Surface-to-Borehole Electromagnetic Experiment at Roosevelt Hot Springs: A Feasibility Study

Abstract

The electrical resistivity structure of a geothermal reservoir is a function of many reservoir properties, such as temperature, water salinity, the presence of stream, hydrothermal alteration mineralogy, porosity, and fracture density and orientation. Thus, determining the resistivity structure of a particular reservoir can be of great use in planning optimal exploitation of the resource. There are many conceivable ways of estimating the resistivity structure of a reservoir form geophysical measurements. In this paper, we describe one method in which a coil receiver is situated in borehole and the transmitter is a current line grounded on the earth's surface. This particular method is easy to use in the field and can give good resolution of conductive features to detect fracture zones at depth in the vicinity of Well-9 at Roosevelt Hot Springs.