Logistic Support of a Manned Underwater Production Complex

ISBN-13: 9789400966574 / Angielski / Miękka / 2011 / 129 str.

PhD M. Jones

Opis

The support of subsea oil and gas production operations involves the use of many underwater work systems. Divers can be used for support tasks in water depths to 300 m, but at more extreme depths operations become restrictively expensive and the efficiency of task performance is reduced. Remote controlled unmanned vehicles can replace the diver to a limited extent, performing inspection and maintenance tasks and supporting drilling opera tions. Operations in deepwaters performed by remote controlled vehicles and one man submersible vehicles, such as JIM and WASP, are more cost effective than the use of divers. The areas of operation of the more complex multi-manned submersibles and bells are today generally restricted to their use for diver lock-out operations, manned intervention to subsea enclosures and the deployment of other underwater work systems. Oil and gas exploration activity is being undertaken in progres sively deeper waters. In the North Sea, Shell have discovered a large gas accumulation off the Norwegian coast in 323 m water depth and B. P. have made oil finds West of the Shetlands in 500 m and West of Eire in 450 m. Exploration drilling is today being carried out in many areas of the world in water depths greater than 1000 m, i. e. Western Mediterranean, Offshore Argentina, Offshore Western Australia and in the Niger Basin, West Africa. The existing discoveries of Shell and B. P.

Spis treści

1 Introduction.- 2 The Environment of Operations.- 2.1 Introduction.- 2.2 The Ocean Environment.- 2.3 Ocean Environmental Parameters: Continental Slope.- 2.3.1 Pressure.- 2.3.2 Temperature.- 2.3.3 Salinity.- 2.3.4 Density.- 2.3.5 Currents.- 2.3.6 Turbidity Currents.- 2.3.7 Bottom Sediments.- 2.3.8 Seismic and Volcanic Activity.- 2.3.9 Waves.- 2.3.10 Corrosion.- 2.3.11 Fouling.- 2.3.12 Ice.- 2.3.13 Hostile Sea Life.- 2.3.14 Debris on the Ocean Floor.- 2.3.15 Light Transmission.- 2.3.16 Sound Transmission.- 3 Operational Requirements and Systems Constraints.- 3.1 Introduction.- 3.2 Operational Parameters.- 3.3 Operational Requirements.- 3.3.1 Auxiliary Operational Requirements.- 3.4 System Constraints.- 3.4.1 Environmental Constraints.- 3.4.2 Support System Constraints.- 3.4.3 Production System Constraints.- 3.4.4 Human Factor Constraints.- 3.5 Candidate Logistic Support Systems.- 3.5.1 Surface Support Vessels.- 3.5.2 Mid-water Vehicles.- 3.5.3 Sea-Bottom Systems.- 3.6 Critical Operational Areas.- 4 Transit and Emplacement of Structures.- 4.1 Introduction.- 4.2 Site Preparation and Assessment.- 4.3 Towing.- 4.3.1 Draught and Width.- 4.3.2 Hydrodynamic Considerations.- 4.3.3 Towing Speed.- 4.4 Emplacement at Site Location.- 4.4.1 Dynamic Response of Emplaced Structure to Currents and Seismic Forces.- 5 Logistic Support Loads.- 5.1 Introduction.- 5.2 Costs of Support Operations.- 5.3 Liberal Design of the Complex.- 5.4 Logistic Payloads.- 5.4.1 Personnel.- 5.4.2 Food.- 5.5 Logistic Support Operating Philosophy.- 6 Support Vehicle.- 6.1 Introduction.- 6.2 Submersibles: General.- 6.2.1 Submersibles: General Characteristics.- 6.3 Operational Role of the Submersible.- 6.3.1 Task Requirements.- 6.3.2 System Constraints to Submersible Operations.- 6.4 Submersible Features.- 6.4.1 Pressure Hulls.- 6.4.2 Ballast System.- 6.4.3 Propulsion and Manoeuvring System.- 6.4.4 Submersible Control.- 6.4.5 Mating.- 6.4.6 Power Requirements.- 6.4.7 Sensors.- 6.4.8 Navigation.- 6.4.9 Communications.- 6.4.10 Life Support.- 6.4.11 Support Systems.- 6.5 Bells.- 6.6 Autonomous Submarine.- 7 Ingress/Egress System for Complex.- 7.1 Introduction.- 7.2 Basic Philosophy of the Ingress/ Egress System.- 7.3 Ingress/Egress System Concept.- 7.3.1 Configuration of Structure.- 7.3.2 Environmental Conditions.- 7.3.3 Logistic Support Requirements.- 7.4 Access Chamber.- 7.4.1 Access Chamber as Safe Haven and/or Escape Capsule.- 7.4.2 Access Chamber Services: Transfer Operations.- 7.5 Resupply Operations.- 7.5.1 Transfer Operations.- 7.5.2 Sequence of Transfer Operations.- 7.5.3 Transfer of Injured Personnel from Complex.- 7.5.4 Hatches.- 7.5.5 Dimension Restrictions.- 7.5.6 Mating to Access Chamber.- 7.6 Potential Hazards.- 7.6.1 Impact Collision.- 7.6.2 Currents.- 7.6.3 Seal Failure.- 7.6.4 Hatch Protection.- 7.6.5 Warning Devices.- 8 Surface and Subsea Support Systems.- 8.1 Introduction.- 8.2 Underwater Vehicle Launch and Recovery.- 8.2.1 Submersibles.- 8.2.2 Bells.- 8.3 Support System Concepts.- 8.3.1 Permanently Moored Tanker.- 8.3.2 Semi-submersible Utilities Platform.- 8.3.3 Semi-submersible Workover Platform.- 8.3.4 SWATH Vessel.- 8.3.5 Autonomous Submarine.- 8.3.6 Summary.- 8.4 Inverted Support System Concept.- 8.5 Conclusion.- 9 Conclusions.- 10 Recommendations.- References.