A downhole steering tool comprising a first member, fixedly coupled with a drill string, and a second member, proximate the first member and rotatable substantially freely with respect to the first member. A first sensor is operable to measure a difference in rotation rates of the first and second members. A second sensor is operable to measure a substantially real-time rotation rate of the second member in the wellbore. A tool controller is operable to process sensor signals from the first and second sensors to determine a rotation rate of the drill string. Surface-initiated changes in the rotation rate of the drill string are then utilized by the downhole steering tool for steering and other control.

Systems and methods for extracting minerals from an underground mineralization zone located below the surface at an oil and gas drilling site. The system includes a vertical drilling means for drilling a vertical bore extending from the surface at the oil and gas drilling site into the mineralization zone, a second horizontal drilling means for drilling at least one horizontal production bore into the mineralization zone. The first horizontal drilling means and the second horizontal drilling means are configured to return material from the mineralization zone to the surface where the mineral content of the material is analyzed and a separator separates minerals, waste and drilling mud from the material. The method includes steps of drilling a horizontal assessment bore, analyzing assessment material for a desired mineral, drilling a horizontal production bore, producing production material containing the desired mineral, and separating the desired material from waste and drilling mud.

Methods, systems, and devices for downhole evaluation using a sensor assembly that includes a sensor plate, wherein a surface of the sensor plate forms a portion of an exterior surface of a downhole tool. Methods may include submerging the surface of the sensor plate in a downhole fluid in a borehole; activating the sensor assembly to generate a guided wave that propagates along the sensor plate, wherein propagation of the guided wave along the sensor plate is dependent upon a parameter of interest of the downhole fluid; and using information from the sensor assembly relating to the propagation of the guided wave along the sensor plate to estimate the parameter of interest. Methods may include isolating an opposing surface of the sensor plate from the downhole fluid. The guided wave may be an interface guided wave or may propagate in the plate between the surface and an opposing surface.

A method of forming a wellbore includes providing a drilling assembly comprising one or more lengths of casing and an axially retracting assembly having a first tubular; a second tubular at least partially disposed in the first tubular and axially fixed thereto; and a support member disposed in the second tubular and movable from a first axial position to a second axial position relative to the second tubular, wherein, in the first axial position, the support member maintains the second tubular axially fixed to the first tubular, and in the second axial position, allows the second tubular to move relative to the first tubular; and an earth removal member disposed below the axially retracting assembly. The method also includes rotating the earth removal member to form the wellbore; moving the support member to the second axial position; and reducing a length of the axially retracting assembly.

A logging tool electronics system is disclosed with noise minimization features and pulse compression signal processing techniques to improve the signal-to-noise ratio of array induction logging tools. The borehole is radiated with a magnetic field produced by a configurable multi-frequency and/or multi-amplitude sine wave signal stimulus section driving a fully differential single transmitter coil. Received signals from multiple mutually balanced fully differential receiver arrays are processed by receiver signal chains using adaptive algorithms under firmware control. The received signals are used to determine the conductivity and resistivity of the formation surrounding the borehole.

A method of transitioning from rotary to slide drilling while maintaining a bit of a bottom hole assembly (“BHA”) on a wellbore bottom includes (a) recording a first toolface value of the BHA that is coupled to a drill string; (b) identifying a correlation between the first toolface value and a first quill position of a quill coupled to the drill string; (c) identifying a breakover torque for the drill string; (d) performing rotary drilling; (e) recording a second toolface value while the bit remains on the wellbore bottom; (f) receiving, while the bit remains on the wellbore bottom, a target toolface value; (g) calculating, while the bit remains on the wellbore bottom, an unwind amount to unwind the drill string; and (h) unwinding the drill string by the unwind amount to bring the second toolface value closer to the target toolface value while the bit remains on the bottom.

A method of transitioning from rotary to slide drilling while maintaining a bit of a bottom hole assembly (“BHA”) on a wellbore bottom includes (a) recording a first toolface value of the BHA that is coupled to a drill string; (b) identifying a correlation between the first toolface value and a first quill position of a quill coupled to the drill string; (c) identifying a breakover torque for the drill string; (d) performing rotary drilling; (e) recording a second toolface value while the bit remains on the wellbore bottom; (f) receiving, while the bit remains on the wellbore bottom, a target toolface value; (g) calculating, while the bit remains on the wellbore bottom, an unwind amount to unwind the drill string; and (h) unwinding the drill string by the unwind amount to bring the second toolface value closer to the target toolface value while the bit remains on the bottom.

Apparatus for splitting rock, the apparatus comprising: a housing; a drill assembly mounted to the housing and configured to move longitudinally relative to the housing, the drill assembly comprising a shaft having a proximal end and a distal end, a drive element for selectively rotating the shaft and a drill bit mounted to the distal end of the shaft for drilling a hole into rock; a splitter assembly mounted to the housing and configured to move longitudinally relative to the housing, the splitter assembly comprising a tether and a wedge, the tether and the wedge being configured to be moved independently relative to one another; wherein the wedge comprises a proximal end and a distal end, the proximal end of the wedge being wider than the distal end of the wedge; wherein the tether comprises a radially-reduced profile when the wedge is disposed proximal to the tether, and wherein the tether comprises a radially-expanded profile after the wedge is moved distally relative to the tether.

Apparatus for splitting rock, the apparatus comprising: a housing; a drill assembly mounted to the housing and configured to move longitudinally relative to the housing, the drill assembly comprising a shaft having a proximal end and a distal end, a drive element for selectively rotating the shaft and a drill bit mounted to the distal end of the shaft for drilling a hole into rock; a splitter assembly mounted to the housing and configured to move longitudinally relative to the housing, the splitter assembly comprising a tether and a wedge, the tether and the wedge being configured to be moved independently relative to one another; wherein the wedge comprises a proximal end and a distal end, the proximal end of the wedge being wider than the distal end of the wedge; wherein the tether comprises a radially-reduced profile when the wedge is disposed proximal to the tether, and wherein the tether comprises a radially-expanded profile after the wedge is moved distally relative to the tether.

Expandable reamers are configured to operate in a first, retracted state in which a plurality of blades is in a retracted position when a sliding sleeve is in a first sleeve position and a seat is in a first seat position, to operate in a second, extended state in which the plurality of blades is movable to an extended position when the sliding sleeve is in at least a second sleeve position and the seat is in the first seat position, and to operate in a third, retracted state in which the plurality of blades is returned to the retracted position when the sliding sleeve is in the at least a second position and the seat is in a second seat position.