Abstract: Various implementations directed to a system and method for using a magnetometer in a gyro-while-drilling (GWD) survey tool are provided. In one implementation, a method may include acquiring gyroscopic data using gyroscopic sensors of a GWD survey tool while the tool is disposed at a first position within a wellbore. The method may also include acquiring first magnetic data using a magnetometer of the GWD survey tool while the tool is disposed at the first position. The method may further include determining an offset value for the magnetometer based on the gyroscopic data and the first magnetic data. The method may additionally include acquiring second magnetic data using the magnetometer while the tool is disposed at second positions within the wellbore. The method may also include determining magnetic azimuth values for the tool disposed at the second positions based on the second magnetic data and the offset value.

Abstract: Various implementations described herein refer to an apparatus having an instrument cluster with accelerometers and gyroscopic sensors. The apparatus may include a controller that communicates with the instrument cluster, receives measurement data from the accelerometers and the gyroscopic sensors, and acquires a computed tool orientation of a drilling tool based on the measurement data from the accelerometers and the gyroscopic sensors. The controller may generate tool steering commands for the drilling tool based on a difference between a planned tool orientation and the computed tool orientation.

Abstract: Various implementations described herein are directed to a method for surveying a wellbore. A statistical estimation process that combines magnetic survey measurement data and gyroscopic survey measurement data to form error estimates in a magnetic survey system is applied. The error estimates are used to correct magnetic survey data provided by the magnetic survey system. Magnetic only survey data is used when convergence of the error estimates has occurred. Information that facilitates drilling the wellbore is provided.

Abstract: Various implementations described herein are directed to a method for surveying a wellbore. A statistical estimation process that combines magnetic survey measurement data and gyroscopic survey measurement data to form error estimates in a magnetic survey system is applied. The error estimates are used to correct magnetic survey data provided by the magnetic survey system. Magnetic only survey data is used when convergence of the error estimates has occurred. Information that facilitates drilling the wellbore is provided.

Abstract: Various implementations described herein refer to a method. The method may include receiving first gyro-while-drilling (GWD) survey data acquired using a first survey tool disposed within a wellbore. The method may include receiving second GWD survey data acquired using a second survey tool disposed within the wellbore. The method may include generating a survey of the wellbore based on the first GWD survey data and the second GWD survey data for directional control of wellbore trajectories.

Abstract: A system and method for providing information regarding the tortuosity of a wellbore path is provided. The method includes receiving data from a plurality of survey stations of a wellbore survey. The method further includes defining a plurality of reference lines for the wellbore path. The method further includes determining a plurality of displacements of the wellbore path from the plurality of reference lines.

Abstract: Systems and methods are provided for producing a continuous survey of a previously drilled portion of a wellbore. The method includes receiving a plurality of stationary survey measurements taken at a corresponding plurality of locations along the portion of the wellbore. The method further includes receiving at least one continuous survey including a plurality of continuous survey measurements taken between a pair of stationary survey measurements of the plurality of stationary survey measurements. The method further includes combining the plurality of stationary survey measurements and the plurality of continuous survey measurements to produce the continuous survey of the portion of the wellbore.

Abstract: Various implementations directed to a method and apparatus for initialization of a wellbore survey tool are provided. In one implementation, a method may include positioning a survey tool at a predetermined orientation relative to a directional reference system, where the survey tool is configured to acquire continuous survey data while disposed within a wellbore, and where the survey tool comprises a drop survey tool, a wireline survey tool, or a slickline survey tool. The method may also include using the directional reference system to generate a first signal indicative of an orientation of the directional reference system with respect to a reference direction. The method may further include using the first signal to determine an initial orientation of the survey tool with respect to the reference direction. The method may additionally include moving the survey tool after the initial orientation of the survey tool has been determined.

Abstract: Systems and methods are provided for producing a continuous survey of a previously drilled portion of a wellbore. The method includes receiving a plurality of stationary survey measurements taken at a corresponding plurality of locations along the portion of the wellbore. The method further includes receiving at least one continuous survey including a plurality of continuous survey measurements taken between a pair of stationary survey measurements of the plurality of stationary survey measurements. The method further includes combining the plurality of stationary survey measurements and the plurality of continuous survey measurements to produce the continuous survey of the portion of the wellbore.

Abstract: A system and method for providing information regarding the tortuosity of a wellbore path is provided. The method includes receiving data from a plurality of survey stations of a wellbore survey. The method further includes determining a plurality of tortuosity parameter values for the wellbore path within a corresponding plurality of analysis windows, wherein each analysis window has at least one tortuosity parameter value.

