Control of drilling system operations based on drill bit mechanics

Abstract

Implementations described and claimed herein are directed to systems and methods for controlling operations of a drilling system based on drill bit mechanics. During a drilling operation, sensor signals corresponding to mechanics of a drill bit are collected and processed to generate drill bit mechanics data and corresponding mechanical rock property data. A drilling measurement system is then operated based on whether the rock property data indicates the drill bit is actively engaged with or disengaged from a subterranean formation. The mechanical rock property data may also be used to detect characteristics of the subterranean formation and to control the drilling system based on the presence and/or nature of the characteristics.

What is claimed is: 
     
         1 . A method of controlling a drilling measurement system during a drilling operation to form a wellbore in a subterranean formation using a drill bit, the method comprising:
 receiving sensor signals corresponding to mechanics of the drill bit from one or more sensors;   processing the sensor signals to generate drill bit mechanics data; and   operating the drilling measurement system in a first mode when the drilling measurement system determines, based on the drill bit mechanics data, that the drill bit is actively engaged with the subterranean formation, wherein in the first mode the drilling measurement system at least one of transmits drilling data to a remote receiver and stores drilling data in non-transitory memory of the drilling measurement system, the drilling data including at least one of the drill bit mechanics data and mechanical rock property values derived from the drill bit mechanics data.   
     
     
         2 . The method of  claim 1 , further comprising:
 operating the drilling measurement system in a second mode when the drilling measurement system determines, based on the drill bit mechanics data, that the drill bit is disengaged from the subterranean formation, wherein in the second mode the drilling measurement system deactivates functionality corresponding to at least one of transmitting the drilling data to a remote and storing the drilling data in the non-transitory memory of the drilling measurement system.   
     
     
         3 . The method of  claim 1 , wherein in the first mode the drilling measurement system transmits the drilling data to a remote receiver using mud pulse telemetry. 
     
     
         4 . The method of  claim 1 , wherein in the first mode, the drilling measurement system transmits the drilling data to a mud pulser using a short hop wireless communication protocol for transmission to the remote receiver. 
     
     
         5 . The method of  claim 1 , wherein operating in the first mode further comprises:
 transmitting at least a portion of the drill bit mechanics data to a digital signal processing (DSP) module; and   transforming the drill bit mechanics data, using the DSP module, from a time domain format to a frequency domain format.   
     
     
         6 . The method of  claim 1 , further comprising transitioning from the second mode to the first mode in response to determining the drill bit is actively engaged with the subterranean formation, wherein transitioning from the second mode to the first mode includes energizing at least one of a memory module including the non-transitory memory, a digital signal processing (DSP) module configured to transform the drill bit mechanics data from a time domain format to a frequency domain format, and an interface module for transmitting the drilling data to the remote receiver. 
     
     
         7 . The method of  claim 1 , further comprising transitioning from the first mode to the second mode in response to determining the drill bit is disengaged from the subterranean formation, wherein transitioning from the first mode to the second mode includes deenergizing at least one of a memory module including the non-transitory memory, a digital signal processing (DSP) module configured to transform the drill bit mechanics data from a time domain format to a frequency domain format, and an interface module for transmitting the drilling data to the remote receiver. 
     
     
         8 . The method of  claim 1 , wherein the drilling measurement system determines whether the drill bit is actively engaged with the subterranean formation by:
 deriving a mechanical property value from the drill bit mechanics data; and   determining the mechanical property value is within a predetermined range indicating active engagement with the subterranean formation.   
     
     
         9 . The method of  claim 1 , wherein the drill bit mechanics data includes an axial acceleration of the drill bit and a lateral or rotary acceleration of the drill bit. 
     
     
         10 . A drilling measurement system configured to be disposed adjacent a drill bit of a drill string, the drilling measurement system comprising:
 one or more sensors configured to measure mechanics of the drill bit during a drilling operation to form a wellbore in a subterranean formation using the drill bit;   an acquisition module communicatively coupled to each of the one or more sensors and the computer readable memory, wherein the acquisition module is in communication with at least one first tangible machine readable media including computer executable instructions to perform the operations of:
 receiving sensor signals corresponding to mechanics of the drill bit from the one or more sensors; and 
 processing the sensors signals to generate drill bit mechanics data; and 
   a control module in communication with the acquisition module that selectively activates one or more functions of the drilling measurement system based on whether the drill bit mechanics data indicates that the drill bit is one of actively engaged with the subterranean formation and disengaged from the subterranean formation.   
     
