Calcium Scale Inhibition of Stimulated Oilfield Produced Water Using Polyaspartic Acid/Aminomethanesulfonic Acid

Abstract Polyaspartic acid modified by sulfonic acid group (PASP/ASA) was synthesized and characterized, and then its comprehensive scale inhibition performance was tested in the laboratory simulated environment as an oilfield scale inhibitor. By statically experiment the performance of polyaspartic acid/aminomethanesulfonic acid in inhibiting CaSO 4 and CaCO 3 scale under different synthesis condition, results present that the maximum scale inhibition efficiency of the prepared PASP/ASA for CaSO 4 and CaCO 3 scale is 100 % and 83.36 % at the dosage of 2.5 mg L −1 and 10 mg L −1 , respectively. However, the average scale inhibition efficiency of PASP/ASA can reach 61.63 % which is higher than 51.21 % of PASP at both dosage of 30 mg L −1 . PASP/ASA and unmodified PASP exhibit unequal calcium scale inhibition performance because of the introduction of −SO 3 H. The scale crystal morphology analyzed by SEM and X‐ray diffraction revealed that the calcium scale crystals were eliminated in the presence of PASP/ASA by chelation, electrostatic dispersion and lattice distortion mechanism.