Patent attributes
An apparatus for reducing torque in a drill string includes a clamp assembly having a first clamp segment and a second clamp segment, the first and second clamp segments each including two circumferential ends, the two circumferential ends of the first clamp segment being configured to be connected to the two circumferential ends of the second clamp segment so as to secure the clamp assembly around an oilfield tubular and prevent the clamp assembly from rotating relative to the oilfield tubular. An outer diameter surface of each of the first and second clamp segments is generally continuous in an axial direction. The apparatus also includes an outer sleeve positioned around the clamp assembly, wherein the clamp assembly is configured to rotate with the oilfield tubular and with respect to the outer sleeve.