# US 10,871,041 B2 · Centralizer for downhole probes > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 10,871,041 B2 - Document ID: US10871041B2 - Status: Granted - Kind: B2 - Application number: 16/228,400 - Filed: 2018-12-20 - Published: 2019-07-04 - Granted: 2020-12-22 - Earliest claimed: 2012-11-06 - Assignees: Evolution Engineering Inc. - Applicants: Evolution Engineering Inc. - Inventors: Aaron W. Logan; Justin C. Logan; Patrick R. Derkacz - Web page: https://patentgrep.com/patent/US10871041B2 ## CPC - E21B 47/017: Protecting measuring instruments - E21B 7/00: Special methods or apparatus for drilling - E21B 17/00: Drilling rods or pipes; Flexible drill strings; Kellies; Drill collars; Sucker rods; {Cables;} Casings; Tubings - E21B 17/1078: {Stabilisers or centralisers for casing, tubing or drill pipes (E21B17/1007 - E21B17/1064 take precedence)} - E21B 17/16: Drill collars - E21B 23/01: for anchoring the tools or the like (E21B23/02 - E21B23/06 take precedence; anchoring of drives in the borehole E21B4/18) - E21B 23/02: for locking the tools or the like in landing nipples or in recesses between adjacent sections of tubing (E21B23/03 - E21B23/06 take precedence) - 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 - E21B 47/107: using acoustic means - E21B 47/13: by electromagnetic energy, e.g. radio frequency - E21B 17/003: {with electrically conducting or insulating means (E21B17/028 and E21B17/023 take precedence)} - E21B 47/135: using light waves, e.g. infrared or ultraviolet waves - E21B 47/18: through the well fluid {, e.g. mud pressure pulse telemetry} - E21B: EARTH OR ROCK DRILLING; OBTAINING OIL, GAS, WATER, SOLUBLE OR MELTABLE MATERIALS OR A SLURRY OF MINERALS FROM WELLS ## Abstract An assembly for use in subsurface drilling includes a downhole probe supported by a centralizer. The centralizer comprises a tubular member that extends around the downhole probe. A wall of the centralizer is fluted to provide inward contact points that support the downhole probe and outward contact points that bear against a bore wall of a section of drill string. The downhole probe may be supported for substantially its entire length. ## Claims ### Claim 1 A centralizer for use in subsurface drilling, the centralizer comprising: an elongated tubular member having a wall formed to provide a cross-section that provides first outwardly-convex and inwardly-concave lobes, the first lobes arranged to contact a bore wall of a bore in a section of drill string at a plurality of spots spaced apart around a circumference of the bore wall; a plurality of inwardly-projecting portions, each of the plurality of inwardly-projecting portions arranged between two adjacent ones of the plurality of first lobes; and one or more notches formed in one end of the tubular member and configured to anchor the centralizer against rotation in the bore. ### Claim 2 (depends on 1) The centralizer according to claim 1 in combination with the section of drill string wherein the one or more notches each engage a corresponding key on a landing shoulder within the bore. ### Claim 3 (depends on 1) The centralizer according to claim 1 in combination with the section of drill string wherein the one or more notches engage corresponding teeth of a ring held axially against a landing within the bore. ### Claim 4 (depends on 1) The centralizer according to claim 1 wherein the inwardly-projecting portions comprise inwardly-projecting lobes that are inwardly-convex and outwardly-concave. ### Claim 5 (depends on 1) The centralizer according to claim 1 wherein a thickness of the wall is substantially uniform. ### Claim 6 (depends on 5) The centralizer according to claim 5 wherein the wall has a thickness in the range of about 0.1 to 0.3 inches. ### Claim 7 (depends on 6) The centralizer according to claim 6 wherein the wall has a thickness in the range of about 0.15 to 0.25 inches. ### Claim 8 (depends on 1) The centralizer according to claim 1 wherein the cross-section provides two to eight first lobes. ### Claim 9 (depends on 1) The centralizer according to claim 1 wherein the plurality of first lobes are equally angularly separated around a longitudinal centerline of the centralizer. ### Claim 10 (depends on 1) The centralizer according to claim 1 wherein the first lobes are provided by longitudinally-extending ridges on an outer surface of the centralizer. ### Claim 11 (depends on 1) The centralizer according to claim 1 wherein the wall of the centralizer comprises a fibre-filled thermoplastic material. ### Claim 12 (depends on 11) The centralizer according to claim 11 wherein the thermoplastic material comprises PEEK or PET. ### Claim 13 (depends on 1) The centralizer according to claim 1 wherein the wall is made of an electrically-insulating material. ### Claim 14 (depends on 1) The centralizer according to claim 1 wherein the wall of the centralizer is resiliently deformable. ### Claim 15 (depends on 1) The centralizer according to claim 1 wherein the first lobes extend along helical paths along the length of the centralizer. ### Claim 16 (depends on 1) A downhole assembly comprising: a drill string section having a bore extending longitudinally through the drill string section; a downhole probe located in the bore of the drill string section; and a centralizer according to claim 1 in an annular region of the bore surrounding the downhole probe with the one or more notches engaging at least one member that projects from the drill string section. ### Claim 17 (depends on 16) The downhole assembly according to claim 16 wherein the drill string section comprises a landing in the bore, and the centralizer engages a key on the landing such that the centralizer is anchored against rotation relative to the bore. ### Claim 18 (depends on 16) The downhole assembly according to claim 16 wherein the drill string section comprises a ring comprising teeth, the ring is axially held against a landing within the bore, and the notches on the end of the elongated tubular member engage the teeth, wherein engagement of the notches on the end of the elongated tubular member with the teeth anchor the centralizer against longitudinal and rotational movement relative to the bore. ### Claim 19 (depends on 16) The downhole assembly according to claim 16 wherein the probe comprises one or more outwardly projecting features engaged between the inwardly-projecting portions of the centralizer. ### Claim 20 (depends on 16) The downhole assembly according to claim 16 wherein the notched end of the centralizer engages a landing in the bore and the centralizer is held axially between the landing and a threaded member.