US 11,852,012 B2
Advanced passive interference management in directional drilling system, apparatus and methods
Rudolf Zeller, Seattle, WA (US); Gary Garrabrant, Seattle, WA (US); Timothy Bayliss, Maple Valley, WA (US); and Scott Phillips, Kent, WA (US)
Assigned to Merlin Technology, Inc., Kent, WA (US)
Filed by Merlin Technology, Inc., Kent, WA (US)
Filed on Mar. 24, 2023, as Appl. No. 18/126,001.
Application 16/782,948 is a division of application No. 16/538,038, filed on Aug. 12, 2019, granted, now 10,598,007, issued on Mar. 24, 2020.
Application 16/538,038 is a division of application No. 15/635,884, filed on Jun. 28, 2017, granted, now 10,378,338, issued on Aug. 13, 2019.
Application 18/126,001 is a continuation of application No. 17/752,144, filed on May 24, 2022, granted, now 11,613,990.
Application 17/752,144 is a continuation of application No. 17/322,530, filed on May 17, 2021, granted, now 11,352,876, issued on Jun. 7, 2022.
Application 17/322,530 is a continuation of application No. 16/782,948, filed on Feb. 5, 2020, granted, now 11,008,856, issued on May 18, 2021.
Prior Publication US 2023/0272708 A1, Aug. 31, 2023
Int. Cl. E21B 47/13 (2012.01); E21B 47/024 (2006.01); E21B 47/0228 (2012.01); E21B 7/04 (2006.01); E21B 47/107 (2012.01)
CPC E21B 47/13 (2020.05) [E21B 7/046 (2013.01); E21B 47/024 (2013.01); E21B 47/0228 (2020.05); E21B 47/107 (2020.05)] 20 Claims
OG exemplary drawing
 
1. A system, comprising:
a transmitter that is configured to move through the ground in a region during an operational procedure while transmitting a depth signal at a depth frequency that is selectable in a rebar frequency range below a threshold frequency to provide at least some immunity to passive interference and which is also subject to electromagnetic noise that can vary within said region; and
a portable device configured to (i) measure the electromagnetic noise at a plurality of incrementally spaced apart frequencies in the rebar frequency range and (ii) compare the measured noise to a low noise threshold to identify a lowest one of the frequencies having a measured noise that satisfies the low noise threshold as a potential depth frequency.