API RP 13J

This standard covers the physical properties, potential contaminants, and test procedures for heavy brine fluids manufactured for use in oil and gas well drilling, completion, fracturing, and workover fluids.

This standard provides methods for assessing the performance and physical characteristics of heavy  brines for use in field operations. It includes procedures  for evaluating the density or specific gravity, the clarity or amount of particulate matter carried in the brines, the crystallization point or the temperature at which the brines make the transition between liquid and solid at atmospheric pressure (a discussion of crystallization temperature under pressure is provided in Annex C), the pH, iron contamination, and buffering capacity.