FIELD: physics; geophysics.
SUBSTANCE: invention relates to geoelectrical exploration. The device for determining subsurface properties has a long housing with a longitudinal axis and is designed for placing in the well. On the housing there is a transmitter which is designed for transmitting electromagnetic energy, and a receiver placed on the housing at a distance less than two inches (5 cm) from the transmitter and is meant for receiving electromagnetic energy. The transmitter or the receiver has at last one antenna, the axis of which is inclined towards the longitudinal axis of the housing. The transmitter and the receiver are placed in insulating material inside the long housing. The transmitter can operate at frequency ranging from 1 MHz to 500 MHz. The sensor can include a triaxial antenna system or an antenna system with cross-dipoles.
EFFECT: possibility of measuring resistivity of rocks with high resolution in wells, drilled using drill fluids of any type, including chemically based drill fluid; independence from deviation of the instrument.
22 cl, 19 dwg
