SHELL RISK-BASED INSPECTION (S-RBI) Basics & Related Approach to Corrosion under Insulation (CUI)

Transcription

1 Shell Global Solutions SHELL RISK-BASED INSPECTION (S-RBI) Basics & Related Approach to Corrosion under Insulation (CUI) Presented by: Maarten Lorenz Materials & Inspection Technology Shell Research & Technology Centre, Amsterdam, The Netherlands

2 Shell Global Solutions Pacesetting Concept CUI Conference PACESETTING PROGRAM sustained top 10% performance for more than 5 years HSE PROGRAM HYDRO CARBON MANAGEMENT MERIT REVIEW ORGANISATION MANAGEMENT OF ASSETS M anufacturing E nhanced R eliability I mprovement T eam RISK AND RELIABILITY MANAGEMENT Integrated versions of: Reliability Centred Maintenace Risk-Based Inspection Instrumented protective functions Shell Global Solutions 2

3 S-RBI in Relation to Risk & Reliability Management RISK AND RELIABILITY MANAGEMENT (RRM): RISK-BASED INSPECTION -> optimised inspection plan RELIABILITY CENTRED MAINTENANCE -> cost effective maintenance plan INSTRUMENTED PROTECTIVE FUNCTIONS -> minimum design and testing requirements Shell Global Solutions 3

4 Why Apply Risk-Based Inspection? CUI Conference To move away from time based inspection governed by minimum compliance with rules, regulations and standards for inspection. To apply a strategy of doing what is needed for safeguarding integrity and improving reliability as well as availability of the plant by planning and executing those inspections that are needed. Risk-Based Inspection may provide economic benefits: reduce inspection scope, shorter shutdowns, longer run length, fewer unplanned shutdowns. Shell Global Solutions 4

5 RBI = TEAM EFFORT CORROSION ENGINEER PLANT INSPECTOR MAINTENANCE ENGINEER PROCESS TECHNOLOGIST OPERATOR AUTHORITY REPRESENTATIVE (on request) Shell Global Solutions 5

6 S-RBI RELATED TOOLS CUI Conference Maintenance and Inspection Database Electronic Drawings (VISIO) Corrosion Control Manual S-RBI (RRM) Manual Trending Software S-RBI ANALYSIS S-RBI (RRM) Software Statistical Recipe Book Degradation Library NDT Handbook FFP Handbook Shell Global Solutions 6

7 S-RBI Analysis based on Corrosion Loops What is a Corrosion Loop? A PRACTICAL WAY TO DESCRIBE, UNDERSTAND AND CHECK DEGRADATION MECHANISMS IN A UNIT part of the unit subjected to: the same process conditions the same failure mechanisms the same materials selection criteria one operating window control of degradations via process control values agreed by team (boundary conditions for RBI) deviation should be reported 12-E-101 Loop 1 CORROSION LOOP 12-D-101 Loop 2 12-E-102 Loop 3 12-K-101 1st stage 12-G-101 to burn pit same process conditions same degradation mechanisms Shell Global Solutions 7

8 The Shell Risk-Based Inspection (S-RBI) Process DEGRADATION MECHANISM SUSCEPTIBILITY CONSEQUENCE Criticality Matrix REMNANT LIFE HISTORY & CONDITION INHERENT CRITICALITY Interval Matrix CONFIDENCE RATING INSPECTION PLAN Shell Global Solutions 8

9 Susceptibility To Failure CUI Conference Determine potential degradation mechanisms for the Loop For those degradation mechanisms, identify the StF per item for each item since there can be differences in temperature etc. For each item, analyse the different degradation mechanisms separately since they may result in different failure modes Different inspection techniques/intervals may be required Monitoring scheme to be indicated for non-age realated degradations Shell Global Solutions 9

10 Assessment of Consequence of Failure Score Table on: Economic consequences Health & Safety consequences Environmental consequences CUI Conference Shell Global Solutions 10

11 S-RBI Criticality Matrix CUI Conference Susceptibility HIGH NEGLI- NEGLIGIBLE NO INSPECTION REVIEW ONLY L MEDIUM L M MH H E LOW N L M MH GIBLE N N L M MH S-RBI NEGLI GIBLE LOW MED IUM MH H E E LOW HIGH Consequences MEDIUM H EXTEN SIVE MEDIUM-HIGH INSPECTION PLAN EXTREME HIGH RECTIFY DETAILED ANALYSIS Shell Global Solutions 11

