# US 2014/0190747 A1 · System and method for automatic weight-on-bit sensor calibration > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 2014/0190747 A1 - Document ID: US20140190747A1 - Status: Published application - Kind: A1 - Application number: 13/518,769 - Filed: 2011-06-29 - Published: 2014-07-10 - Earliest claimed: 2011-06-29 - Assignees: Halliburton Energy Services, Inc. - Inventors: Richard T. Hay - Web page: https://patentgrep.com/patent/US20140190747A1 ## CPC - E21B 47/00: Survey of boreholes or wells (monitoring pressure or flow of drilling fluid E21B21/08) - E21B 41/00: Equipment or details not covered by groups E21B15/00 - E21B40/00 - E21B 44/00: Automatic control systems specially adapted for drilling operations, i.e. self-operating systems which function to carry out or modify a drilling operation without intervention of a human operator, e.g. computer-controlled drilling systems; Systems specially adapted for monitoring a plurality of drilling variables or conditions - E21B 47/007: Measuring stresses in a pipe string or casing (for locating blocked portions of pipes E21B47/09) - E21B 47/024: of devices in the borehole (determining slope or direction of the borehole E21B47/022) - G01G 23/01: Testing or calibrating of weighing apparatus - E21B: EARTH OR ROCK DRILLING; OBTAINING OIL, GAS, WATER, SOLUBLE OR MELTABLE MATERIALS OR A SLURRY OF MINERALS FROM WELLS - G01G: WEIGHING (sorting by weighing B07C5/16) ## Abstract A system and method for automatic weight-on-bit sensor calibration is described. Embodiments of the invention automatically compensate the measurements of a weight-on-bit sensor based on one or more of mass, hole inclination, buoyancy, drag, and mud flow, resulting in a more accurate axial force measurement below the weight-on-bit sensor at various hole inclinations. This measurement is observed by removing some of the effects masking the actual force being applied to the axial face of the drill bit. ## Claims ### Claim 1 A method for optimizing weight measurements in drilling operations, the method comprising: calculating a net axial force applied to a weight sensor using a hole inclination and a weight on the weight sensor; determining a correction value with the net axial force; and calibrating the weight sensor with the correction value. ### Claim 2 (depends on 1) The method of claim 1, wherein the correction value is determined using at least one of a subsequent hole inclination, a buoyancy force, a drag force, a mud flow force, and a pipe pressure. ### Claim 3 (depends on 2) The method of claim 2, wherein the buoyancy force is calculated using at least one of a mud density and a density of the mass below the weight sensor. ### Claim 4 (depends on 2) The method of claim 2, wherein the drag force is calculated using a dynamic coefficient of friction. ### Claim 5 (depends on 2) The method of claim 2, wherein the mud flow force accounts for at least one of piston effects and a fluid friction force. ### Claim 6 (depends on 1) The method of claim 1, further comprising: calculating a corrected weight on bit using the correction value and a subsequent weight on the weight sensor. ### Claim 7 (depends on 6) The method of claim 6, further comprising: displaying the corrected weight on bit. ### Claim 8 (depends on 6) The method of claim 6, further comprising: adjusting a bottom hole assembly using the corrected weight on bit. ### Claim 9 (depends on 1) A computer readable medium programmed with computer executable instructions therein for performing the method of claim 1. ### Claim 10 A system for optimizing weight measurements in drilling operations, the system comprising: a weight sensor that measures a weight on the weight sensor; a processor coupled to the weight sensor that: calculates a net axial force applied to the weight sensor using a hole inclination and the weight on the weight sensor, determines a correction value using the net axial force, and calibrates the weight sensor using the correction value; and a memory coupled to the processor. ### Claim 11 (depends on 10) The system of claim 10, wherein the processor determines the correction value using at least one of a subsequent hole inclination, a buoyancy force, a drag force, a mud flow force, and a pipe pressure. ### Claim 12 (depends on 11) The system of claim 11, wherein the buoyancy force is calculated with at least one of a mud density and a density of the mass below the weight sensor. ### Claim 13 (depends on 11) The system of claim 11, wherein the drag force is calculated with a dynamic coefficient of friction. ### Claim 14 (depends on 11) The method of claim 11, wherein the mud flow force accounts for at least one of piston effects and a fluid friction force. ### Claim 15 (depends on 10) The system of claim 10, wherein the processor further calculates a corrected weight on bit using the correction value and a subsequent weight measured by the weight sensor. ### Claim 16 (depends on 15) The system of claim 15, further comprising: a display that displays the corrected weight on bit. ### Claim 17 (depends on 16) The system of claim 16, wherein the display is a weight on bit interface. ### Claim 18 (depends on 15) The system of claim 15, further comprising: a controller that adjusts a bottom hole assembly using the corrected weight on bit. ### Claim 19 (depends on 10) The system of claim 10, wherein the weight sensor is a weight-on-bit sensor. ### Claim 20 (depends on 10) The system of claim 10, wherein the weight sensor is integrated into at least one of a measurement-while-drilling (MWD) assembly and a logging-while-drilling (LWD) assembly.