A new safety valve was requi red by North Sea Operators for-their prospective sub-sea completions.~he valve would have to combIne compatibility with low~ressur~s~b~sea wellhead controls with hIgh relIabIlIty. ----Fall of 1980.This paper discusses the design parameters and features of the safety system as well as the. perfor!Uance of the system in tests and In servIce.

Well completions for tension leg platforms require special consideration in key areas. Standard downhole equipment including subsurface safety valves can be used in a conventional manner from TLP's. Special designs, however, may be required for annular safety systems or sales risers.