Evaluating the effect of emulsion on wax deposition prevention of oil from fang oil field

Abstract

Due to the COVID-19 situation, the energy consumption demand right now declines. However, the trend predicted by EIA is that the demand will be fully recovered at the end of 2022. Thus, it is important to maintain the production without disruption from flow assurance issue. In addition, wax deposition is one of the important issues for flow assurance. To manage the wax deposition, there are 3 major methods which are mechanical, thermal and chemical methods. The chemical method can easily be utilized. For this study, wax deposition prevention is studied with chemical method. Also, the study is investigating the effect of emulsion on wax deposition by using two chemicals, n-heptane and poly (maleic anhydride-alt-1-octadecane) or PMAO. Also, pour point, WAT and wax deposition are measured with several aspects such as emulsion, temperature and chemical concentration. For the effect of emulsion on the wax deposition, the presence of emulsion with increasing water cut initially increases amount of wax deposition in the case of water cut from 0% to 40% and the amount of wax deposition decreases by comparing amount of wax deposition from 40 to 80%. Also, for the effect of emulsion on wax inhibitor performance, water cut increases with more diminishing effect of wax inhibitor with all cases of inhibitor performance. For inhibitor performance, n-heptane plays a major role for pour point, wax appearance temperature and wax deposition measurement illustrated by the higher inhibitor performance comparing to the crude oil and its emulsion without chemical. Also, the performance increases with an increase in concentration. However, PMAO has its own optimum concentration at 7500 ppm which yields the highest effect of inhibitor performance for all cases of water cut and all shear rates for WAT. By adding more concentration for PMAO beyond optimum concentration, the inhibitor performance reduces comparing to optimum concentration. For the better effect of inhibitor performance, 10% and 15% n-heptane which exhibits the high performance and economical aspect and PMAO at 7500 ppm are mixed to obtain the optimum concentration. It is found that 15% n-heptane with 7500 ppm of PMAO yields higher inhibitor performance than that at 10% n-heptane with PMAO for amount of wax deposition.