This publication provides practical guidance on marine operations of jack-up type barges and jack-up towing and positioning. It examines each stage of the operation and identifies best practice and potential hazards.
The Oilfield Seamanship series describes and explains standard techniques used in marine operations in offshore oilfields. The series concentrates on towing, anchor handling, barge mooring and moving, the operation of jack-up vessels afloat, the practice of stability control on semi-submersibles and ballast control techniques.
CONTENTS – SECTION ONE
Marine Operations of Jack-up Type Barges
PART 1. General comments on moving Jack-ups
PART 2. Sequence of events – with examples of General Checklists
PART 3. Jacking Down and Getting Afloat – with examples of Pre-move Checklists
PART 4. Jacking Down, Leg Cord Loadings
PART 5. Pulling Legs, Deep Penetration – Cautions
PART 6. Pulling Legs, Deep Penetration – Freeing Methods
PART 7. Transit Afloat
PART 8. Leg Wedges and Rack Chocks – use of
PART 9. Daily Checklist for Afloat Operations – with example of Standing Orders
PART 10. Transit Operations Afloat – Heavy Weather Seamanship
PART 11. Transit Operations Afloat – Extreme Storm Conditions. Preparations and Planning
PART 12. Transit Operations Afloat – Damage Control. Flooding
PART 13. Criteria for Field and Inter Field Moves
PART 14. Decision Making Process. Moving Operations, Jacking Criteria
PART 15. Notes on the Towage – with example of Poor Planning
PART 16. Preparations for Ocean Tow
PART 17. Arrival at New Location – with example of Positioning Procedure
PART 18. Manoeuvring Diagrams and Tug Deployment
PART 19. Going onto Location - Open Location, 2 Tugs
PART 20. Calculation of Leg Footing Position – example
PART 21. Rig Positioning – Leg Torque and Tension
PART 22. Pre-loading and Associated Operations
PART 23. Pre-load Methods
PART 24. Pre-loading 4 Leg Jack-ups
PART 25. Pre-loading 4 Leg Jack-ups – Notes on Hydraulic Jacking Systems
PART 26. Pre-loading in Areas of Extreme Tidal Ranges
PART 27. Pre-loading – Cautions, Notes and Examples
PART 28. Punch Through
PART 29. Testing an Unknown Bottom – Pre-loading Methods
PART 30. Leg Footing’s Strength – Hard Bottoms
PART 31. Soil Classification – Tables and Tests
PART 32. Site Investigation. Hazards and Evaluation
PART 33. Elevated Operations – Calculating Leg Reactions
PART 34. Leg Foundation Stability
PART 35. Monitoring Sea Bed Conditions – and recommending Corrective Actions. Scour and Associated Problems
PART 36. Locating Alongside Platforms – General Procedures
PART 37. Locating onto Jackets – Post Hole Problems
PART 38. Correction of Misalignment. Elevated Operations
PART 39. Locating onto Sub-Sea Templates/Well Heads
PART 40. Working in areas of Large Tidal Range
PART 41. Jacking Machinery – General Notes
PART 42. Rig Movers Equipment
PART 43. Warranty Surveyor’s Role and Duties – with examples of typical recommendations
PART 44. Motion Limits – Diagrams and their Use
PART 45. Guidelines for Moving in a series of Field Moves
PART 46. Operations Manual – Extracts from examples of Afloat Operations Instructions
PART 47. Pre-move Checklist – examples
PART 48. Matt Supported Units
PART 49. Positioning
CONTENTS – SECTION TWO
Jack-up Towing and Positioning
PART 1. General – Use of Tugs
PART 2. Gear Make Up and Strength Calculations
PART 3. Making Fast Main Tow Gear
PART 4. Towing Positions
PART 5. Leaving Open Location – 2 Boats
PART 6. Going onto Open Location – 2 Boats
PART 7. Going onto Open Location – 2 Boats – Sequence of Events
PART 8. Going onto Location – 2 Boats. Using a Stern Bridle
PART 9. Going onto Open Location – 3 Boats
PART 10. Positioning Alongside Platforms
PART 11. Positioning onto a Platform – Basic Procedure
PART 12. Positioning around a Platform Complex
PART 13. Walking onto a Platform
PART 14. Positioning onto Platforms – Alternative Methods of Control
PART 15. Positioning Using Harbour Tugs
Appendix 1. PED 4-16/90. Jack-up Towing/Moving
Appendix 2. Method of Calculating Tow Forces
Appendix 3. Use of Jack-up. Heavy Lift Operations
Appendix 4. Selecting Tugs for Jack-up Operations
The purpose of this book is to give practical advice on the management of jack-up barges afloat and during positioning and elevating operations.
It is not written for particular types of jack-up unit and all types have slightly different methods of operating systems such as jacking equipment.
Jack-up barges are essentially land based work platforms which can be moved from place to place by floating the platforms.
To assume that a jack-up barge is a seagoing vessel is most unwise. The loss rate of jack-ups under tow, compared to other similar specialised craft, is high and reflects their vulnerability to the normal perils of the sea.
An examination of the reports of numerous losses or cases of severe damage shows that the basic causes were, in general, bad judgement, lack of proper planning and poor voyage management.
It is not often appreciated that the crews of a jack-up may spend many months operating their vessel far divorced from the forces of the sea, elevated many metres above the surface. The transition to afloat operations is rapid and in the alien environment of the sea, habits acceptable when elevated are very difficult to change in a matter of a few hours
For more detailed information on jack-up stability and ocean towing refer to other volumes in this series, Volume 5 covering Stability and Ballast Control and Volume 3 covering Anchor Handling and Towing.
The majority of this text refers to independent leg jack-up units. Matt jack-ups share most of the characteristics of independent leg types and the main differences are dealt with in a separate section (part 48).
Witherbys titles are developed using scripts developed by technical experts that are peer reviewed within work groups. Typically, they seek to improve understanding of the regulations, recommendations and guidelines issued by Industry.
Witherbys staff have significant expertise in the fields of navigation and hazardous cargoes as well as in the presentation of complex subjects in a graphic and easy to understand manner.