气藏污水回注井表面活性剂降压增注技术

Surfactant Depressurizing and Increasing Injection Technology for Sewage Injection Wells in Gas Reservoir

郭程飞 蒋光迹 韩静静 郭现红

GUO Chengfei JIANG Guangji HAN Jingjing GUO Xianhong

针对气藏污水回注井回注压力升高、回注能力降低的生产问题，根据油藏注水井表面活性剂降压增注的技术思路，开展气藏回注井储层条件下的降压增注技术研究。通过考察表面活性剂和回注水的配伍性及润湿反转能力，优选了杂双子表面活性剂ZS-11，并采用该表面活性剂进一步开展相渗实验和降压增注实验。研究结果表明，杂双子表面活性剂ZS-11在高温（130℃）、高矿化度（80000 mg/L）回注储层条件下，具有配伍性好、润湿反转能力强的特点，可将岩心润湿性由亲水向中性润湿转变。驱替实验结果表明，杂双子表面活性剂ZS-11溶液（有效物含量0.2%）能使水测渗透率分别为1.42×10-3、1.78×10-3、5.27×10-3、10.53×10-3 μm2的岩心的液相相对渗透率提高21.2%~ 52.8%，气液两相渗流区间增大9.3%、等渗点饱和度降低3.3%~6.2%，特别对低渗岩心降压效果更为明显，降压幅度达到41.0%。实验结果为解决气藏污水回注压力高的生产问题供新思路及方法。

According to the technical idea of surfactant depressurizing and increasing injection technology for injection wells in oil reservoir，the technology is studied for sewage water injection wells in gas reservoir to solve the production problems of increasing pressure and reducing capacity of water injection. By studying the compatibility between surfactant and water injection and the wettability reversal，the hybrid Gemini surfactant ZS-11 was selected，the phase permeability experiments and the depressurizing and increasing injection experiments was carried out. The results showed that ZS-11 had a good compatibility and strong wettability reversal ability at high temperature（130℃）and high salinity（80000 mg/L）formation condition，which made the core wettability changed from hydrophilic wetting to neutral wetting. Displacement experiments showed that the ZS-11solution with effective content of 0.2% could increase the relative permeability of liquid phase by 21.2%—52.8%，widened the gas-liquid two-phase permeability range by 9.3%，and decreased the saturation of equal permeability point by 3.3%—6.2% for cores with water permeability of 1.42× 10-3，1.78×10-3，5.27×10-3 and 10.53×10-3 μm2，respectively. Moreover，the effect of depressurizing and increasing injection was more obvious especially for low-permeability core，decreasing amplitude being up to 41%. The experimental results provide a new idea and method for solving the production problem of high sewage injection pressure in gas reservoir.

10.19346/j.cnki.1000-4092.2020.01.012