Microbial Paraffin-Removal Technology Using Paraffin-Degrading and Biosurfactant-Producing Strain

Abstract

Paraffin deposition on the walls of wells and collection pipelines, which causes problems for the production and transportation of crude oil, is a common phenomenon 1 .Several methods have been used to overcome the problem of paraffin deposition, including mechanical, thermal, chemical and microbial methods 2,3 . For mechanical treatment, which is not harm for the strata, but the stability is not strong, also is time-consuming. Thermal treatment, which is improved on paraffin removal, results in the formation damage by concentrating heavier ends of the oil and paraffin, which can be mobilized by the heat available through hot oiling, The chemical treatment, which needs less investment in equipment, is costly and highly toxic 4,5 . Microbial treatment has many outstanding advantages: simple construction, low operating costs, the role of a long cycle does not affect the quality of the oil strata without any damage.In this work, paraffin-degrading strain was obtained by separation and purification experiment from paraffinic oil production wells in Daqing Oilfield. The paraffin-degrading strain was named as P1 and biosurfactant-producing strain was named as S1. As an indicator of the degradation of paraffin, strain P1 and strain S1 were added in different proportions and then the optimum proportion was obtained. Research of mixed The paraffin-degrading strain, isolated from waxy oil production wells in Daqing oilfield, were obtained by separation and purification experiment. The paraffin-degrading strain P1 was identified through 16S rDNA sequence analysis, which exhibited the highest similarities to Bacillus anthracis strain XFB-BN. The biosurfactant-producing strain was obtained by laboratory saved. After paraffin-degrading and biosurfactant-producing strain treatment, the paraffin degradation rate could reach to 68.2 %, the paraffin prevention rate could reach to 80.7 %, the reduction rate of crude oil viscosity was 62.4 %. By analyzing the data, the paraffin-degrading and biosurfactant-producing strain had better effect on microbial prevention of wax deposition.