US 11,739,634 B2
Dedicated sub for look-ahead applications
Andreas Hartmann, Celle (DE); Jens Behnsen, Hannover (DE); Kersten Kraft, Celle (DE); and David Boesing, Hannover (DE)
Assigned to BAKER HUGHES OILFIELD OPERATIONS LLC, Houston, TX (US)
Filed by Andreas Hartmann, Celle (DE); Jens Behnsen, Hannover (DE); Kersten Kraft, Celle (DE); and David Boesing, Hannover (DE)
Filed on Aug. 12, 2021, as Appl. No. 17/400,448.
Claims priority of provisional application 63/064,793, filed on Aug. 12, 2020.
Prior Publication US 2022/0049602 A1, Feb. 17, 2022
Int. Cl. E21B 49/00 (2006.01); E21B 47/13 (2012.01); E21B 47/013 (2012.01); E21B 7/04 (2006.01); E21B 47/0228 (2012.01); G01V 3/30 (2006.01)
CPC E21B 49/00 (2013.01) [E21B 7/04 (2013.01); E21B 47/013 (2020.05); E21B 47/0228 (2020.05); E21B 47/13 (2020.05); G01V 3/30 (2013.01)] 20 Claims
OG exemplary drawing
 
1. A method of drilling a wellbore through an earth formation, comprising:
disposing a first antenna at a first location of a drill string;
disposing a second antenna at a second location of the drill string, wherein the first antenna has a first specific moment smaller than a second specific moment of the second antenna;
operating one of the first antenna and the second antenna as a transmitter to transmit a transmitted signal; and
operating the other of the first antenna and the second antenna as a receiver to receive a received signal in response to the transmitted signal;
determining a property of the earth formation from the received signal.