Abstract: Measurement and/or control units located within a borehole are inductively coupled to a flat three phase power cable segment without piercing the armor around the cable. For drawing power from the cable, C-shaped, L-shaped or straight core(s) with winding(s) around at least a portion thereof are positioned proximate to one or both end conductors, outside the armor, with significantly overlapping the center conductor. For impressing or detecting signals on the cable, straight core(s) with winding(s) around at least a portion thereof are disposed on one or both sides of the cable, outside the armor, across all three conductors with the core oriented transverse to the cable conductors.

Abstract: Data or control signals are communicated over a three phase power cable supplying power from a surface location to a motor/pump assembly located within a wellbore utilizing modulated radio frequency signals. The radio frequency signals may be impressed on the power cable through physical taps to the power cable conductors or by reactive coupling to the power cable. The transmission frequency is selected from a range of frequencies which propagate through the motor windings and up the power cable with sufficient amplitude to be received and processed. The modulated RF signal may be transmitted concurrently with the three phase power on the power cable, and simultaneous bidirectional communications between the surface and downhole locations may be supported utilizing, for example, discrete frequencies for transmission in different directions.

Abstract: Data or control signals are communicated over a three phase power cable supplying power from a surface location to a motor/pump assembly located within a wellbore utilizing modulated radio frequency signals. The radio frequency signals may be impressed on the power cable through physical taps to the power cable conductors or by reactive coupling to the power cable. The transmission frequency is selected from a range of frequencies which propagate through the motor windings and up the power cable with sufficient amplitude to be received and processed. The modulated RF signal may be transmitted concurrently with the three phase power on the power cable, and simultaneous bidirectional communications between the surface and downhole locations may be supported utilizing, for example, discrete frequencies for transmission in different directions.

Abstract: An inductor is wound axially around a cylindrical center structure, such as a core or form, so that each turn includes portions extending axially along a circumferential outer surface of the center structure and portions extending across the end surfaces of the center structure. Adjacent axial portions, which are preferably but not necessarily consecutive turns, carry current in the same direction to the extent possible. External magnetic fields therefore fall off rapidly and at least partially offset so that the inductor can handle high currents such as those relating to filtered electric power transmitted into a borehole for powering artificial lift equipment.

Abstract: An inductance balancer is connected between a drive and a flat three phase power transmission cable employed to carry power to a remote load. The inductance balancer includes a first inductance device (e.g., a single wound inductor) connecting the center cable conductor to the drive and raising the total effective inductance of the center cable conductor to the inductance of either of the outer cable conductors at maximum inductance. The inductance balancer also includes a second inductance device connecting both outer conductors to the drive and adding an inductance equal to that of the first inductance device when current exists only on an outer conductor and the center conductor, but adding no inductance to the outer conductors when current exists only on those two conductors.

Abstract: An inductor is wound axially around a cylindrical center structure, such as a core or form, so that each turn includes portions extending axially along a circumferential outer surface of the center structure and portions extending across the end surfaces of the center structure. Adjacent axial portions, which are preferably but not necessarily consecutive turns, carry current in the same direction to the extent possible. External magnetic fields therefore fall off rapidly and at least partially offset so that the inductor can handle high currents such as those relating to filtered electric power transmitted into a borehole for powering artificial lift equipment.