Internal riser rotating flow control device

Abstract

A rotating flow control device, and more particularly a rotating control flow device for use inside a riser assembly during offshore drilling activities. The rotating flow control device has a stationary housing adapted to mount between the interconnected ends of riser pipe. The bearing assembly of the rotating flow control device is entirely contained within the riser pipe and maybe remotely detached and removed from the stationary housing. The rotating flow control device may be positioned in the riser such that it effectively isolates the riser slip joint from pressurized well bore returns.

What is claimed is: 
     
         1 . A rotating flow control device apparatus for use inside a riser, the riser comprising a string of riser pipes, each such riser pipe having two ends whereby the ends of adjacent riser pipes are interconnected to form the string, the apparatus comprising;
 (a) a tubular stationary housing mounted inside the riser, the stationary housing having a first end and a second end, the second end having a connector, the connector being adapted to form part of the interconnection between the ends of two interconnected adjacent riser pipes whereby the second end of the stationary housing is rigidly attached to the riser and the first end of the stationary housing is contained within, but not attached to, the riser;   (b) a removable bearing assembly releasably mounted on the stationary housing, the bearing assembly comprising an outer housing, and an axially rotatable inner tubular shaft; and   (c) a stripper element attached to the inner tubular shaft.   
     
     
         2 . The apparatus of  claim 1  wherein the ends of the riser pipe are flanged and the connector at the second end of the stationary housing is flanged. 
     
     
         3 . The apparatus of  claim 2  wherein the flanged connector of the stationary housing is sandwiched between the flanged ends of the interconnected adjacent riser pipes. 
     
     
         4 . The apparatus of  claim 3  wherein the flanged connector and the flanged ends of the riser pipe have aligned bolt holes and bolts are employed to secure the interconnection. 
     
     
         5 . The apparatus of  claim 1  wherein the bearing assembly is releasably mounted on the stationary housing by means of a moveable latch projecting from the stationary housing that engages a complementary pocket in the outer housing of the bearing assembly. 
     
     
         6 . The apparatus of  claim 5  wherein the moveable latch is spring loaded. 
     
     
         7 . The apparatus of  claim 5  wherein the moveable latch may be actuated remotely using hydraulic pressure. 
     
     
         8 . The apparatus of  claim 5  wherein the moveable latch may be actuated remotely using pneumatic pressure. 
     
     
         9 . The apparatus of  claim 5  comprising a plurality of spring loaded latches and a plurality of complementary pockets. 
     
     
         10 . The apparatus of  claim 1  wherein the riser further comprises a slip joint and the apparatus is mounted in the riser beneath the slip joint. 
     
     
         11 . The apparatus of claim I wherein the stripper element is elastomeric. 
     
     
         12 . A system for controlling pressurized wellbore returns in a riser extending from a surface drilling platform to a subsea wellhead, the system comprising;
 (a) the apparatus of  claim 1 ;   (b) a flow spool having at least one port, the flow spool being positioned in the riser between the apparatus and the wellhead; and   (c) the at least one port of the flow spool being connected to a pipe extending to the surface and whereby the at least one port may be selectively opened and closed remotely from the drilling platform.   
     
     
         13 . A rotating flow control device apparatus for use inside a conventional riser pipe, the riser pipe having a first end and a second end, the apparatus comprising;
 (a) a stationary housing having a first end and a second end;   (b) a bearing assembly comprising an outer housing, and an axially rotatable inner tubular shaft, the bearing assembly being releasably mounted on the stationary housing;   (c) an elastomeric stripper element attached to the inner tubular shaft;   whereby the second end of the stationary housing is adapted to rigidly attach to either the first or second end of the riser pipe and whereby the bearing assembly is entirely contained within the riser pipe.   
     
     
         14 . The apparatus of  claim 13  wherein the ends of the riser pipe are flanged and the second end of the stationary housing forms a complementary flanged connector. 
     
     
         15 . The apparatus of  claim 13  wherein the bearing assembly is releasably mounted on the stationary housing by means of a moveable latch projecting from the stationary housing that engages a complementary pocket in the outer housing of the bearing assembly.