System and method for estimating velocity of a downhole component

Abstract

A system for estimating a velocity of a downhole component is disclosed. The system includes: a sensor configured to produce a sensor signal that is proportional to at least one of a position and an acceleration of the downhole component; and a circuit in communication with the sensor and configured to receive the sensor signal and generate an output signal indicative of an instantaneous velocity of the downhole component. A method of estimating a velocity of a downhole component is also disclosed.

1 . A system for estimating a velocity of a downhole component, the system comprising:
 a sensor configured to produce a sensor signal that is proportional to at least one of a position and an acceleration of the downhole component; and   a circuit in communication with the sensor and configured to receive the sensor signal and generate an output signal indicative of an instantaneous velocity of the downhole component.   
     
     
         2 . The system of  claim 1 , wherein the sensor signal is a voltage signal. 
     
     
         3 . The system of  claim 1 , wherein the sensor is selected from at least one of an accelerometer and a strain gauge. 
     
     
         4 . The system of  claim 1 , wherein the sensor is an accelerometer configured to generate an input voltage proportional to an acceleration of the downhole component, and the circuit is an integrator circuit. 
     
     
         5 . The system of  claim 4 , wherein the integrator circuit is an active integrator circuit having an operational amplifier. 
     
     
         6 . The system of  claim 1 , wherein the sensor is a position sensor configured to generate an input voltage proportional to a position of the downhole component, and the circuit is a differentiator circuit. 
     
     
         7 . The system of  claim 6 , wherein the integrator circuit is an active differentiator circuit having an operational amplifier. 
     
     
         8 . The system of  claim 1 , wherein the component is a drill bit. 
     
     
         9 . The system of  claim 1 , wherein the instantaneous velocity is related to a rate of penetration (ROP) of the component. 
     
     
         10 . The system of  claim 1 , wherein the sensor includes one or more sensors positioned to measure at least one of the acceleration and a change of the position of the downhole component along at least one axis. 
     
     
         11 . The system of  claim 10 , wherein the at least one axis extends along a direction selected from at least one of an axial direction parallel to a borehole, a radial direction perpendicular to the axial direction, and a tangential direction perpendicular to the radial and axial directions. 
     
     
         12 . A method of estimating a velocity of a downhole component, the method comprising:
 lowering a sensor into a borehole in an earth formation, the sensor configured to produce a sensor signal that is proportional to at least one of a position and an acceleration of the downhole component;   activating the sensor to generate the sensor signal; and   transmitting the signal to a circuit and generating an output signal indicative of an instantaneous velocity of the downhole component via the circuit.   
     
     
         13 . The method of  claim 12 , wherein the sensor signal is a voltage signal. 
     
     
         14 . The method of  claim 12 , wherein the sensor is selected from at least one of an accelerometer and a strain gauge. 
     
     
         15 . The method of  claim 12 , wherein the sensor is an accelerometer configured to generate an input voltage proportional to an acceleration of the downhole component, and generating the output signal includes integrating the input voltage over a selected period of time via the circuit. 
     
     
         16 . The method of  claim 15 , wherein integrating includes integrating the input voltage with an active integrator circuit having an operational amplifier. 
     
     
         17 . The method of  claim 12 , wherein the sensor is a position sensor configured to generate an input voltage proportional to a position of the downhole component, and generating the output signal includes differentiating the input voltage over a selected period of time via the circuit. 
     
     
         18 . The method of  claim 17 , wherein differentiating includes differentiating the input voltage with an active differentiation circuit having an operational amplifier. 
     
     
         19 . The method of  claim 12 , wherein the instantaneous velocity is related to a rate of penetration (ROP) of the component. 
     
     
         20 . The method of  claim 12 , wherein lowering the sensor includes drilling at least a portion of the borehole.