During extension, the reamer block of an expandable reamer pushes on an upper plate. Extension is limited by contact with a spring retainer. To adjust the maximum extension of the expandable reamer, a spacer is placed between the expandable block and the spring retainer. The spacer reduces the amount of longitudinal travel of the expandable reamer, thereby reducing the extension of the expandable reamer.

The disclosure provides a drill bit including a bit body and a blade extending from the bit body. The blade includes a first element protruding from a surface of the blade and a second element protruding from the surface of the blade. The first element and the second element are each configured to extend or retract relative to the surface of the blade and are coupled to each other such that when the second element retracts relative to the surface of the blade, the first element extends relative to the surface of the blade. The first element is disposed within a first pocket formed in the surface of the blade, and the second element is disposed within a second pocket formed in the surface of the blade. A communication channel is formed between the first pocket and the second pocket.

A downhole drilling apparatus, passing through a subterranean borehole, may mark an inner wall of the borehole with a marking element. A sensor, spaced axially from the marking element on the drilling apparatus, may subsequently sense the marking as it passes. A rate of penetration of the drilling apparatus may be calculated by dividing an axial distance, between the marking element and the sensor, by a time interval, between when the marking element marks the inner wall and when the marking is sensed by the sensor. Alternately, a second sensor, spaced axially from the first, may also sense the marking. A rate of penetration may then be calculated by dividing an axial distance, between the two sensors, by a time interval, between when the two sensors sense the marking.

A reamer includes a housing, a first reamer block, and a second reamer block. The first reamer block includes a leading wall. A second reamer block includes a trailing wall, the trailing wall including a recess. The leading wall is inserted into or nested in the recess to increase the coverage-to-exposure ratio.

Automated systems and methods for drilling while driving foundation components are provided. In some cases, based on detected conditions, it may be desirable for an automated controller to change the bore diameter of a drill bit during a drilling and driving operation. The need for this may be determined based on monitoring the output of one or more sensors related to one or more corresponding performance metrics of the drilling and driving operation.

A reamer drill bit includes a body having an outer surface defining a plurality of grooves, and a cutter arm with an interior surface. Each groove extends from a first end of the body to a second end of the body and has at least one groove recess, at least one groove peak connected by a sloped section, and a track arranged in the sloped section. The cutter arm is slidably attached to the body, is configured to expand radially away from the body, and is configured to slide longitudinally relative to the body along the track. The interior surface of the cutter arm includes at least one arm valley, and at least one arm protrusion. The at least one groove recess receives the at least one arm protrusion and the at least one arm valley receives the at least one groove peak.

A tool for building a wellbore includes a tool body with a flow passage extending axially therethrough, a piston chamber formed radially through the tool body that intersects the flow passage of the tool body, a piston disposed in the piston chamber, at least one actuation element that exerts a force between the piston and the piston chamber, and a sleeve disposed within the flow passage of the tool body that includes at least one cutout. When the sleeve is in a first position within the tool body, the cutout is axially offset from the piston, and when the sleeve is in a second position, the cutout is axially aligned with the piston.

A drill bit for drilling a bore, the drill bit comprising: an outer housing; a primary cutting structure defining a cutting plane of a first diameter; a flow path arranged to let drilling fluid flow through the drill bit; and a deployable blade assembly at least partially located within the outer housing, the deployable blade assembly comprising a cutting structure and being arranged to be axially movable from a first position, in which the deployable cutting structure is recessed with respect to the primary cutting structure, towards the cutting plane, to a second position; wherein when the deployable blade assembly is in the second position, the deployable cutting structure defines a cutting diameter which is less than or equal to the first diameter.

A single trip casing cutting and pulling assembly which includes a casing spear (12), a mud motor (16) and a casing cutter (18), wherein a valve (14) is located between the casing spear (12) and the mud motor (16). The casing spear is operated by fluid flow from surface and the valve (14) prevents operation of the casing cutter (18) until the casing spear (12) is set and casing cutting is required. A method is described for cutting and pulling casing which does not require any rotation of the drill string to operate any part of the casing cutting and pulling assembly. An embodiment is described which includes retrieving the seal assembly (48) on the same trip. Further embodiments describe performing an integrity test and a circulation test on the same trip with the option of making further cuts at shallower depths on the same trip until a section of cut casing can be recovered.

A retrievable whipstock assembly for a wellbore includes a whipstock including a longitudinal body and an anchor connection, a deflection surface provided on the longitudinal body with a first engagement element, and a drilling assembly including a drill housing and a second engagement element. The second engagement element is selectively extendible between a recessed position and an extended position. In the extended position the second engagement element is engageable with the first engagement element.