向油藏中注海水或采出水采油会促进硫酸盐还原菌（SRM）代谢生成H2S，导致油藏酸化，并由此引发微生物腐蚀等重大的环境及生产问题。已有研究表明，硝酸盐可通过调节油藏多种微生物生理类群的代谢过程抑制硫酸盐还原菌的活性，从而抑制油藏酸化。但油藏环境的巨大异质性和油藏内微生物群落结构和功能的多样性决定了油藏酸化及其控制的微生物学机理的复杂和不确定性。本项目以我国渤海湾海域高温油藏为研究对象，重点通过批次培养实验和模拟油藏酸化的微宇宙实验研究硝酸盐介导的硫酸盐还原、硝酸盐还原、硫化物氧化等过程及其交互作用规律，并采用454高通量测序技术结合功能基因阵列技术在微生物群落结构与功能水平上揭示渤海湾海域油藏酸化及其生物控制的微生物学机理。研究结果将丰富油藏环境中微生物生理生态学知识内涵，深化油藏生态系统中碳、硫、氮微生物地球化学循环关键过程及其交互作用的科学认识，并为我国海域油藏酸化控制研究提供科学依据。

Injection of sulfate-containing sea water or produced water into oil reservoirs to enhance oil production will stimulate the activities of sulfate-reducing microorganisms, with production of great amount of H2S, causing oil reservoir souring. The consequent problems such as microbial corrosion pose great challenges to oil industry. As previously reported, nitrate could mediate the activities of varieties of microorganisms,especially the heterotrophic nitrate-reducing bacteria and nitrate-reducing, sulfide-oxidizing bacteria to inhibit the oil reservoir souring. However, this process is strongly influenced by the great heterogeneities and diverse microbial communities among oil reservoirs.The microbiology of souring and its control by nitrate is still poorly understood in high-temperature offshore oil reservoirs at Bohai Bay. In this proposal, we aim to elucidate the microbial interactions of sulfate reduction, nitrate reduction and sulfide oxidation, by adopting pyrosequencing analysis and functional gene arrays techniques. The results are expected to throw light on how and to what extend nitrate mediates the element cycling of carbon,sulfur and nitrogen in high-temperature oil reservoirs, and to provide scientific clues for effective and efficient control of microbial souring in offshore oil reservoirs in China.