油气微生物数量变化特征模拟实验

Simulated experimental research on quantity change characteristics of oil and gas microorganisms

以江苏油田某油气区地表土壤样品为介质,构建了确定性油气背景信息的气藏和油藏模拟环境,通过模拟实验研究油气微生物在不同轻烃渗漏条件下的数量变化特征。结果表明,以轻烃为碳源的微生物在数量上呈现较快增长并最终达到平台期,无烃供给条件下,微生物数量逐渐减少。油气微生物数量与轻烃渗漏通量短期内正比,长期驯化后,不同轻烃体积分数所对应的微生物数量趋于一致。气指示基因pmoA和油指示基因bmoX分别对气藏环境和油藏环境具有良好的响应,特异性较强。在无烃供给的枯竭油藏模拟条件下,微生物呈消亡状态。模拟实验印证了地表油气微生物对下伏油气藏具有一定的响应,初步阐明了轻烃渗漏环境下油气微生物数量变化的特征。

Based on the surface soil samples of an oil and gas area in Jiangsu oilfield, a gas reservoir and reservoir simulation environment with certain oil and gas background information was constructed. The quantity change characteristics of oil and gas microorganisms under different light hydrocarbon seepage conditions were studied through simulation experiments by using surface soil samples from a certain area in Jiangsu oilfield. The results showed that the number of microorganisms using hydrocarbons as carbon source increased rapidly and finally reached a plateau stage, while the number of microorganisms without hydrocarbon supply decreased gradually. The number of microorganisms was proportional to light hydrocarbon leakage flux in a short time, however, after long-term domestication under different leakage flux, the number of microorganisms tended to be uniform. The abundance of gas indicator gene pmoA and oil indicator gene bmoX have good response and specificity to gas and oil reservoir environment respectively. Microorganisms were in a state of extinction under the simulation condition of exhausted reservoir without hydrocarbon supply. Through simulation experiments, the response of surface oil and gas microorganisms to underlying reservoirs is verified, and the quantitative variation characteristics of oil and gas microorganisms under light hydrocarbon seepage environment are preliminarily clarified.