A control system for a subsea well

摘要

A control system for a subsea well, comprises a tree (1) provided with a hydraulic control supply line (15) for opening a downhole safety valve as a result of hydraulic pressure in the line. A part (17) of the line is carried by a structure (6) which is subject to the pressure of production fluid from the well in use of the system so that the line is separable in response to a failure of the integrity of the structure.