Abstract: A method of acoustic telemetry in a drill string in a wellbore, comprises; transmitting an acoustic signal related to a parameter of interest from a transmitting location into the drill string; detecting signals propagated through the drill string at a receiving location, where the detected signals including noise; determining a drill string transfer matrix defining the propagation of signals through a transfer interval between the receiving location and the transmitting location; and using the detected signals and the drill string transfer matrix for obtaining an estimate of the acoustic signal.

Abstract: A drilling system provides indications of the lithology of the formation being drilled by dynamically measuring at least one parameter of interest that is affected by the lithology of the formation being drilled. Suitably positioned sensors make dynamic measurements of parameters such as downhole weight on bit, bit torque, bit revolutions, rate of penetration and bit axial acceleration. One or more processors use the sensor measurements in conjunction with predetermined lithological models to determine whether the measurements indicate a change in formation lithology. Suitable models can be on derived expressions such as rock drillability, drilling response, dynamic drilling response, normalized or dimensionless torque; and formation shear strength. The lithological indications provided by the processor can be used to adjust drilling parameters, steer the BHA, monitor BHA health, and provide depth locations for bed boundaries and formation interfaces.

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: A method of acoustic telemetry in a drill string in a wellbore, comprises; transmitting an acoustic signal related to a parameter of interest from a transmitting location into the drill string; detecting signals propagated through the drill string at a receiving location, where the detected signals including noise; determining a drill string transfer matrix defining the propagation of signals through a transfer interval between the receiving location and the transmitting location; and using the detected signals and the drill string transfer matrix for obtaining an estimate of the acoustic signal.

Abstract: A drilling system provides indications of the lithology of the formation being drilled by dynamically measuring at least one parameter of interest that is affected by the lithology of the formation being drilled. Suitably positioned sensors make dynamic measurements of parameters such as downhole weight on bit, bit torque, bit revolutions, rate of penetration and bit axial acceleration. One or more processors use the sensor measurements in conjunction with predetermined lithological models to determine whether the measurements indicate a change in formation lithology. Suitable models can be on derived expressions such as rock drillability, drilling response, dynamic drilling response, normalized or dimensionless torque; and formation shear strength. The lithological indications provided by the processor can be used to adjust drilling parameters, steer the BHA, monitor BHA health, and provide depth locations for bed boundaries and formation interfaces.

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: A method of acoustic telemetry in a drill string in a wellbore, comprises transmitting an acoustic signal related to a parameter of interest from a transmitting location into the drill string. The signals propagated through the drill string are detected at a receiving location, where the detected signals include noise. A drill string transfer matrix is determined defining the propagation of signals through a transfer interval between the receiving location and the transmitting location. The detected signals and the drill string transfer matrix are used for obtaining an estimate of the acoustic signal.