BGR-01 Gamma And Electrical Property Probe

The BGR-01 combination probe contains the gamma detector and the electrodes for the resistivity measurement. The probe has a 40-mm diameter non- magnetic non- conductive housing, which is pressure, rated to 3,000 meters. The probe is controlled by an on- board microprocessor that samples the potential between the two electrode arrays at a rate of 2 samples per second. The potential range of the measurement is +/-50V and has a resolution of 0.1mV. When switching the current generator "OFF" the BGR-01 probe will measure the spontaneous potential voltages in the borehole.

The signals from the gamma sensor in the probe are integrated in four different energy windows over a time of 0.5 seconds. The four windows are calibrated to the four windows:

• Total Count = 0.10 - 3.00 MeV
• Potassium (K₄₀) = 1.37 - 1.57 MeV
• Uranium (Bi₂₁₄) = 1.66 - 1.86 MeV
• Thorium (Tl₂₀₈) = 2.40 - 2.80 MeV

The standard gamma detector used in the probe is a 25mm by 76 mm crystal ( 1”x 3 “ CsI ). Larger sizes are available and are listed under options.
The gamma / resistivity combination probe is designed for use with all standard IFG logging systems that include the BIN-04 digital data interface, 4 conductor logging cable and the data acquisition software. The probe is controlled by an on-board microprocessor that transmits all the data along the logging cable to the surface console for the re-formatting and the transfer to a microcomputer. The microcomputer and the acquisition software (DAS) display and record the data in real time. Up to a total of 20 different parameters can be viewed during logging, in either graphic or numeric format. The recording format is in continuos or incremental mode.

Post processing software (PC-LOG) is available to process the recorded data. For this process the probe can be calibrated for window stripping, dead time corrections and to compute the energy concentration in parts per million (ppm).