SUBSEA INSTALLATION WITHOUT A HEAVY LIFT VESSEL A STEP CHANGE IN SUBSEA INSTALLATION Subsea Deployment Systems Ltd.
Subsea Deployment Systems Ltd. PRODUCT •An alternative to an HLV for the recovery of subsea structures •Low cost •Allows even the smallest crane vessel to recover large structures •Operations largely independent of weather •Safer than a conventional lift •Schedule flexibility 2
Subsea Deployment Systems Ltd. MARKET •Installation or decommissioning of subsea structures •100t to several 1000t •Optimum range 200t to 1000t •80m to 3000m water depth •Hostile environments 3
Subsea Deployment Systems Ltd. ECONOMICS •SDS + AHT @ $50k/day compared to an HLV @$1m/day •Minimal risk of weather delays •Year round operation + VS 4
Subsea Deployment Systems Ltd. SAFETY AND ENVIRONMENT •Low tech / fail safe •Operations can be suspended at any time (no point of no return) •Operations insensitive to weather •Negligible dynamic loading •Structures are not recovered to deck •Reduced risk of catastrophic loss •Fewer personnel •Low carbon footprint 5
Subsea Deployment Systems Ltd. THE SDV MAIN COMPONENTS TOW CHAIN CLUMP WEIGHT TOW CHAIN CLUMP CONTROL CONTROL CHAIN WEIGHT CHAIN CONTROL BUOYANCY MODULES BUOYANCY CONTROL TOWER TOWER MODULES CASTLE CASTL E BALLAST BALLAST LOCKER LOCKER STRUCTUR FLOODABLE STRUCTURE FLOODABLE HULL E HULL 6
Subsea Deployment Systems Ltd. SYSTEM VARIATIONS 7
Subsea Deployment Systems Ltd. LOAD OUT •Lifted •Float off •Submersible barge •Floating dock •Dry dock •SUBMERSIBLE BARGE 8
Subsea Deployment Systems Ltd. SURFACE TOW •Shallow surface tow •Flood tanks •Insert tow chain clump weight •Pay out tow wire 9
Subsea Deployment Systems Ltd. SUBMERGED TOW •Adjust tow wire and speed •Slow down to lower the system •Pay out tow wire to lower clump weight 10
Subsea Deployment Systems Ltd. LOWER STRUCTURE •AHT disconnects the tow wire •Lower control chains into the control chain towers •Slew crane to create lead on control chains •Pay out chain until the system is neutral 11
Subsea Deployment Systems Ltd. CONTROL CHAIN TOWERS •Rotational control •Lateral control •On ‐ bottom weight •Vertical control 12
Subsea Deployment Systems Ltd. DYNAMICS • Response governed by the natural period of the system • Typically the natural period of a >1000t system > 120s • Increased weather window for set down • Minimal dynamic loading on the surface crane and structure 13
Subsea Deployment Systems Ltd. INSTALLATION •AHT manoeuvres the system to final target 14
Subsea Deployment Systems Ltd. BALLASTING • Lower system slowly on to target • Pay out remaining control chain into control chain towers • Install ballast weight to balance the payload weight 15
Subsea Deployment Systems Ltd. LIFT ‐ OFF • WROV disconnects payload • Deploy down lines and reconnect to the control chains • Recover the control chains until the subsea deployment vessel starts rising • Continue raising until well clear of subsea assets 16
Subsea Deployment Systems Ltd. RETURN TO SHORE • Recover control chains until clear of the control chain towers • AHT tows the subsea deployment vessel back to shore 17
Subsea Deployment Systems Ltd. DYNAMICS FULL (30x) VESSEL & SDV (SHADOWS) SDV CLOSE-UP (SHADOWS) 18
Subsea Deployment Systems Ltd. SEASTATE STATISTICS • Subject to operational windows and seasonal variations 19
Subsea Deployment Systems Ltd. INHERENT SAFETY • Total Loss Minimised – “Close To Neutral” • Insensitive to weather • No point of ‘no return’ • Rigging failure • Buoyancy loss TOW WIRE FAILURE (10x) 20
Subsea Deployment Systems Ltd. 21
Subsea Deployment Systems Ltd. POTENTIAL APPLICATIONS INSTALLATION DECOMMISSIONING • 100t to several 1000t • Operation is fully reversible structures for new structures • Water depth 80m – 3000m • Interfacing flexibility with existing structures • Hostile environments • Minimal dynamic loading • Existing structures recovered without lifting to deck • Large skip 22
Subsea Deployment Systems Ltd. ADVANTAGES •Low CAPEX/OPEX •Simple and robust technology •Safe •Suitable for deep water and harsh environments •Heavy lift capacity •Greater availability compared to HLV •Potential for phased installation and early production •Potential for fewer structures, tie ‐ ins and interfaces 23
Subsea Deployment Systems Ltd. HLV SUPPLY • LIGHTER (<150t) •Market is mainly over supplied •Generally not suitable for deepwater / hostile locations • MIDMARKET (150T – 400T) •Most of the vessels have other primary functions •Capacity drops significantly in deep water / hostile locations • LARGER (400T+) •Very limited availability • Opportunities exist for alternative lifting solutions 24
Subsea Deployment Systems Ltd. STATUS •UK patent was awarded September 2010. •Outline designs and installation procedures have been developed for the Gorgon and Shtokman developments. •Detailed study performed for Apache for the installation of two structures at Forties. •Technical evaluation has been performed by a major installation contractor resulting in an offer to buy the patent outright. •SDS is seeking a partner to assist in bringing the system to market. 25
Subsea Deployment Systems Ltd.
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