ppm — Oil & Gas Glossary

Abbreviation for the expression of concentration, parts-per-million. For solid and liquid concentrations, ppm is stated in weight (mass) units. For example: (1) Calcite in a ground barite sample is 400 ppm. (2) Calcium chloride in a water solution is 250,000 ppm. Note that the relationship of ppm to weight percentage is 10,000 ppm = 1 wt.%. For gases, ppm is