Abstract: Systems, methods and apparatuses to aid with directional drilling through a subterranean formation are described. A model is provided that is indicative of: (i) one or more frictional forces at one or more contact points of the BHA and a wall of a non-linear borehole through a subterranean formation, (ii) one or more internal torques of the BHA between the one or more contact points, and (iii) one or more internal torques of the drill string between the one or more contact points. Based on the model, a toolface severity is determined for the drilling system, the toolface severity corresponding to a change in angular deflection for a change in applied weight-on-bit (WOB) of the BHA. A design is selected for the drilling system based on a comparison of the toolface severity to another toolface severity for a different design. Drilling may be performed by a drilling system having a bottom-hole assembly (BHA) optimized to reduce fluctuations in toolface orientation along a non-linear borehole.

Abstract: A method for predicting an amount of axial motion of a drill bit having one or more cutters for drilling formation rock includes: receiving lithology data for the formation rock; receiving drilling parameters; calculating confined compressive strength (CCS) of the rock using the received information; calculating an area of cut into the formation rock by each of the one or more cutters; calculating an effective back rake of each of the one or more cutters; calculating a force applied to each of the one or more cutters using the CCS, the area of cut and the effective back rake of the one or more cutters, and by accounting for an orientation of each cutter with respect to a surface of the rock to be cut; and summing the calculated forces applied to each of the one or more cutters to calculate the weight on bit and torque on bit.

Abstract: A drill bit for use in a wellbore is disclosed, including a bit body having a longitudinal axis; and at least one moveable member associated with a lateral extent of the bit body, wherein the at least one moveable member is configured to translate in a member axis that is substantially longitudinal. Further, a method of drilling a wellbore is disclosed, including providing a drill bit including a bit body having a longitudinal axis and at least one movable member associated with a lateral extent of the bit body; conveying a drill string into a formation, the drill string having the drill bit at the end thereof; drilling the wellbore using the drill string; and selectively translating at least one movable member in a member axis that is substantially longitudinal.

Abstract: A cutting element for an earth-boring tool includes a substrate and a volume of superabrasive material disposed on a substrate. The volume of superabrasive material has an exposed outer surface with a non-planar geometry. The cutting element is configured to be located and oriented on an earth-boring tool so as to remove subterranean earth formation material by compressing and fracturing or plastically deforming the formation material with at least a portion of the exposed outer surface of the volume of superabrasive material during use of the earth-boring tool in an earth-boring operation. The exposed outer surface of the volume of superabrasive material includes a first area having a first average surface finish roughness and a second area having a second average surface finish roughness greater than the first average surface finish roughness. Earth-boring tools carrying such cutting elements and methods of forming such earth-boring tools are also disclosed.

Abstract: Earth-boring tools include a cutting element positioned on a drill bit body at a radial distance from a longitudinal axis thereof. At least two formation-engaging elements are positioned at the same radial distance from the longitudinal axis as the cutting element. The formation-engaging elements are recessed from a cutting profile of the cutting element by a distance within about 10% of d, wherein d=(?*x)/(1800*y), where ? is an angle between the formation-engaging element and the cutting element, x is a rate of penetration of the drill bit body, and y is a rotation speed of the drill bit body. Additional earth-boring tools include at least one cutting element and at least two formation-engaging elements recessed from a cutting profile of the at least one cutting element at a common angle. Methods relate to forming such earth-boring tools.

Abstract: Methods of forming a volume of hard material on a component of a downhole tool include depositing a film of amorphous carbon on a substrate, irradiating the film of amorphous carbon to form a liquid carbon in an undercooled state, and quenching the liquid carbon to form a layer of quenched carbon on the substrate. A downhole tool comprises a component and a volume of hard material comprising quenched carbon disposed on a surface of the component. Additional downhole tools comprise a component and a polycrystalline compact comprising quenched carbon grains disposed on a surface of the component.

