ISST 2007 ISST 2007 A New Prediction for A New Prediction for - PowerPoint PPT Presentation

ISST 2007 ISST 2007 A New Prediction for A New Prediction for Deterioration eterioration of the Corrosion Protection System of the Corrosion Protection System of the Oil Storage Barges of the Oil Storage Barges H.Sugimoto Shipbuilding Research Centre of Japan (SRC) Y.Horii Japan Oil , Gas and Metals National Corporation (JOGMEC)

Today’s Topics 1. OUTLINE OF OIL STORAGE BARGES 1. OUTLINE OF OIL STORAGE BARGES 2. 2. DIAGNOSTIC SYSTEM FOR CORROSION DIAGNOSTIC SYSTEM FOR CORROSION PROTECTION SYSTEM PROTECTION SYSTEM 3. ACCCELRATED AGING TEST DATA AND 3. ACCCELRATED AGING TEST DATA AND ACTUAL DATA ACTU AL DATA 4. RESULTS OF PREDICTION 4. RESULTS OF PREDICTION 5. POTENTIAL SIMULATION OF CORROSION 5. POTENTIAL SIMULATION OF CORROSION PROTECTION SYSTEM PROTECTION SYSTEM

Revision of the Rules(1997) １） Spe Special Su ial Survey rvey Old Old New New In 12 years ＝＝＝ > One / within 5 years In 12 years ne / within 5 years (A (All B Barges) (Represent rges) (Representat ative Barge) ive Barge) In Dry Dock ＝＝＝ > In Dry Dock In Dry Dock > In Dry Dock or Mooring Site or Mooring Site 2) Survey Program 2) Survey Program Once/ 12 years Once/ 12 years ＝＝＝ > Planned Survey System lanned Survey System Once/ 25 years(max) Once/ 25 years(max) (Kamigoto Barges) (Kamigoto arges)

Kamigoto Oil Storage Base Kamigoto base: 390Lx97Bx27.6Dx5 barges 880mlx5=4400ml Shirashima base: 397Lx82Bx25.4x8 barges 700mlx8=5600ml

Structure of Kamigoto Storage Barge Water Tank Ine nert g gas Se Sea w a water Oil il

Corrosion Protection System System System Location Lo tion 250 μ m Oil st Oil storage tank orage tank Upper T Upper T/E 250 Middl Middle no pai no paint Bottom T/E 250 μ m Bottom T/E 2 250 μ m Water tank Water tank T/E T/E/ 250 + A + Aluminum a anode Si Side de an and d bottom bottom To Topside pside P/E 400 400 μ m 400 μ m shell shell Wate Wa terline rline P/E P/E 400 +Alum +Aluminum Ano m Anode ed T/E 400 μ m Immers Immersed T/E 400 +Alum +Aluminum a m anode IZ 75 μ m Upper deck Upper deck IZ 75 100 μ m +P/E +P/E 100

Deterioration Pattern of Total Corrosion Performance Quality Paint+anode １ ０ ０ ％ Tim e Deterioration of paint Repair Anoe depletion １ ０ ０ ％ Full protection C orrosion Full protection Tim e Tim e

Deterioration Diagnosis Flow Actual Barge Accelerated Aging Test Measurement (Specimen) ・ Paint ・ Paint -Impedance -Impedance -Adhesion. -Adhesion. -Current density -Current density (paint resistance) ・ Anode -Weight reduction Matching with Test Data Deterioration Curve -Paint resistance -Impedance -Anode-Weight reduction -Adhesion. -Current density Acceleration Factor (paint resistance, anode weight reduction) Deterioration Curve for Actual Barge Paint deterioration curve Anode deterioration curve Estimation of Protection System Life

Impedance Data of Accelerated Aging Tests and Actual Tank 7 10 6 10 5 10 ２ ） Impedance（Ωm 4 10 □ Actual Data 3 10 for sea water tank (Aug.2002) 2 10 Test Data for sea water tank T/E(250μm） 1 10 0 10 0 50 100 150 200 250 300 350 400 450 Accelerated Aging Test(Days)

Current Density Data of Accelerated Aging Tests and Actual Tank 12 Test Data for sea water tank 11 T/E250μ m 10 9 Average 2 ) Current Density(mA/m 8 7 Upper bound □ Actual Data for sea water tank 6 (Aug. 2002) 5 Lower bound 4 3 2 ○ Monitoring Data (2004) 1 0 0 50 100 150 200 250 300 350 400 450 Accelerated Aging Test(Days)

