Abstract: An apparatus for detecting an electromagnetic signal originating in a wellbore includes an antenna comprising a pair of spaced apart electrodes in the ground spaced apart by a first distance having a midpoint at a second distance from the wellbore. The system includes at least one of a shielded electrical cable connecting each electrode to an input of a detector circuit, wherein the shielding is connected to produce common mode noise rejection; b) a second spaced apart electrode pair antenna spaced apart by one half the first distance and having a midpoint spaced ?2/2 times the second distance from the surface of the wellbore, c) a second electrode pair antenna having a common midpoint with and being orthogonal to the at least one electric dipole antenna; and d) wherein the at least one electric dipole antenna is disposed in a second wellbore, the second wellbore having substantially no electrically conductive pipe therein.

Abstract: An apparatus for detecting an electromagnetic signal originating in a wellbore includes an antenna comprising a pair of spaced apart electrodes in the ground spaced apart by a first distance having a midpoint at a second distance from the wellbore. The system includes at least one of a shielded electrical cable connecting each electrode to an input of a detector circuit, wherein the shielding is connected to produce common mode noise rejection; b) a second spaced apart electrode pair antenna spaced apart by one half the first distance and having a midpoint spaced ?2/2 times the second distance from the surface of the wellbore, c) a second electrode pair antenna having a common midpoint with and being orthogonal to the at least one electric dipole antenna; and d) wherein the at least one electric dipole antenna is disposed in a second wellbore, the second wellbore having substantially no electrically conductive pipe therein.

Abstract: A dynamically controllable variable displacement axial piston pump is described. In an embodiment, the pump comprises a rotating cylinder with hydraulic pistons that contact the face of a swash plate. The angle of the swash plate can be controlled to thereby control the movement of the pistons, the displacement of the pump, and the power generated by the pump. The dynamically controllable variable displacement axial piston pump may be used in combination with a rotary steerable apparatus, including such an apparatus as described herein that uses hydraulic pistons to actuate the deflection of the bit, or in combination with other downhole tools and devices. When used down hole in a drill string with a drilling mud powered turbine, the dynamically controllable variable displacement pump limits and regulates the power provided to the tool over a wide range of drilling mud weights and flow rates.

Abstract: The rotary steerable drilling tool and system described herein combines both point-the-bit and push-the-bit techniques to actively change the direction of the borehole trajectory. In this system, the deflection of the drill bit is limited to a single degree of freedom relative to a coordinate system that is fixed to and rotates with the rotary steerable drilling tool, resulting in a simplified attachment of the bit assembly and bias unit mechanics. Further, steering of the well is accomplished by dynamically controlling the spatial phase and amplitude of the coherent symmetrical bidirectional reciprocating deflections of the drill bit relative to a fixed terrestrial datum as the tool is rotating, simultaneously pointing and pushing the bit.

Abstract: The rotary steerable drilling tool and system described herein combines both point-the-bit and push-the-bit techniques to actively change the direction of the borehole trajectory. In this system, the deflection of the drill bit is limited to a single degree of freedom relative to a coordinate system that is fixed to and rotates with the rotary steerable drilling tool, resulting in a simplified attachment of the bit assembly and bias unit mechanics. Further, steering of the well is accomplished by dynamically controlling the spatial phase and amplitude of the coherent symmetrical bidirectional reciprocating deflections of the drill bit relative to a fixed terrestrial datum as the tool is rotating, simultaneously pointing and pushing the bit. The amplitude and force of the bit deflections can be variably controlled during steering operations to dynamically adjust the instantaneous build rate as needed. When steering is not active, the bit can be mechanically locked into the neutral position.

Abstract: Described are a system and method for converting a typical two-level logic signal to a pair of differential logic signals. In accordance with one embodiment, a field programmable gate array (FPGA) is configured to provide a digital signal and its complement on a pair of output terminals. A resistor network connected to these output terminals converts the complementary signals to a pair of differential signals having current and voltage levels within the range established by the LVDS specification. For maximum efficiency, the values of the resistors that make up the resistor network can be selected to match the 100 ohm input resistance exhibited by LVDS receivers.

Abstract: Novel high voltage electronic amplifiers that are capable of being monolithically integrated using low voltage semiconductor fabrication processes are described and claimed. A cascade of low voltage current mirrors is described that can act as a high voltage amplifier output circuit. A transconductor and level shift circuit is also described that can be employed in the high voltage amplifier output circuit. A high voltage current source is described and is constructed from the series combination of a low voltage transistor and a parasitic field oxide transistor. Additionally, a differential amplifier having bias-current shunting transistors is described that can be used to limit quiescent current from the output power supply of the high voltage amplifiers.