Determination of paraffin and asphaltene precipitation conditions: A study of flow assurance for heavy oil production

Abstract

Raw petroleum is a perplexing blend of hydrocarbons which comprises of aromatics, paraffin, naphthenic, saps and asphaltenes. At the point when the temperature of raw petroleum is decreased, the overwhelming parts, similar to paraffin, will accelerate and store on the pipe inner divider as a wax-oil gel. The gel store comprises of wax gems that trap some measure of oil. As the temperature gets cooler, more wax will precipitate and the thickness of the wax gel will increase, causing gradual solidification of the crude and eventually the oil stop moving inside the offshore pipeline. The presence of paraffin wax in heavy crude oil has caused variety of problems and fouling in wellbore, production tubing and refineries. It has change the flow behaviour of the heavy crude oil.In this study, nature of heavy components in heavy crude oil will be studied to understand well about the paraffin wax precipitation and depositional. Two type of heavy crude oil samples were used in this study and determination of Wax Appearance Temperature (WAT) by using three different method i.e. ASTM Standard Visual Method, Say-bolt Viscometer Methods and Differential Scanning Calorimeter. Comparison will be made among these three methods to test the experiment accuracy and its WAT sensitivity. Next, wax inhibitor i.e. Toluene and Cyclohexane will be added to the heavy crude oil specimen to test the possibility in WAT reduction. An overall understanding on the nature of paraffin wax, wax depositional mechanism and remediation techniques will be achieved.