Abstract: An earth-boring tool may include a body and at least one rotatable cutting structure assembly. The rotatable cutting structure assembly may include a leg, a rotatable cutting structure rotatably coupled to the leg, and a resistance actuator configured to impose rotational resistance on the rotatable cutting structure relative to the leg. An earth-boring to may include a plurality of rotatable cutting structure assemblies coupled to the bit body and a plurality of blades coupled to the body. A method of drilling a borehole may include rotating an earth-boring tool within the borehole, causing rotational resistance to be imposed on at least one rotatable cutting structure of the earth-boring tool, causing a blade of the earth-boring tool to be pushed into a sidewall of the borehole, and side cutting the sidewall of the borehole with the blade.

Abstract: A cutting element for an earth-boring tool includes a substrate and a volume of superabrasive material disposed on a substrate. The volume of superabrasive material has an exposed outer surface with a non-planar geometry. The at least one cutting element is configured to be located and oriented on an earth-boring tool so as to remove subterranean earth formation material by compressing and fracturing or plastically deforming the formation material with at least a portion of the exposed outer surface of the volume of superabrasive material during use of the earth-boring tool in an earth-boring operation. The exposed outer surface of the volume of superabrasive material includes a first area having a first average surface finish roughness and a second area having a second average surface finish roughness greater than the first average surface finish roughness. Earth-boring tools carrying such cutting elements and methods of forming such earth-boring tools are also disclosed.

Abstract: A method of controlling drill bit trajectory in a subterranean formation includes receiving drilling parameters for operating a specific bottomhole assembly (BHA), constructing, with a computer processor, a directional drill-ahead simulator including a computer model of the BHA and the subterranean formation, calculating axial motion and lateral motion of a drill bit connected to a bottom end of the BHA using formation parameters and drilling parameters, predicting bit walk of the drill bit by accounting for and calculating contact forces and frictional forces between the BHA and a wall of a borehole in the subterranean formation using the computer model of the BHA, and determining an adjusted drill bit trajectory to account for the predicted bit walk. The method includes determining adjusted drilling parameters for operating the BHA to substantially follow the adjusted drill bit trajectory and operating the BHA according to the adjusted drilling parameters.

Abstract: A drill bit for use in a wellbore is disclosed, including a bit body having a longitudinal axis; and at least one moveable member associated with a lateral extent of the bit body, wherein the at least one moveable member is configured to translate in a member axis that is substantially longitudinal. Further, a method of drilling a wellbore is disclosed, including providing a drill bit including a bit body having a longitudinal axis and at least one movable member associated with a lateral extent of the bit body; conveying a drill string into a formation, the drill string having the drill bit at the end thereof; drilling the wellbore using the drill string; and selectively translating at least one movable member in a member axis that is substantially longitudinal.

Abstract: A method of generating a directional response of a drill bit based on one or more drilling parameters includes performing actual or simulated tests with a drill bit in a test material having a strength under different experimental drilling parameters and recording the results of the plurality of tests. A representation of an expected directional response of the drill bit is formed based on the results. Current drilling parameters are receiving current drilling parameters at a computing device and the directional response is generated based on the current drilling parameters by utilizing the representation.

Abstract: Methods of evaluating performance of simulated drilling operations may involve accepting characteristics of an earth formation. A drill path, a plurality of quality evaluation standards, and selection of a bottom hole assembly (BHA) and at least one earth-boring tool may be accepted. A drilling operation attempting to follow the drill path using the BHA and the drill bit may be simulated. Performance of the BHA and the drill bit in the drilling operation may be evaluated relative to the quality evaluation standards. At least one aspect of the simulated drilling operation may be changed, and simulation of the drilling operation, performance evaluation, and change of the aspects of the drilling operation may be iterated. Performance of each drilling operation may be compared to the other drilling operations, and an improved aspect of a drilling operation may be output relative to the comparative performance of the drilling operations.

Abstract: A method for predicting a path of a borehole that will be drilled in a rock formation by a bottomhole assembly (BHA) having a drill bit includes: constructing a model of the BHA; calculating confined compressive strength of the rock formation using an axial motion drill bit model that receives drilling parameter, drill bit design and lithology information; calculating lateral motion of the drill bit using a lateral motion drill bit model; calculating a ratio of lateral motion to axial motion using the lateral motion drill bit model; calculating an inclination angle and an azimuthal direction of the BHA using a BHA steering model that receives the ratio; and iterating the above steps by updating the BHA model to include extending the borehole an incremental distance in the direction of the inclination angle and the azimuthal direction and displacing the BHA the incremental distance in the extended borehole.

