The disclosed embodiments include a rotating survey tool. The rotating survey tool includes a first sensor array that in operation collects a first set of survey measurements during a downhole drilling operation. Additionally, the rotating survey tool includes a second sensor array directly coupled to the first sensor array that in operation collects a second set of survey measurements while a drill bit drills during the downhole drilling operation. Further, the second set of survey measurements has a greater base accuracy than the first set of survey measurements.

A directional drilling system that includes a drill bit that drills a bore through rock. The drill bit includes an outer portion of a first material and an inner portion coupled to the outer portion. The inner portion includes a second material.

A pullback device for attaching to a rotary drill bit that has a pair of wrench flats on its base without disassembling or removing the rotary drill bit from a drill string. The pullback device includes an anchoring portion including a collar configured to engage with the wrench flats of the rotary drill bit. The pullback device includes a plurality of arms, each of the plurality of arms having a first end including an attachment location configured to attach product to the pullback device for pullback of the product by the drill string, and each of the arms including a second end opposite the first end, the second end attached to the collar.

A variable build motor downhole tool allows changing the build rate in a directional drilling operation without pulling the drill string from the hole and replacing a fixed build sub in the drill string. A pad can be extended upon command to increase the build rate and retracted upon command to decrease the build rate. The pad is mounted on an insert disposed within an outer housing and extends outwardly through the outer housing by action of one or more pistons. Electronics housed in the variable build motor tool are used to receive commands from uphole and cause the pistons to extend, forcing the pad outward to increase the build rate.

A method for constructing a wellbore includes drilling a wellbore along a trajectory using a bit; reaming the diameter of a portion of the drilled wellbore to enlarge a portion of the wellbore; and altering the trajectory of the bit by applying a lateral force to the enlarged diameter wellbore. Reaming the diameter of the portion of the drilled wellbore increases the dogleg of the wellbore.

Control valves can allow for a steering assembly of a drill string. An exemplary control valve can include a first valve element including a first orifice, the first valve element being movable by actuation by a motor, and a second valve element including an orifice, wherein flow passing through the first valve element orifice passes through the second orifice and into a flow channel to be in fluid communication with a piston bore to exert pressure against a piston movable within the piston bore, the piston being coupled to a steering pad for applying force against the wellbore wall to steer a direction of the drill string. The first valve element is movable with respect to the second valve element to change flow through the first valve element orifice and the second valve element orifice to modify fluid pressure within the flow channel that is exerted against the piston.

A drill bit forming a borehole in the earth may be urged sideways, creating a curve in the borehole, by a cross-sectional shape of the borehole. For example, a borehole with a cross-sectional shape comprising two circular arcs of distinct radii, one larger and one smaller than a gauge of the drill bit, may push the drill bit away from the smaller circular arc and into the larger circular arc. Forming a borehole with such circular arcs may be accomplished by extending a cutting element from a side of the drill bit for only a portion of a full rotation of the drill bit. The relative radii and angular ranges occupied by the circular arcs may affect a radius of curvature formed in the borehole. The radii and angular ranges occupied by these circular arcs may be adjusted by altering the timing of extension and retraction of the extendable cutting element.

Control valves can allow for a steering assembly of a drill string. An exemplary control valve can include a first valve element including a first orifice, the first valve element being movable by actuation by a motor, and a second valve element including an orifice, wherein flow passing through the first valve element orifice passes through the second orifice and into a flow channel to be in fluid communication with a piston bore to exert pressure against a piston movable within the piston bore, the piston being coupled to a steering pad for applying force against the wellbore wall to steer a direction of the drill string. The first valve element is movable with respect to the second valve element to change flow through the first valve element orifice and the second valve element orifice to modify fluid pressure within the flow channel that is exerted against the piston.

The disclosed embodiments include a rotating survey tool. The rotating survey tool includes a first sensor array that in operation collects a first set of survey measurements during a downhole drilling operation. Additionally, the rotating survey tool includes a second sensor array directly coupled to the first sensor array that in operation collects a second set of survey measurements while a drill bit drills during the downhole drilling operation. Further, the second set of survey measurements has a greater base accuracy than the first set of survey measurements.

An earth-boring tool includes a body, at least one blade extending axially from the body, at least one cutting element mounted at a leading face of the at least one blade and at least one hybrid ovoid mounted at an axial end of the at least one blade and rotationally trailing the at least one cutting element. The at least one hybrid ovoid includes a cylindrical base portion, a domed upper portion extending from a top of the cylindrical base portion, and an at least substantially planar cutting surface formed in at least the domed upper portion and defining a cutting edge extending angularly through an angle of at least 180, the at least substantially planar cutting surface is configured for a shear-type cutting action, oriented substantially in the direction of intended bit rotation, and exhibits a lesser aggressiveness than the aggressiveness of the at least one cutting element.