METHOD FOR DIRECT SEARCH FOR LOCAL OBJECTS IN OFFSHORE AND DEVICE WHICH IMPLEMENTS SAID METHOD FOR MID-SEA Russian patent published in 1998 - IPC

FIELD: prospecting in offshore in regions both covered with polar ice and in mid-sea using circular electric dipole. SUBSTANCE: method involves induction of electromagnetic field by means of axial-symmetry application of electric field to ground by means of circular electric dipole which is designed as supplying electrodes, one of which is located in central region of circumference which radius is R and which is shaped by external supplying electrodes, which are connected to central electrode by means of power supply lines. Then method involves measuring of transient mode of electric and magnetic constituents of field along radial lines from center of circumference and judging characteristics of environment under investigation using these results. Circular electric dipole radius R is not less than quarter of required depth of investigation. Maximal working current in each power supply line is set by alternation of area of connection of electrode surface to sea water. Electric constituent is measured only in presence of magnetic constituent. Area of investigation is limited to circle which radius is less than 5R. Design of device which implements said method in mid-sea involves combination of power supply electrodes with buoy. Power supply lines are located inside pieces of insulated cable which provides mechanical connection between central buoy with housings of external buoys each of which is connected to two adjacent buoys by means of identical pieces of non-conducting cable and has electric motor which is connected to screw propeller by shaft. EFFECT: increased functional capabilities. 3 cl, 4 dwg