不同金属离子条件下微生物对聚合物溶液黏度的影响及作用机制

Influence and mechanism of microbes on polymer solution viscosity in different metal ions conditions

为了减少采油过程中因为金属离子导致的聚合物黏损,从而提高原油采收率,利用从大庆油田腐蚀管道筛选出的降黏菌S,通过向聚合物培养基中添加不同种类及浓度的金属离子,将降黏菌S对聚合物黏度的影响及作用机制进行了研究。结果表明:在2 000 mg/L的聚合物质量浓度下,向基础降黏培养基中加入10~50 mg/L的金属离子,Mn^(2+)、Fe^(2+)和Fe^(3+)的加入可以很大程度地提高降黏菌S的降黏率,最高黏损率分别为38.3%、35.6%、34.7%;K~+的加入对降黏菌S的降黏率影响不大;Cu^(2+)、Zn^(2+)的加入会降低菌S所引起的黏损;因此要控制采油体系中Mn^(2+)、Fe^(2+)和Fe^(3+)的含量,从而降低聚合物黏损;K~+离子含量也不宜太多。适当增加采油体系中Zn^(2+)、Cu^(2+),减少聚合物黏损,或者将6种离子均以质量浓度30 mg/L混合加入会降低聚合物黏损。研究成果对油田减少聚合物黏损,提高原油采收率提供了一定的方法和理论支撑。

In order to reduce polymer viscosity loss caused by metal ions in oil production process and to enhance oil recovery,the influence and acting mechanism of viscosity reducing bacteria S on polymer viscosity is studied by adding different kinds and concentrations of metal ions to polymer culture medium using viscosity reducing bacteria S screened from corroded pipelines of Daqing Oilfield.The results show that at polymer concentration of 2000 mg/L,metal ions ranging from 10~50 mg/L are added to basic viscosity reducing medium,among which adding Mn2+,Fe2+and Fe3+significantly increases the viscosity reduction rate of viscosity reducing bacteria S,with the highest viscosity loss rates reaching 38.3%,35.6%and 34.7%,respectively.K+has little effect on the viscosity reduction rate of viscosity reducing bacteria S.Adding Cu2+and Zn2+reduces viscosity loss caused by bacterial S,thus it is necessary to control the content of Mn2+,Fe2+and Fe3+in oil recovery system,so as to reduce polymer vis-cosity loss.K+content also should not be too high.Properly increasing the contents of Zn2+and Cu2+in oil recovery system can reduce polymer viscosity loss,or mixing all 6 kinds of ions at concentration of 30 mg/L may reduce poly-mer viscosity loss.The research provides method and theoretical support for reducing polymer viscosity loss to en-hance oil recovery.