Abstract: Improved method and apparatus for directionally applying high pressure jets to well casing or liners to clean openings in the casing, liner and the adjacent geologic formation which are plugged with foreign matter. High velocity jets of liquid having a velocity in excess of 700 feet per second are jetted from jet orifices having a 1/16th to 1/4th inch diameter and having a standoff distance between 5 and 100 diameters of the orifice from the openings to remove substantially all plugging material from the openings. Power swivels permit rotation and Kelly hoses allow reciprocation of the jet tool and tubing string while maintaining high pressure in the apparatus.