FIELD: physics.
SUBSTANCE: electromagnetic probe 1 measures electromagnetic properties of a geological formation GF in an bounded zone surrounding a well borehole WBH. The well-bore hole is filled with a well fluid DM. The probe comprises a pad 2 having a first face defining a first area meant to be in contact with the well borehole wall WBW. The probe 1 further comprises: at least two transmitting antennae 4A, 4B defining a central point CP between them, each antenna lying at a distance d0 from the central point, and at least a first 5A, 5B and a second set 5C, 5D of receiving antennae, each set comprising a first receiving antenna 5A, 5C and a second receiving antenna 5B, 5D. The first receiving antenna lies on one side of the transmitting antennae and the second receiving antenna lies on other side of the transmitting antennae so that each set encompass the transmitting antennae 4A, 4B. The probe 1 further comprises a coaxial cable with an open end 6A, placed on the first surface and lying perpendicular to the first area between the transmitting antenna 4A and the receiving antenna 5B.
EFFECT: high accuracy.
17 cl, 8 dwg
