Patent ID: 6220359
Filing Date: 2001-04-24
Classification: E21B

Abstract:
A safety valve for downhole use in a well, the safety valve comprising:(a) a housing having(i) an interior fluid flow passage therethrough and(ii) at least one circulating port in the housing for providing fluid communication between the interior fluid flow passage and the exterior of the housing;(b) a piston operatively positioned within the housing for movement between a first position and a second position in response to a fluid pressure differential between the interior fluid flow passage and the exterior of the housing;(c) a slip operatively connected to the piston, whereby(i) over a first range of the movement of the piston the slip moves with the piston, and(ii) over a second range of the movement of the piston the slip does not move with the piston;(d) a flow valve operatively connected to the slip for opening and closing the interior fluid flow passage of the housing during the first range of the movement of the piston; and(e) a circulating valve operatively connected to the piston for opening and closing the circulating port during the second range of the movement of the piston.