Abstract: An apparatus comprising an electrically powered device. The apparatus comprises a functional device, a device electrical terminal, a casing, a power supply and a casing electrical terminal. The apparatus is characterised in that corresponding physical retaining means are provided on the device and the casing respectively, to ensure that physical connection between the device electrical terminal and the casing electrical terminal is maintained, during use of the apparatus. The physical retaining means of the apparatus automatically engages when the device is moved into the desired position relative to the casing.

Abstract: A wet connection system suitable for use in hydrocarbon wells preferably comprises one or more elongate, small diameter conduits (50) which extend down the wellbore (2) and terminate adjacent a locating structure (11) on the production tubing (10). Equipment (70) deployed at the locating structure is connected to one or more self supporting conductors (30) which extend down the conduits from the wellhead (5). Preferably the conductors are retractable and the conduits are sealingly connected to the equipment, allowing the equipment and conductors to be deployed and recovered independently of each other and to be flushed with dielectric oil (99) pumped down the conduits after re-connection.

Abstract: A wet connection system suitable for use in hydrocarbon wells preferably comprises one or more elongate, small diameter conduits (50) which extend down the wellbore (2) and terminate adjacent a locating structure (11) on the production tubing (10). Equipment (70) deployed at the locating structure is connected to one or more self supporting conductors (30) which extend down the conduits from the wellhead (5). Preferably the conductors are retractable and the conduits are sealingly connected to the equipment, allowing the equipment and conductors to be deployed and recovered independently of each other and to be flushed with dielectric oil (99) pumped down the conduits after re-connection.

Abstract: A downhole electrical wet connector comprising a plug which is slidingly inserted into a socket, the socket comprising a series of wiper seals spaced apart by separation zones, each zone being individually supplied with dielectric fluid from a separate reservoir. A retractable insert is arranged in the socket and displaced by the plug during connection. The fluid pressure in each zone is individually regulated relative to ambient wellbore pressure and the pressure in adjacent zones and optionally equalised to minimise loss of fluid.

Abstract: A wet connection system comprises a fixed tubing with an orientation profile and redundant, first and second fixed wet connectors, and an electrical submersible pump assembly (ESP) comprising a wet connector and an orientation element for engaging the orientation profile. The ESP can be reconfigured, for example, by interchanging its component modules so as to change the position of its wet connector with respect to the orientation element, whereby the wet connector on the ESP can be engaged alternatively with either one of the fixed wet connectors when the orientation element is engaged with the orientation profile in the same deployed position of the ESP.

Abstract: An ESP is suspended downhole on a cable comprising spirally wound copper clad steel conductors surrounded by nonmetallic sheathing wound in an opposite spiral direction, preferably in the direction of rotation of the rotor of the ESP. The torque exerted on the cable by the ESP is reacted against the conductors, relieving stress from the sheathing so that the cable may be light in weight yet support substantial loads.

Abstract: An electrical connection for use in boreholes or other remote environment has first and second conductive members. The two conductive members are movable to form an electrical contact. Also provided is a means for urging dielectric fluid around the electrical contact formed by the first conductive member and second conductive member as the first and second conducting members are moved together.

Abstract: A synchronous permanent magnet motor is controlled independently of position sensing means by determining the system parameters including the motor impedance and back-emf and the cable impedance and supplying power according to a predefined voltage:frequency ratio which is determined based on said system parameters to provide a desired rate of acceleration determined by the supply voltage.

Abstract: A drive means for downhole use comprises an input shaft and an output shaft, the input shaft being coupled to a means of rotation, the input shaft and the output shaft being torsionally coupled, the output shaft being coupled to the rotor of the progressive cavity pump, the input shaft lies in a first axis and the output shaft lies in a second axis, the second axis being parallel to the first axis but spaced from it so that the output shaft rotates about its axis while describing a circular path.

Abstract: A pump system for use in with a downhole pipe string has a pump comprising at least one cylinder with at least one piston inside the cylinder, the movement of the piston causing fluid to be drawn into the pump through a pump inlet before being pushed out through a pump outlet. The pump is housed in a tube having a cammed surface formed by internal wall of the tube, and the piston has a cam follower such that rotation of the piston relative to the tube causes the piston to move relative to the cylinder. Further, a pump system is shown which has two or more such pumps arranged along the downhole pipe string, the pump outlets feeding into a common manifold. The strokes of the piston or pistons of one pump may be out of step with the strokes of the piston or pistons of another pump such that the outlet stream is more uniform.

