Abstract: A downhole assembly that includes tubulars rotationally coupled to one another. An interface is between adjacent tubulars that makes up at least a portion of the rotational coupling. Certain surfaces of adjacent tubulars come into contact with one another when adjacent tubulars are rotationally coupled; and which are defined as contact surfaces. Each contact surface is profiled with facets that are complementary to facets on a corresponding contact surface of an adjacent tubular. The profiling of the contact surfaces is such that when a contact surface is brought together with a corresponding contact surface; facets on the contact surface abut facets on the corresponding contact surface along planes that are oblique or parallel with an axis of the tubular. At least some of a rotational torque transmitted between adjacent tubulars occurs across the abutting facets.

Abstract: An embodiment of a coupling device includes an elongated coupler body configured to be deployed at a borehole string and connected to a downhole component of a borehole string. The coupler body has a longitudinal axis, and the coupler body has a torsional stiffness sufficient to transmit rotational motion to the connected downhole component. The coupling device also includes at least one recess formed in a wall of the coupler body, the at least one recess extending along a periphery of the coupler body in a direction generally perpendicular to the longitudinal axis. The at least one recess is configured to impart a bending stiffness that is less than or equal to a reference bending stiffness, and the torsional stiffness and the bending stiffness are selected to modify a mode shape of an undesired torsional oscillation.

Abstract: Systems and methods for damping torsional oscillations of downhole systems are described. The systems include a downhole drilling system disposed at an end of the downhole system in operative connection with a drill bit. A damping system is installed on the downhole drilling system, the damping system having at least one damper element configured to dampen at least one HFTO mode. At least one mode-shape tuning element is arranged on the drilling system. The at least one mode-shape tuning element is configured and positioned on the drilling system to modify at least one of a shape of the HFTO mode, a frequency of the HFTO mode, an excitability of the HFTO mode, and a damping efficiency of the at least one damper element.

Abstract: A downhole assembly that includes tubulars rotationally coupled to one another. An interface is between adjacent tubulars that makes up at least a portion of the rotational coupling. Certain surfaces of adjacent tubulars come into contact with one another when adjacent tubulars are rotationally coupled; and which are defined as contact surfaces. Each contact surface is profiled with facets that are complementary to facets on a corresponding contact surface of an adjacent tubular. The profiling of the contact surfaces is such that when a contact surface is brought together with a corresponding contact surface; facets on the contact surface abut facets on the corresponding contact surface along planes that are oblique or parallel with an axis of the tubular. At least some of a rotational torque transmitted between adjacent tubulars occurs across the abutting facets.

Abstract: A vibration isolating coupler including a first coupler portion, a second coupler portion including an external surface and an internal surface portion, and a vibration isolating portion extending between the first coupler portion and the second coupler portion. The vibration isolating portion including a first solid annular portion and a second solid annular portion. The vibration isolating portion including a plurality of slots extending from the first solid annular portion toward the second solid annular portion forming a plurality of vibration isolating elements. Each of the plurality of vibration isolating elements is disconnected from adjacent ones of the plurality of vibration isolating elements by a corresponding one of the plurality of slots. The plurality of vibration isolating elements enabling torsional rotation of the first coupler portion relative to the second coupler portion.

Abstract: Systems and methods for damping vibrations of downhole systems are described. The systems include a downhole component configured to be disposed downhole and a shock-damping system at least one of on or in the downhole component, the shock-damping system configured to reduce torsional oscillations of the downhole component by imparting a selected shock to the downhole component. The selected shock is selected to generate damping of the torsional oscillations of the downhole system.

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 system for drilling a borehole into the earth's subsurface includes a drill bit configured to rotate and penetrate through the earth's subsurface, and a vibration isolation device configured to isolate vibration that is caused at the drill bit, the vibration having an amplitude. The amplitude of the vibration downhole of the vibration isolation device is at least 20% higher than the amplitude of the vibration uphole of the vibration isolation device.

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: An example system for optimal storage of load data for lifetime prediction for a piece of equipment used in a well operation includes a sensor collecting load data of the piece of equipment and a processing device for executing computer readable instructions. The computer readable instructions include: determining a lifetime model for the piece of equipment; calculating a bucket size using one of the lifetime model and a distribution of load data; discretizing a load data spectrum into one or more buckets using the calculated bucket size; assigning the collected load data to the one or more buckets of the load data spectrum; storing the collected load data assigned to the one or more buckets to a memory; and determining a lifetime estimation of the piece of equipment based on the load data assigned to the one or more buckets of the load data spectrum and stored to the memory.

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 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: 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: A vibration isolating coupler including a first coupler portion, a second coupler portion including an external surface and an internal surface portion, and a vibration isolating portion extending between the first coupler portion and the second coupler portion. The vibration isolating portion including a first solid annular portion and a second solid annular portion. The vibration isolating portion including a plurality of slots extending from the first solid annular portion toward the second solid annular portion forming a plurality of vibration isolating elements. Each of the plurality of vibration isolating elements is disconnected from adjacent ones of the plurality of vibration isolating elements by a corresponding one of the plurality of slots. The plurality of vibration isolating elements enabling torsional rotation of the first coupler portion relative to the second coupler portion.

Abstract: Systems and methods for damping torsional oscillations of downhole systems are described. The systems include a downhole drilling system disposed at an end of the downhole system in operative connection with a drill bit. A damping system is installed on the downhole drilling system, the damping system having at least one damper element configured to dampen at least one HFTO mode. At least one mode-shape tuning element is arranged on the drilling system. The at least one mode-shape tuning element is configured and positioned on the drilling system to modify at least one of a shape of the HFTO mode, a frequency of the HFTO mode, an excitability of the HFTO mode, and a damping efficiency of the at least one damper element.

Abstract: A downhole assembly that includes tubulars rotationally coupled to one another. An interface is between adjacent tubulars that makes up at least a portion of the rotational coupling. Certain surfaces of adjacent tubulars come into contact with one another when adjacent tubulars are rotationally coupled; and which are defined as contact surfaces. Each contact surface is profiled with facets that are complementary to facets on a corresponding contact surface of an adjacent tubular. The profiling of the contact surfaces is such that when a contact surface is brought together with a corresponding contact surface; facets on the contact surface abut facets on the corresponding contact surface along planes that are oblique or parallel with an axis of the tubular. At least some of a rotational torque transmitted between adjacent tubulars occurs across the abutting facets.

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: Unwanted oscillations of a drill string while a borehole is being drilled are limited by adjusting a drilling parameter. Measurements related to oscillations of the drill string can be extrapolated by calculation to a position of interest along the drill string using a mode identified from one or more determined modes and a stability criterion that models the drill string. The stability criterion includes a specific modal damping for each of the one or more determined modes. The position of interest may correspond to a location of a tool or component that may be damaged by the unwanted oscillations. If the tool or component can be damaged by the oscillations as calculated, then the drilling parameter is adjusted to limit those oscillations.

Abstract: An example system for optimal storage of load data for lifetime prediction for a piece of equipment used in a well operation includes a sensor collecting load data of the piece of equipment and a processing device for executing computer readable instructions. The computer readable instructions include: determining a lifetime model for the piece of equipment; calculating a bucket size using one of the lifetime model and a distribution of load data; discretizing a load data spectrum into one or more buckets using the calculated bucket size; assigning the collected load data to the one or more buckets of the load data spectrum; storing the collected load data assigned to the one or more buckets to a memory; and determining a lifetime estimation of the piece of equipment based on the load data assigned to the one or more buckets of the load data spectrum and stored to the memory.

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.