Conductor Integrity Management & Solutions

Transcription

1 Conductor Integrity Management & Solutions Delivering safe, reliable, cost effective solutions to the North Sea.

2 Contents 1. Late Life Asset Management 2. Conductors 3. Loadings 4. Internals 5. External 6. Integrity Issues 7. Integrity Issues (2) 8. Integrity Issues (3) 9. What were we dealing with? 10. Analysis 11. Approach by SETS 12. Rope Access Solution 13. Cleaning & Inspection 14. Repair Types 15. Remote Repair 16. Inspection & Install Tooling 17. No Vessel for Subsea Work

3 1 Late Life Asset Management > 150 Fixed Assets in the North Sea at an average age of 18yrs + Beyond field life expectation Continued operation in a low $/bbl environment Asset Integrity and Well / Asset Value balance of utmost importance for sustainability Highest Value Data, gained by economic methods, allows a sustainable Integrity management system

4 28 Conductors Asset structural component Well load sharing Implications for well integrity management Environmental sheathing for well casings Corrosion protection for surface casing Run during early phase operations Robust design has permitted field life extension Not necessarily fit for purpose for late life operations

5 38 Loadings In service, the conductor is subject to: Environmental loading due to waves and currents Impact loads due to contact with conductor guides Operational loads (BOP weight during work over scenarios) Corrosive environments

6 48 Internals Annuli contents will vary and may not be understood, especially in older wells Surface casing (generally) carries well load across underwater zone Load sharing can be complex and affected by deterioration of conductor Casing integrity implications for well barriers to maintain safe operations

7 58 External Conductors Standard heavy walled pipe, typically diameter Spanning between horizontal guide frames Joint connector integrity. Older asset connectors susceptible to corrosion and low fatigue life Connector structural capacities of considerable importance

8 6 Integrity Issues A few of our favourite things: Fretting at guides Internal corrosion (@LAT) External corrosion (at connectors) Connector integrity Casing integrity Poor subsea inspection Poor data management

9 7 Integrity Issues (2) 1) Fretting, Cracking and through wall material loss 2) Failed 60% Circumferential crack in fretted area running up through unfretted conductor (now cleaned) 3) Failed CGF Through wall defect and water ingress to surface casing

10 8 Integrity Issues (3) 1) Failed Connector in Air Gap, usually repaired when found with Structural clamp 2) Failed connector Subsea, requires more thought and there are numerous horror stories of repair attempts 3) Failed connector Threads appear to have been machined. Unknown until conductor pulled as cleaning proved difficult with inspection not being on priority list

11 9 What were we dealing with? Range of fretting noted during ROV flyby At least 8 Conductors with heavy fretting and TWD Conductor guide bucket damage multi level Annuli integrity & at risk? Splash zone operations so specific levels unknown but some tracking by historical ROV footage possible. An Asset which is economic, but borderline as to how fragile that level of economic is. Marine Growth and access issues impacting any semblance of Asset Integrity requirements or Risk Based Inspection criteria Could we have done something sooner to prevent bigger maintenance spend now?

12 10 Analysis Understand current condition & determine implications of identified damage Build model across all conductors based on current condition and loadings Consideration of unique defect situations: separation at guide & connector above

13 Approach by SETS 11 SETS believe, a third eye look at any challenge can give a clearer picture to what can be achieved. Our approach is based on Minimising Risk, Maximising Value for all projects, through Early Engagement and Disruptive Thinking methods. SETS can guide an operator through a Phase stage gate process to de-risk any the project. r DSV 100k/day r ROV 65k/day a SETS 20k/day SETS approach will ensure all options are considered whether using an ROV, DSV or Rope access technique. We will ensure the focus is on Minimising Risk, Maximising Value ROV/DSV Is not the only option.

14 Rope Access Solution No Vessels Under deck Rope access deployed solution Ability to clean and Inspect material loss within Conductor guide Frame at circa -15m Repeatable, economic method to allow build of Integrity management solution Ability to analyse and advise repair / maintenance requirement from SETS pre-prepared solutions

15 138 Cleaning & Inspection 1) Cleaning & Inspection Tool Installed in the Airgap to the Conductor by the Rope Access team 2) The Tool is run down the conductor, cleaning using HP water Jet nozzles rotating around the conductor 3) The Tool cleans do to and through the Conductor guide frame 4) The Tools attached Laser arm allows the measurement of material loss due to Fretting down through the guide Frame

16 148 Repair Types 1) Type 1: Is a pretty standard Wear sleeve, for minimal damage and protection 2) Type 2: Will provide Shear Support were Fretting / TWD has occurred 3) Type 3 / 4: Provides shear & Axial support through guide where this is not present due to condition 4) Type 5: Where connector has failed, full moment clamp

17 158 Remote Repair 1) Repair Clamp installed in the Airgap by the Rope Access Team 2) SETS Installation Tool interfaced to clamp within the Airgap 3) Clamp & Install Tool Run to Repair Site & Torqued as required 4) SETS Install Tooling detaches from Repair and recovered to surface by RA Team

18 168 Inspection & Install Tooling 1) Cleaning & Inspection Tool 2) Type 1 Wear Sleeve 3) Type 2 RA install in Airgap 4) Type 2 in location ready for install

19 17 14 No Vessels for Subsea works

20 Early engagement. Disruptive thinking.