According to a first aspect of the invention there is provided a cutter head arrangement comprising a cutter head portion including a (substantially cylindrical) cutter head side wall to define a chamber (or cavity) surrounded by the cutter head side wall. A substantially circular rim portion extends from (a distal end of) the cutter head side wall, the rim portion defining a working, contact face of the cutter head portion. A recessed wall portion extends away from the rim portion inwardly into the chamber so as to be surrounded by the cutter head side wall, with the rim portion and/or the recessed wall portion being fitted with a plurality of cutter elements, to enable the cutter head portion to blind bore a pilot hole in use. The recessed wall portion that extends away from the rim portion inwardly into the chamber is a substantially conical body so as to define a conical recess (proximate a central region of the cutter head portion, at a distal end of the cutter head portion). The conical body accordingly defines an inwardly extending apex that terminate substantially in line with a central axis of the cutter head portion.

In accordance with embodiments of the present disclosure, systems and methods for utilizing hybrid mechanical-laser drilling tools, such as drill bits and hole-openers, are provided. Such drilling tools may include mechanical cutters in addition to laser cutting mechanisms designed to focus laser beams toward a subterranean formation. The mechanical cutters and laser cutting mechanisms may work in combination to advance a wellbore through the subterranean formation. The drilling tools may be controlled to vary the amount of energy output through the mechanical drilling via the cutters and through the laser-assisted drilling via the lasers.

A rotary tool for operation within an underground wellbore or within tubing in a wellbore has at least one force-sensitive element attached to the tool body and positioned to contact the conduit wall, wherein the force-sensitive element comprises an outer portion to contact the wellbore or tubing wall, at least one connecting portion which is more compliant than the outer portion and through which the outer portion is connected to the tool body, and at least one sensor responsive to force on the outer portion transmitted through the force-sensitive element to the tool body. The sensors may resolve forces into measurable forces on three axes. Possible rotary tools include drill bit, reamer, mill, stabilizer and rotary steerable system for a drill bit.

The invention discloses an anchor rod multi-section reaming machine tool and an application thereof. The machine tool is used cooperatively with an anchor rod drill rig (M), wherein a hydraulic cylinder (41) is connected with a hydraulic station (1) through a pipe, and the hydraulic cylinder (41) is fixed at a lower end of a drill rod (M1) of the anchor rod drill rig (M) and connected with the hydraulic station (1). A piston (412) is arranged inside a cylinder body (411) of the hydraulic cylinder (41) and axially moves relative to the cylinder body (411) such that the cylinder body (411) is divided into a hydraulic cylinder upper chamber (4111) and a hydraulic cylinder lower chamber (4112) which have variable volume. An upper end of a piston rod (413) is fixed at a lower portion of the piston (412) and a lower end of the piston rod (413) is fixed at an upper portion of an arch pressing device fixing disc (42); and an arch pressing device (43) comprises a pair of upper arch arms (431) and a pair of lower arch arms (432), upper ends of the upper arch arms (431) are rotatably connected with a central position of a lower portion of the arch pressing device fixing disc (42), lower ends of the upper arch arms (431) are rotatably connected with upper ends of the lower arch arms (432), and lower ends of the lower arch arms (432) are rotatably connected with a central position of an upper portion of a base plate (44). The machine tool can perform multi-site variable-section reaming at different positions and improve the anti-pull-out property of an anchor rod.

A steerable well bore drilling device and method are disclosed. The steerable well bore drilling device comprises a drill string, a bit coupled to the drill string, a drilling motor within the drill string and driving the bit, and a pair of eccentric reamers coupled to the drill string and positioned between the bit and the motor.

A steerable well bore drilling device and method are disclosed. The steerable well bore drilling device comprises a drill string, a bit coupled to the drill string, a drilling motor within the drill string and driving the bit, and a pair of eccentric reamers coupled to the drill string and positioned between the bit and the motor.

A reamer device that uses polycrystalline diamond compact (PDC) cutting elements mounted to the reamer blades. The device includes a body that defines a cutting face, a gage region and an extended end, and includes multiple blades disposed along the gage region of the body. Each of the multiple blades multiple planar surfaces, and a plurality of cutting elements positioned along the length of each of the multiple blades. The cutting elements disposed along second and third planar surfaces of each blade being slightly offset from the other blades such that in application the rotating multiple blades cause an upwardly spiraling effect.

A reamer device that uses polycrystalline diamond compact (PDC) cutting elements mounted to the reamer blades. The device includes a body that defines a cutting face, a gage region and an extended end, and includes multiple blades disposed along the gage region of the body. Each of the multiple blades multiple planar surfaces, and a plurality of cutting elements positioned along the length of each of the multiple blades. The cutting elements disposed along second and third planar surfaces of each blade being slightly offset from the other blades such that in application the rotating multiple blades cause an upwardly spiraling effect.

A downhole tool configured to enlarge a borehole may include at least one blade extending laterally from a central portion of the tool. The one or more blades may each include a gage portion, and cutting elements comprising substantially circular cutting faces may be affixed to each of the one or more blades. Each of the one or more cutting elements may include a cutting edge comprising an arcuate peripheral cutting face portion for contacting the borehole. Cutting faces of at least one cutting element on a gage portion of the at least one blade may exhibit a cutting face back rake angle greater than a cutting face back rake angle of cutting elements on at least one other portion of the at least one blade.

A downhole tool configured to enlarge a borehole may include at least one blade extending laterally from a central portion of the tool. The one or more blades may each include a gage portion, and cutting elements comprising substantially circular cutting faces may be affixed to each of the one or more blades. Each of the one or more cutting elements may include a cutting edge comprising an arcuate peripheral cutting face portion for contacting the borehole. Cutting faces of at least one cutting element on a gage portion of the at least one blade may exhibit a cutting face back rake angle greater than a cutting face back rake angle of cutting elements on at least one other portion of the at least one blade.