API RP 13M pdf download.Recommended Practice for the Measurement of Viscous Properties of Completion Fluids 2 Terms and definitions For the purposes of this document, the following terms and definitions apply. 2.1 bob fixed inner cylinder of a concentric-cylinder viscometer 2.2 completion fluid any fluid used during the completion phase of a well 2.3 concentric-cylinder viscometer rotational viscometer that consists...