Abstract: A wellbore survey tool and methods for estimating a direction of highest gamma ray intensity of a gamma ray distribution are provided. The tool includes a body having a center axis. The body is configured to be placed within a wellbore. The tool further includes a plurality of gamma ray detectors within the body. Each detector of the plurality of gamma ray detectors has a direction of maximum gamma ray sensitivity with the direction having a non-zero component perpendicular to the center axis. The non-zero components of the plurality of gamma ray detectors are spaced circumferentially about the center axis.

Abstract: A system and method for providing information regarding the tortuosity of a wellbore path is provided. The method includes receiving data from a plurality of survey stations of a wellbore survey. The method further includes determining a plurality of tortuosity parameter values for the wellbore path within a corresponding plurality of analysis windows, wherein each analysis window has at least one tortuosity parameter value.

Abstract: A computer-based method of generating a survey of a wellbore section is provided. The method includes analyzing a plurality of surveys of the wellbore section to identify survey measurements that do not comprise gross errors, generating an initial weighted average survey, and calculating an initial set of measurement differences between the identified survey measurements and the initial weighted average survey. The method further includes calculating a plurality of error term estimates for the plurality of surveys and using the plurality of error term estimates to correct the identified survey measurements. The method further includes generating an updated weighted average survey and calculating an updated set of measurement differences between the identified survey measurements and the updated weighted average survey.

Abstract: A system and method for providing information regarding the tortuosity of a wellbore path is provided. The method includes receiving data from a plurality of survey stations of a wellbore survey. The method further includes defining a plurality of reference lines for the wellbore path. The method further includes determining a plurality of displacements of the wellbore path from the plurality of reference lines.

Abstract: Various implementations directed to correction of rotation rate measurements are provided. In one implementation, a method may include receiving rotation rate measurements about a first axis and a second axis from first gyroscopic sensors. The method may include receiving a first rotation rate measurement about a third axis from a second gyroscopic sensor. The method may include determining an estimated rotation rate measurement about the third axis based on the rotation rate measurements about the first axis and the second axis. The method may include determining a bias value based on a difference between the first rotation rate measurement about the third axis and the estimated rotation rate measurement. The method may include receiving second rotation rate measurements about the third axis from the second gyroscopic sensor. The method may include correcting the second rotation rate measurements about the third axis based on the determined bias value.

Abstract: A method and an apparatus are provided for determining an orientation of a tool with respect to a reference direction. The tool is configured to be moved along a wellbore and to generate information usable to determine an orientation of the tool. At least one first signal is indicative of an orientation of a directional reference system with respect to the reference direction. Information regarding a relative orientation of the tool with respect to the directional reference system is used to determine the orientation of the tool with respect to the reference direction in response at least in part to the at least one first signal.

Abstract: Systems and methods are provided for producing a continuous survey of a previously drilled portion of a wellbore. The method includes receiving a plurality of stationary survey measurements taken at a corresponding plurality of locations along the portion of the wellbore. The method further includes receiving at least one continuous survey including a plurality of continuous survey measurements taken between a pair of stationary survey measurements of the plurality of stationary survey measurements. The method further includes combining the plurality of stationary survey measurements and the plurality of continuous survey measurements to produce the continuous survey of the portion of the wellbore.

Abstract: A wellbore survey tool and methods for estimating a direction of highest gamma ray intensity of a gamma ray distribution are provided. The tool includes a body having a center axis. The body is configured to be placed within a wellbore. The tool further includes a plurality of gamma ray detectors within the body. Each detector of the plurality of gamma ray detectors has a direction of maximum gamma ray sensitivity with the direction having a non-zero component perpendicular to the center axis. The non-zero components of the plurality of gamma ray detectors are spaced circumferentially about the center axis.

Abstract: Various implementations directed to correction of rotation rate measurements are provided. In one implementation, a method may include receiving rotation rate measurements about a first axis and a second axis from first gyroscopic sensors. The method may include receiving a first rotation rate measurement about a third axis from a second gyroscopic sensor. The method may include determining an estimated rotation rate measurement about the third axis based on the rotation rate measurements about the first axis and the second axis. The method may include determining a bias value based on a difference between the first rotation rate measurement about the third axis and the estimated rotation rate measurement. The method may include receiving second rotation rate measurements about the third axis from the second gyroscopic sensor. The method may include correcting the second rotation rate measurements about the third axis based on the determined bias value.

Abstract: Systems and methods for the down-hole automatic mechanical coupling and alignment of a first sensor module and a second sensor module are provided. A mating element of a first sensor module includes a sheath with a first cam and a shroud surrounding the first cam. A second mating element of a second sensor module includes a second cam complementary to the first cam. Upon mating, the sheath surrounds at least a portion of the second mating element and the first cam seats against the second cam, with a predetermined axial orientation with respect to each other.