# US 2021/0277724 A1 · System and method for centralizing a tool in a wellbore > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 2021/0277724 A1 - Document ID: US20210277724A1 - Status: Published application - Kind: A1 - Application number: 16/686,271 - Filed: 2018-12-20 - Published: 2021-09-09 - Earliest claimed: 2018-12-20 - Assignees: Halliburton Energy Services, Inc. - Applicants: Halliburton Energy Services, Inc. - Inventors: Edward Harrigan; Adan Hernandez Herrera; Wesley N. Ludwig - Web page: https://patentgrep.com/patent/US20210277724A1 ## CPC - E21B 17/10: Wear protectors; Centralising devices {, e.g. stabilisers} - E21B 17/1021: {with articulated arms or arcuate springs} - E21B 43/117: Shaped-charge perforators (E21B43/118 takes precedence) - E21B 43/1185: Ignition systems - E21B 43/119: Details, e.g. for locating perforating place or direction - E21B: EARTH OR ROCK DRILLING; OBTAINING OIL, GAS, WATER, SOLUBLE OR MELTABLE MATERIALS OR A SLURRY OF MINERALS FROM WELLS ## Abstract A centralizing perforating gun for perforating a tubular in a wellbore include a gun housing, perforating charges positioned within the gun housing and detonatable to perforate the tubular, and a centralizing system. The centralizing system includes an extendable member configured to move between a retracted position and an extended position. The extendable member is configured to engage a surface of the tubular in the extended position, thereby biasing the centralizing perforating gun away from the surface of the tubular. ## Claims ### Claim 1 A centralizing perforating gun for perforating a tubular in a wellbore, the gun comprising: a gun housing; perforating charges within the gun housing and detonatable to perforate the tubular; and a centralizing system comprising an extendable member extendable between a retracted position and an extended position, wherein the extendable member is configured to engage a surface of the tubular when extended, thereby biasing the centralizing perforating gun away from the surface of and centralized within the tubular. ### Claim 2 (depends on 1) The system of claim 1, further comprising a power charge ignitable to extend the extendable member from the retracted position to the extended position. ### Claim 3 (depends on 2) The system of claim 2, wherein the power charge is ignitable to extend the extendable member prior to detonation of the perforating charges. ### Claim 4 (depends on 2) The system of claim 2, comprising a detonator detonatable separately from the power charge to initiate a ballistic sequence that detonates the perforating charges. ### Claim 5 (depends on 2) The system of claim 2, wherein the extendable member is positioned in a chamber that is pressure isolated from the perforating charges. ### Claim 6 (depends on 1) The system of claim 1, comprising a second extendable member extendable between a second retracted position and a second extended position, wherein the second extendable member is configured to engage the surface of the tubular when extended, thereby biasing the centralizing perforating gun away from the surface of and centralized within the tubular, and wherein the extendable member and second extendable member are positioned on opposite longitudinal sides of the perforating charges. ### Claim 7 (depends on 6) The system of claim 6, further comprising: a first power charge ignitable to extend the extendable member from the retracted position to the extended position; and a second power charge ignitable to extend the second extendable member from the second retracted position to the second extended position. ### Claim 8 (depends on 1) The system of claim 1, wherein the extendable member is positioned within the gun housing. ### Claim 9 (depends on 1) The system of claim 1, wherein the extendable member comprises a bladder positioned around at least a portion of the gun housing. ### Claim 10 (depends on 9) The system of claim 9, wherein detonation of the perforating charges is configured to puncture the bladder. ### Claim 11 (depends on 9) The system of claim 9, wherein the bladder is pressure isolated from the perforating charges. ### Claim 12 (depends on 1) The system of claim 1, wherein the extendable member comprises an arm rotatable about a pin to move the arm between the retracted position and the extended position. ### Claim 13 (depends on 13) The system of claim 13, further comprising a piston coupled to a portion of the arm such that axial motion of the piston causes rotation of the arm. ### Claim 14 A method for centralizing a perforating gun comprising: conveying the perforating gun comprising a gun housing downhole into a wellbore; igniting a power charge to extend an extendable member from a retracted position to engage a surface of a tubular within a wellbore in an extended position, thereby biasing the perforating gun away from the surface of the tubular; and detonating perforating charges positioned within the gun housing to perforate the tubular. ### Claim 15 (depends on 14) The method of claim 14, further comprising extending the extendable member before detonating the perforating charges. ### Claim 16 (depends on 14) The method of claim 14, further comprising retracting the extendable member after detonating the perforating charges ### Claim 17 (depends on 14) The method of claim 14, further comprising retracting the extendable member in response to rupturing a rupture disc. ### Claim 18 (depends on 14) The method of claim 14, wherein the extendable member is positioned in a chamber that is pressure isolated from the perforating charges. ### Claim 19 (depends on 14) The method of claim 14, wherein the extendable member is a bladder positioned around at least a portion of the gun housing, and detonating the perforating charges punctures the bladder. ### Claim 20 A system for perforating a wellbore, the system comprising: a wireline; and perforating guns positioned along the wireline, each perforating gun comprising: a gun housing; perforating charges within the gun housing and detonatable to perforate the tubular; and a centralizing system comprising an extendable member configured to move between a retracted position and an extended position, wherein the extendable member is configured to engage a surface of the tubular in the extended position, thereby biasing the respective perforating gun away from the surface of and centralized within the tubular.