In situ method and apparatus for inspecting and repairing subsea wellheads

In a marine riser having external hydraulic lines extending along the riser, the improvement comprising securing at least two such hydraulic lines to the riser substantially parallel to each other forming substantially unobstructed track means along the riser joint and from one joint to another for receiving a carriage adapted to run on such tracks, and carriage means adapted to run on such hydraulic line track for travel along the exterior of the riser, and means for moving such carriage along such track.

In a marine riser having external hydraulic lines extending along the riser, the improvement comprising securing at least two hydraulic lines to the riser substantially parallel to each other forming substantially unobstructed track means along the riser joint and from one joint to another for receiving a carriage adapted to run on such tracks and shunt track means associated with said hydraulic line tracks to provide an extension of said hydraulic line track means beyond such hydraulic lines.

A marine riser connector having a flanged portion with spaced openings in the outer circumference thereof to allow unobstructed track means to extend along the axis thereof and spaced clearances adjacent to said openings in said flanged portion to allow substantially unobstructed guidance along said track means.

In a marine riser having external hydraulic lines extending along the riser, the improvement comprising securing at least two hydraulic lines to the riser substantially parallel to each other forming substantially unobstructed track means along the riser joint and from one joint to another for receiving a carriage adapted to run on such tracks, said carriage has a plurality of wheels adapted to mount on said hydraulic line track means and said riser comprises a plurality of riser joints having end flanges for connection together end to end and wherein said flanges have circumferentially spaced slots providing openings through said flanges for passage of said carriage wheels running on said track means.

A manipulator carriage adapted for mounting on a pair of spaced substantially parallel tubular tracks, said carriage having a plurality of opposing wheels each engaging said tracks with substantially concave surfaces, said engagement being on substantially opposite sides of said tracks.

In a marine riser having external hydraulic lines extending along the riser, the improvement comprising securing at least two hydraulic lines to the riser substantially parallel to each other forming substantially unobstructed track means along the riser joint and from one joint to another for receiving a carriage adapted to run on such tracks, the riser includes a hydraulic connector and swivel assembly having retractable orienting pins adapted to be inserted into an orientation hole in said swivel assembly for orienting the riser relative to the blow-out preventer stack and means for retracting said orienting pins to permit rotation of said riser string relative to said blow-out preventer stack.