Abstract: A system and method for performing seismic prospecting and monitoring during drilling of a well are disclosed. The system generates energy, such as acoustic vibrations and electromagnetic energy, at a downhole location and imparts the same into the surrounding earth. The energy may be imparted by the drilling operation itself, or may be generated by a downhole apparatus. Downhole sensors are provided which sense the energy after it has passed through the earth surrounding the wellbore. The sensed energy is either communicated to the surface, or is communicated to a downhole computer for analysis, with the results of the analysis communicated to the surface. Due to the use of both downhole generation and sensing of the energy, high frequency energy may be used. As a result, the resolution of the resulting survey is improved over techniques which utilize surface detectors for energy traveling through the earth.

Abstract: A phase shift keyed telemetry system is disclosed, which is particularly adapted to demodulation of phase shift keyed signals where the medium of transmission is non-ideal, such that transitional cycles are present at each change of phase of the transmitted data. Demodulation is accomplished by comparison of the input signal to a reference signal generated from the input signal itself. The reference signal is generated by frequency dividing the input signal, preferably after full wave rectifying, by a multiple which is larger than the number of transitional cycles expected; the frequency divided signal is then multiplied in frequency to substantially match the frequency of the input signal. The use of the divider and multiplier removes the effects of transitional cycles of varying phase in generating the reference signal.

Abstract: A cryosonde for a logging tool wherein the refrigerant chamber for cooling the germanium crystal detector has an easily replaceable rupture means which will fail before the chamber, itself, will rupture.

Abstract: An improved strobe lamp holder is formed of a member with a semi-circular appearing, trough-like, reflective curved inner surface in the direction of the axis of the member. Covering the light emitting opening of the lamp is a light diffusing material. Covering the open ends of the trough-like curved surface is a light confining material. The holder is adapted for placement of a strobe bulb inside the trough-like curved surface, diffusive material and light confining ends is a strobe bulb. The improved strobe lamp holder is adapted to emit light rays in a predominantly rectangular pattern with the length of the rectangle oriented perpendicular to the axis of the reflecting curved surface. The improved strobe lamp holder is designed for use in centrifuge measurement of liquid production into or out of mineral cores.