Abstract: A cable and coiled tubing suspends an electrically powered tool in a borehole and providing the tool with electrical power by the cable, the cable being disposed in the coiled tubing, the cable incorporating a conducting member which carries the majority of the tensile stress on the cable, and without the cable being secured along its length to the inside of the coiled tubing. The cable may be capable of supplying high voltage electrical power, in which case the cable comprises a conducting member having a steel core, an outer cladding of copper, and at least one insulating layer surrounding the outer cladding of copper, the copper making up between 20% and 40% of the total copper and steel content of the cable, the cable being able to support at least its own weight.

Abstract: A wet connection system suitable for use in hydrocarbon wells preferably comprises one or more elongate, small diameter conduits (50) which extend down the wellbore (2) and terminate adjacent a locating structure (11) on the production tubing (10). Equipment (70) deployed at the locating structure is connected to one or more self supporting conductors (30) which extend down the conduits from the wellhead (5). Preferably the conductors are retractable and the conduits are sealingly connected to the equipment, allowing the equipment and conductors to be deployed and recovered independently of each other and to be flushed with dielectric oil (99) pumped down the conduits after re-connection.

Abstract: A seal assembly (10?; 30?) comprises a plurality of deformable annular seals (10; 30), each having an annular recess (17) at one end, which are inserted one by one in a relaxed condition in coaxial stacked relation into an annular bore (54) and then compressed axially one by one so that an insert body (16; 32) enters into the recess in each seal, radially energising it. The insert body may comprise an opposite end (16) of the adjacent seal, or a body (32) of fluid or gel. The inner wall of each seal comprises a sealing surface and at least one sealing bead protruding radially inwardly from the sealing surface; the sealing surface limits the depth to which the bead can penetrate the casing of the cable.

Abstract: A cable clamp device for use in a well bore to secure cables to pipes and the like includes a flexible fastening member of relatively uniform cross-section, and a block that accepts the fastening member as it encompasses the circumference of the pipe in a loop. The cable clamp also and accepts the cable running axially along the pipe. The flexible fastening member overlaps itself, and is secured in a loop by deformation of its material. The height of the block from the surface of the pipe is greater than the height of the outer surface of the flexible fastening member and the surface of the pipe. The end surfaces of the clamp are angled with respect to the perpendicular of the pipe's surface.

Abstract: An electric submersible pump and motor assembly for downhole applications has an electric motor having a stationary nonrotating through bore, a pump driven by the electric motor, a deployment line upon which the electric motor and pump may be lowered down through a production tube, and a seal for sealing the assembly against the production tube. An inlet upstream of the seal through which well bore fluid may flow extends through the pump and the stationary nonrotating through bore of the motor, and the fluid may exit through an outlet open to the well bore downstream of the seal.

Abstract: An assembly for downhole applications comprises has an electric motor, a pump driven by the electric motor and having a lower pump inlet and an upper pump outlet, and a deployment tube from which the assembly is suspended from and by means of which the assembly can be lowered through the well. A nonrotating hollow shaft forms a bore extending from the tube through the motor and the pump to an assembly opening at the bottom of the assembly such that a device suspended on a wireline or coiled tube may be lowered through the deployment tube and pass through the electric motor and pump to a part of the well below the pump inlet. The motor is linked outside the bore to the pump for driving the pump.

Abstract: A cable is installed in coiled tubing for use in. downhole wells; the cable having an expandable jacket (22) extruded around it. After being installed in the coiled tubing, and the expandable jacket is caused to expand, securing the cable in the coiled tubing. The expandable jacket is caused to expand by the application of heat or by the application of a liquid hydrocarbon. The expandable jacket may be discontinuous along the length of the power cable, discontinuous portions being provided by interspersing the expandable jacket with sections non-expandable material.

Abstract: A system for installing a powered device in a downhole tube has a power line extending down a production tube and terminating in a power connector or contact. The powered device toolstring is down the tube and has a corresponding power connector or contact. The two connectors or contacts are aligned as the connector or contact of the line approaches the connector or contact of the tool. Then the two contacts are fitted together such that they make electrical connection when the powered device toolstring is located adjacent to the power connector or contact of the production tube.

Abstract: A drive means for downhole use comprises an input shaft and an output shaft, the input shaft being coupled to a means of rotation, the input shaft and the output shaft being torsionally coupled, the output shaft being coupled to the rotor of the progressive cavity pump, the input shaft lies in a first axis and the output shaft lies in a second axis, the second axis being parallel to the first axis but spaced from it so that the output shaft rotates about its axis while describing a circular path.

Abstract: An electric-motor assembly for installation in a borehole to power a downhole tools such as a pump has a first impermeable tube defining an axis and a stator fixed in the tube and having a series of coiled windings and laminations and electrically insulating potting in which the laminations and windings are imbedded. The windings have a connection to an electronically controlled power supply. An annular rotor in the tube radially surrounding the stator includes a permanent magnet coaxial with the windings. The tube seals the stator and rotor from the environment.