Abstract: A system and method of monitoring a pressure, temperature, and/or vibration of a hostile environment without requiring the use of active electronics or an oscillator circuit in that environment. The system and method interrogate a resonant pressure sensor and a resonant or passive temperature sensor connected to a transmission line and located at least 100 feet (30.48 m) away from a network analyzer. The system and method use the reflected frequencies from the sensors to determine the pressure, temperature, and/or vibration. If the sensors are networked by the transmission line or a network filter, the reflected portion can include the reflected transmission energy. The applied signal and reflected portion travel along the transmission line, which is preferably impedance matched to that of the system. If a multi-conductor cable is used, the effects of the cable's length and temperature are compensated for via a system calibration when in field use.

Abstract: A system and method of monitoring a pressure, temperature, and/or vibration of a hostile environment without requiring the use of active electronics or an oscillator circuit in that environment. The system and method interrogate a resonant pressure sensor and a resonant or passive temperature sensor connected to a transmission line and located at least 100 feet (30.48 m) away from a network analyzer. The system and method use the reflected frequencies from the sensors to determine the pressure, temperature, and/or vibration. If the sensors are networked by the transmission line or a network filter, the reflected portion can include the reflected transmission energy. The applied signal and reflected portion travel along the transmission line, which is preferably impedance matched to that of the system. If a multi-conductor cable is used, the effects of the cable's length and temperature are compensated for via a system calibration when in field use.

Abstract: A subterranean drill bit operable with a rotational drive source is provided for drilling in subterranean earthen materials to create a borehole having a borehole wall. The drill bit comprises a drill bit body having a base portion, a gauge portion and a face portion disposed about a bit axis. A plurality of diamond cutting elements are fixedly disposed on and project from the face portion and are spaced from one another. The cutting elements are disposed for causing a net radial imbalance force during the drilling along a net radial imbalance force vector substantially perpendicular to the bit axis. A substantially continuous cutter devoid region is disposed on the gauge portion about the force point, and a bearing support is disposed in the cutter devoid region about the force point for substantially continuously contacting the borehole wall during the drilling.

Abstract: A drill bit includes a drill bit body, a cutting member and a fluid course extending in front of the cutting member. The fluid course includes a progressively widening diffuser having a particular design which allows pressure recovery in a fluid flowed through an axial bore of the drill bit body, through a narrow throat of the fluid course in front of the cutting member, and out the progressively widening diffuser of the fluid course. As a result, a significantly reduced pressure is obtained in front of the cutting member, which reduced pressure is below a borehole pressure where the drill bit is used.