Control of oilfield tools using multiple magnetic signals

Abstract

A system and method for magnetically communicating with downhole tools. One or more magnetic sources are used to generate multiple magnetic signals with each signal corresponding to a different function of the downhole tool. The signals may be based on various signal characteristics including pulses, frequencies, particular signal strengths, durations, or any combination of measurable signal characteristics.

1 . A method for operating a downhole tool, comprising:
 generating a first magnetic signal;   detecting the first magnetic signal using a magnetic sensor;   performing a first function of the downhole tool in response to the first magnetic signal;   generating a second magnetic signal;   detecting the second magnetic signal using the magnetic sensor; and   performing a second function of the downhole tool in response to the second magnetic signal.   
     
     
         2 . The method of  claim 1  wherein
 the first magnetic signal and the second magnetic signal are based on one of the group of a quantity of magnetic pulses, a duration of a magnetic field, a frequency of a magnetic field, and a strength of a magnetic field. 
 
     
     
         3 . The method of  claim 1  wherein
 the first and the second function are each one of the group of moving a component of the downhole tool or changing an operating mode of the downhole tool. 
 
     
     
         4 . The method of  claim 3  wherein
 at least one of the first and the second function is moving a component of the downhole tool and the component is moved by an electromechanical actuator. 
 
     
     
         5 . The method of  claim 3  wherein
 at least one of the first and the second function is changing an operating mode of the downhole tool and the operating mode is a sleep mode in which operation of the downhole tool is suspended until the at least one of the first and the second function is performed a second time. 
 
     
     
         6 . A system for operating a downhole tool, comprising:
 a downhole tool, comprising
 a magnetic sensor for detecting a first and a second magnetic signal; 
 means for performing at least a first and a second function of the downhole tool; 
 a controller connected to the magnetic sensor and the means for performing the first and the second function, wherein:
 an actuator performs the first function in response to the first magnetic signal; and 
 the actuator performs the second function in response to the second magnetic signal; and 
 
   at least one magnetic source for creating the first and second magnetic signals.   
     
     
         7 . The system of  claim 6 , wherein
 at least one of the first and the second function is moving a component of the downhole tool and the means for performing the at least one of the first and the second function is an electromechanical actuator.   
     
     
         8 . The system of  claim 6  wherein
 at least one of the first and the second function is changing an operating mode of the downhole tool, the operating mode being a sleep mode in which operation of the downhole tool is suspended until the at least one of the first and the second function is performed a second tune; and 
 the means for performing the at least one of the first and the second function is executing instructions by the controller. 
 
     
     
         9 . The system of  claim 6  wherein
 the first magnetic signal and the second magnetic signal are based on one of the group of a quantity of magnetic pulses, a duration of a magnetic field, a frequency of a magnetic field, and a strength of a magnetic field. 
 
     
     
         10 . The system of  claim 6  wherein
 the downhole tool is one of the group of a sliding sleeve tool, a packer, or a control valve. 
 
     
     
         11 . The system of  claim 6  wherein
 the at least one magnetic source comprises at least one magnetic ball. 
 
     
     
         12 . The system of  claim 6  wherein
 the at least one magnetic source comprises a magnetic source tool. 
 
     
     
         13 . The system of  claim 12  wherein
 the magnetic source tool comprises at least one permanent magnet. 
 
     
     
         14 . The system of  claim 12  wherein
 the magnetic source tool comprises at least one electromagnet. 
 
     
     
         15 . A magnetically-operable downhole tool, comprising
 a magnetic sensor for detecting a first and a second magnetic signal;   at least one actuator for performing a first function of the downhole tool and a second function of the downhole tool;   a controller connected to the magnetic sensor and the at least one actuator, wherein:
 the actuator performs the first function in response to a first command generated by the controller when the magnetic sensor detects a first magnetic condition; and 
 the actuator performs the second function in response to a second command generated by the controller when the magnetic sensor detects a second magnetic condition. 
   
     
     
         16 . The system of  claim 6  wherein
 the downhole tool is one of the group of a sliding sleeve tool, a packer, or a control valve. 
 
     
     
         17 . The system of  claim 6 , wherein
 at least one of the first and the second function is moving a component of the downhole tool and the means for performing the at least one of the first and the second function is an electromechanical actuator.   
     
     
         18 . The system of  claim 6  wherein
 at least one of the first and the second function is changing an operating mode of the downhole tool, the operating mode being a sleep mode in which operation of the downhole tool is suspended until the at least one of the first and the second function is performed a second time; and 
 the means for performing the at least one of the first and the second function is executing instructions by the controller. 
 
     
     
         19 . The system of  claim 6  wherein
 the first magnetic signal and the second magnetic signal are based on one of the group of a quantity of magnetic pulses, a duration of a magnetic field, a frequency of a magnetic field, and a strength of a magnetic field. 
 
     
     
         20 . The system of  claim 6  wherein
 the downhole tool is one of the group of a sliding sleeve tool, a packer, or a control valve.