Abstract: For clearing of the bore liners of geothermal wells, disclosed is a clearing tool that can be used without a drive motor, but with a drive hammer, to clear mineral deposits from the inside of the bore liners of geothermal wells. A forward end clears unwanted material from a live well. An aft end engages with a hammer device. The tool also has working surfaces to bear against and to cut through or to break up the unwanted material, at least one bypass passage conveying fluid from the live well through the clearing tool, and at least one exhaust passage communicating with the hammer device and conveying exhaust gases from the hammer to exhaust exit ports. The location of at least one exhaust exit port is a location that is situated aft of a forward face of the forward end of the clearing tool.