Power savings mode for ocean bottom seismic data acquisition systems

Abstract

Embodiments of the invention provide methods, systems, and apparatus for conserving power while conducting an ocean bottom seismic survey. Sensor nodes placed on an ocean floor may be configured to operate in at least an idle mode and an active mode. Each node may adjust its mode of operation from idle mode to active mode.

What is claimed is: 
     
       1. A method for marine seismic data collection, comprising:
 operating an array of sensor nodes in an idle mode, wherein the idle mode is configured to conserve power consumption by the sensor nodes; 
 determining whether seismic data is expected at one or more of the sensor nodes in the array based on proximity to a vessel configured to generate a signal for communication with the sensor nodes, wherein the proximity is determined within a predefined distance of the vessel based on the signal received from the vessel; 
 in response to determining that seismic data is expected, selectively operating the one or more sensor nodes in an active mode; and 
 collecting the seismic data with the one or more sensor nodes while selectively operating in the active mode, wherein sensor nodes within the predefined distance of the vessel are operating in the active mode and other sensor nodes in the array are operating in the idle mode. 
 
     
     
       2. The method of  claim 1 , wherein the signal comprises an acoustic signal used for communication with the sensor nodes. 
     
     
       3. The method of  claim 1 , further comprising the vessel towing a source configured to generate the signal. 
     
     
       4. The method of  claim 1 , wherein the one or more nodes are configured to identify a predefined sequence of signals with predefined separation, duration and frequency to prevent the one or more nodes from being activated in response to noise. 
     
     
       5. The method of  claim 1 , further comprising deploying the array of sensor nodes on a sea floor or bed below a water surface. 
     
     
       6. The method of  claim 5 , wherein deploying the array of sensor nodes comprises deploying the one or more sensors nodes on the sea floor using a remotely operated vehicle. 
     
     
       7. The method of  claim 5 , further comprising transferring the signal to the sensor nodes from a device configured to float at a predefined distance below the water surface. 
     
     
       8. The method of  claim 5 , wherein deploying the array of sensor nodes comprises programming the one or more sensor nodes to navigate through a water column to predetermined locations on the sea floor. 
     
     
       9. The method of  claim 5 , wherein deploying the array of sensor nodes comprises placing the one or more sensor nodes along one or more ocean bottom cables and deploying the one or more ocean bottom cables on the sea floor. 
     
     
       10. A marine seismic array comprising:
 a plurality of sensor nodes deployed on a sea floor or bed, wherein the sensor nodes are configured to initiate operation in an idle mode; and 
 a sensor disposed in each of the sensor nodes, the sensor configured to detect a signal generated by a vessel for communication with the sensor nodes; 
 wherein the sensor nodes are configured to selectively adjust the idle mode to an active mode based on proximity to the vessel, wherein proximity is determined within a predefined distance of the vessel based on the signal such that one or more of the sensor nodes operate in the active mode in an active zone of the array, within the predefined distance of the vessel, and 
 wherein the sensor nodes, when no longer within the predefined distance of the vessel, are further configured to selectively adjust the active mode to the idle mode, such that others of the sensor nodes operate in the idle mode outside the active zone. 
 
     
     
       11. The marine seismic array of  claim 10 , wherein the sensor disposed in each of the sensor nodes comprises an acoustic sensor configured for detecting the signal. 
     
     
       12. The marine seismic array of  claim 10 , wherein the signal comprises an electromagnetic signal. 
     
     
       13. The marine seismic array of  claim 10 , further comprising a source towed by the vessel, wherein the source is configured to generate the signal. 
     
     
       14. The marine seismic array of  claim 10 , further comprising a device configured to transfer the signal to the sensor nodes, the device further configured to float at a predefined distance below a water surface above the sea floor or bed. 
     
     
       15. The marine seismic array of  claim 10 , wherein the active mode is configured for the one or more sensor nodes in the active zone to collect seismic data while conducting a seismic survey. 
     
     
       16. The marine seismic array of  claim 15 , wherein the idle mode is configured for the other sensor nodes outside the active zone to conserve power. 
     
     
       17. The marine seismic array of  claim 16 , wherein the sensor nodes are configured to operate in the idle mode if it is determined that seismic data collection has stopped, wherein a predefined period of time has passed since receiving the signal. 
     
     
       18. A seismic sensor node configured for deployment on a sea floor or bed in an ocean bottom array, the sensor node comprising:
 a processor; 
 at least one acoustic sensor configured to detect an acoustic signal; 
 at least one seismic sensor configured to record seismic signals; and 
 memory comprising a mode selection program executable on the processor to perform operations comprising:
 initiating the sensor node in an idle mode configured to conserve power; 
 determining whether seismic data is expected at the sensor node based on proximity to a vessel configured to generate the acoustic signal for communication with the sensor node, wherein proximity is determined within a predefined distance of the vessel based on the acoustic signal; 
 in response to determining that seismic data is expected at the sensor node:
 operating the sensor node in an active mode; and 
 collecting seismic data while in the active mode; 
 
 
 wherein the sensor node is configured to selectively operate in the active mode to collect the seismic data in an active zone of the array and to selectively adjust the active mode to the idle mode to conserve power outside the active zone, when no longer within the predefined distance of the vessel. 
 
