An over-bit backreamer. The backreamer is configured to be placed over a bit without detaching the hit from a drill string associated with a pilot bore. The backreamer has an internal surface that conforms to a steering surface of the hit. Rotation is transferred from the bit to the backreamer at the internal surface. The backreamer further defines a flange which interacts with a feature, such as a heel, on the bit. The flange and heel form a shoulder which transfers pullback force to the bit. The backreamer comprises a pullback eye that pulls a product pipe back through the borehole.

A well tool for generating a notch in an open-hole wellbore, includes a tool body having a housing defining at least one slot and an interior volume. The tool body includes a cutting device disposed in the interior volume, configured to form a notch in a formation. The cutting device includes a shaft disposed in the interior volume of the housing having a first portion with a first exterior threads that extend around the first portion in a first direction, and a second portion having second exterior threads that extend around the second portion in a second direction opposite the first direction. The cutting device includes multiple blades configured to extend radially outward toward the formation through the slot or inward away from the formation and having a first blade extending from the first portion of the shaft and a second blade extending from a second portion of the shaft.

The present invention relates to a collapsible drill bit for use in formation drilling and a method of formation drilling. The drill bit includes a main body having a first cutting diameter and includes a front end with a cutting face supporting one or more cutting elements and a rear end configured to operatively connect to a drill string. The drill bit also includes a retractable portion between the front end and the rear end, the retractable portion including at least one cutting face supporting one or more cutting elements, the retractable portion configured to move between an expanded position in which the retractable portion has a second cutting diameter and a collapsed position in which the retractable portion has a diameter less than or equal to the first cutting diameter. Wherein the retractable portion is caused to move into the collapsed position upon an application of a sufficient force.

A drilling device for drilling a hole in the ground and/or rock and having in its drilling head a plurality of drilling wing bits arranged at equal distribution with their mutual position being adjustable such that the wing bits are located within a minimum diameter dimension and, on the other hand, adjustable such that they are located to drill a hole with a maximum size diameter and that the drilling device is arranged to pull, during drilling, a protective pipe into the hole at least when drilling the hole in the ground. An outer circumference of the wing bits includes a circumferential groove arranged to receive a ring belonging to a front part of the protective pipe, to an inner surface thereof, when the wing bits are adjusted to a diameter size substantially larger than the minimum diameter dimension in order to pull the protective pipe via the wing bits.

A well tool for generating a notch in an open-hole wellbore, includes a tool body having a housing defining at least one slot and an interior volume. The tool body includes a cutting device disposed in the interior volume, configured to form a notch in a formation. The cutting device includes a shaft disposed in the interior volume of the housing having a first portion with a first exterior threads that extend around the first portion in a first direction, and a second portion having second exterior threads that extend around the second portion in a second direction opposite the first direction. The cutting device includes multiple blades configured to extend radially outward toward the formation through the slot or inward away from the formation and having a first blade extending from the first portion of the shaft and a second blade extending from a second portion of the shaft.

The invention relates to a drilling tool for producing a bore in the ground, comprising a rotatably drivable basic body, a removal means at a lower end of the basic body for removing soil material, and at least one adjustable removal element, which is adjustable between a radially inner retraction position and a radially outer extension position in which the removal element protrudes radially outwards relative to the basic body in order to widen a bore diameter. According to the invention it is provided that for adjusting the removal element, an adjustment mechanism with a rotary member is provided, which is rotatable on the basic body about the drilling axis between a first rotary position and second rotary position, that at least one removal element is arranged on a pivot arm which is pivotable relative to the basic body between a first pivot position, in which the at least one removal element is in its retraction position, and a second pivot position, in which the at least one removal element is in its extension position, and that an actuating cam is provided on the rotary member and/or on the at least one pivot arm, by means of which actuating cam a rotary movement of the rotary member can be converted into a pivot movement of the at least one pivot arm.

An over-bit backreamer. The backreamer is configured to be placed over a bit without detaching the hit from a drill string associated with a pilot bore. The backreamer has an internal surface that conforms to a steering surface of the hit. Rotation is transferred from the bit to the backreamer at the internal surface. The backreamer further defines a flange which interacts with a feature, such as a heel, on the bit. The flange and heel form a shoulder which transfers pullback force to the bit. The backreamer comprises a pullback eye that pulls a product pipe back through the borehole.

An underreamer for connection with a rotary pipe string includes inner and outer body sections which form a body structure to provide a fluid flow path therethrough for communicating with piston and cylinder means formed between the body sections for receiving drilling fluid to effect telescopic movement between the body sections permitting engagement of cutter arms and support of said cutter arms on the outer body of the underreamer utilizing a slideable, non-pivoting stop block. Cutter arms are pivotally mounted on the inner body section and, upon engagement of the cutter arms to effect underreaming are fully supported on the outer body section thereby minimizing damage from vibration and repeated use on the threaded inner body sections.

The invention relates to a drilling tool for producing a bore in the ground, comprising a rotatably drivable basic body, a removal means at a lower end of the basic body for removing soil material, and at least one adjustable removal element, which is adjustable between a radially inner retraction position and a radially outer extension position in which the removal element protrudes radially outwards relative to the basic body in order to widen a bore diameter. According to the invention it is provided that for adjusting the removal element, an adjustment mechanism with a rotary member is provided, which is rotatable on the basic body about the drilling axis between a first rotary position and second rotary position, that at least one removal element is arranged on a pivot arm which is pivotable relative to the basic body between a first pivot position, in which the at least one removal element is in its retraction position, and a second pivot position, in which the at least one removal element is in its extension position, and that an actuating cam is provided on the rotary member and/or on the at least one pivot arm, by means of which actuating cam a rotary movement of the rotary member can be converted into a pivot movement of the at least one pivot arm.

A well tool for generating a notch in an open-hole wellbore, includes a tool body having a housing defining at least one slot and an interior volume. The tool body includes a cutting device disposed in the interior volume, configured to form a notch in a formation. The cutting device includes a shaft disposed in the interior volume of the housing having a first portion with a first exterior threads that extend around the first portion in a first direction, and a second portion having second exterior threads that extend around the second portion in a second direction opposite the first direction. The cutting device includes multiple blades configured to extend radially outward toward the formation through the slot or inward away from the formation and having a first blade extending from the first portion of the shaft and a second blade extending from a second portion of the shaft.