# US 11,028,685 B2 · Downhole rate of penetration measurement > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 11,028,685 B2 - Document ID: US11028685B2 - Status: Granted - Kind: B2 - Application number: 16/025,956 - Filed: 2018-07-02 - Published: 2020-01-02 - Granted: 2021-06-08 - Earliest claimed: 2018-07-02 - Assignees: Schlumberger Technology Corporation - Applicants: Novatek IP, LLC - Inventors: Malcolm Taylor; Scott R. Woolston; Jonathan D. Marshall; David Hoyle - Web page: https://patentgrep.com/patent/US11028685B2 ## CPC - E21B 45/00: Measuring the drilling time or rate of penetration - E21B 7/04: Directional drilling - E21B 10/42: Rotary drag type drill bits with teeth, blades or like cutting elements, e.g. fork-type bits, fish tail bits (characterised by wear resisting parts E21B10/46; by conduits or nozzles for drilling fluid E21B10/60; by detachable or adjustable parts E21B10/62) - E21B 47/024: of devices in the borehole (determining slope or direction of the borehole E21B47/022) - E21B 47/09: Locating or determining the position of objects in boreholes or wells {, e.g. the position of an extending arm}; Identifying the free or blocked portions of pipes - E21B: EARTH OR ROCK DRILLING; OBTAINING OIL, GAS, WATER, SOLUBLE OR MELTABLE MATERIALS OR A SLURRY OF MINERALS FROM WELLS ## Abstract A method for determining a rate of penetration of a drill bit during an earth drilling operation may comprise first urging an element to extend out from a working face of the drill bit. As drilling progresses, this extended element may then be forced back into the drill bit by an internal surface of a borehole being formed. A rate at which the element retracts back into the working face may be measured to aid in estimating a rate of penetration of the drill bit into the earth. ## Claims ### Claim 1 A method for determining a rate of penetration of a downhole drilling operation, comprising: urging an element to extend from a working face of a drill bit, wherein urging the element to extend is performed once a specific retraction displacement of the element is reached, and the element is free to rotate relative to the working face of the drill bit; and measuring a rate of retraction of the element into the working face due to force from an internal surface of a borehole. ### Claim 2 (depends on 1) The method of claim 1, further comprising repeatedly alternating between urging and measuring. ### Claim 3 (depends on 2) The method of claim 2, wherein urging the element to extend is performed at intervals selected to increase a rate of penetration of the drill bit. ### Claim 4 (depends on 2) The method of claim 2, further comprising detecting variation in a maximum extension of the element. ### Claim 5 (depends on 2) The method of claim 2, further comprising: altering a force urging the element to extend; comparing the measured rate of retraction during application of different urging forces; and projecting the compared measured rates to a point of zero rate to estimate a weight on bit. ### Claim 6 (depends on 1) The method of claim 1, wherein urging the element to extend displaces a portion of the internal surface. ### Claim 7 (depends on 6) The method of claim 6, wherein displacing the portion of the internal surface increases a rate of penetration of the drill bit. ### Claim 8 (depends on 6) The method of claim 6, wherein displacing the portion of the internal surface comprises crushing the portion. ### Claim 9 (depends on 1) The method of claim 1, further comprising independently measuring the time spent urging and measuring. ### Claim 10 (depends on 9) The method of claim 9, further comprising projecting the measured rate of retraction onto the time spent urging to estimate a rate of penetration of the drill bit. ### Claim 11 (depends on 10) The method of claim 10, further comprising estimating a depth of the drill bit based on the estimated rate of penetration. ### Claim 12 (depends on 10) The method of claim 10, wherein projecting the measured rate of retraction onto the time spent urging comprises accounting for a change in rate of penetration due to a force of the urging. ### Claim 13 (depends on 1) The method of claim 1, further comprising: measuring an azimuth and inclination of the drill bit during the measuring of the rate of retraction; and estimating a radius of curvature traveled by the drill bit based on the measured azimuth, inclination and rate of retraction. ### Claim 14 (depends on 13) The method of claim 13, further comprising comparing the estimated radius of curvature to a target radius of curvature and adjusting a steering process based thereon. ### Claim 15 (depends on 1) The method of claim 1, wherein urging the element to extend comprises translating the element along a rotational axis of the working face. ### Claim 16 (depends on 15) The method of claim 15, wherein the element comprises an axially symmetrical geometry where it makes contact with the internal surface, and the element extends from the working face at the rotational axis of the drill bit. ### Claim 17 A method for determining a rate of penetration of a downhole drilling operation, comprising: urging an element to extend from a working face at a rotational axis of a drill bit; measuring a rate of retraction of the element into the working face due to force from an internal surface of a borehole; measuring an azimuth and inclination of the drill bit during the measuring of the rate of retraction; and estimating a radius of curvature traveled by the drill bit based on the measured azimuth, inclination and rate of retraction. ### Claim 18 (depends on 17) The method of claim 17, wherein urging the element to extend is performed once a specific retraction displacement of the element is reached. ### Claim 19 A method for determining a rate of penetration of a downhole drilling operation, comprising: urging an element to extend from a working face of a drill bit, wherein the element is free to rotate relative to the working face of the drill bit; and measuring a rate of retraction of the element into the working face due to force from an internal surface of a borehole.