Corrosion Control at VMT Dr. Rust, Inc. Corrosion Control at VMT R. Heidersbach Dr. Rust, Inc. R. Heidersbach K. Prakash R. Guise January 17, 2013
Emphasis of Project • Objective not to second guess • Objective is an assessment of what was seen and obvious reliability issues that need to be addressed • Goal for both Alyeska and RCAC – Prevent corrosion-related environmental damage
Objectives • Evaluate corrosion control at Valdez Marine Terminal – Only for systems that can cause oil pollution • Emphasis on procedures • Review condition of – Corrosion control efforts – Tanks, piping, berths and related equipment • Recommend changes, if any, that should be considered
Dr. Rust Inc • • Bob Heidersbach Kash Prakash – Direct contractor to – Tanks PWSRCAC – Coatings – Pipes and corrosion inhibitors – Berth facilities • Bob Guise – Cathodic protection 9/20/2012 Board Meeting PWSRCAC
Thanks Alyeska PSC PWSRCAC • Barry Roberts • Tom Kuckertz • Linda Swiss • Steve Lacatena • Anna Carey • Clay Forsyth • Donna Schantz • Doug Fleming • Mark Swanson • Tawna Beer-Burns, Coffman • Cecilia Sanchez, Baker Hughes
Priorities--crude oil marine terminals Equipment Corrosive Environments • Piping • Oil – Most likely to leak – Largest volume of potential – Pitting corrosion most likely pollutants largest pollution corrosion-related leak initiator risk • Berthing/dock facilities • Fire fighting equipment – At waters edge – Safety • Pipelines – Perhaps equal in operational – Buried priority, but less likely to – Hard to inspect produce pollution – ECDA coming • Vapor recovery standard/requirement • Oily water • Tanks – Most corrosive liquid – Large volume of oil environment – Easy to inspect – Expensive internal inspections
Scheduling and Timeline • Pre-visit Activities – Prior to July 31, 2012 – Requests for and analysis of documentation • Anchorage Activities – July 31-August 3, 2012 – Documents review -- Alyeska’s Anchorage office • Valdez Field Work – August 6 – 9, 2012 – Monday – Admin, safety, security, document requests, facilities access requests – Tuesday – Look at Berth 4, tanks, CP, piping, fire foam systems – Wednesday – Look at Berth 5 and other VMT locations, – Thursday – Exit briefing • Draft report – September 2012 • Final Report – Revise and review – October thru December 2012 • Final report – Proposed for acceptance -- January 2013
Changes in Oilfield Corrosion Problems • As oilfields age, corrosivity increases • Inspection and corrosion control efforts need to be increased in ageing fields/terminals • Decreased production decreased funding for maintenance and inspection at the same time that needs for these efforts increase
OK/Almost OK Areas
Internal corrosion of pipes • Control is by corrosion inhibitor – Injected batches on 2-week intervals • Effectiveness of corrosion inhibitors and biocides is monitored by coupons – Inserted/removed twice per year – Standard weight loss and pit depth report • State of the art in the 1970s • Still most common method of monitoring corrosivity and effectiveness of corrosion inhibitors
Structural Integrity Structural Integrity • Covered by Alyeska MP-166.3.21, VMT • Covered by Alyeska MP-166.3.21, VMT Facility Underwater Inspections Facility Underwater Inspections
• Concern before August Fire-suppression AFFF — Fluoroprotein Foam efforts Foam • No longer a corrosion concern • Concern before this week’s efforts • “Spiders” in tanks have • No longer a corrosion concern experienced some • “Spiders” in tanks have experienced some corrosion – External in “deadleg” corrosion locations – External in “deadleg” locations – Now part of Alyeska – Now part of Alyeska T-500 tank inspection T-500 tank inspection protocol (2012 protocol (2012 paragraph additions) paragraph additions)
Tanks • Tank inspection is OK – Possible exceptions are roof and vapor recovery systems which were not considered in this project’s efforts – Need to review summer 2012 inspection results • Corroded foam spiders now included in Alyeska procedure
API 653 Scope • Includes foam fire suppression systems • Alyeska T-500 – New section 3.4 on Fire Foam System added early 2012
Cathodic Protection — Buried Piping • Good – Follow strictest industrial/regulatory practice • NACE SP0169 • Coming – ECDA • NACE SP0502-2008, Pipeline External Corrosion Direct Assessment Methodology • Coming from US DOT
Cathodic protection Industrial waste water line • Ductile cast iron • Bell and spigot connections • No jumpers – Questionable continuity • Jumpers • Lead or jute packing poor or no electrical continuity at joints – stray current – Questionable cathodic protection beyond the first joint
ECDA — External corrosion direct assessment • External corrosion direct assessment • NACE SP0502 — Pipeline External Corrosion Direct Assessment Methodology • Will be required by US DOT at some time in the future • Requires digs and inspection in selected locations • Controversial, – Evolving methodology – RBI-related
Cathodic Protection Cathodic Protection — Berth Berth Platform Legs--OK Platform Legs • OK
Cathodic Protection--Tanks • Tank bottoms – Pay attention to readings • Rectifiers turned off almost instant depolarization based on measurements in August 2012 • Stray current from nearby systems? – Soil side only?
