Riser connector

#All prior art mechanical riser connectors require manual operations at the riser joint, such as adjusting actuator bolts, in order to make the connection between the riser members. Generally, either a subsea diver is used to perform these manual operations or the connection is made at the surface and the riser is then lowered or driven into its operating position. Both of these procedures are expensive and time consuming. There are no prior art mechanical riser connectors that can be connected by remote activation.

#Most prior art mechanical riser connectors also require manual operations at the riser joint in order to disconnect the riser members. However, there is one prior art mechanical riser connector that can be remotely disconnected without any manual operations at the riser joint. To disconnect this riser connector, a shifting tool is attached to the end of a tubing string and is lowered into the riser. The shifting tool engages a sleeve and slides the sleeve upward. The movement of the sleeve releases a latch that connects the riser members. Since the riser members are disconnected when the sleeve is shifted in one longitudinal direction, this riser connector is susceptible to being inadvertently disconnected with movement of any object inside the riser connector in that longitudinal direction. Examples of objects which may inadvertently shift the sleeve thereby disconnecting the riser members are pigs used to clean out the riser and tubing strings which pass through the riser. The consequences of inadvertent disconnection of the riser connector can be devastating.

#The present invention discloses a riser connector comprising a first tubular member, a second tubular member which telescopes over one end of said first tubular member and remotely activated connecting means attached to at least one of the tubular members for connecting said tubular members together. The connecting means is remotely activated by a shifting tool which is insertable in the bores of said tubular members.

#FIG. 1 is a partial cross-sectional view of the riser connector and the shifting tool prior to activation of the connecting means.

#FIG. 2 is a partial cross-sectional view of the riser connector in FIG. 1 wherein the shifting tool has activated the connecting means thereby connecting the tubular members.

#FIG. 3 is a partial cross-sectional view of the riser connector in FIG. 1 wherein the shifting tool has shifted the connecting means in one longitudinal direction prior to disconnection.

#As illustrated in FIG. 1, the riser connector assembly includes a first tubular member A which telescopes over a second tubular member B, and connecting means C. The connecting means C is comprised of a latch means D which connects the tubular members when held in engagement with the second tubular member B, locking sleeve E for holding the latch means D in engagement, locking means F for locking the locking sleeve E in a position where locking sleeve E holds latch means D in engagement, actuator sleeve G for moving the locking sleeve to that position and for unlocking the locking means F, and resilient urging means H for returning the actuator sleeve G to its normal position. As illustrated in FIGS. 2 and 3, the connecting means C is remotely activated by mechanical means such as shifting tool I which is attached to the end of tubing string J or to the end of a line. As illustrated in FIG. 5, the shifting tool I is comprised of an inner housing K, an outer housing L, an outer sleeve M and a retainer sleeve N. The outer sleeve M includes first rectractable engagement means O for engaging the actuator sleeve G and second retractable engagement means P for engaging the locking sleeve E. Additionally, releasable attachment means Q governs the retraction of second engagement means P.

#As illustrated in FIGS. 4a and 4b, the first tubular member A is comprised of tubing subs 10, 11, 12, 13 and 14 which are attached to each other by threaded connections with tubing sub 10 being the top sub and tubing sub 14 being the bottom sub. All of these tubing subs have longitudinal bores. The bottom end of tubing sub 14 has beveled inner surface 14a for guiding the first tubular member A over the end of the second tubular member B. Sealing means 15 in annular recess 13a on the interior of tubing sub 13 prevents fluid communication between the exterior and the interior of the tubular members and contains any pressure differentials between inside and outside of the assembly.

#Collar 16 is attached to the exterior of the second tubular member B. Collar 16 serves as a means of limiting the telescoping movement of the first tubular member A over the second tubular member B since the first tubular member A can only move over the second tubular member B until the bottom end of tubing sub 14 abuts the top rim of collar 16.