变异系数在油藏微生物激活剂筛选中的应用

为了筛选克拉玛依油田93#油井内源微生物最佳激活剂配方,采用不同激活剂对油藏微生物进行了选择性激活,对激活后的腐生菌、产甲烷菌、反硝化细菌、硫酸盐还原菌、硫细菌、铁细菌数量进行了检测,同时以变异系数为指标对激活效果进行评价,并结合原油降解率及降黏率进行验证。实验结果表明:当可溶性淀粉为碳源、KNO3为氮源、K2HPO4为磷源,且三者质量浓度分别为10,4,1 g/L时,能够较好地刺激油藏有益内源菌的生长,对硫酸盐还原菌、硫细菌、铁细菌等对采油不利的细菌起到一定的抑制作用,说明变异系数可以作为油藏微生物激活剂配方筛选的评价指标之一,为后续现场试验提供理论基础。

Application of variation coefficient in selection of reservoir microorganism activator

In order to select the best activator formula of indigenous microorganisms for No.93 oil well in Karamay Oilfield, different activator formula were used to activate the reservoir microorganisms seleetively. The saprophyte, methane-producing bacteria, denitrifying bacteria, sulfate-reducing bacteria, sulfur bacteria and iron bacteria were detected after activation. The activation effect was evaluated in terms of variation coefficient and was verified, combined with the degradation rate of crude oil and viscosity break rate. Experimental result shows that the growth of beneficial indigenous microorganisms can be activated, and the harmful bacteria for oil recovery, ineluding sulfate-redueing bacteria, sulfur bacteria and iron bacteria, can be inhibited when soluble starch is used as carbon source, KNO3 as nitrogen source, K2HPO4 as phosphorus source, and their concentration is respectively 10, 4, 1 g/L. It is stated that the variation coefficient is regarded as one of evaluation indexes for the selection of Ihe reservoir nfieroorganisms activator formula, which can provide a base for sequent field test.