Decommissioning Ageing Infrastructure: Abandoning or Re-Routing Hydrocarbon Pipelines Dave Vernon - Director of Isolation Services
Overview Abandonment and Decommissioning Pipeline Disconnection Pipeline Rerouting Pipeline Abandonment Riser Isolation Flow Line Plugging The 130 metre high Brent Delta topside heading for Hartlepool, UK Photo: Shell / Allseas STATS GROUP Slide: 2
Typical Mature Field Overview Decommissioned In Decommissioning Image: TAQA Bratani STATS GROUP Slide: 3
Hub Platform Configuration Several pipelines in the image are scheduled for disconnection in the near future Image: TAQA Bratani STATS GROUP Slide: 4
Why Double Block and Bleed Isolation Equipment? Pipeline Diver Safety Positive Pressure Diver Safety Negative Pressure Environmental Protection Reduced Diver Time Reduced Flushing and Purging Operations Downstream production unaffected (upstream too with pre-installed bypass) STATS GROUP Slide: 5
Equipment for Isolation and Abandonment Abandonment and Decommissioning Remote Tecno Plug Tethered Tecno Plug BISEP Pipeline Connector (Sleeve or Adaptor) Pipe End Plugs STATS GROUP Slide: 6
Secondary Seal Integrity Test: Leak-Off Test 1) Pressure locked in the annulus 2) Pressure behind (inboard) vented Secondary seal tested with full differential pressure in correct direction. STATS GROUP Slide: 7
Primary Seal Integrity Test: Build-Up Test 1) Pipeline pressure in front (outboard) 2) Annulus pressure vented and locked in Primary seal tested with full differential pressure in correct direction. STATS GROUP Slide: 8
Dual Redundancy Activation: Fail-Safe Self-energisation (Self-Locking) feature maintains a safe isolation while differential pressure (above the verified minimum pressure) exists across the tool. The isolation plug has two separate activation mechanisms Dual Redundant Activation. The isolation tool is activated and held in place by internal hydraulics AND energised and mechanically locked by the differential pressure. Both separate activation mechanisms need to be removed to unset the plug. NOTE: Permanent abandonment plugs include an additional mechanical lock which removes long term reliance on the hydraulics STATS GROUP Slide: 9
Passive Unset: Fail-Safe Passive Unset feature ensures the Tecno Plug is always recoverable upon job completion. Fail-safe in unlikely event of communication system issues. Passive Unset happens when tail pressure is equalised with the head pressure. This de-latches the locked in hydraulic pressure; open circuited to return. Equalising the pressure across the plug removes self energisation force. Once equalised the plug will then passively unset without any active control input. NOTES: Isolation cannot be unset until the breaking containment operation is completed and the pressure behind the plug is raised to pipeline isolated pressure. If the pressure is equalised, the plug will become unset unless it is actively commanded not to unset. The passive unset is done in a safe and controlled manner only when the pressure is equalised across the tool. STATS GROUP Slide: 10
Case Study: Pipeline Disconnect & Abandonment Abandonment and Decommissioning 8 Triple BISEP Pipeline Bypass STATS GROUP Slide: 11
Case Study: Pipeline Disconnect & Abandonment STATS GROUP Slide: 12
Case Study: Pipeline Disconnect & Abandonment Disconnect and Abandonment Final Pipeline Configuration STATS GROUP Slide: 13
Case Study: Subsea Platform Bypass STATS GROUP Slide: 14
Animation: Subsea Platform Bypass Animation 1 STATS GROUP Slide: 15
Thank You For Your Attention Questions? for more information visit www.statsgroup.com sales@statsgroup.com STATS GROUP Slide: 16
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