     
     
       19. The seismic sensor node of  claim 18 , wherein the seismic sensor node is configured for deployment on the sea floor or bed using a remotely operated vehicle. 
     
     
       20. An ocean-bottom cable comprising a plurality of seismic sensor nodes deployed on the sea floor as recited in  claim 18 . 
     
     
       21. A method comprising:
 operating an array of ocean bottom sensor nodes in an idle mode,   wherein the idle mode is configured to conserve power consumption by the sensor nodes, and   wherein operating in the idle mode comprises operating at least one sensor to detect a signal generated by a vessel for communication with the sensor nodes; and   in response to receiving the signal generated by the vessel, selectively adjusting a mode of operating each of the sensor nodes in the array from the idle mode to an active mode, wherein a higher precision clock is used to operate the sensor nodes in the active mode and a lower precision clock is used to operate the sensor nodes in the idle mode;   wherein the higher precision clock operates at a greater frequency than the lower precision clock; and   wherein the sensor nodes are further configured to selectively adjust the active mode to the idle mode, such that the sensor nodes operate in the idle mode.    
     
     
       22. The method of claim 21, wherein operating the sensor node in the idle mode comprises operating one or more devices of the sensor node in a low power mode or shutting off power to one or mode devices of the sensor node.  
     
     
       23. The method of claim 21, wherein the signal comprises an acoustic signal defined by at least one of a predefined threshold amplitude, a predefined frequency range, and a predefined signal sequence.  
     
     
       24. The method of claim 21, wherein the sensor node is an autonomous ocean bottom node.  
     
     
       25. The method of claim 21, wherein the sensor node is deployed on a sea floor or sea bed.  
     
     
       26. The method of claim 21, further comprising deploying the sensor node on a sea floor or bed with a remotely operated vehicle.  
     
     
       27. The method of claim 21, wherein the at least one sensor comprises a hydrophone.  
     
     
       28. The method of claim 21, further comprising powering the sensor node with an energy storage system comprising a rechargeable battery, a fuel cell, or a combination thereof.  
     
     
       29. The method of claim 21, wherein the higher precision clock consumes more power than the lower precision clock.  
     
     
       30. The method of claim 21, further comprising the at least one sensor actively receiving signals in the idle mode, wherein the at least one sensor receives an acoustic signal, and wherein fewer than all available sensors in the sensor node are operated so that power savings are achieved while maintaining ability to receive communications.  
     
     
       31. A method comprising:
 deploying a plurality of sensor nodes in an array on a seabed, wherein each of the sensor nodes is initiated to operate in an idle mode;   selecting a lower precision clock to operate the sensor nodes in the idle mode;   initiating a signal generated by a vessel for communication to the sensor nodes;   selectively adjusting a mode of operation of each of the sensor nodes in the array from the idle mode to an active mode based on the signal generated by the vessel; and   selecting a higher precision clock to operate each of the sensor nodes in the array in the active mode, wherein the higher precision clock operates at greater frequency than the lower precision clock; and   wherein the sensor nodes are further configured to selectively adjust the active mode to the idle mode, such that the sensor nodes operate in the idle mode.    
     
     
       32. The method of claim 31, wherein operating the sensor nodes in the idle mode comprises operating one or more devices of the sensor nodes in a low power mode or shutting off power to one or more devices of the sensor nodes.  
     
     
       33. The method of claim 31, further comprising operating fewer than all available sensors in the sensor node, wherein power savings are achieved in the idle mode while maintaining ability to receive communications.  
     
     
       34. An ocean bottom seismic sensor node configured for deployment in an array of sensor nodes, comprising:
 a processor;   an acoustic sensor;   a particle motion sensor;   a lower precision clock and a higher precision clock, wherein the higher precision clock operates at greater frequency than the lower precision clock; and   memory comprising a mode selection program which, when executed by the processor is configured to perform operations comprising:
 operating the sensor node in an idle mode, 
 wherein the idle mode is configured to reduce power consumption by the sensor node, and 
 wherein operating in the idle mode comprises operating the acoustic sensor to detect an acoustic signal generated by a vessel for communication with the sensor node; 
   in response to the acoustic signal generated by the vessel, selectively adjusting a mode of operating the sensor node from the idle mode into an active mode, wherein each sensor node in the array is adapted to selectively adjust the mode of operation from the idle mode to the active mode; and   selecting a clock for operating the sensor node, based on the mode, wherein the higher precision clock is selected to operate the sensor node in the active mode and the lower precision clock is selected to operate the sensor node in the idle mode;   wherein the sensor node is further configured to selectively adjust the active mode to the idle mode, such that the sensor node operates in the idle mode.    
     
     
       35. The sensor node of claim 34, wherein operating in the idle mode comprises operating the processor in a low power mode or shutting off power to the at least one particle motion sensor.  
     
     
       36. The sensor node of claim 34, wherein the signal is defined by at least one of a predefined threshold amplitude, a predefined frequency range, and a predefined signal sequence.  
     
     
       37. The sensor node of claim 34, wherein the sensor node is an autonomous ocean bottom node deployed to a sea floor or bed.