Abstract: A device for transferring torque to a drill bit in a borehole having a borehole axis includes a support element configured to rotate in the borehole about the borehole axis, a torque transferring element configured to transfer torque from the support element to the drill bit and further configured to isolate torsional oscillations that are created at the drill bit from the support element, a blocking element configured to block rotation of the torque transferring element relative to the support element about the borehole axis in at least one direction, and a bearing element between the support element and the drill bit.

Abstract: An embodiment of a system for estimating a parameter of an earth formation includes at least one formation parameter sensor disposed at a first downhole component and configured to measure a parameter of an earth formation to generate formation parameter data, and one or more processors in operable communication with the at least one formation parameter sensor. The one or more processors are configured to perform: generating a mechanics model of at least one of the first downhole component and a second downhole component, the mechanics model based on geometrical data representing at least one of the first downhole component and the second downhole component; estimating a misalignment of the at least one formation parameter sensor by using the mechanics model; and correcting the formation parameter data based on the misalignment.

Abstract: A method of operating a Moineau system to substantially eliminate vibrations, the method includes rotating a first rotational member, and rotating a second rotational member. Each of the first rotational member and the second rotational member includes a plurality of lobes. A first rotational speed of one of the first rotational member and the second rotational member is selected based on 1) a second rotational speed of the other of the first rotational member and the second rotational member and 2) the number of lobes of one of the first rotational member and the second rotational member to maintain eccentric force of one of the first and second rotational members below a predetermined threshold.

Abstract: Examples of techniques for optimal storage of load data for lifetime prediction for a piece of equipment used in a well operation are disclosed. In one example implementation according to aspects of the present disclosure, a method may include: using a lifetime model for the piece of equipment used in the well operation; discretizing, by a processing device, a load data spectrum into one or more buckets, the one or more buckets having a bucket size, wherein the bucket size of at least one bucket is based on one of the lifetime model and a distribution of load data; collecting load data of the piece of equipment; assigning, by the processing device, the collected load data to the one or more buckets of the load data spectrum; and storing, by the processing device, the collected load data assigned to the one or more buckets to a memory.

Abstract: A method for selecting drilling parameters for drilling a borehole penetrating the earth with a drill string. The method includes: measuring vibration-related amplitudes of the drill string during operation using one or more vibrations sensor to provide amplitude measurements; determining with a downhole processor one or more modal properties comprising one or more eigenfrequencies of the drill string using the amplitude measurements, the determination being made by including any excitation force in a white noise term of a model of the drillstring; and selecting drilling parameters that apply an excitation force at a frequency that avoids a selected range of frequencies that bound the one or more eigenfrequencies using the processor.

Abstract: A method and apparatus for predicting a formation parameter at a drill bit drilling a formation is disclosed. A vibration measurement is obtained at each of a plurality of depths in the borehole. A formation parameter is obtained proximate each of the plurality of depths in the borehole. A relationship is determined between the obtained vibration measurements and the measured formation parameters at the plurality of depths. A vibration measurement at a new drill bit location is obtained and the formation parameter at the new drill bit location is predicted from the vibration measurement and the determined relation. Formation type can be determined at the new drill bit location from the new vibration measurement and the determined relationship.

Abstract: A method of predicting behavior of a drilling assembly includes: generating a mathematical representation of a geometry of each of a plurality of components of a drilling assembly, the plurality of components including a plurality of cutters and one or more additional components configured to at least one of: support the plurality of cutters and operably connect the plurality of cutters to the drill string, the one or more additional components including a drill bit crown; simulating one or more operating conditions incident on the drilling assembly representation, and simulating an interaction between the plurality of components and an earth formation; and predicting physical responses of the drilling assembly representation to the one or more conditions.

Abstract: A method of predicting behavior of a drilling assembly includes: generating a mathematical representation of a geometry of each of a plurality of components of a drilling assembly, the plurality of components including a plurality of cutters and one or more additional components configured to at least one of: support the plurality of cutters and operably connect the plurality of cutters to the drill string, the one or more additional components including a drill bit crown; simulating one or more operating conditions incident on the drilling assembly representation, and simulating an interaction between the plurality of components and an earth formation; and predicting physical responses of the drilling assembly representation to the one or more conditions.

Abstract: A method for adjusting a drilling parameter of a drill string includes: determining one or more modes of the drill string; sensing a first oscillation amplitude at a first position in the drill string and/or an oscillation parameter of the drill string at the first position or a second position to provide measured first oscillation amplitude data and/or measured oscillation parameter data; identifying a mode of the drill string using one or more determined modes and a stability criterion and at least one of the measured first oscillation amplitude data and the measured oscillation parameter data; calculating an oscillation amplitude at a position of interest in the drill string using the identified mode and at least one of the measured first oscillation amplitude data, the measured oscillation parameter data and the stability criterion; and adjusting the drilling parameter in response to the calculated oscillation amplitude at the position of interest.

Abstract: An embodiment of a method of detecting and correcting for spiraling in a downhole carrier includes: deploying the carrier in a borehole in an earth formation as part of a subterranean operation; acquiring time based data from at least one sensor disposed at the carrier; acquiring time and depth data, the time and depth data correlating time values with depths of the carrier; generating a depth based profile based on the time based data and the time and depth data; generating a frequency profile by transforming the depth based profile into the frequency domain; detecting a spiraling event based on an amplitude of the frequency profile; and taking corrective action based on detecting the spiraling event.

