Pressure-balanced stab connection

Abstract

Apparatus for connecting portions of subsea flow conduits includes a stab member with a body and having a bore therethrough, one end of which exits from the stab body through a side port. A stab receptacle includes a bore for receiving the stab body, and a flow bore intersecting the receiving bore and leading to the exterior of the receptacle. The side port communciates with the receptacle flow bore when the stab member is landed in the receiving bore. Seals above and below the side port seal the receiving bore above and below the intersection of the receptacle flow bore and receiving bore. The cross-sectional areas of the seals exposed to internal fluid pressure are substantially equal, resulting in zero blow-apart force on the stab connection. Alternatively, the lower seal can have a larger exposed cross-sectional area than the upper seal, resulting in a net force tending to hold the connection teogether. Split retainer rings having external chamfer surfaces are mounted on the stab body above and below the lower seals. The retainer rings are disposed in grooves allowing the rings limited sliding radial movement with respect to the stab body. The stab receptacle is mounted to a support frame with relatively long, thin, vertically disposed studs which resist vertically directed forces but permit lateral and rotational deflection of the stab receptacle when acted upon by non-vertical forces. The stab body bore and receptacle flow bore include shaped portions to reduce turbulence of fluids flowing therethrough.