - Seamless PipeAp - O&G Well DrillingCd - Corrosion Fatigue
Cm - Micrography by OMDf - Pitting

+3 more from this case →

ML00169 — Drill Pipe Fracture in the Pipe BodyM - Low Alloy Medium Carbon QTP - Drill PipeAp - O&G Well DrillingCd - Corrosion Fatigue
ML00169 / Nov.2020
Drill Pipe Fracture in the Pipe Body
M - Low Alloy Medium Carbon QTP - Drill PipeAp - O&G Well DrillingCd - Corrosion Fatigue
Cm - Aspect Before AnalysisDf - Fatigue Fracture
ML00169 / Nov.2020
Drill Pipe Fracture in the Pipe Body
M - Low Alloy Medium Carbon QTP - Drill PipeAp - O&G Well DrillingCd - Corrosion Fatigue
Cm - Aspect Before AnalysisDf - General View
ML00169 / Nov.2020
Drill Pipe Fracture in the Pipe Body
M - Low Alloy Medium Carbon QTP - Drill PipeAp - O&G Well DrillingCd - Corrosion Fatigue
Cm - Aspect Before AnalysisDf - Fracture
ML00169 / Nov.2020
Drill Pipe Fracture in the Pipe Body
M - Low Alloy Medium Carbon QTP - Drill PipeAp - O&G Well DrillingCd - Corrosion Fatigue
Cm - Nital Etched Micrography by OMDf - Uniform Structure
ML00169 / Nov.2020
Drill Pipe Fracture in the Pipe Body
M - Low Alloy Medium Carbon QTP - Drill PipeAp - O&G Well DrillingCd - Corrosion Fatigue
Cm - Nital Etched Micrography by OMDf - Martensite

+18 more from this case →