What causes asphaltene precipitation?
Asphaltene precipitation is caused by a number of factors including changes in pressure, temperature, and composition. The two most prevalent causes of asphaltene precipitation in the reservoir are decreasing pressure and mixing of oil with injected solvent in improved oil recovery (IOR) processes.
What is asphaltene onset pressure?
1. n. [Enhanced Oil Recovery] As pressure decreases, the pressure at a given test temperature that first causes asphaltene to precipitate from a reservoir fluid.
How do you prevent asphaltene deposition?
One method to prevent or reduce asphaltene deposition in the wells is to control pressure, temperature and/or flow rate to avoid the conditions where asphaltenes precipitate.
What is asphaltene used for?
Asphaltenes in the form of asphalt or bitumen products from oil refineries are used as paving materials on roads, shingles for roofs, and waterproof coatings on building foundations.
What is asphaltene content?
Asphaltenes are complex, highly aromatic compounds with a high-molecular weight that usually contain sulphur, nitrogen, and oxygen as well as metals such as vanadium, nickel, and iron.
How do you test for asphaltenes?
Some of the older but more popular methods for determining the stability of asphaltenes are the Asphaltene–Resin ratio and the Oliensis Spot Test. Newer tests include solvent titration with solids detection and the Colloidal Instability Index (CII).
How do you treat asphaltene?
Until recently, the conventional way to treat asphaltene deposition was through remediation. Remediation methods include solvent soaks with aromatic solvents and/or aromatic solvents blended with dispersants and physical removal such as wirelining, pigging, hydroblasting, and drilling.
What causes asphaltene in diesel fuel?
Asphaltenes are formed when diesel fuel is heated under high pressure as it passes through fuel injection systems. The increase in pressure, new fuel injection system combined with high temperatures actually cook fuel and can create small pieces of tar about 2 microns in size — asphaltenes.