     
         11 . The drilling measurement system of  claim 10 , wherein the first tangible machine readable media further includes computer executable instructions to perform the operation of:
 deriving a mechanical rock property value from the drill bit mechanics data,   wherein determining the drill bit mechanics data indicates the drill bit is actively engaged with the subterranean formation includes determining the mechanical rock property value is within a predetermined range and determining the drill bit mechanics data indicates the drill bit is disengaged from the subterranean formation includes determining the mechanical rock property value is outside the predetermined range.   
     
     
         12 . The apparatus of  claim 10 , wherein the sensor signals correspond to an axial acceleration of the drill bit and a lateral or rotary acceleration of the drill bit. 
     
     
         13 . The drilling measurement system of  claim 10  further comprising:
 at least one of a communication module, a memory module, and a digital signal processing (DSP) module communicatively coupled to the control module, 
 wherein the control module is in communication with at least one second tangible machine readable media including computer executable instructions to perform the operations of activating the at least one of the communication module, the memory module, and the digital signal processing (DSP) module in response to the drill bit being actively engaged with the subterranean formation. 
 
     
     
         14 . The drilling measurement system of  claim 13 , wherein the second tangible machine readable media further includes computer executable instructions to perform the operations of deactivating the at least one of the communication module, the memory module, and the digital signal processing (DSP) module in response to the drill bit being disengaged from the subterranean formation. 
     
     
         15 . The drilling measurement system of  claim 13 , wherein the drilling measurement system comprises the communication module and, when activated, the communication module transmits drilling data to a remote receiver, the drilling data including at least one of the drill bit mechanics data and mechanical property values of the subterranean formation derived from the drill bit mechanics data. 
     
     
         16 . The drilling measurement system of  claim 15 , wherein:
 the communication module is communicatively coupleable to a mud pulser for communication of the drilling data to the remote receiver using mud pulse telemetry, and   the communication module is configured to transmit the drilling data to the mud pulser using a short hop communication protocol.   
     
     
         17 . The drilling measurement system of  claim 13 , wherein the drilling measurement system comprises the memory module and, when activated, the memory module stores drilling data, the drilling data including at least one of the drill bit mechanics data and mechanical property values of the subterranean formation derived from the drill bit mechanics data. 
     
     
         18 . The drilling measurement system of  claim 13 , wherein the drilling measurement system comprises the DSP module, the DSP module communicatively coupled to the one or more accelerometers and, when activated, the DSP module receives time-domain drill bit mechanics data from the acquisition module and converts the time-domain drill bit mechanics data into frequency-domain drill bit mechanics data. 
     
     
         19 . An acquisition unit for use in a drilling measurement system configured to be coupled to a drill string, the drill string including a drill bit, the acquisition unit communicatively coupleable to one or more sensors, the acquisition module comprising:
 at least one processor; and   at least one tangible machine readable media communicatively coupled to the at least one processor, the at least one tangible machine readable media including computer executable instructions that, when executed by the at least one processor, perform the operations of:
 receiving sensor signals corresponding to mechanics of the drill bit from the one or more sensors; 
 processing the sensor signals to generate drill bit mechanics data; and 
 determining a drilling state based on the drill bit mechanics data, the drilling state corresponding to whether the drill bit is actively engaged with the subterranean formation or disengaged from the subterranean formation; and 
 updating a drilling state variable in accordance with the drilling state. 
   
     
     
         20 . The acquisition unit of  claim 19 , wherein the sensor signals correspond to an axial acceleration of the drill bit and a lateral or rotary acceleration of the drill bit. 
     
     
         21 . The acquisition unit of  claim 20 , further comprising at least one integrator communicatively coupled to the at least one processor, the at least one integrator configured to derive at least one of an axial velocity of the drill bit, a lateral velocity of the drill bit, a rotary velocity of the drill bit, an axial displacement of the drill bit, a lateral displacement of the drill bit, and a rotary displacement of the drill bit from the sensor signals. 
     
     
         22 . The acquisition unit of  claim 20 , wherein determining the drilling state includes obtaining the root mean square of drill bit mechanics data corresponding to the axial acceleration of the drill bit and the root mean square of drill bit mechanics data corresponding to the lateral or rotary acceleration of the drill bit. 
     
