Abstract: This invention relates to a measurement tool and method of use, and in particular to a measurement tool for use in determining a parameter of a stationary or moving fluid. The measurement tool has been designed primarily for use in borehole formation testing. The measurement tool can measure the dielectric constant of a fluid within a pipe or surrounding the tool. The pipe or wall between the tool and the fluid is electrically insulating. The tool has pair of capacitor plates mounted adjacent to the pipe or wall, a signal generator which can deliver an alternating electrical signal to at least one of the capacitor plates, and a detector for measuring a signal dependent upon the electrical capacitance between the capacitor plates. The measurement tool can additionally measure the electrical resistivity of the fluid.

Abstract: A borehole cutting assembly for directional cutting in a borehole, the assembly comprising an input pipe and a cutting head rotatably mounted on the input pipe such that the orientation of the cutting head relative to the input pipe can be altered to determine the direction of cutting of the borehole. A cutting tool and cutting tool motor are mounted on the cutting head to enable the cutting tool to be rotatably driven relative to the cutting head so that when the cutting tool is loaded in use the cutting head is subject to a tool reaction torque that acts to rotate the cutting head to change the orientation of the cutting head. The cutting head is rotatably mounted on the input pipe by a controlled torque coupling comprising a progressive cavity pump having a rotor and a stator each provided with drive formations arranged to define a fluid flow cavity therebetween. Rotation of the rotor relative to the stator forces fluid flow through the cavity to counteract the tool reaction torque.

Abstract: The invention relates to the generation of electricity from flowing fluid and in the preferred embodiment to a horizontal axis turbine and generator assembly. The present invention is applicable to water turbines and the invention is described in relation to this application. It is however to be appreciated that it is applicable to wind turbines.

Abstract: An electric submersible pump contains an AC permanent magnet motor having three or more phases A, B, C and has a drive circuit for supplying varying drive signals to all the phases of the motor at the same time. Each drive signal is constituted by a cyclically smoothly varying voltage applied to the corresponding motor phase during driving of the motor. The circuit includes switches (902, 903) for each motor phase, a control arrangement for turning the switches (902, 903) on and off at a frequency greater than the frequency of the cyclically smoothly varying voltages, and a filter (907, 908) for filtering the output voltages of the switches (902, 903) to produce the cyclically smoothly varying voltages. Such a drive circuit drives all the phases of the motor continuously such that damaging transients will not arise and without requiring the motor emf or drive signals to be sinusoidal.

Abstract: This invention relates to a measurement tool and method of use, and in particular to a measurement tool for use in determining a parameter of a stationary or moving fluid. The measurement tool has been designed primarily for use in borehole formation testing. The measurement tool can measure the dielectric constant of a fluid within a pipe or surrounding the tool. The pipe or wall between the tool and the fluid is electrically insulating. The tool has pair of capacitor plates mounted adjacent to the pipe or wall, a signal generator which can deliver an alternating electrical signal to at least one of the capacitor plates, and a detector for measuring a signal dependent upon the electrical capacitance between the capacitor plates. The measurement tool can additionally measure the electrical resistivity of the fluid.

Abstract: This invention relates to a measurement tool, and in particular to a measurement tool for use in determining the density and/or viscosity of a stationary or moving fluid. The measurement tool has been designed for use in borehole applications during the location and exploitation of oil and gas reserves. The measurement tool has a resilient pipe with a substantially uniform cross-section along its length, and the fluid is located within the pipe. The pipe carries an exciter which is connected to a signal generator, the exciter and signal generator being adapted to impart transverse and/or rotational oscillations to the pipe. Measuring the frequency of the oscillations can be used to determine the density and/or the viscosity of the fluid within the pipe.

