Abstract: A method for making dynamic gravity toolface measurements while rotating a downhole measurement tool in a borehole is disclosed. The method includes processing magnetic field measurements and accelerometer measurements to compute a toolface offset and further processing the toolface offset in combination with a magnetic toolface to obtain the dynamic gravity toolface. Methods for correcting dynamic and static navigational sensor measurements to remove sensor biases, for example, are also disclosed.

Abstract: A method for placement of electrodes includes determining spatial distribution of a signal caused by generating an electromagnetic field in an instrument disposed in drill string used to drill a wellbore. The electromagnetic field comprises encoded measurements from at least one sensor associated with the instrument. Voltages induced by noise are measured across at least one pair of spaced apart electrodes placed at a plurality of positions spaced apart from a surface location of the wellbore. A spatial distribution of noise is estimated using the measured voltages. Positions for placement of at least two electrodes are selected using the spatial distribution of signal and the spatial distribution of noise.

Abstract: A method for placement of electrodes includes determining spatial distribution of a signal caused by generating an electromagnetic field in an instrument disposed in drill string used to drill a wellbore. The electromagnetic field comprises encoded measurements from tromagnetic at least one sensor associated with the instrument. Voltages induced by noise are measured across at least one pair of spaced apart electrodes placed at a plurality of positions spaced apart from a surface location of the wellbore. A spatial distribution of noise is estimated using the measured voltages. Positions for placement of at least two electrodes are selected using the spatial distribution of signal and the spatial distribution of noise.

Abstract: A method for making dynamic gravity toolface measurements while rotating a downhole measurement tool in a borehole is disclosed. The method includes processing magnetic field measurements and accelerometer measurements to compute a toolface offset and further processing the toolface offset in combination with a magnetic toolface to obtain the dynamic gravity toolface. Methods for correcting dynamic and static navigational sensor measurements to remove sensor biases, for example, are also disclosed.

Abstract: A method for making dynamic gravity toolface measurements while rotating a downhole measurement tool in a borehole is disclosed. The method includes processing magnetic field measurements and accelerometer measurements to compute a toolface offset and further processing the toolface offset in combination with a magnetic toolface to obtain the dynamic gravity toolface. Methods for correcting dynamic and static navigational sensor measurements to remove sensor biases, for example, are also disclosed.

Abstract: A method for magnetic ranging includes switching an electromagnet deployed in a target wellbore between at least first and second states and acquiring a plurality of magnetic field measurements at a magnetic field sensor deployed on a drill string in a drilling wellbore while the electromagnet is switching. The magnetic field measurements may be sorted into at least first and second sets corresponding to the first and second states of the electromagnet. The first and second sets of magnetic field measurements are then processed to compute at least one of a distance and a direction from the drilling well to the target. The electromagnet may be automatically switched back and forth between the first and second states independently from the acquiring and sorting of the magnetic field measurements.

Abstract: Methods for determining a distance from a drilling well to a magnetized target well include acquiring magnetic field measurements from the drilling well. The acquired magnetic field measurements are made at a plurality of spaced apart locations in the drilling well. The acquired magnetic field measurements are processed to obtain a ratio including at least one of the following: (i) a ratio of a magnetic field intensity to a first spatial derivative of a magnetic field, (ii) a ratio of a magnetic field intensity to a second spatial derivative of a magnetic field, and (iii) a ratio of a first spatial derivative of a magnetic field to a second spatial derivative of the magnetic field. The ratio (or ratios) is then processed to obtain the distance from the drilling well to the magnetized target well.

Abstract: A method for making dynamic borehole azimuth measurements while drilling includes processing cross-axial magnetic field measurements in combination with accelerometer measurements to compute the dynamic borehole azimuth. In one or more embodiments, the cross-axial magnetic field measurements and the accelerometer measurements may be used to compute the magnitude of a cross-axial magnetic field component, a toolface offset, and a borehole inclination, which may in turn be used to compute the dynamic borehole azimuth. The disclosed methods may utilize near-bit sensor measurements obtained while drilling, thereby enabling a near-bit dynamic borehole azimuth to be computed while drilling.

Abstract: A method for reducing noise in downhole fluid communications includes processing first and second received signals in combination with a strobe signal from an active pump to obtain pump signatures at first and second spaced measurement locations. The pump signatures are used to compute a transfer function of the fluid channel between the two measurement locations. The transfer function may then be used to estimate the telemetry signal traveling in the uphole direction.

Abstract: The disclosure provides a method which includes transmitting signals over a time period between a downhole location and a surface location during drilling of a wellbore; recording the time of each signal at the surface using a surface clock and the time of each signal downhole using a downhole clock; and correcting the downhole measurements using the recorded times.

