State Key Laboratory of Heavy Oil Processing, China University of Petroleum, Beijing, 102249, P.R. China.
State Key Laboratory of Marine Resource Utilization in South China Sea, Hainan University, Hainan, 570228, P.R. China.
Sci Rep. 2019 Oct 31;9(1):15772. doi: 10.1038/s41598-019-52330-2.
Low permeability oil reservoirs are a widespread petroleum reservoir type all over the world. Therefore, methods to recover these reservoirs efficiently are of importance to guarantee energy supply. Here we report our novel stimulation of indigenous microbes by optimizing the water cut in low permeability reservoirs for green and enhanced oil recovery. We aimed to investigate the characteristics of indigenous bacterial communities with changes in water cut in reservoirs by high-throughput sequencing technology, and reveal the mechanism and characteristics of the crude oil biotreatment under different crude oil-water ratio conditions and the optimum activation time of indigenous functional microbial groups in reservoirs. The indigenous microbial metabolism products were characterized by gas chromatography mass spectrometry. Results showed that Acinetobacter (47.1%) and Pseudomones (19.8%) were the main functional genus of crude oil degradation at the optimal activation time, and can reduce the viscosity of crude oil from 8.33 to 5.75 mPa·s. The dominant bacteria genus for oil recovery after activation of the production fluids was similar to those in the reservoirs with water cut of 60-80%. Furthermore seven mechanism pathways of enhancing oil recovery by the synergistic of functional microbial groups and their metabolites under different water cut conditions in low permeability reservoirs have been established.
低渗透油藏是世界范围内广泛存在的一种石油储层类型。因此，高效开发这些油藏的方法对于保证能源供应至关重要。在这里，我们报告了通过优化低渗透油藏的水驱，利用土著微生物进行新型刺激，以实现绿色和提高石油采收率。我们旨在通过高通量测序技术研究水驱变化对油藏中土著细菌群落特征的影响，揭示不同油水比条件下原油生物处理的机制和特征，以及油藏中土著功能微生物群的最佳激活时间。通过气相色谱-质谱联用技术对土著微生物代谢产物进行了表征。结果表明，在最佳激活时间，Acinetobacter（47.1%）和Pseudomones（19.8%）是原油降解的主要功能属，可将原油粘度从 8.33 降低至 5.75 mPa·s。产液激活后提高采收率的优势菌属与水驱 60-80%的油藏相似。此外，在不同水驱条件下，通过功能微生物组及其代谢物的协同作用，建立了低渗透油藏提高采收率的 7 条机制途径。
