METHOD AND APPARATUS FOR DETERMINING PERMEABLE ZONES IN SUBSURFACE EARTH FORMATIONS

摘要

METHOD AND APPARATUS FOR DETERMININGPERMEABLE ZONES IN SUBSURFACE EARTHFORMATIONSABSTRACT OF THE DISCLOSUREIn accordance with an illustrative embodiment of thepresent invention, a method and apparatus for logging an earthformation of interest is disclosed that provides an indicationof the presence of permeable and impermeable zones in the earthformation. As described more specifically in the disclosure,main and auxiliary currents are emitted into the earthformation surrounding the borehole. The currents are measuredand two parameters are produced: a first parameter that isrelated to the auxiliary current, and a second parameter relatedto the-main current and the first parameter. Furthermore, aratio of the second parameter to the first parameter is provided.These measurements are used to obtain indications of thepermeability of the subsurface earth formation.