API Spec 13A (R2015)

This International Standard covers physical properties and test procedures for materials manufactured for use in oil- and gas-well drilling fluids. The materials covered are barite, haematite, bentonite, nontreated bentonite, OCMA-grade bentonite, attapulgite, sepiolite, technical-grade low-viscosity carboxymethylcellulose (CMC LVT), technical-grade high-viscosity carboxymethylcellulose (CMC-HVT), starch, low-viscosity polyanionic cellulose (PAC-LV), high-viscosity polyanionic cellulose (PAC-HV), drilling-grade Xanthan gum, and barite 4,1. This International Standard is intended for the use of manufacturers of named products.

This edition of API Spec 13A is the identical national adoption of ISO 13500, Petroleum and natural gas industries-Drilling Fluids-Specifications and testing, and includes the addition of an API Monogram Annex.