This standard describes a test method to screen scale inhibitors for their ability to prevent precipitation of BaSO4 or SrSO4, or both, from oilfield brines. The test method does not fix such critical variables as test brine composition, test temperature, and test duration. It is the responsibility of the user of this standard to determine the most appropriate choices for these parameters. For example, Pritchard, et al.2 address static tests using North Sea brines. This standard is intended only for ranking the performance of different scale inhibitors under laboratory conditions. It is not intended to establish field treatment rates. CAUTION: Unique field conditions encountered may alter the performance ranking of the scale inhibitors. Factors such as reaction kinetics, fluid velocity, transient composition, temperature and pressure changes, scale adherence, and solids dispersion can significantly affect scale deposition under field conditions. Consideration of these parameters is outside the scope of this standard. However, field conditions, field brine composition, and other variables noted above should be considered at some point in the scale inhibitor evaluation prior to final selection for field use.