     
         23 . The acquisition unit of  claim 19 , wherein determining the drilling state includes:
 deriving a mechanical property value from the drill bit mechanics data;   determining the drill bit is actively engaged with the subterranean formation when the mechanical property value is within a predetermined range; and   determining the drill bit is disengaged from the subterranean formation when the mechanical property is outside the predetermined range.   
     
     
         24 . The acquisition unit of  claim 23 , wherein the mechanical property value is at least one of Poisson's ratio and Young's Modulus of Elasticity. 
     
     
         25 . The acquisition unit of  claim 19 , further comprising an amplifier communicatively coupled to the at least one processor, wherein determining the drilling state includes amplifying the sensor signals using the amplifier. 
     
     
         26 . The acquisition unit of  claim 19 , further comprising at least one filter communicatively coupled to the at least one processor, wherein determining the drilling state includes at least one of low-pass filtering, high-pass filtering, and band-pass filtering one of the sensor signals or a secondary signal derived from the sensor signals using the at least one filter. 
     
     
         27 . The acquisition unit of  claim 19  further comprising at least one analog-to-digital converter communicatively coupled to the at least one processor, wherein the sensor signals are analog signals and determining the drilling state includes converting the sensor signals or a secondary signal derived from the sensor signals into a digital signal using the analog-to-digital converter. 
     
     
         28 . The acquisition unit of  claim 19  further comprising a decimator communicatively coupled to the at least one processor, wherein the sensor signals are an analog signal and determining the drilling state includes decimating a digital signal derived from the sensor signals using the decimator. 
     
     
         29 . The acquisition unit of  claim 19 , wherein the drilling state variable is stored in at least one of the at least one tangible machine readable media and a remote memory communicatively coupled to the acquisition module. 
     
     
         30 . A method of controlling a drilling system during a drilling operation to form a wellbore in a subterranean formation using a drill bit, the method comprising:
 receiving sensor signals corresponding to mechanics of the drill bit from one or more sensors;   processing the sensor signals to generate drill bit mechanics data;   deriving mechanical rock property data from the drill bit mechanics data;   identifying a characteristic of the subterranean formation based on the mechanical rock property data; and   in response to identifying the characteristics of the subterranean formation, modifying an operational parameter of the drilling system to change a drilling system behavior.   
     
     
         31 . The method of  claim 30 , wherein the characteristic of the subterranean formation is a geological feature of the subterranean formation. 
     
     
         32 . The method of  claim 31 , wherein the geological feature includes at least one of a fracture, a boundary, a bedding plane, or a discontinuity within the subterranean formation. 
     
     
         33 . The method of  claim 30 , wherein modifying the operational parameter of the drilling system includes modifying a direction of the drill bit. 
     
     
         34 . The method of  claim 33 , wherein modifying the direction of the drill bit includes rotating a bent sub coupled to the drill bit. 
     
     
         35 . The method of  claim 33 , wherein the characteristic of the subterranean formation is a geological feature of the subterranean formation and the direction of the drill bit is modified to maintain the drill bit at a predetermined distance relative to the geological feature. 
     
     
         36 . The method of  claim 33 , wherein the characteristic of the subterranean formation is a geological feature of the subterranean formation and the direction of the drill bit is modified to maintain the drill bit at a predetermined orientation relative to the geological feature. 
     
     
         37 . The method of  claim 30 , wherein modifying the operational parameter includes modifying a rotational rate of at least one of the drill bit and a top drive of the drilling system. 
     
     
         38 . The method of  claim 30 , wherein modifying the operational parameter includes changing between a rotational drilling mode in which each of a downhole motor and a top drive of the drilling system rotate and a slide drilling mode in which the top drive does not rotate. 
     
     
         37 . The method of  claim 30 , wherein identifying the characteristic of the subterranean formation includes predicting a bias to which the drill bit will be subjected to when drilling through the formation. 
     
     
         38 . The method of  claim 37 , wherein modifying the operational parameter includes modifying a direction of the drill bit to offset the bias. 
     
     
         39 . The method of  claim 30 , wherein the characteristics of the subterranean formation is a susceptibility of the subterranean formation to a fracturing operation, the method further comprising at least one of modifying or supplementing the mechanical rock property data to include an identifier indicating the susceptibility. 
     
     
         40 . The method of  claim 30 , wherein modifying the operational parameter of the drilling system includes stopping a drilling operation. 
     
     
         41 . The method of  claim 31  further comprising, in response to identifying the formation property, generating a message and transmitting the message to a remote computing device.