Subsea structure monitoring systems and methods

Abstract

A subsea structure monitoring system can include a base device configured to be secured to a subsea structure. The subsea structure monitoring system can also include a release mechanism disposed within the base device, where the release mechanism has a default state and a released state. The subsea structure monitoring system can further include a buoy detachably coupled to the release mechanism, where the buoy includes a housing that houses a communication module and a switch. The subsea structure monitoring system can also include a trigger that is configured to convert the release mechanism from the default state to the released state. The release mechanism can be converted from the default state to the released state when the trigger exerts a minimum force on the release mechanism.

What is claimed is: 
     
         1 . A subsea structure monitoring system comprising:
 a base device configured to be secured to a subsea structure;   a release mechanism disposed within the base device, wherein the release mechanism has a default state and a released state;   a buoy coupled to the release mechanism, wherein the buoy comprises a housing that houses a communication module and a switch; and   a trigger that is configured to convert the release mechanism from the default state to the released state,   wherein the release mechanism is converted from the default state to the released state when the trigger exerts a minimum threshold force on the release mechanism, wherein the minimum threshold force is applied by the trigger when the subsea structure moves a threshold distance from a default position, wherein the release mechanism, when in the released state, releases the buoy, and wherein the buoy, upon being released, is configured to float toward a surface of the water and activate the communication module using the switch.   
     
     
         2 . The subsea structure monitoring system of  claim 1 , wherein the buoy further comprises an energy storage device disposed within the housing, wherein the energy storage device is configured to be inactive when the switch is open, and wherein the energy storage device is configured to provide power, triggered by the switch closing, to the communication module. 
     
     
         3 . The subsea structure monitoring system of  claim 1 , wherein the switch comprises a pressure switch, wherein the pressure switch is configured to be open when the pressure switch is exposed to pressure above a threshold value, and wherein the pressure switch is configured to be closed when the pressure switch is exposed to pressure below the threshold value. 
     
     
         4 . The subsea structure monitoring system of  claim 1 , wherein the buoy further comprises an activation mechanism disposed within the housing, wherein the activation mechanism is configured to initiate the communication module when the base device is secured to the subsea structure. 
     
     
         5 . The subsea structure monitoring system of  claim 4 , wherein the activation mechanism comprises a reed switch and a removable magnet, wherein the magnet opens the reed switch when the magnet is positioned proximate to the reed switch, and wherein the reed switch is closed when the magnet is removed from the activation mechanism. 
     
     
         6 . The subsea structure monitoring system of  claim 5 , wherein the magnet is configured to be removed from the activation mechanism once the base device is secured to the subsea structure. 
     
     
         7 . The subsea structure monitoring system of  claim 1 , wherein the housing of the buoy comprises a non-metallic material. 
     
     
         8 . The subsea structure monitoring system of  claim 1 , wherein the switch comprises a pressure-activated switch that is configured to close when the pressure-activated switch detects a pressure that approaches atmospheric pressure. 
     
     
         9 . The subsea structure monitoring system of  claim 1 , wherein the trigger comprises a pressure-activated mechanical device that releases a resilient device when a pressure within the pressure-activated mechanical device falls below a threshold value, wherein the resilient device, when released, pushes a plunger attached to the release mechanism away from the release mechanism to convert the release mechanism from the default state to the released state. 
     
     
         10 . The subsea structure monitoring system of  claim 1 , wherein the subsea structure moves the threshold amount from the default position in any direction. 
     
     
         11 . The subsea structure monitoring system of  claim 1 , further comprising:
 a buoy tether having one end coupled to the release mechanism and an opposite end coupled to the buoy.   
     
     
         12 . The subsea structure monitoring system of  claim 1 , wherein the communication module is configured to communicate a position of the base device on the subsea structure. 
     
     
         13 . The subsea structure monitoring system of  claim 1 , wherein the subsea structure comprises a pipeline, and wherein the base device comprises a pipe clamp that clamps around the pipeline. 
     
     
         14 . The subsea structure monitoring system of  claim 1 , wherein the trigger comprises a base device tether assembly having a first end and a second end, wherein the first end is coupled to the release mechanism, and wherein the second end is configured to be anchored to a non-transient object. 
     
     
         15 . A buoy of a subsea structure monitoring system for a subsea structure, the buoy comprising:
 a non-metallic housing configured to be disposed in water without letting the water enter therein;   a control circuit disposed at least in part within the non-metallic housing, wherein the control circuit comprises:
 an energy storage device configured to provide power to the control circuit; 
 a communication device configured to store a location of a base device of the subsea structure monitoring system and to send communication signals; 
 a first switch configured to have an open position when the non-metallic housing is disposed proximate to the base device and a closed position after the non-metallic housing is released toward a surface of the water; and 
 a second switch configured to be normally closed; and 
   an activation device configured to open the second switch until the base device is placed in position relative to the subsea structure.   
     
     
         16 . The buoy of  claim 15 , wherein the activation device comprises a magnet having a first polarity, wherein the second switch comprises a reed switch having a second polarity that opposes the first polarity. 
     
     
         17 . The buoy of  claim 15 , wherein the first switch comprises a pressure-activated switch that closes as the pressure-activated switch experiences a pressure that is substantially similar to atmospheric pressure. 
     
     
         18 . A method for monitoring a subsea structure, the method comprising:
 affixing a base device of a subsea structure monitoring system to the subsea structure, wherein the subsea structure monitoring system further comprises a release mechanism, a buoy, and a trigger;   securing the trigger to the release mechanism, wherein the trigger is configured to convert the release mechanism from a default state to a released state when the trigger exerts a minimum threshold force on the release mechanism, wherein the minimum threshold force is applied to the release mechanism when the subsea structure moves a threshold distance from a default position, wherein the release mechanism, when in the released state, releases the buoy, and wherein the buoy, upon being released, is configured to float toward a surface of the water and activate the communication module using the switch; and   activating, after affixing the base device to the subsea structure, a control circuit comprising a switch, an energy storage device, and a communication module of the buoy, wherein the control circuit remains open when the release mechanism holds the buoy proximate to the base device, and wherein the control circuit opens after the release mechanism achieves the released state and releases the buoy.   
     
     
         19 . The method of  claim 18 , wherein activating the control circuit comprises removing a magnetic device from proximity of an additional switch in the control circuit, wherein the additional switch closes when the magnetic device is removed, and wherein the switch is open at pressures near the non-transient object. 
     
     
         20 . The method of  claim 18 , wherein the trigger comprises a base device tether assembly having a first end and a second end, wherein the first end is coupled to the release mechanism, and wherein the second end is configured to be anchored to a non-transient object proximate to the base device, wherein the release mechanism is configured to convert from the default state to the released state when the base device tether assembly exerts the minimum threshold force on the release mechanism.