"FOREWORD a. This recommended practice in under the jurisdiction of the API committee on Standardization of Drilling fluid Materials. b. B. The purpose of this recommended practice is to provide standard procedures for the testing of drilling fluids. It is not a detailed manual on mud control procedures. It should be remembered that the agitation history and temperature of testing have a profound effect on mud properties c. Metric ""SI"" unit equivalents have been included in this publication in parentheses following the U.S. customary units. d. Additional publications under jurisdiction of this committee; Spec 13A Specification for Drilling Fluid Materials RP 13B-1 Recommended Practice for Standard Procedure for Field Testing Water-based Drilling Fluids RP 13B-2 Recommended Practice for Standard Procedure for Field Testing Oil-Based Drilling Fluids RP 13C Bulletin on Drilling Fluids Processing Equipment RP 13D Bulletin on the Rheology of Oil Well Drilling-Fluids RP 13E Recommended Practice for Shale Shaker Screen Cloth Designation RP 13G Recommended Practice for Drilling Mu Report From RP 13J Recommended practice for Testing heavy Brines RP 13K Recommended Practice for Chemical Analysis of Barite"