Patent ID: 6116268
Filing Date: 2000-09-12
Classification: E21B,F15B,Y10T

Abstract:
Wellhead safety valve control system for opening and closing a surface safety valve (SSV) and a surface controlled subsurface safety valve (SCSSV), said system comprising a first dump valve and a first safety valve circuit operably associated with said surface safety valve, a second dump valve and a second safety valve circuit operably associated with said surface controlled subsurface safety valve, an SSV trip control circuit operably associated with said first dump valve, an SCSSV trip control circuit operably associated with said second dump valve, a pump for pumping hydraulic fluid, said pump being operably associated with said first and second safety valve circuits and at least one check valve to operably isolate said SCSSV trip control circuit of said second dump valve from said SSV trip control circuit of said first dump valve.