US Patent 7210529 Casing brush tool

A casing brush tool for cleaning interior walls of a well bore casing. The brush tool has a free rotating sleeve mounted on a mandrel with bearings mounted between the sleeve and the mandrel to facilitate rotation. The sleeve carries a plurality of non-axial rows of bristles that are arranged to wind in a spiral, or helical fashion from one end of the sleeve to the other end. When moved in and out of the casing, the spiral rows of bristles cause rotation of the sleeve and by contacting the walls of the casing, clean the casing of the extraneous matter. A casing brush assembly may incorporate one or more of the brush tools. If more than one brush tool is used, it is preferred to use the sleeves having opposite direction of bristle rows such that the sleeves rotate in opposite directions when lowered into the well bore or retrieved from the casing.