Experimental Study on the Effect of Inhibitors on Wax Deposition

Abstract

A challenge facing offshore oil production is wax deposition. It leads to increases in operational and remedial costs while suppressing oil production. Wax inhibitors are one of the mitigation technologies that had been examined its influence on crude oil viscosity, pour point and wax appearance temperature (WAT). The performance of some of wax inhibitors was evaluated to determine their effects on the pour point, wax appearance temperature and the viscosity of the crude oil using the programmable Rheometer rig at gradient temperatures (55°C) and shear rate 120 1/s before and after adding 1000 ppm and 2000 ppm of inhibitors to the crude oil. Three different inhibitors which were not tested before were prepared in the lab of this study. These inhibitors works well compared with its original components. The first inhibitor was coded Mix01 by mixing polyacrylate polymer (C16-C22), and copolymer + acrylated monomers. The reduction of pour point of the waxy crude oil was up to a 16.6oC at 2000 ppm concentration and this reduces the crude oil viscosity to about 61.9% at a seabed temperature of 4oC. The second inhibitor was coded Mix02, by mixing polyacrylate polymer (C16-C22), alkylated phenol in heavy aromatic naphtha, and copolymer dissolved in solvent naphtha. At 2000 ppm, the reduction of pour point of the crude oil up to a 15.9oC and decreases the viscosity to 57% at a seabed temperature of 4oC. Finally, the third inhibitor was Mix03, by mixing polyacrylate polymer (C16-C22), and brine (H2O + NaCl). At 1000 ppm concentration, the reduction of pour point of the oil was up to a 14.4oC and reduced the viscosity to 52.5% at a seabed temperature of 4oC. This unique blend of the inhibitory properties and significant reduction in pour point temperatures and crude oil viscosity is providing an original development in wax mitigation technology.