A small-diameter three-component fluxgate magnetometer probe with gyroscopic and inclinometer orientation has been developed to meet U. S. Geological Survey design and performance specifications for measurement of the direction and intensity of the Earth's magnetic field in vertical and inclined boreholes. The orthogonal fluxgate magnetometer elements have a measurement resolution of 10 nanoteslas (nT) and a range of plus or minus 80,000 nT. The gyroscope has an effective resolution of one degree, and the orthogonal inclinometers, 0. 1 degree. The magnetometer probe has been field tested in several holes drilled through volcanic rocks in Nevada. Results indicate that reversals of polarization can be detected, and some rock units in this area appear to be characterized by unique magnetic signatures.
Additional publication details
THREE-COMPONENT BOREHOLE MAGNETOMETER PROBE FOR MINERAL INVESTIGATIONS AND GEOLOGIC RESEARCH.
Soc of Professional Well Log Analysts
Houston, TX, USA
Larger Work Title:
Transactions of the SPWLA Annual Logging Symposium (Society of Professional Well Log Analysts)
Transactions of the SPWLA Twenty-Sixth Annual Logging Symposium.