Abstract: A method for predicting a change in lateral displacement with a change in axial displacement of a drill bit drilling in a formation rock includes: constructing a virtual representation of the drill bit and the formation rock, the drill bit having a gage pad configured to remove rock by wearing or crushing the rock during moving contact and a cutter configured to cut into the rock during moving contact with the rock; adjusting lateral penetration depth until rock reactive force equals a side force applied to the drill bit to provide an adjusted lateral penetration depth; removing formation rock to where the pad and the cutters contact the rock at the adjusted lateral penetration depth and to a selected axial displacement of the drill bit; moving the drill bit in a drilling direction to the end of the currently drilled borehole; and iterating the adjusting, the removing, and the moving.

Abstract: A method for predicting an amount of axial motion of a drill bit having one or more cutters for drilling formation rock includes: receiving lithology data for the formation rock; receiving drilling parameters; calculating confined compressive strength (CCS) of the rock using the received information; calculating an area of cut into the formation rock by each of the one or more cutters; calculating an effective back rake of each of the one or more cutters; calculating a force applied to each of the one or more cutters using the CCS, the area of cut and the effective back rake of the one or more cutters, and by accounting for an orientation of each cutter with respect to a surface of the rock to be cut; and summing the calculated forces applied to each of the one or more cutters to calculate the weight on bit and torque on bit.

Abstract: Earth-boring tools include a cutting element positioned on a drill bit body at a radial distance from a longitudinal axis thereof. At least two formation-engaging elements are positioned at the same radial distance from the longitudinal axis as the cutting element. The formation-engaging elements are recessed from cutting profile of the cutting element by a distance within about 10% of d, wherein d=(?*x)/(1800*y), where ? is an angle between the formation-engaging element and the cutting element, x is a rate of penetration of the drill bit body, and y is a rotation speed of the drill bit body. Additional earth-boring tools include at least one cutting element and at least two formation-engaging elements recessed from a cutting profile of the at least one cutting element at a common angle. Methods relate to forming such earth-boring tools.

Abstract: A method of predicting behavior of a drilling assembly includes generating, by a processor, a mathematical representation of a geometry of drill bit that includes a plurality of earth contacting portions, the plurality of earth contacting portions including a plurality of cutters and one or more additional components; estimating, with a separate model for each earth contacting portion, contact with the earth formation during a drilling operation; and estimating one or more forces on the one or more earth contact portions during the drilling operation based on the estimated contact.

Abstract: Disclosed is a method for estimating downhole lateral vibrations a drill tubular disposed in a borehole penetrating the earth or a component coupled to the drill tubular. The method includes rotating the drill tubular to drill the first borehole and performing a plurality of measurements in a time window of one or more parameters of the drill tubular at or above a surface of the earth during the rotating using a sensor. The method further includes estimating the downhole lateral vibrations using a processor that receives the plurality of measurements.

Abstract: A method of designing a drill bit includes: defining a representation of a first drill bit including at least a first cutter having a first face, the first cutter being disposed on the representation of the first drill bit in a first orientation; simulating in a first simulation on a computing device off-axis rotation of the first drill bit in a simulated subterranean formation; determining that the first face included, during the first simulation, a first face orientation direction that was oriented different than a face cutting direction by an amount that exceeds a predetermined threshold; and defining the first drill bit such that the first cutter is disposed in a second orientation.

Abstract: A method of generating a directional response of a drill bit based on one or more drilling parameters includes performing actual or simulated tests with a drill bit in a test material having a strength under different experimental drilling parameters and recording the results of the plurality of tests. A representation of an expected directional response of the drill bit is formed based on the results. Current drilling parameters are receiving current drilling parameters at a computing device and the directional response is generated based on the current drilling parameters by utilizing the representation.