Correlation development of wax deposition prediction from fang oil field

Abstract

In petroleum industry, wax deposition is a critical operational challenge. It occurs in various locations in the petroleum production chain including well tubing. Hexane, chemical inhibitor, is used to prevent the wax problem of oil from Fang oilfield by the measurement of pour point, wax appearance temperature (WAT) and wax deposition. An increasing shear rate can reduce WAT and the deposited amount increases with lowering the temperature in Fang crude oil. Moreover, the non-linear regression analysis of Fang crude oil with and without hexane in different conditions are done for all three tests. Those regression analysis equations can predict WAT at different shear rates and wax deposited weight amount at different temperature of crude oil in Fang. The effects of parameters such as hexane concentration, temperature and shear rate on pour point, WAT and wax deposition are studied. The higher hexane concentration can reduce pour point. The more hexane concentration was used, the higher WAT reduction was observed. Both higher hexane concentration and temperature give the less amount of wax deposit. The calculated WAT is attained from intersection point between equations and modified Ronningsen’s correlation is used for wax deposition prediction. The percent difference between the experimental and calculated results are compared. Both increasing hexane concentration percent and shear rate make calculated WAT decrease and the selected equations can be applied in both concentration and shear rate perceptive. Increasing hexane concentration and decreasing temperature can lower wax deposition amount in Modified Ronningsen’s correlation and this correlation works well with both different solvent concentrations and temperatures.