# US 2021/0277726 A1 · Bottomhole assembly (bha) stabilizer or reamer position adjustment methods and systems employing a cost function > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 2021/0277726 A1 - Document ID: US20210277726A1 - Status: Published application - Kind: A1 - Application number: 16/330,536 - Filed: 2016-12-08 - Published: 2021-09-09 - Earliest claimed: 2016-12-08 - Assignees: Halliburton Energy Services, Inc. - Applicants: Halliburton Energy Services, Inc. - Inventors: Jason D. Dykstra; Xingyong Song; Venkata Madhukanth Vadali - Web page: https://patentgrep.com/patent/US20210277726A1 ## CPC - E21B 10/30: Longitudinal axis roller reamers, e.g. reamer stabilisers - E21B 17/10: Wear protectors; Centralising devices {, e.g. stabilisers} - E21B 17/1078: {Stabilisers or centralisers for casing, tubing or drill pipes (E21B17/1007 - E21B17/1064 take precedence)} - 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: EARTH OR ROCK DRILLING; OBTAINING OIL, GAS, WATER, SOLUBLE OR MELTABLE MATERIALS OR A SLURRY OF MINERALS FROM WELLS ## Abstract A system that includes a drillstring with a bottomhole assembly (BHA). The system also includes at least one stabilizer or reamer integrated with the BHA, wherein each of the at least one stabilizer or reamer includes a position adjustment assembly. The system also includes a processing unit that provides control signals to each position adjustment assembly, wherein the control signals are based on a cost function. ## Claims ### Claim 1 A system that comprises: a drillstring with a bottomhole assembly (BHA); at least one stabilizer or reamer integrated with the BHA, wherein each of the at least one stabilizer or reamer includes a position adjustment assembly; and a processing unit that provides control signals to each position adjustment assembly, wherein the control signals are based on a cost function. ### Claim 2 (depends on 1) The system of claim 1, wherein the cost function accounts for predicted BHA states and a position range for each stabilizer or reamer. ### Claim 3 (depends on 1) The system of claim 1, wherein each position adjustment assembly is configured to adjust at least an axial position of a respective stabilizer or reamer along the BHA. ### Claim 4 (depends on 1) The system of claim 1, wherein the at least one stabilizer comprises a plurality of axially-spaced stabilizers. ### Claim 5 (depends on 1) The system of claim 1, wherein the position adjustment assembly comprises a position lock/unlock component. ### Claim 6 (depends on 1) The system of claim 1, wherein the position adjustment assembly comprises an actuator component. ### Claim 7 (depends on 1) The system of claim 1, wherein the position adjustment assembly comprises a sliding track component or roller component. ### Claim 8 (depends on 1) The system of claim 1, wherein the cost function includes at least four of a vibration magnitude term, a stabilizer or reamer position term, a drill bit wear term, a trajectory error term, an uncertainty term, a stabilizer or reamer wear term, a rate of penetration term, and a borehole tortuosity term. ### Claim 9 (depends on 8) The system of claim 8, wherein the processing unit applies weights to at least some of the terms of the cost function. ### Claim 10 (depends on 8) The system of claim 8, wherein the processing unit adjusts at least some of the terms or term weights of the cost function over time. ### Claim 11 (depends on 1) The system of claim 1, further comprising a data storage in communication with the processing unit, wherein the data storage stores a look-up table (LUT) of values related to the cost function, and wherein the processing unit selects the control signals based at least in part on the LUT values. ### Claim 12 (depends on 1) The system according to claim 1, wherein the processing unit is part of the BHA. ### Claim 13 A method that comprises: deploying a drillstring in a borehole, the drillstring having a bottomhole assembly (BHA) with at least one stabilizer or reamer, each stabilizer or reamer having a position adjustment assembly; generating, by the processing unit, control signals for each position adjustment assembly based on a cost function; and adjusting, by at least one position adjustment assembly, a position of each respective stabilizer or reamer in response to the control signals. ### Claim 14 (depends on 13) The method of claim 13, further comprising obtaining, by a processing unit, predicted BHA states, wherein the cost function accounts for the predicted BHA states and a position range for each stabilizer or reamer. ### Claim 15 (depends on 13) The method of claim 13, wherein said adjusting comprises operating a lock/unlock component of the position adjustment assembly. ### Claim 16 (depends on 13) The method of claim 13, wherein said adjusting comprises operating an actuator component of the position adjustment assembly. ### Claim 17 (depends on 13) The method of claim 13, wherein the cost function includes at least four of a vibration magnitude term, a stabilizer or reamer position term, a drill bit wear term, a trajectory error term, an uncertainty term, a stabilizer or reamer wear term, a rate of penetration term, and a borehole tortuosity term. ### Claim 18 (depends on 17) The method of claim 17, further comprising adjusting at least some of the terms or term weights of the cost function over time. ### Claim 19 (depends on 13) The method according to claim 13, further comprising applying the cost function to a time-domain optimization problem to select control signals for each position adjustment assembly. ### Claim 20 (depends on 13) The method according to claim 13, further comprising applying the cost function to a frequency-domain optimization problem to select control signals for each position adjustment assembly.