Site Requirements 



The ideal location for an offshore mooring would be a nearshore 

 area protected from strong winds, waves and currents, with a natural 

 water depth greater than the draft of the largest vessel expected during 

 the life of the project. All SPM's are located where the sea floor 

 geology is stable and capable of anchoring the SPM firmly in place. 



A major siting criterion is the route of the submarine pipeline, 

 landfall, and onshore pipeline or terminal. Considerations for pipeline 

 siting are discussed in Section 2.4.2. 



SPM's are most commonly found in newer oil areas in foreign countries 

 where other deep water port facilities are impractical or economically 

 infeasible. In older producing and market areas, such as the United 

 States, SPM's may be built to serve existing or proposed oil and gas 

 related facilities. They will be located near pipelines and storage 

 terminals, and to a lesser extent, refineries. The siting of oil storage 

 terminals is presented in Section 2.3.6, and that of refineries in 

 Section 2.4.3. 



Construction/Installation 



Both tankers and SPM's are fabricated at shipyards. Conventional 

 equipment is used and construction activities introduce no major 

 disturbances to the area. Installation of the SPM requires support 

 tugs, supply ships and a derrick barge for driving the piles that attach 

 the SPM base to the sea floor. Installation of the SPM itself is 

 relatively uncomplicated and has little ecologic impact. Critical 

 submarine pipe laying and burial are covered in Section 2.2.3. 



Operations 



SPM: oil is loaded and unloaded through a pipeline and floating 

 hose attached to the vessel's manifold. CALM systems have been built 

 with multi-purpose manifolds and floating hoses to facilitate several 

 operations simultaneously, such as refueling and crude oil transfer. 

 After the transfer of fluids, the floating hoses retract to the buoy. 

 The oil being transferred in a SALM system is pumped through a floating 

 hose, a pipe within the anchor leg and the submarine pipe to an onshore 

 storage tank. 



A sophisticated monitoring system safeguards unloading and loading 

 activities. Regular inspections are scheduled to check the structural 

 stability of the entire SPM system and pipelines to sufficiently protect 

 against ruptures and leakage. 



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