Abstract: A borehole cutting assembly for directional cutting in a borehole, the assembly comprising an input pipe and a cutting head rotatably mounted on the input pipe such that the orientation of the cutting head relative to the input pipe can be altered to determine the direction of cutting of the borehole. A cutting tool and cutting tool motor are mounted on the cutting head to enable the cutting tool to be rotatably driven relative to the cutting head so that when the cutting tool is loaded in use the cutting head is subject to a tool reaction torque that acts to rotate the cutting head to change the orientation of the cutting head. The cutting head is rotatably mounted on the input pipe by a controlled torque coupling comprising a progressive cavity pump having a rotor and a stator each provided with drive formations arranged to define a fluid flow cavity therebetween. Rotation of the rotor relative to the stator forces fluid flow through the cavity to counteract the tool reaction torque.

Abstract: A method of pumping wellbore fluid, comprising the steps of: installing an electric submersible pump in a wellbore; and operating the pump at more than 4,500 rpm to pump the wellbore fluid. Pumping in this manner provides a number of advantages in use in that the required high-speed motor and pump is shorter for a given power than existing arrangements, and provides increased reliability due to reduced complexity. A much shorter motor/pump combination also allows such equipment to be used in deviated boreholes with a reduction in damage due to mishandling and bending, as well as facilitating assembly and testing in the manufacturer's plant.

Abstract: An electrical connector assembly for a cable having a plurality of insulated conductors comprises a body having a respective recess for receiving a terminating pin each of the conductors. A respective spigot sealingly engages within each of the recesses and has a passage for receiving an associated one of the terminating pins. Furthermore a seal is associated with each of the spigots for sealing the spigot relative to the associated terminating pin. The provision of a separate spigot for each of the conductors and for sealing engagement within a respective recess in the body enables the spigots to be sealingly fitted to the conductors prior to each spigot being introduced into its recess and sealingly engaged therein. This provides improved insulation of the conductor and increased creepage distance between the mating electrical parts and the outer surface of the housing of the assembly.

Abstract: A downhole electric motor for a submersible pump has at least three phases and comprises a permanent magnet rotor and a stator bearing phase windings A, B and C in slots (2206) in the stator. Each phase winding A, B, C incorporates a coil extending through a respective pair of adjacent stator slots (2206) and surrounds a respective portion of the stator between the slots (2206). Furthermore adjacent coils of each pair of phase windings A, B, C extend through opposite parts of a respective one of the slots (2206), so that these coils extend alongside one another in the slot, either being separated by a gap through which cooling fluid may be pumped to cool the coils, or being separated by a thermally conductive projection (3110), with which the coils are in thermal contact, extending at least part of the way across the slot. Such a winding arrangement is advantageous in ensuring that the motor has a long life.

Abstract: An electrical connector assembly for a cable having a plurality of insulated conductors comprises a body having a respective recess for receiving a terminating pin each of the conductors. A respective spigot sealingly engages within each of the recesses and has a passage for receiving an associated one of the terminating pins. Furthermore a seal is associated with each of the spigots for sealing the spigot relative to the associated terminating pin. The provision of a separate spigot for each of the conductors and for sealing engagement within a respective recess in the body enables the spigots to be sealingly fitted to the conductors prior to each spigot being introduced into its recess and sealingly engaged therein. This provides improved insulation of the conductor and increased creepage distance between the mating electrical parts and the outer surface of the housing of the assembly.

Abstract: This invention relates to a measurement tool, and in particular to a measurement tool for use in determining the density and/or viscosity of a stationary or moving fluid. The measurement tool has been designed for use in borehole applications during the location and exploitation of oil and gas reserves. The measurement tool has a resilient pipe with a substantially uniform cross-section along its length, and the fluid is located within the pipe. The pipe carries an exciter which is connected to a signal generator, the exciter and signal generator being adapted to impart transverse and/or rotational oscillations to the pipe. Measuring the frequency of the oscillations can be used to determine the density and/or the viscosity of the fluid within the pipe.

