API RP 13B-1 – Field Testing Water-based Drilling Fluids, Fifth Edition, Includes Errata 1 (2020) and Errata 2 (2021)
This recommended practice provides standard proceduresfor determining the following characteristics of water-baseddrilling fluids:
a) drilling fluid density (mud weight); b) viscosity and gel strength; c) filtration; d) water, oil, and solids contents; e) sand content; f) methylene blue capacity; g) pH; h) alkalinity and lime content; i) chloride content; j) total hardness as calcium; k) low-gravity solids and weighting material concentrations.
Annexes A through K provide additional test methods that may be used for:
chemical analysis for calcium, magnesium, calcium sulfate, sulfide, carbonate, and potassium;
determination of shear strength;
determination of resistivity;
removal of air;
drill-pipe corrosion monitoring;
sampling, inspection, and rejection;
rig-site sampling;
calibration and verification of glassware, thermometers, timers, viscometers, retort cup, and drilling fluid balances;
permeability plugging testing at high temperature and high pressure for two types of equipment;
