聚驱后微生物驱提高采收率室内实验研究

Indoors Laboratory Study on MEOR after Polymer Flooding

从大庆油田各聚驱区块取样256个,从中优选出4株以聚合物和原油为碳源的菌株,鉴定P24为志贺氏菌(Shigellasp.)、P150为脱蜡棒杆菌(Corynebacterium deparraffinicum)、P178为野油菜黄单胞菌(Xanthomonascampestris)、L510为枯草芽孢杆菌(Bacillus subtilis)。菌株在聚合物条件下生长,活菌数达106～107个.mL-1,聚合物溶液粘度由18.6mPa.s降至1.0mPa.s。菌株在模拟油层厌氧条件下生长繁殖,作用后原油全烃色谱分析表明,∑C21/∑C22比值增加了61.7%,(C21+C22)/(C28+C29)比值增加了60.8%,饱和烃含量平均增加11.37%,芳烃含量降低,非烃和沥青质含量分别减少6.6%和2.9%,含蜡量、含胶量分别降低了17.56%和26.54%,恩氏蒸馏的初馏点下降了80℃,凝固点由41℃降至28℃。物理模拟驱油实验表明,聚驱后微生物驱可比聚驱提高采收率3%～5%(OOIP),聚驱后微生物驱再加上后续聚驱保护段塞的注入方式可进一步提高采收率7%(OOIP)以上,模型实验的重复性较好。

Lab research on MEOR applied after polymer flooding had been studied in this paper. 256 Samples were chosen from polymer flooding areas,from which 4 strains with polymer and oil as carbon source were se- lected out. Strains P24,P150,P178 and L510 were identified to be Shigella sp. ,Corynebacteriurn deparraffini- curn,Xanthomonas campestris arid Bacillus subtilis. When strains grew in polymer solutions, the live strain number achieved to 106 -107 cell · mL-1 ,and viscosity of polymer solution decreased from 18.6 mPa · s to 1.0 mPa· s. When the strains grew under simulated anaerobic environmental condition, for the crude oil reacted with strains,the total hydrocarbon chromatographic analysis results showed that the ratio of ∑C21/∑C22 in- creased 61.7 %, and the ratio of （C21 ＋ C22 ）/（C28 ＋ C29 ） increased 60.8%, the wax content and colloid content decreased 17.56% and 26.54% respectively;the initial boiling point for Engler distillation decreased 80 °C ;the freezing point decreased from 41 °C to 28 °C ;the saturated hydrocarbon content increased 11.37%, arene con- tent decreased, non-hydrocarbon content and asphaltene content decreased 6.6 % and 2.9 %, respectively. Physi- cal simulation displacement experiments showed that MEOR applied after polymer flooding enhanced oil recovery 3-5% （OOIP） than polymer flooding. MEOR with subsequent polymer flooding enhanced oil recovery 7% （OOIP） than polymer flooding,and the experimental results had good repeatability.