Enhanced oil recovery with D-Limonene diluted in brine

Abstract

D-Limonene, a compound consisting of terpenes in its dextrogyrous form, is commonly used as a degreaser, hydrocarbon waste cleaner and as a sand oil separator. In this work, the use of this chemical is proposed as an alternative for enhanced oil recovery (EOR). Two oils from the southeast basin of Mexico (one medium and one extra-heavy oil) were tested for viscosity reduction with D-Limonene. The viscosity of the heavier oil @25 °C is 117,000 cP. The addition of 5% D-Limonene decreased the viscosity to 55,000 cP at same conditions, which corresponds to 53% reduction. The addition of D-Limonene also reduced the percentage of asphaltenes and paraffins in oil and increased the percentage of aromatics and resins (according to SARA analysis). D-Limonene was diluted (3% v/v) in brine and EOR tests were performed on a bioclastic sandstone rock with the medium oil. The rock has a helium permeability of 2.6 mD, slightly higher than the carbonated rocks, both characteristic of the Mexican Republic. The rock was characterized by scanning electron microscopy (SEM), porosimetry and X-ray diffraction. Contact angles were measured to know the humectability of rock with respect to oil, brine and D-Limonene. Coreflooding tests were carried out in a CoreFlood equipment at 50 °C and an average of 62.6% oil recovery with 3% D-Limonene diluted in brine was achieved. It should be noted that D-Limonene is a biodegradable and harmless product. • Oil recovery achieved with 3% D-Limonene diluted in brine was 62.6%. • Oil recovery achieved resembles other works using solvents, nanoparticles, or other chemicals with different toxicity • TD-Limonene is a biodegradable, environmentally friendly and harmless alternative product to the actual techniques of EOR