Adsorption and Desorption Characteristics of Mineral Scale Inhibitors as Related to the Design of Squeeze Treatments

Abstract

Abstract Five structurally different scale inhibitors were studied using a kinetic adsorption-desorption technique. Adsorption was fast. All inhibitors adsorbed to a similar degree. Desorption was slow. There were large differences in the degree to which different inhibitors desorbed. The kinetic desorption characteristics are more important in picking an appropriate squeeze chemical than are the adsorption characteristics. The study realistically modeled the flow rate, contact time and brine composition that might be found in an oilfield reservoir. Adsorption was measured on limestone at 40°C and sand at 40°C and 80°C. The inhibitors were diethylenetriamine pentamethylenephosphonic acid, hydroxyethylidene diphosphonic acid, a triethanolamine phosphate ester, a polyacrylic acid, and a polymeric phosphonate inhibitor.