Spectral Core Gamma System is capable of measuring the natural radioactivity from
cores. Using an advanced detector and data acquisition routine, Core Laboratories'
Spectral Core Gamma Unit offers: total gamma ray recorded in API units; elemental
contributions recorded in terms of Potassium (%), Uranium (ppm), and Thorium (ppm)
and a calibrated bulk density value. Core logging speed is variable - research experiments
with this unit have determined that the optimum data acquisition logging rate is
up to 2.75 feet per minute for four inch diameter cores and 0.55 feet per minute
for two inch diameter cores. A 6.5 inch diameter virgin lead shield around the detector
and tunnel minimizes background gamma radiation allowing core up to 5.5 inch in
diameter to be analyzed with minimal natural radiation interference. The use of
the latest Digital Signal Processing (DSP) technology allows improved signal to
noise ratio, enhanced resolution and superior data accuracy in the combined DSP/Amplifier
Board. Use of the board allows direct PC control of all signal processing, power
supply and amplifier functions for the detector.
Standard instrument is supplied with computer controlled conveyor system, detector
module, low level Cesium source for bulk density determination, control and data
acquisition module, computer hardware and software including HP DeskJet printer.
The Control software operates all verifier and measurement modes of the system.
The report software provides core gamma logs with both vertical and horizontal scaling
options, for compatibility with a variety of downhole logs. Data are logged to hard
disk. The conveyor, with all mechanical components, is integrated into a compact,
rugged, utilitarian system.