Abstract: A method for analyzing fluid withdrawn from a subsurface formation includes disposing the withdrawn fluid in a chamber and maintaining the fluid in the chamber substantially at a same temperature and pressure as exists in the subsurface formation. Electric current is passed through the fluid in the chamber using at least one electrode made from a selected metal, the electric current comprising direct current and alternating current of frequency sufficient to determine at least one of (i) resistance of the fluid sample in the chamber directly and (ii) from the direct current determine a polarization resistance of the at least one electrode.

Abstract: A downhole communication system and method is presented for communicating between a downhole location within a wellbore and a surface location. The system preferably comprises a first and second telemetry module, a downhole tool, and an interface electrically connecting the downhole tool to the first and second telemetry modules. The first telemetry module is connected to a string and positioned downhole within the wellbore, and configured to receive communication signals via acoustic propagation or low frequency electromagnetic transmission. The second telemetry module is connected to the string and positioned downhole within the wellbore, and configured to receive communication signals via fluid pressure pulse commands. The downhole tool is operatively connected to the string. And the interface is adapted to selectively relay digital communication signals between the downhole tool and at least one of the first and second telemetry modules.