Abstract: Electrically conductive proppants and methods for detecting, locating, and characterizing same are provided. The electrically conductive proppant can include a substantially uniform coating of an electrically conductive material having a thickness of at least 500 nm. The method can include injecting a hydraulic fluid into a wellbore extending into a subterranean formation at a rate and pressure sufficient to open a fracture therein, injecting into the fracture a fluid containing the electrically conductive proppant, electrically energizing the earth at or near the fracture, and measuring three dimensional (x, y, and z) components of electric and magnetic field responses at a surface of the earth or in an adjacent wellbore.

Abstract: A system to provide power to a downhole-type tool includes a downhole-type electric motor that can be positioned in a wellbore and a variable speed drive electrically connected to the electric motor, in which the downhole-type electric motor can operate at rotary speeds of at least 6,000 rotations per minute (rpm), the variable speed drive can control and supply power to the electric motor when the electric motor is positioned at a downhole location inside the wellbore, and the variable speed drive can be at a surface of the wellbore.

Abstract: A drill bit may include rings that are rotatable at different speeds along a single axis. The drill bit may be coupled to a motor using multiple driveshafts. Each driveshaft can be coupled to one of the rings. Each driveshaft may transmit a different amount of torque from the motor to the rings to allow each ring to rotate at a different speed. In some aspects, the driveshafts may include a center driveshaft coupled to a pilot ring of the drill bit and an outer driveshaft coupled to an outer ring of the drill bit. The drill bit may include additional rings coupled to the motor by additional driveshafts.

Abstract: In drilling into a subterranean formation, several factors influence the rate of penetration, including, but not limited to, the type of formation being drilled, the weight on bit, and the rotational speed of the drill bit. Disclosed are a system and method for controlling the rotational speed of a drill bit based on regulation of fluid flow to the motor driving the bit, while maintaining at least a minimum flow of fluid to the annulus to clear debris from downhole during drilling. Regulation of fluid flow to the motor and to the annulus may be accomplished utilizing a flow diverter configured to adjust a flow ratio depending on drilling conditions in order to maximize efficiency of the motor downhole during drilling.

Abstract: A downhole tool string comprising a motor unit (3) having a rotational shaft rotating with a rotational motor speed; a gear section; an operational tool having a tool shaft rotated by the gear section (5) at a lower rotational speed than that of the rotational shaft; and a pump unit (8) having a rotor shaft rotated by the motor unit (3) for providing fluid around or past an operational tool (6). The pump unit (8) is arranged between the gear section (5) and the operational tool (6).

Abstract: A seal backup including: a ring-like body, the body including: a first portion of the body having a first generally zig-zag construction, the first generally zig-zag construction facilitative of radial expansion of the first portion; a second portion of the body having a second generally zig-zag construction, the second generally zig-zag construction facilitative of radial expansion of the second portion; a parting feature disposed between the first portion of the body and the second portion of the body facilitative of relative movement between the first portion of the body and the second portion of the body.

Abstract: A reamer for enlarging an underground borehole comprises a plurality of cutter assemblies distributed azimuthally around a longitudinal axis of the tool. Each cutter assembly comprises a supporting structure and a plurality of hard faced cutters secured therein with a hard surface of each cutter exposed and facing in a direction of rotation of the tool and extending radially outwards from the tool axis to a radially outward extremity. These cutters are arranged in a sequence extending axially along the tool. In contrast with convention a1 cutter assemblies, the supporting structure comprises at least one radially outward-facing surface which is positioned to follow behind the leading face of at least one cutter as the tool rotates and which is aligned with the radially outer extremity of the cutter at the same radial distance from the tool axis. Thus the surface area available to contact the borehole wall and stabilize the positioning and motion of the rotating reamer is enhanced.

Abstract: Systems and methods for monitoring characteristics of a drilling mud, a rate of penetration (ROP), and other factors to determine which remedial actions to perform and how to perform them. In conventional drilling operations, there are many systems which operate independently and do not share data, leading to inefficient actions when the operation is viewed as a whole. The systems and methods of the present disclosure enable a bigger picture to be considered, including a cost of replenishing mud, the wear on drilling tools, the effect of running a centrifuge, etc.

Abstract: A downhole coupling system for joining together two segments of a tool string includes two mandrels, each having an interlocking interface at an end that abuts the adjacent mandrel and to communicate torque from one mandrel to the next. Each of the mandrels includes a threaded exterior surface, with the threaded surfaces have opposing thread directions or differing thread pitches. The coupling includes mating internal threads. A plurality of axial grooves is formed in each of the interior surface of the coupling and the exterior surface of one of the mandrels. A keyed latch ring having a plurality of internal keys and a plurality of external keys is included to engage the axial grooves, thereby rotationally locking the coupling relative to the first mandrel and second mandrel.

Abstract: A well tool can include a closure member having open and closed positions, a seat having a flow passage blocked by the closure member in the closed position, and a line extending through the seat. A communication method can include positioning a conduit in an interior of a well tool, and conducting a signal via the conduit between annular structures surrounding a longitudinal flow passage of the well tool. A well system can include a well tool connected in a tubular string, a flow passage of the tubular string extending through the well tool, the well tool including a closure member having open and closed positions, in which the closure member respectively permits and blocks flow through the flow passage, an annular cavity surrounding the flow passage, and a line, the closure member and the line being positioned in the annular cavity in the open position.

