Investigation of the effects of salinity on the amount of asphaltene formed from emulsions Water–Oil

Abstract

Asphaltene deposition is a very serious issue that in addition to clogging the pores, changes wettability, reduces permeability, and, as a result, reduces production and increases process costs. Recent research has shown that water formation can affect asphaltene deposition. In this regard, the effect of various salts including NaCl, KCl, CaCl2, and Na2SO4 in concentrations of 5000, 10000, 20000, 50000, and 100000 ppm on the amount of asphaltene formed from water–oil emulsions was investigated. The ratio of oil to saline water used in this experiment is 1 to 4 and also the amount of asphaltene in the oil used is 5.725%. These experiments were performed by the standard IP-143 test. It was observed that with the increasing concentration of NaCl and KCl, the amount of asphaltene in the oil phase decreases that is due to the presence of monovalent ions. In CaCl2 and Na2SO4 salts due to the presence of ions, multi-capacitance increases. Asphaltene has an aromatic structure with N-, S-, and O- atoms. These functional groups in crude oil with sometimes acidic media can be protonated to form states of organic salts. Moreover, some parts of asphaltene have more electromagnetic properties, which create an oscillating peak.