Figure 32-7. Well "island" in South Mountain Field, California. Because of rough terrain, 

 wells are drilled on level shelves formed by slicing off part of a slope. By use of di- 

 rectional drilling, a series of well heads are located in a row with the wells angling off 

 like spokes of a wheel. Some of the well heads are as much as 1000 feet, laterally, from 

 the producing sand. The wells are serviced by the one production derrick which moves 

 on a curved track (Courtesy Shell Oil Company). 



where it is not possible to build a suitable location; or (3) the terrain is so 

 rugged that suitable locations cannot be made with ease. 



Zoning laws will frequently prohibit the drilling of oil wells within city 

 limits or residential areas, and pools beneath these areas must be developed by 

 drilling directional wells from outside the restricted area. The noise of drilling 

 operations will sometimes rule out the possibility of drilling from a desired 

 location even where not prohibited by zoning laws ; however, modern techniques 

 in sound-proofing drilling rigs and in designing and maintaining production 

 installations are helping to relieve this problem. 



Figure 32-7 is a photograph of a well "island" in the South Mountain Field 

 in California. As can be seen in the photograph, the rugged terrain makes it 

 necessary to drill and service the wells from level shelves cut into the mountain- 

 side. As many wells as feasible are directionally drilled from each shelf to 

 develop as much as possible of the field and keep location costs down. 



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