Patent ID: 6557637
Filing Date: 2003-05-06
Classification: E21B

Abstract:
A disconnect assembly for connecting a lower riser extending downward through a seabed and into a subsea well bore with an upper riser extending downward from a drilling rig to a subsea riser disconnect, such that the subsea riser disconnect may be selectively activated to disengage a lower end of the upper riser from an upper end of the lower riser, the disconnect assembly comprising:a male disconnect member having a central axis; a female disconnect member for receiving the male disconnect member therein, each of the male disconnect member and the female disconnect member being secured to one of the lower end of the upper riser and the upper end of the lower riser; a seal for sealing between the male disconnect member and the female disconnect member; a riser interconnection device actuatable in response to substantially axial movement of the upper riser relative to the lower riser from a connect position for mechanically interconnecting the male disconnect member and the female disconnect member to a release position for releasing the male disconnect member from the female disconnect member upon reciprocating the upper riser relative to the lower riser; and a riser connection lock moveable from a locked position wherein axial movement of the upper riser relative to the lower riser is limited and a release position wherein the upper riser is axially moveable relative to the lower riser in response to substantially axial movement of the upper riser relative to the lower riser, such that the upper riser may be manipulated at the surface to release the riser connection lock and release the upper riser from the lower riser.