FIELD: measuring equipment.
SUBSTANCE: invention relates to downhole logging measurements, in particular to downhole electromagnetic logging tools. A downhole electromagnetic logging tool contains two or more antenna groups located at a distance from each other along the longitudinal axis of the logging tool. Any pair of antenna groups contains at least four antennas, wherein no more than three of these antennas have dipole moments that are inclined relatively to the longitudinal axis of the logging tool. Each group of antennas contains at least one antenna having a dipole moment that is inclined relatively to the longitudinal axis of the logging tool. Dipole moments of antennas of the specified at least four antennas that are not parallel to the longitudinal axis of the logging tool lie in different azimuthal planes. Antennas that are in the same antenna group are located next to each other or in the same location. The logging tool is located in a well penetrating through a reservoir, and, during rotation, it measures a rotation angle of a tool, transmits an electromagnetic signal with one antenna group and receives an electromagnetic signal with another antenna group. Components of a tensor of electromagnetic coupling are determined using the received electromagnetic signal and the measured rotation angle of the tool. Properties of the reservoir are determined using components of a certain tensor of electromagnetic coupling.
EFFECT: determination of total tensor of electromagnetic coupling.
20 cl, 10 dwg
