Microbes can improve the fluidity of waxy crude oil and increase the efficiency of transportation. The cultured Bacillus subtilis 6# and Pseudomonas aeruginosa 3# were mixed and cultured in a ratio of 2∶3, the growth conditions were optimized. DSC, polarizing microscope, HAKEE rheometer and interfacial tensiometer were used to analyze the effect of compound bacteria and waxy crude oil. The results showed that: after treatment with compound bacteria, the wax precipitation point of waxy crude oil decreased by 2.23 ℃, the peak point of wax precipitation decreased by 2.71 ℃, and the wax content of crude oil decreased by 51.64%; the wax crystal structure changed significantly; the apparent viscosity of crude oil decreased by 64.72% at 37 ℃. In addition, the emulsification index of the compound bacteria on liquid paraffin was 55.39%, and the surface tension of the liquid paraffin culture medium was reduced from 79.89 mN/m to 38.83 mN/m. Compared with single bacteria, compound bacteria are more effective in removing wax and reducing viscosity, and have wider application prospects.

Microbial paraffin removal and prevention has the advantages of low cost, safe operation and no damage to the formation. The effects of complex environment on microbial degradation were introduced, the effects of microbial degradation enzymes were analyzed,the effects of organic solvents and biological surfactants produced by microorganisms on the degradation of waxy crude oil were elaborated. Based on this, it is pointed out that the microbial technology should strengthen the research on the production mechanism of microbial degradation enzyme, organic solvent and surfactant, so that the microbial degradation of waxy crude oil has a broader application prospect