be set up at least for changing crews, either by boat or helicopter, and 

 for supplying small items not peculiar to the drilling industry; larger 

 supplies, such as casing, mud, and cement will be supplied from the 

 permanent base. Beyond 150 miles the creation of an independent base 

 becomes increasingly probable [26]. 



3. Sheltered harbor : The availability of adequate sheltered harbors 

 in the general area of offshore leases or proposed areas of activity is a 

 major factor in locating service bases. The harbor must permit the load- 

 ing and sheltering of supply vessels whose size, draft, and capacity 



are three important considerations. At a minimum, the harbor should have 

 the physical dimensions to allow the maneuvering, anchoring, and berthing 

 of a large number of offshore supply boats, ocean-going barges, and other 

 vessels supplying the base. 



Since many supply vessels may sit idle between trips or may be 

 loaded and have to wait for the weather to improve before going to sea, 

 the capacity of a harbor is also significant. Ideally, all vessels 

 should be able to moor at shoreside. However, if sufficient dock spaces 

 are not available for this, capacity must be available to moor the sup- 

 ply vessels two or three abreast at shoreside, or space must be available 

 to safely anchor them in the harbor (20 to 30 feet depth). 



4. Waterfront site : Service-base operation efficiency is measured 

 in terms of turnaround time, the time required by a vessel to dock, to 

 load all of the supplies requested, and to start back to the offshore 

 operations. It is, therefore, desirable that oil service bases be set 

 apart from the plants and boats of the fishing industry and other users 

 of the waterways to avoid delays caused by congestion with other vessels 

 and conflicting use of waterfront facilities. 



The location within the harbor also requires large quantities of 

 flat land, or back-up land, adjacent to the dock locations on the 

 waterfront. At dockside there are minimum requirements for staging 

 areas, silos, warehouses, storage tanks, and open storage, tlowever, 

 the large quantities of pipe goods handled and stored also require 

 flat areas. If flat land is unavailable, it is, of course, possible 

 to cut and fill during the construction of the service base facility. 



5. Airport-heliport : In areas where road and rail connections 

 are undeveloped, it is essential that a service base be connected by 

 road to an airport, preferably one with scheduled main-line service and 

 wiht facilities to handle heavy cargo services and helicopter operations 

 for offshore areas. The principal function of an airport serving off- 

 shore oil operations is the transport of crews to and from the offshore 

 facilities. However, the marine service base also requires the services 

 of the airport and/or heliport: (1) to permit the rotation of the supply- 

 boat crews, (2) to transport emergency supplies and service personnel 



125 



