| 摘要 |
<p>The disclosure is directed to an apparatus and method for determining the water-filled porosity of formations surrounding a borehole by means of an electromagnetic propagation tool. In accordance with one embodiment, a transmitter emits microwave electromagnetic energy into a borehole which is received by two spaced apart receivers within the borehole. The received signals are uti-lized to obtain the attenuation and the relative phase shift of the microwave electromagnetic energy propagating between the spaced locations. The conductivity of the water in the formations surrounding the spaced locations is deter-mined, for example, from the conductivity of the drilling mud being utilized and the nature of the mud filtrate resulting from invasion of the formations by the drilling mud. An indication of the water-filled porosity, .PHI.w, of the formations adjacent the region of the spaced locations in the borehole is provided by a quantity which is directly proportional to the product of the attenuation and phase shift quantities and inversely proportional to the conductivity of the for-mation water.</p> |
