ABSTRACT
The various types of subsurface Safety valve systems are described together with NAM's resoning for selecting present and future safety valve systems. A design review technique was applied to assist in identifying the possible weak points and also providing a basis for selection of the most optimal safety valve system taking Petroleum engineering, operational and mechanical engineering into consideration. The design review on the hydraulicaly operated flapper wireline retrievable flapper valve did not reveal any major weak points apart from the limited test pressure on the landing nipple. The design review process is explained and suggestion for a future developments with respect to type testing, freezing of designs and possible subsequent certification is adressed.
