75℃高温驱油菌的筛选及性能评价

Screening and Performance Evaluation of a Displancement Oil Strain at 75℃High Temperature

污水处理厂的活性污泥经下二门油田稠油驯化半年,从活性淤泥中分离得到一株75℃耐高温驱油功能菌HB,经16SrDNA鉴定其为嗜热芽孢杆菌（Thermophilic Bacillus）。考察了HB菌株的最佳正常条件及HB菌株采油能力。实验结果表明：在75℃培养条件下该菌在盐质量分数为0率3%,pH6.0～9.0,生长良好,其最适盐质量分数为1%,最适pH7.0。在最适生长条件下,油样1#质量浓度为5g/L、接种量为5%时,75℃、120r/min下培养10d,原油降解率可达33%,乳化指数EI为55%,表面张力从74.5mN/m降至41.2mN/m。经HB作用7d后,油样2#、3#中饱和烃所占相对比例降低,芳烃变化较小,非烃相对比例增加,说明HB对饱和烃具有降解作用,使得部分饱和烃转变为非烃;胶质沥青含量分别由28.0%、22.6%降为26.4%、19.9%;凝固点由29.4℃、28.1℃分别降为28.5℃、27.93℃。经HB作用20d后,1#、2#和3#油样的黏度分别由735、682和274mPa·s降至509、467和103mPa·s。微生物作用后原油组分发生改变,降低了原油黏度,改善了原油的物性。

A 75℃ high temperature resistant bacteria （HB）was isolated and cultured from the active sludge sewage treatment plant under the Xia＇ermen oilfield high viscosity heavy oil for domesticating of half a year. The HB was identified as a heat of the genus bacillus （Thermophilic Bacillus）by 16 S rDNA. The culture condition of HB and the performance of the oil recovery of the HB were investigated. The results showed that the HB got good adaptability under the culture condition of salt content of 0-3%, pH value of 6.0-9.0, and the optimum salt concentration and the optimum pH value was found to be 1% and 7.0, respectively. When the cells were grown at the dosage of 5% on optimal conditions oil degradation medium containing 5 g/L （l＇）crude oil at 75℃ and 120 r/min for 10 days, the HB could make oil degradation rate reach to 33%, the emulsified index was up to 55% and the surface tension of the fermented liquid reduced from 74.5 mN/m to 41.2 mN/m. After treated by HB for 7 days, the content of pectin and asphalt of 2#and 3# crude oil reduced from 28.0% and 22.6% to 26.4% and 19.9%, respectively, the freezing point of 2# and 3# crude oil reduced from 29.4℃ and 28.1℃ to 28.5℃ and 27.3℃, respectively. The viscosity of 1# ,2#and 3# crude oil reduced from 735, 682 and 274 mPa-s to 509, 467 and 103 mPa· s, respectively, after treated by HB for 20 d. In a word, microbial activity made the components of crude oil change and the oil property improve.