Preparation and application of new polycarboxylic acid for scale inhibition

Abstract

In oilfield, scaling caused by water injection is becoming increasingly serious by blocking the gathering and transmission pipelines of the oilfield and resulting in a decline in oilfield production and a great loss of production. Oil and gas leakage caused by pipeline scaling, corrosion and perforation has caused irreversible damage to the surrounding environment. In this paper, citric acid and sodium pyrophosphate are used as the main agents, and hydrolytic polymaleic anhydride, polyaspartic sodium and polyepoxysuccinic acid are respectively compounded to establish polycarboxylic acid scale inhibitor. The scale inhibition experiments of CaCO3, CaSO4 and BaSO4 were carried out to obtain a new type of highly effective polycarboxylic acid scale inhibitor formula. For CaCO3, the best formula is 200 ppm citric acid + 30 ppm hydrolyzed polymaleic anhydride. For CaSO4, the best formula is 100 ppm citric acid + 5 ppm sodium polyaspartate.