US 12,392,237 B2
System and method for using a magnetometer in a gyro-while-drilling survey tool
Adrián Guillermo Ledroz, Houston, TX (US)
Assigned to Gyrodata, Incorporated, Sugar Land, TX (US)
Filed by Gyrodata, Incorporated, Sugar Land, TX (US)
Filed on Jun. 14, 2024, as Appl. No. 18/743,369.
Application 18/743,369 is a continuation of application No. 17/547,097, filed on Dec. 9, 2021, granted, now 12,012,847.
Claims priority of provisional application 63/124,005, filed on Dec. 10, 2020.
Prior Publication US 2024/0328304 A1, Oct. 3, 2024
Int. Cl. E21B 47/092 (2012.01); E21B 47/022 (2012.01); E21B 47/024 (2006.01); G01V 3/18 (2006.01); G01V 3/40 (2006.01)
CPC E21B 47/092 (2020.05) [E21B 47/022 (2013.01); E21B 47/024 (2013.01); G01V 3/18 (2013.01); G01V 3/40 (2013.01)] 17 Claims
OG exemplary drawing
 
1. A method, comprising:
acquiring gyroscopic data using one or more gyroscopic sensors of a gyro-while-drilling (GWD) survey tool while the GWD survey tool is disposed at a first position within a wellbore, the GWD survey tool being part of a drill string disposed within the wellbore;
acquiring first magnetic data using a magnetometer of the GWD survey tool while the GWD survey tool is disposed at the first position;
receiving a total magnetic field value and a magnetic dip angle value for the GWD survey tool;
determining an offset value for the magnetometer based on the gyroscopic data, the total magnetic field value, the magnetic dip angle value, a first inclination value, and the first magnetic data, the offset value being expressed by:

OG Complex Work Unit Math
where:
Bzoffset is a z-axis component of the offset value,
Bz1 is the first magnetic data with respect to a z-axis of the GWD survey tool disposed at the first position,
Bt is the total magnetic field value,
θ is the magnetic dip angle value for the GWD survey tool at its geographical location,
Am1 is a first magnetic azimuth value of the GWD survey tool disposed at the first position, and
I1 is the first inclination value;
acquiring second magnetic data using the magnetometer while the drill string performs a drilling operation within the wellbore, the GWD survey tool traversing to one or more second positions within the wellbore during the drilling operation;
determining one or more second magnetic azimuth values for the GWD survey tool during the drilling operation using the second magnetic data, the offset value, the total magnetic field value, and one or more second inclination values; and
performing one or more survey operations with respect to the wellbore during the drilling operation based on the one or more second magnetic azimuth values.