Systems and methods for depth tracking in a downhole environment

Abstract

A method may include drilling a portion of the borehole with a bottomhole assembly (BHA) including a downhole tool. A method may include receiving, at the downhole tool, a zero pulse. A method may include receiving, at the downhole tool, a stand pulse. A method may include determining an added stand length based at least partially on the stand pulse. A method may include adding the added stand length to a total string length.

What is claimed is: 
     
         1 . A method of measuring depth in a borehole, the method comprising:
 drilling a portion of the borehole with a bottomhole assembly (BHA) including a downhole tool;   receiving, at the downhole tool, a zero pulse;   receiving, at the downhole tool, a stand pulse;   determining an added stand length based at least partially on the stand pulse; and   adding the added stand length to a total string length.   
     
     
         2 . The method of  claim 1 , further comprising adding a stand of drill pipe to a drill string in the borehole during the zero pulse. 
     
     
         3 . The method of  claim 1 , wherein the zero pulse is a mud pulse. 
     
     
         4 . The method of  claim 1 , wherein the zero pulse is a rotation per minute (RPM) pulse. 
     
     
         5 . The method of  claim 1 , wherein the stand pulse is a mud pulse. 
     
     
         6 . The method of  claim 1 , wherein the stand pulse is an RPM pulse. 
     
     
         7 . The method of  claim 6 , wherein the RPM pulse is a different RPM from a drilling RPM. 
     
     
         8 . The method of  claim 1 , wherein determining the added stand length includes comparing the stand pulse to a lookup table (LUT) including a plurality of stand lengths corresponding to a plurality of stand pulse parameters. 
     
     
         9 . The method of  claim 8 , wherein the plurality of stand lengths includes at least a first stand with a first quantity of joints and a second stand with a second quantity of joints. 
     
     
         10 . The method of  claim 1 , further comprising:
 determining a true vertical depth (TVD) based at least partially on the total string length.   
     
     
         11 . The method of  claim 10 , wherein the TVD is determined based at least partially on a well plan stored locally on a hardware storage device of the downhole tool. 
     
     
         12 . The method of  claim 10 , wherein the TVD is determined based at least partially on an inclination and azimuth of the BHA. 
     
     
         13 . The method of  claim 1 , wherein determining the added stand length includes incrementing a pipe tally stored locally on a hardware storage device of the downhole tool. 
     
     
         14 . A method of measuring depth in a borehole, the method comprising:
 drilling a portion of the borehole with a bottomhole assembly (BHA) including a downhole tool;   receiving, at the downhole tool, a zero pulse;   receiving, at the downhole tool, a stage pulse;   receiving, at the downhole tool, a stand pulse;   determining an added stand length based at least partially on the stand pulse; and   adding the added stand length to a known drill string length based at least partially on the stage pulse.   
     
     
         15 . The method of  claim 14 , wherein determining an added stand length is based at least partially on the stand pulse and the stage pulse. 
     
     
         16 . The method of  claim 14 , further comprising:
 determining a TVD of the BHA based at least partially on the added stand length and the known drill string length and a well plan stored locally on the downhole tool.   
     
     
         17 . A downhole system comprising:
 a directional steering tool;   a sensor; and   a control unit in data communication with the directional steering tool and the sensor,   the control unit including:
 a processor, and 
 a hardware storage device having instructions stored thereon executable by the processor to cause the control unit to: 
 receive, at the control unit, a zero pulse, 
 receive, at the control unit, a stand pulse, 
 determine an added stand length based at least partially on the stand pulse, and 
 add the added stand length to a total string length. 
   
     
     
         18 . The downhole system of  claim 17 , wherein the sensor is part of a measurement-while-drilling (MWD). 
     
     
         19 . The downhole system of  claim 17 , wherein the instructions further cause the control unit to receive, at the control unit, a stage pulse and reset the total string length to a known string length based at least partially on the stage pulse. 
     
     
         20 . The downhole system of  claim 17 , further comprising a pipe tally stored locally on the hardware storage device.