The setting of the Plant layout, the production of the General Plot Plan discussed in the Guide was related to On-Shore (land) facilities.
The layout of Off-shore facilities differs in a number ways, which derive from the specificities of these facilities, mainly their location in the sea and the limited space available.
The overall layout of an On-Shore facility, depicted on the General Plot Plan, sets that Plant with respect to its surroundings, such as local topography and natural elements, access and exit roads, inlet feedstock and product rundown pipelines, connection to external utilities etc.
That of an Off-Shore facility, depicted on the Overall Field Layout, shows the field architecture, i.e., the number and layout of the field facilities. These facilities will include wellhead platforms, production flowlines, gas and water injection lines, production facilities, gas treatment and compression, utilities, living quarters, helideck, flare, export/off-loading lines etc.
Considerations coming into field architecture will first of all entail safety: location of living quarters and control room, which are permanently manned, as far as practicable from high risk process units, usually by locating utility units in between, location of evacuation area and life boats as shielded as possible from the hazards, location of the flare upwind of all facilities to prevent ignition of gas cloud resulting from a leak etc.
The means that will be used to install the individual facilities, including the type of installation (float-over, lift) and the capacity of the installation barge/crane, will determine their maximum size/weight.
Provision will be made for access of rigs to wellhead platforms for work-over. Access ways and landing areas, that will allow an approach against the current, will be provided for supply boats. This will include boats supplying consumables, such as catering, fuel, water, production chemicals etc. as well as boats ferrying equipment parts sent out for repair, spare parts etc. The landing area of the later will be coordinated with the position of the cranes on the facilities themselves.
Finally, provision for future field developments, such as addition of risers, gas injection facilities etc. will be made in the layout.
