Using a New Mixture of Reagents for Effective Inhibition of Corrosion and Salt Precipitation in the Petroleum Industry
Azizollah Khormali
Abstract
In recent years, universal inhibitors capable of inhibiting both corrosion and salts have attracted much attention in the petroleum industry. In this work, various industrial scale and corrosion inhibitors were used to develop a new mixture of reagents for the prevention of calcium carbonate, barium sulfate, calcium sulfate, and corrosion. The developed mixture of reagents (named DAHAPZ) consists of the following components: DTPMP, ATMP, HEDP, 2-aminoN-decyl-3-phenyl propionamide, 2-propyl-3-ethyl-8-oxychinolin – ZnCl2. When using DAHAPZ, an inhibition efficiency of more than 92% was observed for salts of CaCO3, BaSO4, and CaSO4) and corrosion (for a steel carbon in an acidic environment). After the application of DAHAPZ, the corrosion rate was reduced from 2 mm/year to 0.04 mm/year (an efficiency of 98%). The results of the impedance spectrum test showed that the optimal concentration of DAHAPZ for effective inhibition is 30 ppm. Furthermore, the turbidity test and the measurement of the amount of precipitated salts confirmed the high inhibition performance of DAHAPZ to prevent salt precipitation. DAHAPZ inhibits the salt crystals, which could serve as a protective barrier, thereby reducing the corrosion rate at various temperatures. The deceleration of the crystal growth rate when using DAHAPZ is associated with effective adsorption on the crystals, and a decrease in the crystal surface area for growth. Also, the results of coreflood experiments on the adsorption of the reagents onto the carbonate and sandstone rocks showed that DAHAPZ is more suitable to be used in carbonate reservoirs.