利用生物竞争(Lotka-Volterra)数学模型,以油藏条件下硝酸盐还原菌(NRB)和硫酸盐还原菌(SRB)的菌群演替为对象,研究了两种群竞争性生态关系。利用该数学模型,通过平衡点求解方式,探索了在人工补给硝酸盐电子受体条件下硝酸盐还原菌-硫酸盐还原菌的群态变化规律。在模型分析的基础上,获得了在硝酸盐补给条件下,油藏中NRB和SRB经菌体增殖、底物竞争而实现的稳态抑制系统。同时,该模型还很好地解释了在硝酸盐耗尽时,NRB抑制SRB系统的瓦解和崩溃。通过对NRB-SRB两种群生态系统临界点的求算,获得模拟油藏条件下精确的稳态抑制期规律和计算方法。本研究成果可用于指导油田生产中NRB抑制SRB技术的硝酸盐补给浓度和具体工艺实施。

The biological competition (Lotka-Volterra) mathematic model is employed to establish the bio-inhibition system; the population succession of Nitrate Reducing Bacteria (NRB) and Sulfate Reducing Bacteria (SRB) under the oil reservoir conditions is taken as the research subject, the competitive ecology relation of these two microflora is studied. The equilibrium point solution is used to explore the microflora population variations of NRB and SRB on the condition that the artificial addition of nitrate was adopted as an electron acceptor. Based on the Lotka-Volterra model, the steady-state bio-inhibition system is established between NRB and SRB. In the meantime, when the nitrate is depleted, the bio-inhibition system is collapse and finally breakdown is explained quite well by the model. According to the two critical points of NRB-SRB microflora bio-system, the precise steady-state inhibition period and the nitrate concentration under the condition of oil reservoir are able to be calculated and controlled. The results could greatly improve NRB-SRB bio-inhibition technology and accurately direct the implementation of practical process in the oilfield, which has great significance in the crude oil production.