Ultrasonic Cleaning of Marine Geophysical Equipment

Abstract

Various methods and apparatuses for facilitating cleaning of submerged geophysical equipment using sound waves transmitted at ultrasonic frequencies are disclosed. In some embodiments, one or more transducers may be configured to transmit sound at one or more ultrasonic frequencies. The sound at ultrasonic frequencies may be transmitted in the vicinity of submerged geophysical equipment, such as a sensor streamer towed behind a survey vessel. Obstructions (e.g., barnacle larvae) adhering to surfaces of the geophysical equipment may be loosened or removed altogether when ultrasonic transmissions occur within its vicinity. The transducers used to transmit the ultrasonic frequencies may be implemented in various ways, such as being attached to a remote operated vehicle, a cleaning unit, or as being an integral component of the geophysical equipment.

What is claimed is: 
     
         1 . A method comprising:
 towing geophysical equipment behind a survey vessel; and   cleaning the geophysical equipment while the geophysical equipment is being towed, wherein said cleaning is performed at least in part by transmission of sound at an ultrasonic frequency.   
     
     
         2 . The method as recited in  claim 1 , wherein the transmission of sound at the ultrasonic frequency is performed at least in part by a plurality of transducers internal to the geophysical equipment. 
     
     
         3 . The method as recited in  claim 1 , wherein the transmission of sound at the ultrasonic frequency is performed at least in part by one or more transducers coupled to a remotely operated vehicle (ROV). 
     
     
         4 . The method as recited in  claim 3 , wherein the geophysical equipment is a sensor streamer, and wherein the method further comprises:
 the ROV traversing the length of the sensor streamer; and   transmitting sound at the ultrasonic frequency toward the sensor streamer during said traversing the length of the sensor streamer.   
     
     
         5 . The method as recited in  claim 1 , wherein the geophysical equipment is a sensor streamer, and wherein the transmission of sound at the ultrasonic frequency is performed at least in part by one or more transducers coupled to a streamer-cleaning unit (SCU) that is attachable to the sensor streamer. 
     
     
         6 . The method as recited in  claim 5 , further comprising:
 attaching the SCU to the a first end of the sensor streamer;   the SCU traversing from the first end to a second end of the sensor streamer; and   the SCU transmitting sound at the ultrasonic frequency during said traversing.   
     
     
         7 . The method as recited in  claim 1 , wherein the transmission of sound at the ultrasonic frequency further includes transmitting sound at a plurality of ultrasonic frequencies, and wherein the transmitted sound is generated externally to the geophysical equipment and directed toward the geophysical equipment. 
     
     
         8 . The method as recited in  claim 7 , wherein said transmitting sound at a plurality of ultrasonic frequencies comprises sweeping across a range of ultrasonic frequencies. 
     
     
         9 . An apparatus comprising:
 a cleaning unit configured to clean one or more pieces of geophysical equipment, including by transmission of ultrasonic frequencies.   
     
     
         10 . The apparatus as recited in  claim 9 , wherein the one or more pieces of geophysical equipment include a sensor streamer, and wherein the apparatus includes the cleaning unit and the sensor streamer. 
     
     
         11 . The apparatus as recited in  claim 9 , wherein the one or more pieces of geophysical equipment is include a sensor streamer, and wherein the apparatus is a streamer cleaning unit (SCU) that includes one or more transducers configured to transmit sound at ultrasonic frequencies. 
     
     
         12 . The apparatus as recited in  claim 9 , wherein the apparatus is located in a remotely operated vehicle (ROV), and wherein the ROV includes one or more transducers configured to transmit sound at ultrasonic frequencies. 
     
     
         13 . The apparatus as recited in  claim 9  wherein the one or more pieces of geophysical equipment include a sensor streamer, and wherein the cleaning unit comprises one or more transducers configured to transmit sound at ultrasonic frequencies, wherein the one or more transducers are integrated in the sensor streamer. 
     
     
         14 . The apparatus as recited in  claim 13 , further comprising a control unit coupled to the sensor streamer, wherein the control unit is configured to activate the plurality of transducers responsive to a first input and further configured to deactivate the plurality of transducers responsive to a second input. 
     
     
         15 . The apparatus as recited in  claim 9 , further comprising a control unit coupled to the cleaning unit, wherein the control unit control unit is configured to cause the cleaning unit to transmit sound by sweeping across a range of ultrasonic frequencies. 
     
     
         16 . A method comprising:
 towing geophysical equipment in water behind a survey vessel; and   transmitting sound at one or more ultrasonic frequencies in the water in a vicinity of the geophysical equipment.   
     
     
         17 . The method as recited in  claim 13 , wherein said transmitting comprises one or more transducers on a remotely operated vehicle (ROV) transmitting sound at one or more ultrasonic frequencies. 
     
     
         18 . The method as recited in  claim 17 , wherein the geophysical equipment includes a sensor streamer, and wherein the method further comprises the ROV traversing from a first end of the sensor streamer to a second end of the sensor streamer while transmitting sound at the one or more ultrasonic frequencies. 
     
     
         19 . The method as recited in  claim 16 , wherein said transmitting comprises one or more transducers on a streamer cleaning unit (SCU) transmitting sound at one or more ultrasonic frequencies. 
     
     
         20 . The method as recited in  claim 19 , wherein the geophysical equipment includes a sensor streamer, and wherein the method further comprises:
 attaching the SCU to a first end of the sensor streamer;   initiating transmission of sound at one or more ultrasonic frequencies by the one or more transducers;   the SCU traveling from the first end of the sensor streamer to a second end of the streamer while transmitting sound at one or more ultrasonic frequencies.   
     
     
         21 . The method as recited in  claim 16 , further comprising a plurality of transducers internal to the geophysical equipment transmitting sound at one or more ultrasonic frequencies. 
     
     
         22 . The method as recited in  claim 16 , wherein the transmitting sound includes sweeping across a range of ultrasonic frequencies. 
     
     
         23 . The method as recited in  claim 16 , wherein the transmitting sound includes transmitting sound at a first ultrasonic frequency and at least one additional ultrasonic frequency.