Navigational Planning

The Marine Officer should plan the courses between locations, and routes to be taken through fields with due regard for jackets and barges or other vessels which may be moored in the field. Calculation should be made of the points at which it will be safe to increase the draft by lowering the legs.

Navigational planning should also include the operation of moving off location, and procedures to be adopted for final positioning. When anchor handling is necessary the position of anchors must be considered and if close to flowlines or subsea wells, arrangements should be made to have these or the anchor position buoyed.

The Marine Department will inform the National Navigation Support Service, advising:

• the timing of move
• the old location
• the new location
• any instructions regarding navigational warnings to be issued, which are considered necessary.

Pre-Rig Move Meeting

Prior to moving a rig a meeting, will be arranged bythe Marine Department and will include:

• Marine Officer
• Drilling Supervisor
• Senior Barge Engineer
• Owners Representative
• Partners Representative.

The following points will be discussed:

• penetration at the old location and if jetting is anticipated
• whether a night time departure from location is possible
• weather and sea limits during moving off location
• sailing route, distance, expected duration of tow
• names of towing and anchor handling boats to be used
• whether a night time positioning is possible at new location
• anchor handling procedure to be adopted
• water depth at new location
• expected penetration at new location
• maximum allowable towing draft
• flowlines and subsea wells which must be marked, Marine Officer to have information available
• the supply and backload situation before and after the move. (Marine Officer to liaise with Transport Department prior to the meeting)
• whether Production has to remove gin-poles or other lifting devices
• any additional Production-related work (e.g. connecting, disconnecting risers)
• whether and which flowlines have to be de-pressurised
• status of the well during moving on/off
• the final heading and tolerance
• the final position, (drilling will give the tolerances athwartship and fore and aft).

The information about anchor handling should be passed to the rig to enable the Barge Master/Barge Engineer to make the necessary preparations.

The Production Stations involved, should be kept up to date. Prior to moving a Contractor's Rig, the Owner's Representative, together with the nominated Insurance Representative, if possible, should be invited to the Marine Office to discuss the above points.

Safety

Although the Drilling Supervisor has the overall responsibility on deciding if jacket and wells are safe for the rig to move onto, the Rig Mover should satisfy himself that this is the case by sighting the “Handover Form”.

Briefing of Masters

Immediately before a rig move, Masters of towing and anchor handling boats must be called to Marine Office to discuss all aspects of the operation, including:

• starting time anticipated and destination
• courses between locations and obstructions to avoid
• routes into and out of fields
• details of moving-off operation
• details of final positioning and anchor handling operations
• emergency pin down locations where appropriate
• position of marker buoys if any.

Equipment

The following information and equipment must be provided on the rig to be moved:

• navigation charts
• up-dated Field charts
• workover drawings (if applicable)
• walkie-talkies and sufficient batteries
• tide tables
• departure/arrival location information
• previous rig location information
• up dated mooring buoy information.