The paper French Creek presented at International Water Conference 2011, “Mineral Scale Prediction and Control at Extreme TDS” has been posted to the French Creek Software Online Library.
Abstract
Traditional methods for predicting mineral scale deposition and optimizing scale inhibitor dosages are not effective in high ionic strength brines such as shale fracturing flowback fluids. This paper discusses techniques for modeling scale formation and its inhibition in high to extreme TDS brines. The technology discussed is applicable to fracturing operations, produced waters, seawater membrane systems, and zero discharge industrial environments. The advantages and disadvantages of traditional and virial equation approaches are discussed on a practical basis. The thermodynamics and kinetics of mineral scale prediction and dosage optimization are discussed. Implications of open and closed systems, reducing and oxidizing environments are also covered.Authors note: This paper is directed towards engineers and water treatment chemists as a guide for choosing scale prediction methods which are accurate under the conditions they are evaluating, and to assist them in avoiding inapplicable indices such as the use of a simple index like the Langelier Saturation Index in predicting scale in high TDS reverse osmosis brines or extreme TDS flowback systems. It is not intended as a rigorous “how-to” for physical chemists.