An underground directional drilling system can comprise a plurality of elongated dual-shaft segments coupled together end-to-end in a drilling string. The segments include an inner shaft that is independently rotable relative to an annular outer shaft, with the inner shafts being coupled together and the outer shafts being coupled together. The plurality of dual-shaft segments can comprise a communication segment that comprises a first electrode, a second electrode, a gap portion between the first and second electrodes that provides electrical insulation therebetween, and an electronic communication controller electrically coupled to the first and second electrodes. The communication controller is configured to generate voltage differences between the electrodes that cause electrical pulses to periodically transfer between the electrodes through the gap portion to wirelessly communicate drilling related data from underground to the surface.

A device for removing and preventing paraffin by using electric heating generated from skin effect-based natural gas electricity and an application thereof are disclosed, and the device comprises a natural gas collection portion, a natural gas electricity generation portion and a device for removing and preventing paraffin by using electric heating powered by the natural gas electricity generation portion; the natural gas collection portion is used to collect and separate natural gases discharged from a wellbore; the natural gas electricity generation portion generates electricity with natural gases. The power source required by the electric heating of the steel armored cable of the present invention comes from the natural gas electricity generation portion, and the air source required by the natural gas electricity generation portion can be obtained directly from the associated gases extracted from an oil well.

A completion system and method for intelligent control of multilateral wells. A completion deflector defines a hollow interior that is fluidly coupled with a uphole tubing and downhole main completion strings. Hydraulic, electric, and/or fiber-optic communication line segments extend between the uphole end and downhole end of the completion deflector for providing power, control or communications between the surface and production zones associated with the main wellbore. The communication line segments are located outside the completion deflector interior and may be located within longitudinal grooves formed along the exterior wall surface of the completion deflector. A self-guided, wet-matable connector is provided at the uphole end, which connects the both interior flow path and communication lines, and which may allow connection at any relative radial orientation. The uphole end of the completion deflector has an inclined upper surface for deflecting various tools and strings into a lateral wellbore.

Wellbore ranging methods and systems for active electromagnetic ranging between a pair of conductive tubulars. Methods may include generating a depth-dependent current on one conductive tubular of the pair and a return current on another and thereby causing an injection current to flow into the earth formation by electrically exciting a first conductive tubular of the pair at a first wellhead and a second of the pair at a second wellhead, wherein the return current on the one results from the injection current on the other and is received from the earth formation; making electromagnetic measurements indicative of at least one electromagnetic field resulting from the depth-dependent current in the earth formation; and estimating a relative position of the first conductive tubular with respect to the second tubular using the electromagnetic measurements.

An electromagnetic telemetry system may include an electrically conductive member, a transmitter coupled to the electrically conductive member, the transmitter configured to induce an alternating current along the electrically conductive member, the alternating current representing encoded information, a first receiver coupled to the electrically conductive member, the first receiver configured to receive electromagnetic waves resulting from the alternating current, a second receiver positioned at a location apart from the first receiver, the second receiver configured to receive the electromagnetic waves resulting from the alternating current, and a receiver processing system communicatively coupled to the first receiver and the second receiver, the receiver processing system configured to process the electromagnetic waves received by the first receiver and the second receiver into a combined signal, and decode the combined signal.

Electrically insulated connector bands for Downhole Electrical Disconnect Tools provide power and/or data communication downhole are made from metal having sufficient strength and corrosion resistance to eliminate the need of any vacuum and sealed pressure compensation assembly while being exposed to wellbore fluids. The electrical insulation is achieved by having portions of the connector bands coated with electrically insulating material. An uncoated section of each connector band will provide the electrical path between the male and female mandrels.

A tubular component for oil exploration includes an electromagnetic half-coupler that can be coupled to a half-coupler of another tubular component to allow data transmission, wherein an end portion of the tubular component includes a housing accommodating the half-coupler, the half-coupler including a coupling element and an annular armature for the coupling element, the coupling element including an annular body formed from a material with a high magnetic permeability and an electrical conductor having turns, the armature including a first portion and a second portion configured to accommodate the coupling element, the armature being partially surrounded by an isolating and impervious material to protect the half-coupler against infiltration.

A drillstring first tube portion (10) for connection to further tube portions (24,26) of a drillstring via respective connection means has a side wall (16) including non ferromagnetic material, and at least one downhole survey device (12) mounted directly or indirectly on or within the side wall. The survey device has at least one survey instrument to obtain survey data, a power source (22) and wireless communication means (18) to wirelessly receive and/or transmit survey data within or on the side wall. A method of conducting a downhole survey of drilling using such an apparatus is also disclosed, as well as a method of obtaining data gathered downhole. The survey device and a core orientation device (32) may communicate wirelessly, such as when passing each other.

The transmission line for wired pipe applications includes an inner conductor, an insulating material surrounding the inner conductor, the insulating material having an initial outer diameter, and a wire channel surrounding the insulating material and the inner conductor for at least a portion of a length of the transmission line. The wire channel is formed from at least two profiles forced together to compress the insulating material such that it has a final outer diameter that is less than the initial outer diameter.

Downhole electrical energy harvesting and communication in systems for well installations having metallic structure carrying electric current, for example CP current. In some instances there is a harvesting module (4) electrically connected to the metallic structure (2) at a first location and to a second location spaced from the first location, the first and second locations being chosen such that, in use, there is a potential difference therebetween due to the electric current flowing in the structure (2); and the harvesting module (4) being arranged to harvest electrical energy from the electric current. In addition or alternatively, there may be communication apparatus (4, 5, 6) for communication by modulation of the current, for example CP current, in the metallic structure (2).