A crude oil sample from an oil field in the Middle East was used with an initial viscosity of 336 cp at room temperature and pressure. The asphaltene content in the crude oil was measured using SARA analysis. Following this, a specific volume of the chemical agents was added to the crude oil to measure the viscosity change and the asphaltene behavior. Finally, tests were performed to restabilize asphaltene after it was deposited using different chemical agents. The chemical agents tested were sodium hydroxide, sodium metasilicate, and acetone.
The asphaltene content in the crude oil was measured to be 8.17% by weight using the SARA analysis. To induce asphaltene precipitation, heptane was used. The heptane was mixed with the crude oil using 10% by weight heptane. The solution was mixed vigorously and was left overnight for asphaltene deposition to occur. The phases of asphaltene deposition were monitored and recorded using a high-definition camera. These included asphaltene precipitation (observed using Tyndall Effect), asphaltene flocculation, and finally asphaltene deposition. Following this, asphaltene mitigation was studied using different chemical agents. It was found that the sodium hydroxide had a strong impact on the crude oil due to the high acidity of the oil sample. Sodium metasilicate did not impact the stability of asphaltene greatly. Finally, acetone had a strong impact on asphaltene stabilization, however more than 15% by weight had to be added before the effect was observed. For all experiments, asphaltene stabilization on a 100 ml crude oil sample initiated after a minimum of 30 minutes after integration of the chemical agent. The longest duration for the impact to be observed was 3 hours.
This research shows the significance of utilizing unconventional chemical agents in the mitigation of asphaltene deposition in wellbores and pipelines. This can help reduce equipment failure in the wellbore and can mitigate severe problems that might occur in pipeline during hydrocarbon transportation.