Li Lei, Zhang Chunhui, Su Peidong, Mu Hongmei
School of Chemical & Environmental Engineering, China University of Mining & Technology (Beijing), Beijing 100083, China.
State Key Joint Laboratory of Environment Simulation and Pollution Control, School of Environment, Tsinghua University, Beijing 100084, China.
Microorganisms. 2025 Mar 25;13(4):738. doi: 10.3390/microorganisms13040738.
Silicate bacteria, capable of decomposing silicate minerals that are widely distributed in oil reservoirs, have never been applied in microbial enhanced oil recovery (MEOR). This study investigated a typical silicate bacterium () for the first time in a simulation experiment on low-permeability cores. Meanwhile, a biosurfactant-producing bacterium () and an acid-producing bacterium () that have been widely studied and applied in MEOR were used for comparison. The results show that although is inferior to and in terms of enhancement of oil recovery at the microbial flooding stage, it can maintain efficient dissolution of minerals over extended periods during the subsequent water flooding stage. This is different from the other two bacteria and ultimately leads to a 6.9% enhancement in oil recovery (7.9% for and 4.8% for ). improves oil recovery by increasing the porosity (1.4%) and permeability (12.3 mD) of low-permeability cores through biological weathering. The μCT results show that the pore quantity and pore volume across varying pore radii in low-permeability cores are altered after the MEOR simulation experiment by reducing the quantity and volume of pores with radii less than 10 μm and increasing the quantity and volume of pores with radii between 10 and 25 μm. Under MEOR simulation experimental conditions, slightly degrade saturated hydrocarbons (1.9%), mainly the n-alkanes of C11-C20, but cannot degrade aromatic hydrocarbons, resins, and asphaltenes. The enhanced oil recovery by is attributed to its bio-dissolution under neutral pH conditions, which prevents acid sensitivity damage to low-permeability cores. Thus, its MEOR characteristics are significantly different from the biosurfactant-producing bacterium and acid-producing bacterium . Injecting at the early stages of reservoir development or using it together with other microorganisms should maximize its MEOR effect. This study advances the MEOR framework by extending silicate-dissolving bacteria from agricultural microbial fertilizer systems to MEOR in low-permeability reservoirs, revealing the broad prospects of mineral-targeting microbes for both research and industrial applications in MEOR.
硅酸盐细菌能够分解广泛分布于油藏中的硅酸盐矿物，但从未应用于微生物强化采油（MEOR）。本研究首次在低渗透岩心模拟实验中对一种典型的硅酸盐细菌（）进行了研究。同时，将一种已在MEOR中得到广泛研究和应用的产生物表面活性剂细菌（）和产酸细菌（）用于对比。结果表明，虽然在微生物驱油阶段提高采收率方面不如和，但在后续水驱阶段，它能在较长时间内保持对矿物的高效溶解。这与另外两种细菌不同，最终导致采收率提高了6.9%（为7.9%，为4.8%）。通过生物风化作用增加低渗透岩心的孔隙度（1.4%）和渗透率（12.3毫达西），从而提高采收率。μCT结果表明，在MEOR模拟实验后，低渗透岩心中不同孔径的孔隙数量和孔隙体积发生了变化，半径小于10μm的孔隙数量和体积减少，半径在10至25μm之间的孔隙数量和体积增加。在MEOR模拟实验条件下，会轻微降解饱和烃（1.9%），主要是C11 - C20的正构烷烃，但不能降解芳烃、树脂和沥青质。提高采收率的原因在于其在中性pH条件下的生物溶解作用，可防止对低渗透岩心造成酸敏损害。因此，其MEOR特性与产生物表面活性剂细菌和产酸细菌显著不同。在油藏开发早期注入或与其他微生物联合使用，应能最大限度地发挥其MEOR效果。本研究通过将硅酸盐溶解细菌从农业微生物肥料系统扩展到低渗透油藏的MEOR，推进了MEOR框架，揭示了针对矿物的微生物在MEOR研究和工业应用中的广阔前景。