Corrosion Coupons in Piping • Used for monitoring changes in the environment • Cannot – Identify/measure worst corrosion in the system • Only the corrosion of the coupon — not the system – Deadlegs – Crevices – MIC – Identify when corrosion occurred • Comparison with previous exposure data indication of effectiveness • Misses upsets, etc. • Needs comparisons with previous exposures to ID trends in corrosion rates • Too much data to usefully interpret
Problem Areas • Corrosion under insulation • Inspectability • Communications – Contractor/Alyeska personnel – Problems resolution of problems
Corrosion Under Insulation (CUI) — Berth 5 Crude Oil Line • Good news — • Concern corrosion found/repaired with no leaks into the environment
Previous Observations of Corrosion on Unpainted Welded Joints Corrosion near unpainted welds on insulated piping. Photograph by T. Kuckertz, PWSRCAC staff member, May 29, 2008 at the VMT Ballast Water Treatment Facility
CUI Identified during Fieldwork in Anchorage by Alyeska Corrosion on Berth 4 riser piping caused 70% wall loss in places
Slide from Tom Kuckertz presentation September 2012 Repairs in accordance with standard industrial practice
Summer 2012 CUI Corrosion Inspections Alyeska inspection Alyeska survey • 3 rd year of program to • Project Z683 – VMT inspect selected Crude Header locations External Condition Survey (2012) • 2012 results – Crude oil piping – Maximum pitting 70%+ wall loss – Sleeve repairs
Summer 2012 CUI Corrosion Inspections Good news Questions • VMT found the • When did the corrosion corrosion occur? – Before leaks • Why not discovered Concerns sooner? – 3 rd year of inspection • Over water location program – Previous years did not emphasize over-water locations
Snow-removal damage 2012 Note sharp, angular features on openings
Openings prior to 2012 Piping Leading to Berth 5
Numerous patches at VMT This is good news — inspection/maintenance has occurred
Additional CUI-related Observations
Corrosion coupon box — Corrosion coupon box — full of water on August 7 and again on August 8 full of water on August 7 and again on August 8
Wet pipe above coupon holder Wet pipe above coupon holder
Water droplets Unavoidable “void” space
Note UT grid pattern • Did anyone report the water on the pipe? • Did anyone report the • Contractors see these water on the pipe? locations several • Contractors see these times each year locations several • No requirement to times each year report moisture to • No requirement to Alyeska decision report moisture to makers Alyeska decision makers
Question/problem? • The previous slides show pipes wetted in locations where a contractor pulling corrosion coupons gains access to the pipe twice a year. • Does Alyeska & their contractor have a method of communicating the water accumulation at these “dry” locations? • Possibly install drain holes on bottom of jackets – May lead to melt water intrusion due to high snow loads in some locations at VMT
Corrosion Under Insulation • NACE SP0198 • Not industry- recognized problem in 1970’s
Problem locations for insulated above-ground pipelines
Slide from 2006 RCAC presentation Illustrates problems associated with localized corrosion inspections Best practice — 100% inspection
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