Abstract: This invention relates to a measurement tool and method of use, and in particular to a measurement tool for use in determining a parameter of a stationary or moving fluid. The measurement tool has been designed primarily for use in borehole formation testing. The measurement tool can measure the dielectric constant of a fluid within a pipe or surrounding the tool. The pipe or wall between the tool and the fluid is electrically insulating. The tool has pair of capacitor plates mounted adjacent to the pipe or wall, a signal generator which can deliver an alternating electrical signal to at least one of the capacitor plates, and a detector for measuring a signal dependent upon the electrical capacitance between the capacitor plates. The measurement tool can additionally measure the electrical resistivity of the fluid.

Abstract: An electrical connector assembly for a cable having a plurality of insulated conductors comprises a body having a respective recess for receiving a terminating pin each of the conductors. A respective spigot sealingly engages within each of the recesses and has a passage for receiving an associated one of the terminating pins. Furthermore a seal is associated with each of the spigots for sealing the spigot relative to the associated terminating pin. The provision of a separate spigot for each of the conductors and for sealing engagement within a respective recess in the body enables the spigots to be sealingly fitted to the conductors prior to each spigot being introduced into its recess and sealingly engaged therein. This provides improved insulation of the conductor and increased creepage distance between the mating electrical parts and the outer surface of the housing of the assembly.

Abstract: A method of pumping wellbore fluid, comprising the steps of: installing an electric submersible pump in a wellbore; and operating the pump at more than 4,500 rpm to pump the wellbore fluid. Pumping in this manner provides a number of advantages in use in that the required high-speed motor and pump is shorter for a given power than existing arrangements, and provides increased reliability due to reduced complexity. A much shorter motor/pump combination also allows such equipment to be used in deviated boreholes with a reduction in damage due to mishandling and bending, as well as facilitating assembly and testing in the manufacturer's plant.

Abstract: A method of pumping wellbore fluid, comprising the steps of: installing an electric submersible pump in a wellbore; and operating the pump at more than 4,500 rpm to pump the wellbore fluid. Pumping in this manner provides a number of advantages in use in that the required high-speed motor and pump is shorter for a given power than existing arrangements, and provides increased reliability due to reduced complexity. A much shorter motor/pump combination also allows such equipment to be used in deviated boreholes with a reduction in damage due to mishandling and bending, as well as facilitating assembly and testing in the manufacturer's plant.

Abstract: A method of pumping wellbore fluid, comprising the steps of: installing an electric submersible pump in a wellbore; and operating the pump at more than 4,500 rpm to pump the wellbore fluid. Pumping in this manner provides a number of advantages in use in that the required high-speed motor and pump is shorter for a given power than existing arrangements, and provides increased reliability due to reduced complexity. A much shorter motor/pump combination also allows such equipment to be used in deviated boreholes with a reduction in damage due to mishandling and bending, as well as facilitating assembly and testing in the manufacturer's plant.

Abstract: A method and apparatus for lifting fluids from a well is provided. In one embodiment, a pump assembly comprises a rotary motor adapted to actuate a reciprocating pump. The motor shaft of the rotary motor is threadedly coupled to a drive member of the reciprocating pump. In operation, rotation of the rotary motor causes reciprocation of the reciprocating pump.

Abstract: An electrical connector assembly for a cable having a plurality of insulated conductors comprises a body having a respective recess for receiving a terminating pin each of the conductors. A respective spigot sealingly engages within each of the recesses and has a passage for receiving an associated one of the terminating pins. Furthermore a seal is associated with each of the spigots for sealing the spigot relative to the associated terminating pin. The provision of a separate spigot for each of the conductors and for sealing engagement within a respective recess in the body enables the spigots to be sealingly fitted to the conductors prior to each spigot being introduced into its recess and sealingly engaged therein. This provides improved insulation of the conductor and increased creepage distance between the mating electrical parts and the outer surface of the housing of the assembly.

Abstract: A tubular cutting tool includes two or more sets of electrically actuated retractable anchoring legs mounted at longitudinally spaced apart locations and an electrically driven rotary cutting head with a retractable cutting blade. The anchoring legs can be arranged such that they are capable of compensating for variations in the internal radii of the tubular to be cut, thereby ensuring that the cutting tool is clamped rigidly in position.