Prospects of the Application of Modern Soft-Magnetic Materials in Magnetometric Geophysical Equipment

摘要

In the last decade, the development of borehole magnetometry has been determined by the increasing demand for magnetometric equipment and by the broadening scope of its application. At present, two types of three-component digital ferroprobe borehole magnetometer-inclinometers have been developed at the Institute of Geophysics, Ural Division of the Russian Academy of Sciences. The first type is based on the second harmonic, while the second one is of the time-pulse type. This equipment has been widely used for the prospecting and exploration of iron, non-ferrous and precious metals, and diamond and hydrocarbon deposits, as well as being utilized for the solution of technological problems in oil-and-gas fields. The application of these devices in fundamental research into the oceanic and continental crust, including investigations into deep and superdeep boreholes drilled in different regions of the former Soviet Union and abroad (Germany, Finland, and the Atlantic and Pacific oceans), became a new stage in the development of borehole magnetometry. In order to study the time variations in the Earth's magnetic field at geophysical observatories, magnetovariation stations, developed on the basis of the borehole ferroprobe magnetometer, are used in reference parametric boreholes and at the Kola Superdeep Borehole (Geolaboratory). In the course of geomagnetic investigations into such complex objects, specific features of measurements require not only highly sensitive, but also compact and reliable devices that can operate stably for long durations in the monitoring regime at high temperatures.