Research Of Chemistry-microbial Compound Viscosity Reduction In Heavy Oil Gathering And Transportation

With the continuous development of heavy oil exploitation, it has become an urgent task to transport heavy oil, The key to solve the transportation problem is to reduce the pour point and viscosity of heavy oil, which improve its liquidity, Liaohe heavy oil was used as the research objectives. This paper systematically studied the composition of emulsifying viscosity reducer, the screening of heavy oil degrading bacteria and its performance, gathering-transportation technology of chemistry-microbial compound viscosity reduction.Through orthogonal tests, the optimum formula of viscosity reducer was FB, which composed of op-10, NP-10, NaHCO3, TX-10, and mass ratio was 1:1:1:1. Effects of adding amount of reducer, oil-water volume ratio, temperature and other factors on viscosity reduction were investigated, Optimized conditions were determined that the optimum amount of thinning agent was 200mg/L, oil-water volume ratio was 7:3, processing temperature was 50℃. The heavy oil viscosity reduction rate reached 89.65% by using thinning agent FB, at the best conditions.With heavy oil as the sole carbon source, the F series heavy oil degrading bacteria were successfully screened from the soil, namely, F-1~F-3. Among which strain F-2 has fast growth rate, strongest ability to adapt environment, its microbial biomass was 2.34×109cfu/g, oil spreading diameter reached 5.6cm. Optimum culture conditions for strain F-2 was culture time-7d, concentration of K2HPO4-150mg/L, NH4NO3-100mg/L, oil-2g/L. According to infrared spectrum analysis, the bio-surfactant produced by strain F-2 was unsaturated ring sugar estersThe pH value continue decreasing during the fermentation process of F series strains, indicating acidic substances were form in that process. The effects of micro-organisms of time, inoculum size, temperature and other factors on the F-bacteria effect of degradation of heavy oil were investigate d, strain F-2 gaved the highest degradation tresults. The best conditions determined wasdegradation time: 6d, inoculum size: 6%, temperature: 45℃, the degradation rate of heavy oil under these conditions reached 81.28%, the type of emulsion were transformed into O/W type.Single strain F-2 and hybrid strain F-23 were used in the study of chemistry-microbial compound viscosity reduction technology, the effect of processing time, temperature, nutrient source and other factors on the viscosity reduction were investigated. The optimum processing time was 6d, temperature was 45℃, simultaneously needed to add nitrogen and phosphorus source. At experimental conditions, the heavy oil viscosity eventually reduced to 116.45mPa·s, the rate of viscosity reduction increased to 99.15%, solidifying point reduced to 22.0℃, pour point decreased for 5.5℃, which shown that complex viscosity reduction process could improve heavy oil'sproperties, this technology could be used in heavy oil gathering and transportation. The follow-up experiment was also carried out to study the demulsification in wastewater treatmen. SP-169 was used as demulsifier, the best demulsification conditions through the orthogonal experiment were determined as follow: the best temperature, processing time and adding amount were 30℃, 20min and 100mg/L, respectivly, the rate of dehydration reached 99.35%.