火驱尾气回注井筒流动分布规律

Flowing distribution rule of fireflood exhaust in rejection wells

王苏雯 王寿喜 王力 王勇2

陕西省天然气股份有限公司，陕西 西安 710016 西安石油大学，陕西 西安 710065

Shaanxi Provincial Natural Gas Co., Ltd., Xi′an 710016, China Xi′an Shiyou University, Xi′an 710065, China

火驱尾气处理已成为制约火驱开采技术发展的瓶颈，需要探索和尝试高效环保的火驱尾气回注技术。为了保证回注方案设计的合理性，文中通过建立火驱尾气物性及相态模型、井筒流动水力和热力模型，开发了火驱尾气回注井筒流动分析软件，实现了尾气在回注井筒内流动状态参数及相变规律的精准描述。结果表明：计算结果与HQ井区现场试验数据的相对误差仅为0.67%，确定井口回注压力21 MPa；随井深增加，火驱尾气压力、温度逐渐升高，液相逐渐减少；回注量对井筒内温度分布影响较大，井底压力对井筒内压力分布影响明显。计算结果对后期回注工艺系统设计具有指导意义。

The gas treatment of fireflood exhaust has become a bottleneck restricting the development of fire-flooding technology. Therefore, it is urgently needed to explore a high-efficiency and environmentally friendly fireflood exhaust reinjection technology. In order to guarantee the design rationality of the reinjection scheme, the physical property and phase model of fireflood exhaust, the wellbore hydraulic and thermal model are built, and the flow analysis software for the reinjection of the fireflood exhaust is developed to realize the accurate description of flow state parameters and phase transition law of exhaust in reinjection wellbore. The results show that the relative error between the calculation results and the field test data of HQ well area is only 0.67%, and the wellhead reinjection pressure is determined to be 21 MPa. With the increase of well depth, the pressure and temperature of the fireflood exhaust gradually increase, and the liquid content gradually decreases. The injection rate has a great influence on the temperature distribution in the wellbore, while the well bottom pressure has a significant influence on the pressure distribution in the reinjection wellbore. The calculation results have an important guiding significance for the design of post reinjection process system.

10.6056/dkyqt202001020