Abstract: An electric submersible pumping system uses a small diameter capillary tube and a high pressure injection pump. The tube size is selected so that the frictional flow resistance of the tubing at the desired flow volumes balances the pressure caused by the height difference in the columns of fluid. The flexibility of the system is expanded by tapering the capillary tubing string, preferably, but not necessarily, using a larger inner diameter tube above and a smaller inner diameter tube below. Using calculated lengths of different diameter tubing, the pressure loss due to flow can be adjusted to suit the anticipated well conditions. For example, for a flow rate of two gallons per day of oil, a 4,000 foot well might start with 1,500 feet of 0.069" inner diameter tubing at the top and 2,500 feet of 0.055" inner diameter tubing on the bottom. The high pressure injection pump assures that the surface pressure will never go negative, even if the well productivity or other conditions are unknown or changing.

Abstract: A submersible centrifugal pump is disclosed. It includes a housing with a linear stack of axially mounted pumping units therein. Each unit is constructed as a module with at least a first and a second impeller mounted to a central shaft. A diffuser forms an outer casing which is provided for each impeller. A thrust bearing, lubricated and cooled by the fluid being pumped is supported from and to the outer casing and is arranged to receive axial force from the upstream impellers in each modular unit. A plurality of impellers and diffusers can form a single modular unit.

Abstract: Apparatus is provided to protect an electric submersible motor/pump (ESP) assembly as the normally rigid assembly is inserted into deviated or curved subterranean wells, i.e. directionally or horizontally drilled wells, which apparatus includes flexible joint connection means and cable protection devices.

Abstract: A submersible motor includes a stator section along the entire length of rotor sections attached to the motor shaft, with a rotor bearing and sleeve assembly between each rotor section, each bearing including a fixed key for positioning in longitudinal spacings formed as a part of the stator section, to prevent rotation of the bearing during use.

Abstract: A plug-in type pothead includes specially designed seal sleeves formed from a heat shrinkable polymer. One end of the sleeve has an annular collar about it which, when snugly fitted within the motor lead entry hole of the terminal block, forms a watertight seal between the terminal block and the sleeve. The other end of each of the sleeves is heat shrunk about its respective motor lead to form a watertight seal between the sleeve and the lead. In addition, a gasket between the connecting face of the terminal block and the connecting face of the pothead provides a watertight seal between the pothead and the terminal block. The result is a completely watertight connecting system, extending from the pothead through the terminal block to the motor leads.

Abstract: A submersible centrifugal pump is disclosed. It includes a housing with a linear stack of axially mounted pumping units therein. Each unit constructed as a module with at least a first and a second impeller mounted to a central shaft. A diffuser forms an outer casing which is provided for each impeller. A thrust bearing, lubricated and cooled by the fluid being pumped is supported from and to the outer casing and is arranged to receive axial force from the upstream impellers in each modular unit. A plurality of impellers and diffusers can form a single modular unit.

Abstract: A submersible motor includes a stator section along the entire length of rotor sections attached to the motor shaft, and a non-magnetic rotor bearing and sleeve assembly between each rotor section, with the rotor bearing being releasable but normally interconnected with the stator to prevent its rotation relative to the sleeve which rotates with the motor shaft.

Abstract: An equalizer is located either between a downhole submersible pump and the motor or between a gas separator and its motor. There are at least two, and preferably three, flexible concentric bags spaced about a hollow tube with the first bag nested inside the second and the second is nested inside the third forming three separate spaces, i.e., a first space inside the first bag, a second space between the first and second bag, a third space between the second and third bag and a fourth space between the third bag and inside the housing and fifth space inside the hollow tube. When the motor oil heats up it flows into the first space, then through a passage with check valve into the inside of the hollow tube upwardly, and then across a passage to the second space. Another passage with another check valve connects the second space to the third space. The third space is connected by passage with a third check valve to the area outside the third flexible bag.

Abstract: An apparatus for measuring one or more parameters of the subsurface environment, and telemetering one or more parameters of the subsurface environment to the surface. Apparatus at the surface includes a source of intermediate frequency and voltage, electrical energy for transmission down one or more conductors of a power cable or separate instrument wire to a downhole instrument package. This intermediate frequency voltage is converted to a power supply voltage for generating a high frequency FM signal, in accordance with the magnitude of one or more parameters of the environment. This frequency modulated signal is sent to the surface over the conductors of the power cable and ground. At the surface the signal is demodulated to produce a signal indicative of the transmitted parameter.

Abstract: A submersible centrifugal pump is disclosed. It includes a housing with a linear stack of axially mounted pumping units therein. Each unit constructed as a module with at least a first and a second impeller mounted to a central shaft. A diffuser forms an outer casing which is provided for each impeller. A thrust bearing, lubricated and cooled by the fluid being pumped is supported from and to the outer casing and is arranged to receive axial force from the upstream impellers in each modular unit. A plurality of impellers and diffusers can form a single modular unit.

Abstract: An apparatus for measuring one or more parameters of the subsurface environment, and telemetering one or more parameters of the subsurface environment to the surface. Apparatus at the surface includes a source of intermediate frequency and voltage, electrical energy for transmission down one or more conductors of a power cable or separate instrument wire to a downhole instrument package. This intermediate frequency voltage is converted to a power supply voltage for generating a high frequency FM signal, in accordance with the magnitude of one or more parameters of the environment. This frequency modulated signal is sent to the surface over the conductors of the power cable and ground. At the surface the signal is demodulated to produce a signal indicative of the transmitted parameter.

Abstract: An apparatus for measuring one or more parameters of the subsurface environment, and telemetering one or more parameters of the subsurface environment to the surface. Apparatus at the surface includes a source of intermediate frequency and voltage, electrical energy for transmission down one or more conductors of a power cable or separate instrument wire to a downhole instrument package. This intermediate frequency voltage is converted to a power supply voltage for generating a high frequency FM signal, in accordance with the magnitude of one or more parameters of the environment. This frequency modulated signal is sent to the surface over the conductors of the power cable and ground. At the surface the signal is demodulated to produce a signal indicative of the transmitted parameter.

Abstract: Submersible electric motors for pumping fluid from wells are assembled together in tandem relationship for increasing total output horsepower. Means are provided to make electrical connections just prior to assembly and interconnect the oil flow corridors between motors during assembly. Precompressed spring-loaded thrust bearings compensate for shaft length changes and dampen vibrations. The oil circulation corridors include filtration.

Abstract: Submersible electric motors for pumping fluid from wells are assembled together in tandem relationship for increasing total output horsepower. Means are provided to make electrical connections just prior to assembly and interconnect the oil flow corridors between motors during assembly. Precompressed spring-loaded thrust bearings compensate for shaft length changes and dampen vibrations. The oil circulation corridors include filtration.