Antenna Of An Electromagnetic Probe For Investigating Geological Formations

摘要

An antenna 3 of an electromagnetic probe used in investigation of geological formations GF surrounding a borehole WBH comprises a conductive base 31 and an antenna element 32. The conductive base 31 comprises an opened non-resonant cavity 33. The antenna element 32 is embedded in the cavity 33 and goes right through the cavity. The antenna element 32 is isolated from the conductive base 31. The antenna element 32 is coupled to at least one electronic module via a first 34A and a second 34B port, respectively. The electronic module operates the antenna so as to define either a substantially pure magnetic dipole, or a substantially pure electric dipole.

主权项

1. An antenna of an electromagnetic probe used in investigation of geological formations surrounding a borehole comprising a conductive base and an antenna element, the conductive base comprising an opened non-resonant cavity, the antenna element being embedded in the cavity and going right through the cavity, the antenna configured to radiate a substantially symmetrical electromagnetic field, the antenna defining either a substantially pure magnetic dipole when the electronic module applies a current to the antenna element such that the current increases from one extremity to the middle of the antenna element and decreases from the middle of the antenna element to the other extremity, or a substantially pure electric dipole when the electronic module applies a current to the antenna element such that the current increases from one extremity to the middle of the antenna element and continues to increase from the middle of the antenna element to the other extremity.