Abstract: A method of drilling a borehole in an earth formation includes deploying a drilling assembly including a drill bit and a drill string, and performing a drilling operation according to one or more operational parameters to advance the drilling assembly through the formation, wherein performing the drilling operation includes rotating the drill bit and at least a portion of the drill string. The method also includes, during the advancing, monitoring a downhole condition, determining whether the downhole condition indicates at least one of a cuttings accumulation in the borehole and wear of a downhole component, and in response to the downhole condition indicating the cuttings accumulation or the wear, adjusting at least one operational parameter to induce or adjust an oscillating motion in the drill string, the oscillating motion causing at least one of a reduction in the cuttings accumulation and a reduction of wear of the downhole component.

Abstract: A method for reducing vibrations in a drill tubular coupled to a drill bit configured to drill a borehole in a formation includes: constructing a model of a system having the drill tubular, the model having a mass distribution, a stiffness, and/or a damping of the drill tubular; and calculating a plurality of modes using the model. The method also includes increasing an effective damping of the drill tubular for the plurality of modes by modifying at least one of the mass distribution, the stiffness, and the damping of the drill tubular using a predefined damping criterion, wherein the predefined damping criterion includes a ratio, the ratio having a deflection at the drill bit of at least one mode in the plurality and an eigenfrequency of the at least one mode in the plurality, wherein the deflection at the drill bit is raised to a power other than one.

Abstract: An embodiment of a method of detecting and correcting for spiraling in a downhole carrier includes: deploying the carrier in a borehole in an earth formation as part of a subterranean operation; acquiring time based data from at least one sensor disposed at the carrier; acquiring time and depth data, the time and depth data correlating time values with depths of the carrier; generating a depth based profile based on the time based data and the time and depth data; generating a frequency profile by transforming the depth based profile into the frequency domain; detecting a spiraling event based on an amplitude of the frequency profile; and taking corrective action based on detecting the spiraling event.

Abstract: A method for reducing drill tubular vibrations includes: constructing a mathematical model the drill tubular having mass distribution, material stiffness and material damping; constructing an equation of motion of the drill tubular in one of a time domain and frequency domain; transforming the equation of motion into a modal domain equation of motion to provide a mode shape of the drill tubular at an eigenfrequency, the mode shape providing an amplitude at a position along the drill tubular; comparing the amplitude at the position along the drill tubular to a threshold amplitude value; modifying at least one of the mass distribution, material stiffness and material damping if the amplitude exceeds the threshold value; and iterating the above step until at least one of the amplitude of the latest mode shape at the position is less than or equal to the threshold amplitude value and a predetermined constraint limits the modifying.

Abstract: Examples of techniques for optimal storage of load data for lifetime prediction for a piece of equipment used in a well operation are disclosed. In one example implementation according to aspects of the present disclosure, a method may include: using a lifetime model for the piece of equipment used in the well operation; discretizing, by a processing device, a load data spectrum into one or more buckets, the one or more buckets having a bucket size, wherein the bucket size of at least one bucket is based on one of the lifetime model and a distribution of load data; collecting load data of the piece of equipment; assigning, by the processing device, the collected load data to the one or more buckets of the load data spectrum; and storing, by the processing device, the collected load data assigned to the one or more buckets to a memory.

Abstract: A method of operating a Moineau system to substantially eliminate vibrations, the method includes rotating a first rotational member, and rotating a second rotational member. Each of the first rotational member and the second rotational member includes a plurality of lobes. A first rotational speed of one of the first rotational member and the second rotational member is selected based on 1) a second rotational speed of the other of the first rotational member and the second rotational member and 2) the number of lobes of one of the first rotational member and the second rotational member to maintain eccentric force of one of the first and second rotational members below a predetermined threshold.

Abstract: A method of drilling a borehole in an earth formation includes deploying a drilling assembly including a drill bit and a drill string, and performing a drilling operation according to one or more operational parameters to advance the drilling assembly through the formation, wherein performing the drilling operation includes rotating the drill bit and at least a portion of the drill string. The method also includes, during the advancing, monitoring a downhole condition, determining whether the downhole condition indicates at least one of a cuttings accumulation in the borehole and wear of a downhole component, and in response to the downhole condition indicating the cuttings accumulation or the wear, adjusting at least one operational parameter to induce or adjust an oscillating motion in the drill string, the oscillating motion causing at least one of a reduction in the cuttings accumulation and a reduction of wear of the downhole component.

Abstract: A method for selecting drilling parameters for drilling a borehole penetrating the earth with a drill string. The method includes: measuring vibration-related amplitudes of the drill string during operation using one or more vibrations sensor to provide amplitude measurements; determining with a downhole processor one or more modal properties comprising one or more eigenfrequencies of the drill string using the amplitude measurements, the determination being made by including any excitation force in a white noise term of a model of the drillstring; and selecting drilling parameters that apply an excitation force at a frequency that avoids a selected range of frequencies that bound the one or more eigenfrequencies using the processor.

Abstract: The disclosure is directed to method and apparatus for communication through a fluid. The method includes measuring signals in the fluid at at least two spaced apart positions; estimating a subset of a separation matrix; and using the estimated subset and the signals to estimate a signal sent by the message source. The apparatus may include a message source on a bottom hole assembly; sensors disposed at least two spaced apart locations; and at least one processor configured to: estimate a subset of a separation matrix based on the signals and use the subset to estimate a message signal set by the message source.

Abstract: A method for estimating a location for disposing a tool in a drill tubular having a drill bit includes performing a modal analysis of the drill tubular to determine natural eigenfrequencies and corresponding eigenmodes of torsional oscillations of the model and selecting a predominant natural eigenfrequency and corresponding eigenmode from the determined natural eigenfrequencies and corresponding eigenmodes. The method further includes performing a forced modal analysis of the drill tubular at the predominant eigenfrequency with a force or moment acting on the drill bit to provide a correlation between forced torsional deflection amplitude and position and estimating the position to be within a range of positions wherein a vibration qualification of the tool is greater or equal to the torsional deflection amplitude throughout the range.