氯化钙水型油藏内源微生物激活剂研究

应用最大可能数法(MPN)和高通量测序分析新疆油田氯化钙水型油藏产出液中微生物群落结构。应用离子色谱分析了油藏地层水的离子组成,确定了激活内源微生物的基础及目标。确立以原油乳化效果、激活后烃氧化菌浓度为筛选激活剂的主要指标,进行了内源微生物激活剂的筛选。在单因素实验筛选最佳碳源、氮源和磷源后,采用均匀设计优化了激活剂组分含量,并进行了激活效果评价实验。实验结果表明:优化的激活剂激活地层水中内源微生物后,原油乳化效果明显,提高功能菌群烃氧化菌等菌浓5~6数量级,而硫酸盐还原菌被明显抑制;同时微生物群落结构发生明显改变,细菌生物多样性有所降低,实现了对Pseudomonas、Bacillus、Stenotrophomonas、Pusillimonas和Acinetobacter等常见采油功能菌的高效激活。

Study on indigenous microorganism activator in a Oil Reservoir of Calcium Chloride Water

The activator for enhancing oil recovery in Xinjiang oilfield with reservoir of calcium chloride water was studied. The structures of indigenous microbial community in formation water 9 Block were analyzed with the methods of MPN(most probable number)and high throughput sequencing. The ionic compositions of the water from oil field were also analyzed by means of ion chromatography. Thus, the foundation and objective for activating the indigenous microbial community were determined. In consideration of several mechanisms of enhancing oil recovery by microorganism, the effect of emulsification of crude oil and concentration of HOB were taken as evaluation indexes for screening and optimizing the activator. The optimal carbon source, nitrogen source and phosphorus source for 9 Block were selected by means o f single-factor test. Based on the single-factor test, the composition of the activator was optimized by homogeneous design. Afterwards, the effect of optimal activator on activation was evaluated. The result of these experiments revealed that after activation in 10 days the crude oil can be emulsified obviously by optimal activator,the concentration of HOB can be raised by 5-6 orders of magnitude and SRB are inhibited. Meanwhile, microbial structure community is changed, bacteria biodiversity decline, and functional bacteria including Pseudomonas, Bacillus, Stenotrophomonas, Pusillimonas, Acinetobacter, are activated efficiently.