Monitoring drilling parameters
View Patent ↗Methods and systems are provided for monitoring operational characteristics of a drilling system that includes a bottom hole assembly having a drill collar operably coupled to a drill bit. A device having an elongate beam and at least one pair of sensors is rigidly secured to a part of the bottom hole assembly to measure strain in the part of the bottom hole assembly. The measurement of strain can be used to derive a measurement of at least one operational parameter of the drilling system, such as dog leg severity of a wellbore, torque on bit, and/or weight on bit.
1 . A method for monitoring operational characteristics of a drilling system that includes a bottom hole assembly having a drill collar operably coupled to a drill bit, the method comprising:
using an elongate beam with at least one pair of sensors to measure strain in a part of the bottom hole assembly,
wherein:
the elongate beam comprises a cylindrical body extending along a longitudinal axis;
each sensor in the at least one pair of sensors curves along an exterior surface of the cylindrical body;
the sensors in the at least one pair of sensors are disposed at angular coordinates offset from one another about the longitudinal axis;
the elongate beam is rigidly secured to the part of the bottom hole assembly;
the elongate beam is supported by opposite end mounts coupled to opposite ends of the elongate beam;
the opposite end mounts each include a mounting surface that is rigidly secured to a surface of the part of the bottom hole assembly;
the opposite end mounts each include a plurality of fastener receptacles;
the opposite end mounts each protrude crosswise to the longitudinal axis away from the exterior surface of the cylindrical body of the elongate beam;
the elongate beam with the opposite end mounts is disposed within a recess in the bottom hole assembly;
the part of the bottom hole assembly comprises a drill collar;
the recess extends radially into the drill collar; and
the elongate beam with the opposite end mounts is coupled to the drill collar within the recess.
2 . The method according to claim 1 , further comprising:
deriving a measurement of at least one operational parameter of the drilling system from the measured strain.
3 . The method according to claim 2 , wherein:
the at least one pair of sensors is configured to measure bending strain in the part of the bottom hole assembly; and
the at least one operational parameter is derived from the measured bending strain, wherein the at least one operational parameter comprises dog leg severity of a wellbore being drilled by the bottom hole assembly.
4 . The method according to claim 3 , further comprising:
performing closed loop control of direction of drilling based on the dog leg severity derived from the measured bending strain.
5 . The method according to claim 3 , wherein:
the at least one pair of sensors comprises a single pair of sensors configured to measure bending strain in the part of the bottom hole assembly as the bottom hole assembly rotates.
6 . The method according to claim 3 , wherein:
the at least one pair of sensors comprises two pairs of sensors configured to measure bending strain in the part of the bottom hole assembly without requiring rotation of the bottom hole assembly, wherein each sensor in the two pairs of sensors curves along the exterior surface of the cylindrical body.
7 . The method according to claim 3 , wherein:
the at least one pair of sensors comprises two pairs of sensors configured to measure bending strain in the part of the bottom hole assembly in two orthogonal axes, wherein each sensor in the two pairs of sensors curves along the exterior surface of the cylindrical body, wherein the two pairs of sensors comprise:
a first pair of sensors disposed at first angular coordinates offset 180 degrees from one another about the longitudinal axis; and
a second pair of sensors disposed at second angular coordinates offset 180 degrees from one another about the longitudinal axis, wherein the first and second angular coordinates are offset 90 degrees from one another about the longitudinal axis.
8 . The method according to claim 3 , further comprising:
determining a measure of curvature of the bottom hole assembly from the measured bending strain using a correlation function that relates bending strain to curvature of the bottom hole assembly; and
calculating the dog leg severity based on the measure of curvature of the bottom hole assembly.
9 . The method according to claim 2 , wherein:
the at least one pair of sensors is configured to measure torsional strain in the part of the bottom hole assembly; and
the at least one operational parameter is derived from the measured torsional strain, wherein the at least one operational parameter comprises torque on bit of the drilling system.
10 . The method according to claim 2 , wherein:
the at least one pair of sensors is configured to measure axial strain in the part of the bottom hole assembly; and
the at least one operational parameter is derived from the measured axial strain, wherein the at least one operational parameter comprises weight on bit of the drilling system.
