Abstract: An integral multistage safety valve is designed to provide a second level of protection should a first stage fail. The valve may be used in oil and/or gas wells. The interior portion of the multiphase safety valve is designed so as to reduce turbulence and pressure loss through the valve when the valve is in an open position. The valves may be independently operable, or operable with a single control line. The multi-stage valve reduces the number of body joints required to construct two identical valves thereby reducing cost and potential leak paths and increasing reliability of the system.

Abstract: An integral multistage safety valve is designed to provide a second level of protection should a first stage fail. The valve may be used in oil and/or gas wells. The interior portion of the multiphase safety valve is designed so as to reduce turbulence and pressure loss through the valve when the valve is in an open position. The valves may be independently operable, or operable with a single control line. The multi-stage valve reduces the number of body joints required to construct two identical valves thereby reducing cost and potential leak paths and increasing reliability of the system.

Abstract: A valve for use in a wellbore, the valve having a compensating secondary sealing system for misalignments that inevitably occur in sealing subsurface valves, particularly subsurface safety valves. A sealing system can include a dynamic sealing system and a static sealing system, where the static sealing system establishes one or more line contact surfaces. The line contact surfaces can be leading, in that the forward edge of the seal faces a corresponding engagement portion of the actuator. The actuator can include at least two spherical engagement portions where one of the spherical engagement portions engages resilient and non-resilient seals with line contact surfaces on a downstroke and the other spherical engagement portion engages resilient and non-resilient seals with line contact surfaces on an upstroke. Further, a bearing disposed above seals on a piston of the actuator assists in keeping contaminants out of the seal area of the piston.

Abstract: A subsurface safety valve for controlling fluid flow in a well bore. In one embodiment, the subsurface safety valve includes a tubular member having a longitudinal bore extending therethrough, a curved flapper removably connected to the tubular member. The curved flapper is configured to pivot against the tubular member between an open position and a closed position. The subsurface safety valve further includes a hard seat positioned inside the tubular member, in which the hard seat defines a seating surface configured to receive a sealing surface defined on a bottom periphery portion of the curved flapper to form a sealing interface having a slope that varies along the sealing interface.

Abstract: The present invention provides a more compensating secondary sealing system for misalignments that inevitably occur in sealing subsurface valves, particularly subsurface safety valves. A sealing system can include a dynamic sealing system and a static sealing system, where the static sealing system establishes one or more line contact surfaces. The line contact surfaces can be leading, in that the forward edge of the seal faces a corresponding engagement portion of the actuator. The actuator can include at least two spherical engagement portions where one of the spherical engagement portions engages resilient and non-resilient seals with line contact surfaces on a downstroke and the other spherical engagement portion engages resilient and non-resilient seals with line contact surfaces on an upstroke. Further, a bearing disposed above seals on a piston of the actuator assists in keeping contaminants out of the seal area of the piston.

Abstract: A subsurface safety valve for controlling fluid flow in a well bore. In one embodiment, the subsurface safety valve includes a tubular member having a longitudinal bore extending therethrough, a curved flapper removably connected to the tubular member. The curved flapper is configured to pivot against the tubular member between an open position and a closed position. The subsurface safety valve further includes a hard seat positioned inside the tubular member, in which the hard seat defines a seating surface configured to receive a sealing surface defined on a bottom periphery portion of the curved flapper to form a sealing interface having a slope that varies along the sealing interface.