A Physical Preventive Treatment of Crystallization and Precipitation in the Petroleum Industry

摘要

The plugging of tubings and pipelines by scale,rnasphaltene, and wax is a common problem in the oilrnproduction, transportation and refinery systems. Hotrnoiling, chemical wash and mechanical scraping havernbeen used for many years to restore flow. There may berneconomic benefit to implement preventive treatments. Wernpropose to consider the application of ultrasound as arnpotential preventive treatment. As a physical treatment,rnit is expected to be independent of the details of thernchemical nature of the problem, I.e., it should be equallyrnapplicable to particles such as salt crystals, asphaltenernprecipitates, or wax. We will present experimentalrnresults showing the effects of application of ultrasoundrnduring precipitation and crystallization. Three systemsrnwere tested in this study; crystallization of salt fromrnsaturated aqueous solutions, re-dispersion of asphaltenernin heptane, and pour point depression of diesel withrndifferent wax contents. The results show that, under therninfluence of ultrasound during the phase transition, therernwas a reduction of the size of the salt crystals,rnprecipitated asphaltene was re-dispersed, and therntemperature at the pour point of diesel with different waxrncontents was substantially lowered.