Research on paraffin removal and prevention by Bacillus spp. in high-salinity reservoirs

ABSTRACT

Problems in paraffin deposition occur frequently in oil exploitation. Considering the problem that some paraffin removal and prevention strains cannot grow in high-salinity reservoirs, we domesticated four salt-tolerant laboratory bacterial strains. Crude oil emulsification effect, paraffin removal rate, and paraffin prevention rate of the strains were evaluated. KB and JH-A strains exhibited good paraffin removal and prevention effects, with paraffin removal rates of 51.82% and 81.56%; and 51.82% and 80.90%, respectively. Gas chromatography mass spectrometry analysis of paraffin components before and after biodegradation was performed on KB and JH-A strains. Results showed that relative contents of n-alkanes between C15–C23 and C27–C30 evidently decreased, indicating their good biodegradation. This technique provides a new method for practical application of paraffin removal and prevention in high-salinity reservoirs.

KEYWORDS:

• biodegradation
• crude oil emulsification
• GC-MS analysis
• high salinity reservoir
• paraffin removal and prevention

Acknowledgments

This research was supported by the National Natural Science Foundation of China (No. 51634008), by National Science and Technology Major Project (No. 2017ZX05009-004), and China Petroleum Science and Technology Major Project of Low Carbon Emission (No. 2016E-12).

Additional information

Funding

National Natural Science Foundation of China(51634008), China Petroleum Science and Technology Major Project of Low Carbon Emission(2016E-12), National Science and Technology Major Project(2017ZX05009-004)