Paint Resistance Data of Aging Tests and Actual Tank Data 7 10 □ Actual Data 6 10 for sea water tank (Aug. 2002) Test Data for sea water tank 5 10 ２ ） T/E250μm Paint Resistance(Ωm 4 10 ○Monitoring Data (2004) 3 10 2 10 Upper bound 1 10 Lower bound 0 10 0 50 100 150 200 250 300 350 400 450 Accelerated Aging Test(days)

Prediction of Loss of Anode Weight (Example) 100 14 90 Upper Water Tank（Ｎｏ．１Ｓ） 12 80 （％） Loss of Anode Weight（kg） 70 10 t h 60 g i 8 e W 50 e d 6 o 40 ■A c t u a l D a t a n A a f t e r 1 4 y e a r s 30 2007 f 4 o □ A c t u a l D a t a (scheduled) s 20 s a f t e r 9 y e a r s o 2 L 10 0 0 0 5 10 15 20 25 30 35 40 45 50 Operation Years

Simulation Model for Outside Shell and Bottom Shell of Kamigoto No.2 Barge 1 0 . 0 ( m ) Z Y i d e w a l l o f s h i p S E l e m e n t N o . 1 - 1 5 0 X ) r m i ( a 2 S a c r i f i c i a l a n o d e s . n 3 o E l e m e n t 1 ( L i n e ) y r m R a d i u s : 0 . 0 6 9 ( m ) a ( d 0 n ② L e n g t h : 2 . 0 ( m ) . u o 0 b 2 E l e m e n t N o . 1 2 7 7 1 2 7 8 1 0 . 0 ( m ) ) m ① ) ( 2 m 0 ( ) . 0 0 m . ( 0 5 1 . 3 1 ③ 6 . 0 ( m ) B o t t o m w a l l o f s h i p E l e m e n t N o . 1 5 1 - 2 3 0 c o o r d i n a t e o r i g i n R a d i u s : 0 . 0 6 9 ( m ) L e n g t h : 2 . 0 ( m ) E l e m e n t N o . 1 2 8 1 , 1 2 8 2 R a d i u s : 0 . 0 6 9 ( m ) b o u n d a r y o n s e a w a t e r L e n g t h : 2 . 0 ( m ) E l e m e n t N o . 1 2 7 9 , 1 2 8 0

Results of Potential Simulation P a i n t 1 . 0 0 r e s i s t a n c e 2 （Ωm ） 0 . 9 5 0 1 0 1 1 0 ） 0 . 9 0 V 2 1 0 - ( 3 1 0 l a i 0 . 8 5 4 1 0 t n 5 1 0 e t o 6 1 0 0 . 8 0 P K a m i g o t o N o . 2 0 . 7 5 l i n e ① Anode position 0 . 7 0 0 2 4 6 8 1 0 1 2 1 4 D i s t a n c e （ｍ）

Estimation Curve for Determination of Paint Deterioration Condition by Potential Measurement Paint Resistance ｒ 1 2 3 4 5 10 10 10 10 10 35 400 375 Maximum Potencial Difference, ΔV（mV) 30 350 Lower bound 325 25 Accelerated Aging Test(Days) 300 Upper bound 275 20 250 225 (broken line) (solid line） 15 200 175 10 150 125 5 100 75 K a m i g o t o N o . 2 L i n e ① 0 50 ΔV = 6 6 0 * e x p ( - l o g ( r ) / 0 . 5 2 7 ） 25 -5 0 1 2 3 4 5 2 ） Paint Resistance log(r) （Ωm

Example of Test Specimens for Monitoring １５０ｍｍｘ７０ｍｍｘｔ Recovered Plate from Barge (250 φｍｍ）

Setting of Test Specimen in Air Pipe of Water Tank ９ -Upper Tanks: 9 specimens ３ -Lower Tanks: 3 specimens Periodic Monitoring: Visual inspection Impedance Current density Adhesion Potential

Ｃｏｎｃｌｕｓｉｏｎ Proposed and examined: (1) Master curves of deterioration of paint system by accelerated aging tests is defined. (2) Actual deterioration data of both painting and anode are collected. (3) Method of determine correlation between master curve by tests and actual barge data by measurement at dry-docked survey is established (4) Prediction of a life of present corrosion protection system of immersed portion of the Oil Storage Barges becomes possible. (5) Estimation curve to determine paint deterioration condition using potential measurement are established.