FIELD: mining.
SUBSTANCE: method is based on excitation of impulse electromagnet field and measurement of magnetic fields of eddy currents in rocks. Excitation of electromagnetic field is carried out with the help of electric dipole fed by impulse heteropolar current. Magnetic fields of eddy currents are measured in the period of pause between current pulses by small-sized inductive sensors oriented in three orthogonal directions. Commands are generated by analysis of eddy current magnetic field reduction curves to control position of drilling tool diverter. Device comprises chisel, downhole motor with orientator and diverter, measurement module. Measurement module is arranged in the form of non-magnet high-strength pipe with supply electrodes arranged at the ends, which is rigidly connected to drilling pipes and represents an electric dipole fed by pulse heteropolar current. Measurement module comprises small-sized inductive sensors arranged in pipe body.
EFFECT: increased efficiency of geosteering of horizontal wells in beds of small capacity reservoirs and in close proximity near top of oil or oil-gas reservoir.
2 cl, 4 dwg
