Alkalinity and phosphonate studies for scale prediction and prevention
Hunter, Margaret Ann
Tomson, Mason B.
Master of Science thesis
Scale formation is a problem in many processes that handle large volumes of water. The retention and release of phosphonates, as relates to their use in the squeeze procedure for the petroleum industry, were studied. A new method for measuring bicarbonate alkalinity in the presence of carboxylic acids was developed using a CO$\sb2$ evolution technique. Solubility and core flow-through experiments were used for phosphonate studies. Dissociation constants and solubility products for the aminomethyl and methyl phosphonic acids were determined at 70$\sp\circ$C. The effects of one, three and five phosphonate functional group(s) on the retention and the release of diethylenetriaminepenta(methylene phosphonic acid), aminotri(methylene phosphonic acid), aminomethylphosphonic acid, and methylphosphonic acid were examined. Amine functional group(s) have an effect on retention and release of the phosphonates. The retention of the amine phosphonates under acidic conditions is directly dependent on the number of phosphonate functional groups.
Environmental science; Geochemistry; Petroleum engineering