Abstract: A drill bit includes a bit body including one or more blades extending therefrom and a plurality of cutters secured to the one or more blades. A rolling element assembly is positioned within a cavity defined on the bit body and includes a housing, a rolling element rotatable within the housing about a rotational axis, and one or more bearing elements extendable into a corresponding one or more arcuate grooves defined in the cavity to secure the housing within the cavity. The housing encircles more than 180° but less than 360° of a circumference of the rolling element while leaving a full axial width of the rolling element exposed.

Abstract: An Earth drill bit includes a bit body assembly and a plurality of separately movable cutting elements carried by the bit body assembly. The bit body assembly is arranged around a central bit body axis and includes a hydraulic circuit. The plurality of separately movable cutting elements is movable in a direction parallel to the central bit body axis and supported by fluid in the hydraulic circuit.

Abstract: A drill bit includes a bit body including one or more blades extending therefrom and a plurality of cutters secured to the one or more blades. A rolling element assembly is positioned within a cavity defined on the bit body and includes a housing, a rolling element rotatable within the housing about a rotational axis, and one or more bearing elements extendable into a corresponding one or more arcuate grooves defined in the cavity to secure the housing within the cavity. The housing encircles more than 180° but less than 360° of a circumference of the rolling element while leaving a full axial width of the rolling element exposed.

Abstract: A method includes receiving, at a computer, an Earth formation characteristic and a cutter characteristic of a cutter of an Earth drill bit and determining, with the computer, a cutting characteristic at an interface between the Earth formation and the cutter based on the Earth formation characteristic and the cutter characteristic using an Earth formation crushing model operating on the computer. The Earth formation crushing model includes an empirical determination of stress at the interface in a first of three mutually perpendicular axes and determinations of stress in the remaining two mutually perpendicular axes that are mathematical functions based on the empirical determination of stress. The method also includes outputting the determined cutting characteristic.

Abstract: A computer-implemented method of designing a downhole drilling tool may include generating a three dimensional (3D) downhole drilling tool model including a plurality of cutting elements on a plurality of blades and simulating engagement of the 3D downhole drilling tool model with a 3D model of a borehole bottom. The method may further include calculating a cutting force of a cutting element of the plurality of cutting elements, calculating a wearflat frictional force of the cutting element, and modeling a drilling efficiency of the 3D downhole drilling tool model based on the cutting force of the cutting element and the wearflat friction force of the cutting element. In addition, the method may include determining a design parameter of the 3D downhole drilling tool model based on the drilling efficiency of the 3D downhole drilling tool model.

Abstract: A method includes receiving, at a computer, an Earth formation characteristic and a cutter characteristic of a cutter of an Earth drill bit and determining, with the computer, a cutting characteristic at an interface between the Earth formation and the cutter based on the Earth formation characteristic and the cutter characteristic using an Earth formation crushing model operating on the computer. The Earth formation crushing model includes an empirical determination of stress at the interface in a first of three mutually perpendicular axes and determinations of stress in the remaining two mutually perpendicular axes that are mathematical functions based on the empirical determination of stress. The method also includes outputting the determined cutting characteristic.

Abstract: An Earth drill bit includes a bit body assembly and a plurality of separately movable cutting elements carried by the bit body assembly. The bit body assembly is arranged around a central bit body axis and includes a hydraulic circuit. The plurality of separately movable cutting elements is movable in a direction parallel to the central bit body axis and supported by fluid in the hydraulic circuit.

Abstract: A computer-implemented method of designing a downhole drilling tool may include generating a three dimensional (3D) downhole drilling tool model including a plurality of cutting elements on a plurality of blades and simulating engagement of the 3D downhole drilling tool model with a 3D model of a borehole bottom. The method may further include calculating a cutting force of a cutting element of the plurality of cutting elements, calculating a wearflat frictional force of the cutting element, and modeling a drilling efficiency of the 3D downhole drilling tool model based on the cutting force of the cutting element and the wearflat friction force of the cutting element. In addition, the method may include determining a design parameter of the 3D downhole drilling tool model based on the drilling efficiency of the 3D downhole drilling tool model.

Abstract: Contact stiffness is a key in the FEA modeling of objectives involving contact. The present invention theoretically derives a new method for estimating the contact stiffness based on the base mode of structural frequency responses. The method provides both physical insight and practical guide in contact stiffness estimation, thus avoiding the ambiguity that confronts the contact stiffness estimation in commercial FEA developments and FEA applications. The method works particularly effectively in cases when the objectives under deformation include shell or beam elements. It can alleviate the convergence difficulties and improve the convergence speeds due to overestimated contact stiffness based on the underlying element.