of the area. A total of about 35 million dollars has been spent by oil firms 

 through early 1976 in exploratory activity on the Atlantic Outer Continental 

 Shelf. Less than one-third of this amount was expended on the South Atlantic 

 region (5, p. 19), with data acquisition efforts for the Southeast Georgia Em- 

 bayment receiving the lion's share mainly since the Blake Plateau area isn't 

 scheduled for a lease sale until mid-1978 and lies in deeper water. 



Exploratory drilling follows lease sales, such drilling being done by 

 sophisticated drill rigs. The three most commonly used types of rigs are 

 semi-submersible, jack-up, or floating drill ships. Such drill rigs either 

 move to the site under their own power or are towed to the designated field 

 from existing ports or oil fields. The expected sequence of exploration ac- 

 tivities is explained by Goodman (13, p. 17): 



The rigs are towed to the lease holdings from any of a number 

 of worldwide locations. Support materials are usually stored 

 onshore: drill pipe, drill bits, drilling mud (powder), cement 

 (powder), casing (pipe), catered foods, crews, tools, etc. 

 Transportation to drilling sites is provided by locally-berthed 

 work boats (LOA up to 200-250 feet), crew boats (LOA up to 

 85-110 feet), and helicopters. Repair facilities, divers, 

 ship chandlers, welders, mechanics, and other ancillary support 

 usually locate in the immediate area to provide their special 

 services, many of which are common trades. 



Exploratory drilling continues until the limits of the total 

 field are defined. The number of exploratory wells required 

 depends on the geological structure. The U.S. Geological Sur- 

 vey of the Department of the Interior regulates the procedures 

 for drilling and for numerous other activities related to com- 

 pletion, platform installation, pipelines and other OCS op- 

 erations by publishing "OCS Operating Orders" and by conducting 

 inspections of facilities and operations. 



The Atlantic areas in general pose no known serious drilling problems. Water 



depths are shallow to moderate (600 feet) s and weather may be classed as 



moderate to severe, although storm conditions in the South Atlantic may be 



extremely severe on rare occasions. Most semi-submersible drill rigs will 



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