# US 2019/0376381 A1 · Logging while drilling (lwd) mechanical calipers > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 2019/0376381 A1 - Document ID: US20190376381A1 - Status: Published application - Kind: A1 - Application number: 16/432,999 - Filed: 2019-06-06 - Published: 2019-12-12 - Earliest claimed: 2018-06-06 - Assignees: Schlumberger Technology Corporation - Applicants: Schlumberger Technology Corporation - Inventors: Hiroshi Nakajima; Cong Wang - Web page: https://patentgrep.com/patent/US20190376381A1 ## CPC - E21B 47/08: Measuring diameters or related dimensions at the borehole - E21B 47/01: Devices for supporting measuring instruments on drill bits, pipes, rods or wirelines; Protecting measuring instruments in boreholes against heat, shock, pressure or the like - G01V 2200/16: Measure-while-drilling or logging-while-drilling - E21B: EARTH OR ROCK DRILLING; OBTAINING OIL, GAS, WATER, SOLUBLE OR MELTABLE MATERIALS OR A SLURRY OF MINERALS FROM WELLS - G01V: GEOPHYSICS; GRAVITATIONAL MEASUREMENTS; DETECTING MASSES OR OBJECTS; TAGS (means for indicating the location of accidentally buried, e.g. snow-buried, persons A63B29/02) ## Abstract Logging while drilling (LWD) mechanical calipers are disclosed. An example apparatus to characterize a bore includes a drill collar, a sliding sleeve that moves longitudinally relative to the drill collar, and a sliding block operatively coupled to the sliding sleeve and movable relative to the drill collar. The example apparatus also includes a caliper arm operatively coupled to the sliding block, where the caliper arm is to displace radially outward towards an inner diameter of the bore based on movement of the sliding block, and a caliper sliding sensor to measure a movement of the sliding block. ## Claims ### Claim 1 An apparatus to characterize a bore, the apparatus comprising: a drill collar; a sliding sleeve that moves longitudinally relative to the drill collar; a sliding block operatively coupled to the sliding sleeve and movable relative to the drill collar; a caliper arm operatively coupled to the sliding block, the caliper arm to displace radially outward towards an inner diameter of the bore based on movement of the sliding block; and a caliper sliding sensor to measure a movement of the sliding block. ### Claim 2 (depends on 1) The apparatus as defined in claim 1, further including a drop ball to move the sliding sleeve. ### Claim 3 (depends on 2) The apparatus as defined in claim 2, further including a push spring in contact with the sliding sleeve. ### Claim 4 (depends on 1) The apparatus as defined in claim 1, further including a lock to retain the sliding block, wherein movement of the sliding sleeve releases the lock to move the caliper arm. ### Claim 5 (depends on 1) The apparatus as defined in claim 1, further including a battery, processor, and recording device, wherein the battery is to power the processor and recording device to measure diameters of the bore as the drill collar is moved through the bore. ### Claim 6 (depends on 1) The apparatus as defined in claim 1, wherein the caliper arm includes a bow spring. ### Claim 7 (depends on 1) The apparatus as defined in claim 1, wherein the sliding sleeve is radially disposed within the drill collar. ### Claim 8 (depends on 1) The apparatus as defined in claim 1, wherein the caliper sliding sensor includes an ultrasonic pulse-echo sensor. ### Claim 9 A method comprising: moving a caliper relative to a bore; moving a sliding sleeve of the caliper to expand a caliper arm operatively coupled to a sliding block, the caliper arm to displace radially outward towards an inner diameter of the bore based on movement of the sliding block; and determining, by executing an instruction with a processor, a characteristic of the bore based on the movement of the sliding block. ### Claim 10 (depends on 9) The method as defined in claim 9, further including contacting a drop ball with the sliding sleeve. ### Claim 11 (depends on 10) The method as defined in claim 10, wherein the drop ball is to disengage a lock that retains the sliding block when the drop ball contacts the sliding sleeve. ### Claim 12 (depends on 9) The method as defined in claim 9, wherein determining the characteristic of the bore is based on determining a contact point distance of a bow string. ### Claim 13 (depends on 9) The method as defined in claim 9, further including recording, by executing an instruction with the processor, diameter measurements as the caliper is moved relative to the bore. ### Claim 14 (depends on 9) The method as defined in claim 9, further including controlling, by executing an instruction with the processor, a pump that provides fluid to the bore based on the determined characteristic of the bore. ### Claim 15 (depends on 9) The method as defined in claim 9, wherein the movement of the sliding block is measured by an ultrasonic pulse-echo sensor. ### Claim 16 A non-transitory machine readable medium comprising instructions, which when executed, cause a processor to at least: determine a movement of a sliding block of a caliper, the sliding block operatively coupled to a caliper arm of the caliper, wherein the caliper arm displaces radially outward towards an inner diameter of a bore based on movement of a sliding sleeve of the caliper; and calculate a condition of the bore based on the movement of the sliding block. ### Claim 17 (depends on 16) The non-transitory machine readable medium as defined in claim 16, wherein the instructions cause the processor to determine a degree of cleaning needed for the bore based on the movement of the sliding block. ### Claim 18 (depends on 16) The non-transitory machine readable medium as defined in claim 16, wherein the instructions cause the processor to direct the caliper to be moved relative to the bore. ### Claim 19 (depends on 16) The non-transitory machine readable medium as defined in claim 16, wherein the instructions cause the processor to control a pump that provides fluid to the bore based on the calculated condition. ### Claim 20 (depends on 16) The non-transitory machine readable medium as defined in claim 16, wherein the caliper arm includes a bow spring, and wherein the instructions cause the processor to calculate a contact point distance of a bow spring.