Zhao Fajun, Zhu Guangmeng, Li Guo, Jiang Yifan, Liu Lei
Key Laboratory of Entered Oil Recovery of Education Ministry, Northeast Petroleum University Daqing Heilongjiang 163318 China
Petroleum Production Engineering Research Institute of PetroChina, Daqing Oilfield Company Daqing Heilongjiang 163453 China.
RSC Adv. 2022 Jun 24;12(29):18646-18653. doi: 10.1039/d2ra02118h. eCollection 2022 Jun 22.
The residual oil after polymer flooding in China is highly dispersed. The reservoir's interlayer and intralayer contradictions are prominent, the polymer flooding efficiency is significantly reduced, and the exploitation difficulty is increased. An indoor physical simulation experiment of undertaking fire flooding after polymer flooding is conducted to investigate the recovery measures that can undertake polymer flooding and further improve the recovery degree of residual oil. The stability of the combustion front and the basic parameters of combustion (ISC) were studied, and the crude oil properties before and after the fire flooding were analyzed. The results show that the temperature range and variation trend of the combustion front in the polymer flooding-to-fire flooding experiment are similar to those in the conventional fire flooding experiment. The combustion front advances steadily, indicating that the residual oil can be burned effectively after polymer flooding, providing an application basis for fire flooding. The calculated apparent H/C atomic ratio through the tail gas composition is 1.33, which further demonstrates that a high-temperature oxidation reaction occurs at the combustion front, and the displacement efficiency of the burned oil layer is 72.1%. A comparison of the oil samples before and after fire flooding shows that the carbon number of -alkanes in the oil produced after fire flooding increases, improving the quality of crude oil.
我国聚合物驱后的剩余油高度分散，油藏层间和层内矛盾突出，聚合物驱油效率显著降低，开采难度增大。开展聚合物驱后火驱室内物理模拟实验，研究能接替聚合物驱并进一步提高剩余油采收率的开采措施。研究了燃烧前缘的稳定性和燃烧基本参数（ISC），并分析了火驱前后原油性质。结果表明，聚合物驱转火驱实验中燃烧前缘的温度范围和变化趋势与常规火驱实验相似。燃烧前缘稳定推进，表明聚合物驱后剩余油能有效燃烧，为火驱提供了应用依据。通过尾气组成计算得到的表观H/C原子比为1.33，进一步证明燃烧前缘发生了高温氧化反应，燃烧油层的驱替效率为72.1%。火驱前后油样对比表明，火驱后产出油中烷烃的碳数增加，原油品质得到改善。