11 . A method for monitoring operational characteristics of a drilling system that includes a bottom hole assembly having a drill collar operably coupled to a drill bit, the method comprising:
using an elongate beam with at least one pair of sensors to measure strain in a part of the bottom hole assembly,
wherein:
the elongate beam comprises a cylindrical body extending along a longitudinal axis;
each sensor in the at least one pair of sensors curves along an exterior surface of the cylindrical body;
the sensors in the at least one pair of sensors are disposed at angular coordinates offset from one another about the longitudinal axis;
the elongate beam is rigidly secured to the part of the bottom hole assembly;
the elongate beam is supported by opposite end mounts coupled to opposite ends of the elongate beam;
the opposite end mounts each include a mounting surface that is rigidly secured to a surface of the part of the bottom hole assembly;
the opposite end mounts each include a plurality of fastener receptacles;
the opposite end mounts each protrude crosswise to the longitudinal axis away from the exterior surface of the cylindrical body of the elongate beam;
the elongate beam with the opposite end mounts is disposed within a recess in the bottom hole assembly:
the part of the bottom hole assembly comprises a cover of an instrumentation pocket;
the recess comprises the instrumentation pocket; and
the elongate beam with the opposite end mounts is coupled to the cover within the instrumentation pocket.
12 . The method according to claim 11 , further comprising:
deriving a measurement of at least one operational parameter of the drilling system from the measured strain.
13 . A drilling system comprising:
a bottom hole assembly having a drill collar operably coupled to a drill bit; and
an elongate beam equipped with at least one pair of sensors, wherein the at least one pair of sensors is configured to measure strain in a part of the bottom hole assembly, wherein the elongate beam comprises a cylindrical body extending along a longitudinal axis, wherein each sensor in the at least one pair of sensors curves along an exterior surface of the cylindrical body, wherein the sensors in the at least one pair of sensors are disposed at angular coordinates offset from one another about the longitudinal axis, wherein the elongate beam is rigidly secured to the part of the bottom hole assembly, wherein the elongate beam comprises a central channel extending along the longitudinal axis through the cylindrical body, wherein a thickness of the elongate beam varies along the longitudinal axis, and wherein the thickness is defined between the exterior surface and the central channel.
14 . The drilling system according to claim 13 , wherein:
the at least one pair of sensors is configured to measure bending strain, torsional strain, axial strain, or any combination thereof, in the part of the bottom hole assembly;
the elongate beam is supported by opposite end mounts coupled to opposite ends of the elongate beam;
the opposite end mounts each include a mounting surface that is rigidly secured to a surface of the part of the bottom hole assembly;
the opposite end mounts each include a plurality of fastener receptacles;
the opposite end mounts each protrude crosswise to the longitudinal axis away from the exterior surface of the cylindrical body of the elongate beam; and
the elongate beam with the opposite end mounts is disposed within a recess in the bottom hole assembly.
15 . The drilling system according to claim 13 , wherein:
the at least one pair of sensors comprises a single pair of sensors configured to measure bending strain in the part of the bottom hole assembly as the bottom hole assembly rotates.
16 . The drilling system according to claim 13 , wherein:
the at least one pair of sensors comprises two pairs of sensors configured to measure bending strain in the part of the bottom hole assembly without requiring rotation of the bottom hole assembly; and
each sensor in the two pairs of sensors curves along the exterior surface of the cylindrical body.
17 . The drilling system according to claim 13 , wherein:
the at least one pair of sensors comprises two pairs of sensors configured to measure bending strain in the part of the bottom hole assembly in two orthogonal axes; and
each sensor in the two pairs of sensors curves along the exterior surface of the cylindrical body, wherein the two pairs of sensors comprise:
a first pair of sensors disposed at first angular coordinates offset 180 degrees from one another about the longitudinal axis; and
a second pair of sensors disposed at second angular coordinates offset 180 degrees from one another about the longitudinal axis, wherein the first and second angular coordinates are offset 90 degrees from one another about the longitudinal axis.