Retrievable hydraulic subsea bop control pod

Abstract

Systems and methods for improved hydraulic control systems for actuation of subsea equipment in deep water are disclosed. The hydraulic control system relies on smaller fluid flow associated with a hydraulic pressure pulse to actuate the small volume actuation control valve. In one embodiment, the system includes small diameter control umbilical hoses and pilot-operated valves with low actuation volumes. Particularly, a hydraulic control system for reducing the signal time to a subsea blowout preventer in water depth up to and greater than about 5000 feet. Some embodiments comprise a valve arrangement which hydraulically actuate one side of a hydraulic control function, while simultaneously evacuating the opposing circuit both at the seabed and at the surface. Some embodiments comprise an umbilical hose located proximate the center of an umbilical bundle. Preferably, the umbilical hose has a plurality of layers of reinforcing fibers which increase with the diameter of the reinforcement layer.

1 . A hydraulic control system for a subsea retrievable control pod, comprising:
 a subsea hydraulic umbilical line;   a lower marine riser package having a hydraulic receptacle;   a hydraulic control pod having a hydraulic connector for hydraulically mating with the hydraulic receptacle;   at least one pod umbilical hydraulic connector hydraulically connected through umbilical connector piping to said hydraulic control pod, and   at least one lower marine riser package umbilical hydraulic connector for hydraulically mating with said pod umbilical hydraulic connector and said subsea hydraulic umbilical line;   whereby when said system is operated, a hydraulic flow path exists allowing hydraulic fluid to flow from said subsea hydraulic umbilical line through said lower marine riser package umbilical hydraulic connector through said pod umbilical hydraulic connector and into said hydraulic control pod which is hydraulically connected to the lower marine riser package hydraulic receptacle.   
   
   
       2 . The control system of  claim 1  wherein said pod umbilical hydraulic connector being attached to said hydraulic control pod by a radial control bracket. 
   
   
       3 . The control system of  claim 1 , comprising at least two pod umbilical hydraulic connectors, each connector being attached to said hydraulic control pod by a radial control bracket. 
   
   
       4 . The control systems of  claim 3  wherein at least two radial connector brackets being spaced between about 180 degrees apart and about 45 degrees apart. 
   
   
       5 . The control system of  claim 4 , wherein the radial connector brackets are substantially horizontally opposed, with an inner included angle of about 180 degrees, and in which a vertical plane substantially through the radial connector brackets is substantially tangential to the well center axis. 
   
   
       6 . The control system of  claim 4 , in which the radial connector brackets have the minimum inner included angle. 
   
   
       7 . The control system of  claim 1 , wherein said pod umbilical hydraulic connectors being male wedge-type hydraulic connectors. 
   
   
       8 . The control system of  claim 1 , wherein said pod umbilical hydraulic connectors being female wedge-type hydraulic connectors. 
   
   
       9 . The control system of  claim 1 , wherein said pod umbilical hydraulic connectors are frustoconical-type connectors. 
   
   
       10 . A method of converting a hydraulic control system for a subsea BOP stack and having a hydraulic umbilical line to allow a control pod to be retrieved without detaching the umbilical line, comprising the steps of:
 attaching at least one radial connector bracket to the control pod;   attaching a pod umbilical hydraulic connector to the at least one radial connector bracket;   attaching an umbilical hydraulic connector to a lower marine riser package, and   plumbing the lower marine riser package umbilical hydraulic connector to the hydraulic umbilical line attached the drilling riser, and plumbing the pod umbilical hydraulic connector to a valve in the control pod.   
   
   
       11 . The method of  claim 10 , in which there are two radial connector brackets with an included angle of between about 180 degrees and the minimum included angle.