| 摘要 |
The disclosure is directed to an apparatus and method for determining dielectric constant and/or conductivity of earth formations surrounding a borehole. Electromagnetic energy is generated at a first location by transmitter T in the borehole and the relative attenuation thereof is detected at a second location in the borehole using a first or "close" differential receiver arrangement R1, R2. The relative phase of the electromagnetic energy is also detected at a third location in the borehole, the second location being between the first and third locations, by a second or "far" differential receiver arrangement R3, R4 located at the third location in the borehole. Means 100 are provided for determining the dielectric constant and/or the conductivity of the formations as a function of the detected relative attenuation and relative phase. In a further embodiment of the invention, the attenuation of the electromagnetic energy is also detected at the third location and then combined with the other information to obtain an "ultra deep" conductivity value. <IMAGE> |
