Internal pipeline plug for deep subsea pipe-to-pipe pull-in connection operations
AssigneeShell Oil Company
InventorJohn M. Ward
Life of this patent
Estimating the term…
Abstract
Pressure-tight pipeline plugs are used in subsea connection operations to achieve a lightweight pipe condition which facilitates alignment by easing handling problems. An internal plug is provided for this purpose which is particularly useful for connection operations using a pipe-to-pipe pull-in technique and is capable of sealing, remotely releasing and then being pumped through the line to a terminus.
Claims12
An internal pipeline capable of sealing, releasing and being pumped out of a pipeline comprising, means for sealing a high pressure side of the plug from a low pressure side, means for gripping the pipe wall, pressure release means operable at a set pressure to permit fluid passage, fluid flow control means operable to permit controlled passage of fluid therethrough and, means operable to release the gripping means from the pipe wall when a set pressure relationship of the high pressure side to the low pressure side is attained.
A method for laying a pipeline in an at least near neutral buoyancy condition comprising sealing a gas into at least part of a pipe string between a closure on one end of the pipe string and a pressure activatable plug within the pipe string, connecting the pipe string to another pipe end, activating the plug with fluid pressure to permit flooding the pipe string through the plug, removing the closure, and passing the plug through and out of the pipe string.
Dependencies are inferred from the claim text.