GeoVista - GV International products

Geovista probes can be run alone or connected as a single tool string according to requirements or convenience.

The Data Acquisition System includes a logger to supply power and for bidirectional communication with the probes, and software providing a user interface.

Natural gamma probes measure gamma radiation that is emitted by geological units, the intensity of which depends on the concentration of different radioactive isotopes therein. Geovista has options to meet varying deployment requirements, including filtered sonde for filtering out lower energy gamma and GM probes for high count rates.

The Spectral Gamma sonde measures gamma ray energy to identify and quantify gamma emitting isotopes in strata. The sonde provides a total counts per second value and (if calibrated) a breakdown of K (%), U (ppm), and Th (ppm), calculated from the measured energy spectrum.

The Geovista ELOG probe records 16" and 64" normal resistivity, single point resistance (SPR), and spontaneous potential (SP) measurements. Resistivity logging is widely used in mineral exploration, hydrogeology, formation evaluation, and many other applications.

The Dual Guard Focused Resistivity Probe (DLL3) measures both deep and shallow focussed resistivity, as well as spontaneous potential (SP) from the bridle electrode, it fias superior vertical resolution and depth of penetration than the conventional ELOG probe.

The Geovista Induced Polarisation (IP) Probe comprises four electrodes in AB-MN Wenner configuration. A high DC voltage with alternating polarity is periodically applied to the outer two electrodes. This voltage is applied for a fixed time and then the decaying voltage is measured at the inner two electrodes after a brief delay. The polarizability of different materials is dependent on the electronic configuration. In strata containing metals, the difference in the rate of electrolytic reactions when a current passes across conductive metal grains causes polarisation. An IP effect is also evident when a current is applied to certain clay minerals with surficial negative charges.

This probe boasts a high performance 3-axis fluxgate sensor and a 2-axis accelerometer. The sensors come in three versions according to their measurement noise floor: basic, standard, and low noise. These are used to obtain the values of the resultant of the anomalous vector components after the removal of the normal field. The probe comes with a choice of optional ranges and noise levels and the accelerometer allows for output correction in inclined boreholes. The Magnetometer Probe measures the three orthogonal components of the total.