Bio Solvent EOR: Performance Assessment of Plant Extracts as Asphaltene Inhibitor

Abstract

Changes in pressure and temperature during oil production and transportation most notably during CO₂ injection for enhanced recovery could lead to changes in the oil composition and deposition of asphaltene. Deposition of asphaltene near the wellbore region, production tubing and production facilities could cause severe flow assurance problem. Physical removal of asphaltene is costly and in most cases it is not preferred. A more favorable option is to prevent the asphaltene from precipitation by using inhibitor. The present investigation is to examine the performance of green solvents extracted from plants (coconut, olive, palm, green tea, cinnamon and lemon grass) as asphaltene inhibitors and to compare their performance against a commercial inhibitor – Duo Benzene Sulphonic Acid (DBSA). Plant extracts are known to contain amphiphilic and phenolic compounds, which have the ability to inhibit asphaltene. The performance tests were carried out under different solvent type, concentration and contact time between oil and solvent. Then turbidity and UV-Vis were used to analyze the trace of solid deposits in the oil–solvent solution. It was found that solvent from coconut oil could reduce asphaltene deposit level the most when compared with solvents extracted from other plants. In fact, the coconut extracted solvent showed almost the same performance as that of DBSA at high dosage.

Keywords: Asphaltene deposition, green inhibitor, green solvent, bio solvent, flow assurance