Covers heavy brines commonly used in petroleum and natural gas completion, workover and drill-in-fluids. These brines can be purchased or rented from multiple sources, and are available worldwide. No single source or limited source of supply is included., either by inference or reference. Also provides methodsfor assessing the performance and physical characteristics of heavy brines for used in field operations. It includes procedures for evaluating the density of specific gravity, clarity or amount of particulate matter carried in brine, crystillization point or the temperature (both ambient and under pressure) at which the brines make the transition between liquid and solid, pH, and iron contamination. It also contains a discussin of gas hydrate formation and mitigation, buffering capacity and a standardized reporting form. This edition of API 13J is the identical national adoption of ISO 13503-3:2005, Petroleum and natural gas industries-Competion fluids and materials-Part 3: Testing of heavy brines.