Abstract: A technique enables mechanical control of a directional valve. The technique may utilize a system comprising a directional valve which is mechanically actuatable between a plurality of flow positions. The directional valve is mechanically coupled with an indexer mechanism. The indexer mechanism may be shifted to a plurality of desired indexer positions defined by a cam track. As the indexer mechanism is shifted between indexer positions, the mechanical link between the indexer mechanism and the directional valve mechanically shifts the directional valve to selected flow positions of the plurality of flow positions.

Abstract: The present invention relates to a method of installing an unbonded flexible pipe with a bore for transportation of fluid wherein the unbonded flexible pipe comprises an outer sheath, an inner sealing sheath inside the outer polymer sheath, an annulus between said outer sheath and said inner sealing sheath and at least one metallic armor layer comprising iron located in said annulus, wherein the method comprises filling at least a part of the annulus with a corrosion promoting liquid before or after installing the unbonded flexible pipe between a first installation and a second installation.

Abstract: A bit for drilling a wellbore, includes: a bit body; and a cutting face having an inner cone section and an outer shoulder section. The cutting face includes: a plurality of blades protruding from a bottom of the bit body, each blade extending from a center of the cutting face to the shoulder section; and a plurality of shear cutters mounted along leading edges of the blades. An inner shear cutter of each blade is located in the cone section. Each inner shear cutter includes: a superhard cylindrical cutting table; and a hard substrate having a cylindrical portion attached to the cutting table and a reduced portion extending therefrom. A diameter of the cutting table and the cylindrical portion is greater than a diameter of a majority of the reduced portion. A length of the reduced portion is at least twice that of the cylindrical portion.

Abstract: Disclosed is a hammer reamer comprising cutting wheels, a product-pulling feature, and a hammer component operable to deliver a percussive cycle of an internal piston component. Notably, an internal impact surface within the head of the hammer reamer is positioned relative to the piston component in the hammer consistent with a “sweet spot” position of a drill bit used in a pilot boring configuration. Unlike a slidably engaged drill bit, however, the internal impact surface in the hammer reamer is fixed in place so that the impact surface remains in the “sweet spot” of the piston stroke range. In this way, even though the hammer reamer is being pulled back through a bore while the drill string is being retracted, the hammer component may continue to deliver percussive blows to the hammer reamer head to introduce a vibratory force that contributes to the efficiency of the reaming process.

Abstract: Directional drilling of a borehole involves: positioning an apparatus in a borehole such that a housing of the apparatus and the borehole wall define an outer annular space; flowing drilling fluid to the outer annular space via an inner annular space defined between the housing and an inner drive shaft of the apparatus; actuating a clutch for selectively coupling the housing to the drive shaft for rotation with the drive shaft and for adjusting the tool face of the housing; and actuating a valve to control drilling fluid flow between the outer annular space to a piston chamber, relative to drilling fluid flow between the inner annular space and the piston chamber to thereby control drilling fluid pressure in the piston chamber. The drilling fluid pressure in the piston chamber and a biasing means act in opposing directions on a piston to urge the piston either towards or away from the borehole wall.

Abstract: A method for hydraulic stimulation of rock of a borehole of a well having an internal casing. The method includes positioning a conduit in the casing, the conduit having along its external face expandable tubular sleeves, fixedly linked to the conduit, and at least one aperture before each sleeve placing the internal space of the conduit into communication with the space demarcated by the conduit and each sleeve. A fluid is injected into the conduit under a first pre-determined pressure, which is sufficient to expand the sleeves. For each of the areas of the wall of the well to be stimulated, the method includes: plugging the conduit downstream from a first area to be stimulated; perforating the wall of the conduit and, at least in certain cases, perforating the casing at the first area to be stimulated; and injecting a fluid into the conduit under a second stimulation pressure.

Abstract: Provided are systems and methods for drilling a horizontally-oriented well having a sigmoid-shaped wellbore including an upper sigmoid portion having a downward curving wellbore trajectory and a lower sigmoid portion having an upward curving wellbore trajectory. The upper sigmoid portion having a first trajectory having a generally horizontal gradient at an entry point of the wellbore and that increases in downward gradient to a vertical gradient at an inflection point. The lower sigmoid portion having a second trajectory that includes the vertical gradient at the inflection point and that decreases in downward gradient to a generally horizontal gradient at a horizontal transition point of the wellbore.

Abstract: A junk basket, comprising: mating parts, each mating part comprising an annulus covering portion, a cylindrical wall portion, a nipple seat portion and a nipple connector secured to the annulus covering portion, the cylindrical wall portion forming an interior wall to the annulus covering part; and the mating parts when mated forming an annulus covering surface, a nipple seat and a cylindrical wall forming an interior boundary to the annulus covering surface.

Abstract: Provided are systems and methods for drilling a horizontally-oriented well having a sigmoid-shaped wellbore including an upper sigmoid portion having a downward curving wellbore trajectory and a lower sigmoid portion having an upward curving wellbore trajectory. The upper sigmoid portion having a first trajectory having a generally horizontal gradient at an entry point of the wellbore and that increases in downward gradient to a vertical gradient at an inflection point. The lower sigmoid portion having a second trajectory that includes the vertical gradient at the inflection point and that decreases in downward gradient to a generally horizontal gradient at a horizontal transition point of the wellbore.

Abstract: A sand guard system having an outer housing, a wedge assembly disposed in the outer housing, and an inner tube disposed in the outer housing such that an annulus is formed between the inner tube and the outer housing. The wedge assembly comprises a plurality of wedges coupled together by one or more flexible retaining members such that the wedges are movable radially outward and inward relative to the outer housing. The inner tube has a plurality of slots configured to filter out solids from fluids flowing from the annulus into the inner tube through the slots.