Abstract: An orientation measurement system is deployed in a wellbore drilling system having one or more reservoir imaging and characterization tools, directional tools, and/or other known BHA tools in a rotating section. The orientation measurement system includes a processor receiving signals from a rotary position sensor measuring an angular position of the rotating section relative to the non-rotating section and receiving signals from an orientation sensor determining the orientation of the non-rotating section relative to a reference frame such as highside. The processor uses the first and second signals to determine a tool face of the rotating member relative to the highside and periodically and/or continuously transmits the determined tool face along the BHA via a suitable communication link. The determined tool face is used by the BHA tools to synchronize measurements with highside and/or to determine azimuth.

Abstract: A method for reducing noise in downhole fluid communications includes processing first and second received signals in combination with a strobe signal from an active pump to obtain pump signatures at first and second spaced measurement locations. The pump signatures are used to compute a transfer function of the fluid channel between the two measurement locations. The transfer function may then be used to estimate the telemetry signal traveling in the uphole direction.

Abstract: A method for making dynamic borehole azimuth measurements while drilling includes processing cross-axial magnetic field measurements in combination with accelerometer measurements to compute the dynamic borehole azimuth. In one or more embodiments, the cross-axial magnetic field measurements and the accelerometer measurements may be used to compute the magnitude of a cross-axial magnetic field component, a toolface offset, and a borehole inclination, which may in turn be used to compute the dynamic borehole azimuth. The disclosed methods may utilize near-bit sensor measurements obtained while drilling, thereby enabling a near-bit dynamic borehole azimuth to be computed while drilling.

Abstract: A method for making dynamic gravity toolface measurements while rotating a downhole measurement tool in a borehole is disclosed. The method includes processing magnetic field measurements and accelerometer measurements to compute a toolface offset and further processing the toolface offset in combination with a magnetic toolface to obtain the dynamic gravity toolface. Methods for correcting dynamic and static navigational sensor measurements to remove sensor biases, for example, are also disclosed.

Abstract: A method for drilling a well, the method including: identifying another well proximate to the well being drilled; collecting spatial information for at least a portion of the another well and the well being drilled; estimating a trajectory for at least a portion of the well being drilled and the another well; estimating an uncertainty in spatial information for each trajectory; estimating a probability of a collision with the another well during the drilling of the well by integrating a probability density function using the uncertainties and the trajectories; and performing the drilling in a manner that limits the probability of collision. A system and another method are provided.

Abstract: A multi-station gravity and magnetic survey is carried out in a borehole. The data from the survey are processed to estimate the inclination and azimuth of the borehole. The drill collar relative permeability is estimated, and the estimated drill collar permeability is then used to remove the effects of induced magnetization of the drill collar on the magnetic measurements.

Abstract: A multi-station gravity and magnetic survey is carried out in a borehole. The data from the survey are processed to estimate the inclination and azimuth of the borehole. The drill collar relative permeability is estimated, and the estimated drill collar permeability is then used to remove the effects of induced magnetization of the drill collar on the magnetic measurements.

Abstract: A method for drilling a well, the method including: identifying another well proximate to the well being drilled; collecting spatial information for at least a portion of the another well and the well being drilled; estimating a trajectory for at least a portion of the well being drilled and the another well; estimating an uncertainty in spatial information for each trajectory; estimating a probability of a collision with the another well during the drilling of the well by integrating a probability density function using the uncertainties and the trajectories; and performing the drilling in a manner that limits the probability of collision. A system and another method are provided.

Abstract: A system for drilling a well comprises a tubular member having a bottomhole assembly at a bottom end thereof disposed in a wellbore. A first sensor is disposed in the bottomhole assembly at a predetermined axial location for detecting bending in a first axis and generating a first bending signal in response thereto, where the first axis is substantially orthogonal to a longitudinal axis of the bottomhole assembly. A second sensor is disposed in the bottomhole assembly at the predetermined axial location for detecting bending in a second axis and generating a second bending signal in response thereto, where the second axis is substantially orthogonal to the longitudinal axis. A processor receives the first bending signal and the second bending signal and relates the first bending signal and the second bending signal to a borehole curvature according to programmed instructions.

Abstract: An orientation measurement system is deployed in a wellbore drilling system having one or more reservoir imaging and characterization tools, directional tools, and/or other known BHA tools in a rotating section. The orientation measurement system includes a processor receiving signals from a rotary position sensor measuring an angular position of the rotating section relative to the non-rotating section and receiving signals from an orientation sensor determining the orientation of the non-rotating section relative to a reference frame such as highside. The processor uses the first and second signals to determine a tool face of the rotating member relative to the highside and periodically and/or continuously transmits the determined tool face along the BHA via a suitable communication link. The determined tool face is used by the BHA tools to synchronize measurements with highside and/or to determine azimuth.