12 Confidence Rating indicator for confidence in forecast of degradation rating - very low to very high reflects: stability/predictability of degradation number and quality of previous inspections process stability BETTER CONFIDENCE YIELDS LONGER INSPECTION INTERVALS Shell Global Solutions 12

13 Maximum Inspection Interval CUI Conference WALL THICKNESS INSPECTIONS WT new X X REMNANT LIFE MAXIMUM INSPECTION X INTERVAL WT (min) MINIMUM ALLOWABLE THICKNESS LIFETIME IN YEARS Shell Global Solutions 13

14 Corrosion Under Insulation Shell Global Solutions 14

15 The S-RBI Process for CUI: remnant life not available CUI Conference CORROSION UNDER INSULATION SUSCEPTIBILITY CONSEQUENCE Criticality Matrix REMNANT LIFE HISTORY & CONDITION INHERENT CRITICALITY Strategy Matrix CONFIDENCE RATING MAINTENANCE & INSPECTION STRATEGY Shell Global Solutions 15

16 Determining CUI Susceptibility Score Table on: Operating Temperature Initial Coating Status Insulation Type Wall Thickness & Surface Features Internal Corrosion/Erosion Rate External Coil/Steam Tracing External Environment Shell Global Solutions 16

17 Determining CUI Consequence Score Table on: Economic consequences (including production loss!) Health & Safety consequences Environmental consequences Shell Global Solutions 17

18 Confidence Rating An item s criticality basically determines the inspection/maintenance strategy to be applied. Depending on how well the condition of an item is known, a limited degree of conservatism/opportunism is applied in choosing the inspection/maintenance strategy. CUI Confidence Rating depends on: cladding & insulation condition number & quality of CUI inspections knowledge of CUI promoting conditions Shell Global Solutions 18

19 CUI Strategy Matrix for CS/Low Alloy Steel CUI Conference CRITICALITY EXTREME HIGH MEDIUM-HIGH MEDIUM LOW NEGLIGIBLE (review only) CONFIDENCE RATING VERY LOW LOW MEDIUM HIGH VERY HIGH STRATEGY 0 STRATEGY 1 STRATEGY 1 STRATEGY STRATEGY 2 STRATEGY 2 3 STRATEGY 3STRATEGY 3 STRATEGY 4 NO INSPECTIONS Shell Global Solutions 19

20 CUI Inspection/Maintenance Strategies CUI Conference Effectively five strategies have been developed for the six criticality levels. The coverage and quality of the applied coating/paint may add up to 8 years of CUI protection. Inspection intervals start at the moment the coating/paint protection has ended. Inspection intervals are based on recommended maximum timing. Initial inspection actions always involve delagging. Inspection results may lead to adjusting the strategy level. Shell Global Solutions 20

21 Inspection/Maintenance Strategy s Loop CUI Conference YES Corrective Action Initial Inspection Significant CUI? NO Follow-up Inspection YES Significant CUI? NO Corrective Action Review Strategy (one cycle) Shell Global Solutions 21

22 Non-Intrusive Inspection Techniques for CUI? Thermography? Pulsed Eddy Currents? (real-time) Radiography? Guided-Waves? - finds wet spots, not CUI - requires experienced operator - local measurement of wall thickness - difficult to apply on complex geometries - excellent for determining wall thickness through corrosion products - suitable for small bore connections - accessibility and safety issues - screening technique to detect wall loss - requires experienced operator - only simple pipe geometries Shell Global Solutions 22

23 CUI Inspection/Maintenance Plan: requires pre-screening of the assets prior to application (not applied to items with negligible susceptibility to CUI). does not rely too much on non-intrusive inspection results (screening inspection techniques used to indicate susceptible areas). is harmonised with the S-RBI methodology. is also available for insulated stainless steel items (CUI = Chloride Stress Corrosion Cracking). does not eliminate CUI failures completely, but reduces the effects of these failures to your business to a tolerable level. Shell Global Solutions 23

24 Shell Global Solutions SHELL RISK-BASED INSPECTION (S-RBI) Basics & Related Approach to Corrosion under Insulation (CUI) - thank you for your attention - ANY QUESTIONS OR REMARKS? Presented by: Maarten Lorenz Materials & Inspection Technology Shell Research & Technology Centre, Amsterdam, The Netherlands