Crowding avoidance apparatus and method

Abstract

A crowding avoidance sub (CAS), in or above a bottom hole assembly (BHA) suspended below a drill string, sends sensor data reporting inappropriate, relative, axial motion between movable parts of the CAS, typically near or within a cushion, jar, shock sub, or possibly a motor. Sensors connected to an Intellisys™ data connection system provide a data stream to a computer at the surface. Downhole preprocessing may be convenient but unnecessary. Control of the drive system of the hook feed rate (vertically) may be directly intervened in real time from a data station receiving and processing “travel” or “progress” information received from downhole sensors of the CAS indicating effectively instantly and electronically (rather than slower signals through drilling fluid) whenever the string progresses dangerously faster than the bit or moves dangerously closer thereto, requiring slowing, stopping, or reversing the downward advance of the drill string.

What is claimed and desired to be secured by United States Letters Patent is: 
     
         1 . An apparatus as a crowding avoidance subassembly (CAS) capable of reconciling a speed of advancement (BSA) of a BHA downward, in a bore, with a speed of advancement (SSA) of a drill string downward, the apparatus comprising:
 a housing capable of fitting between the drill string and a drill bit in the BHA, creating the bore into an earthen formation under a force of weight provided exclusively by the BHA;   a base and a slide, in the housing, capable of relative axial motion with respect to one another, the base moving with the BHA, the slide being moving axially with respect to the string and operably connected to pass data in an electronic format up the string toward the surface;   a sensor operably connected in the slide to detect a parameter indicating inappropriate reduction of axial distance between the slide and the bit; and   the sensor, being capable of sending the data, corresponding to the parameter, to a computer controlling a lift system advancing the drill string in the bore and programmed to change the SSA in response to the data in real time.   
     
     
         2 . The apparatus of  claim 1 , wherein the sensor is a physical device providing an electrical signal based on variation of the parameter. 
     
     
         3 . The apparatus of  claim 2 , wherein the parameter reflects a measurement corresponding to at least one of stress, strain, torque, acceleration, vibration, and displacement. 
     
     
         4 . The apparatus of  claim 3 , wherein the displacement is detectable by the sensor passing in proximity to a detectable feature in the base. 
     
     
         5 . The apparatus of  claim 3 , wherein the parameter is a frequency of sound corresponding to vibration. 
     
     
         6 . The apparatus of  claim 5 , wherein the vibration corresponds to one of scraping of a surface of the bit against the formation and bouncing of the bit toward and away from the formation. 
     
     
         7 . The apparatus of  claim 1 , wherein:
 the parameter is a frequency of vibration within the range of human hearing; and   the inappropriate reduction is detectable between the base and the slide.   
     
     
         8 . A method comprising:
 providing a base and slide configured as a crowding avoidance sub (CAS) capable of connecting between a drill string and a BHA configured to drive into a geologic formation, the base and slide being capable of relative motion axially and operably connectable to pass digital data from a sensor detecting the relative motion through the drill string to a controller at a ground surface;   descending the BHA, equipped with the CAS, downward into the formation at a first value of a BHA speed of advance (BSA) corresponding to a rate of descent of the bit and the drill string speed of advance (SSA);   reducing, by action of the formation against the bit, the BSA to a threshold value, less than the first value and deemed to reflect crowding of an unacceptable amount;   detecting, by the sensor, a parameter corresponding to the reducing;   sending from the sensor to a computer at the ground surface a signal reflecting the parameter; and   changing, by the computer, the SSA, based on the signal.   
     
     
         9 . The method of  claim 8 , wherein the detecting, sending, and changing occur in real time. The method of  claim 9 , wherein the parameter represents one of acceleration integrated to reflect motion or position, detection of a feature of the base by the sensor in the slide, and a mechanical parameter corresponding to forces operating in the CAS. 
     
     
         11 . The method of  claim 1 , wherein the computer changes the SSA to one of the current value of the BSA, less than the current value of the BSA, stopped, and a reverse direction. 
     
     
         12 . The method of  claim 8 , wherein the sensor is positioned and capable of detecting the parameter reflecting at least one of sound, proximity, velocity, and position. 
     
     
         13 . The method of  claim 12 , wherein the sensor detects a frequency of vibration constituting a sound within a range of human hearing, and the pitch (frequency) of the sound reflects crowding based on an increase in pitch. 
     
     
         14 . An apparatus capable of reconciling a string speed of advancement (SSA) with a bottom hole assembly (BHA) speed of advancement (BSA) to remediate crowding between the BHA and a drill string in a bore being drilled by a bit in the BHA, the apparatus comprising:
 a base operably capable of securing to and rotating with the BHA;   a slide operably capable of
 connecting mechanically, to rotate with the drill string and to slide axially with respect to the base, and 
 connecting electrically with a data link passing upward through the string to a control computer programmed to avoid crowding by reducing the SSA in response to crowding data from a sensor; and 
   the sensor, in the slide and operable to detect and report as the crowding data, a parameter reflecting at least one of a relative axial position of the base with respect to the slide and a disparity between the SSA and the BSA.   
     
     
         15 . The apparatus of  claim 14 , wherein the sensor is a physical device providing an electrical signal based on variation of the parameter. 
     
     
         16 . The apparatus of  claim 15 , wherein the parameter reflects a measurement corresponding to at least one of stress, strain, torque, acceleration, vibration, and displacement. 
     
     
         17 . The apparatus of  claim 16 , wherein the displacement is detected by the sensor passing in proximity to a detectable feature in the base. 
     
     
         18 . The apparatus of  claim 16 , wherein the parameter is a frequency of a sound generated by the bit against a face of the bore. 
     
     
         19 . The apparatus of  claim 14 , wherein the parameter is a pitch corresponding to a sound generated by the bit moving along a cutting face of the bore.  18 . The apparatus of  claim 16 , wherein the parameter is a frequency of a sound generated by the bit against a face of the bore. 
     
     
         20 . The apparatus of  claim 14 , wherein the parameter represents at least one of a distance and a speed of the slide with respect to the base.