Abstract: A fluid-driven alternator for use in a downhole well bore having fluid flowing therethrough includes a housing and an internal impeller rotatably mounted in the housing. A stator and rotor are mounted within the housing, and the internal impeller is coupled to the rotor. Fluid flowing through the housing rotates the impeller which in turn rotates the rotor. A flow diverter can be provided to direct fluid into the housing.

Abstract: A fluid-driven alternator for use in a downhole well bore having fluid flowing therethrough includes a housing and an internal impeller rotatably mounted in the housing. A stator and rotor are mounted within the housing, and the internal impeller is coupled to the rotor. Fluid flowing through the housing rotates the impeller which in turn rotates the rotor. A flow diverter can be provided to direct fluid into the housing.

Abstract: An apparatus employing a set of inductive coils to transmit AC data and power signals between a downhole apparatus (which may include a sensor and a safety valve) and apparatus at the surface of the earth. In a preferred embodiment, the invention inductively couples a low frequency (less than 3 KHz) AC power signal from an outer wellhead coupler coil to an inner wellhead coupler coil wound around a tubing string. The AC signal propagates down a wireline conductor along the tubing string to a first downhole coupler coil (also wound around the tubing string) and is inductively coupled from the first downhole coupler coil to a second downhole coupler coil within the tubing. The power signal is preferably rectified, and then employed to power various items of downhole equipment. Data from a downhole sensor (whose frequency is preferably in the range from about 1.0 KHz to about 1.5 KHz) is impressed on the second downhole coil to modulate the AC power signal.

Abstract: For the directional drilling of boreholes, the orientation of accelerometer modules, magnetometer modules and gyroscopes or other directional sensing devices must be accurately known and maintained with respect to each other and to external mounting devices. This is accomplished by a self-aligning segmented cylindrical connection which accurately maintains modules in rotational alignment with each other for all three directions of rotation, even if the mating surfaces of the connection experience wear due to rough use in the drilling application or repeated calibration in a calibration fixture. Wedged surfaces on each of the male and female portions of the connection constitute the mating surfaces, and are the only surfaces at which the male and female portions contact one another. A depression between the mating surfaces defined by the female portion permits reproducible angular displacement of one portion with respect to the other even if one or both portions are worn.

Abstract: An inclinometer includes a toroidal race containing a spherical ball free to move therein under the influence of gravity. Signal source and collector electrode assemblies are provided on opposite sides of the toroidal race, and the ball functions to capacitively couple signals on the source electrode to the collector electrode. In one embodiment the source electrode is shaped so that the amplitude of coupling varies with ball position in the race so that the signal on the collector electrode is indicative of ball position. In other embodiments the source electrode is continuous and symmetrical, and signals applied thereto are selected such that a property of the signal coupled to the collector electrode, such as signal phase, varies in accordance with ball position in the race. Three such inclinometers can be combined in a borehold sensor for drilling applications.