空气和 CO₂辅助蒸汽吞吐室内实验研究

Laboratory Study on Air and CO₂ Assisted Steam Stimulation

冷光耀

LENG Guangyao

为了改善常规蒸汽吞吐中后期的开发效果，通过高温高压物性分析仪测定空气和 CO2对普通稠油的溶胀和降黏作用；开展了空气辅助蒸汽吞吐和 CO2辅助蒸汽吞吐室内物理实验，通过对回采水率、采注比、油层平均温度和采出程度等指标分析，评价了不同吞吐方式的开发效果。研究结果表明，空气和 CO2溶于原油后均能使其黏度降低、体积系数增加，但 CO2的降黏溶胀效果更好。蒸汽波及系数和油层平均温度随着吞吐周期的增加而增大，同周期内气体辅助蒸汽吞吐的波及系数和油层平均温度比常规蒸汽吞吐的高。常规蒸汽吞吐中后期注入空气和 CO2，可明显提高周期回采水率、油汽比和采注比。与常规蒸汽吞吐相比，CO2辅助蒸汽吞吐和空气辅助蒸汽吞吐均能够大幅度提高采出程度，其中 CO2辅助蒸汽吞吐开发效果最好。图 5表 2参 14

To improve the development effect of routine steam stimulation in the middle and late period，the swelling and viscosity reduction effect of air and CO2 on common heavy oil was probed using PVT. Air assisted steam stimulation and CO2 assisted steam stimulation was developed by laboratory experiments，and the development effects of two kinds of stimulation was evaluated through index analysis of return water rate，injection production ratio，average temperature of reservoir and recovery degree. Results showed that，after air and CO2 dissolved in crude oil，the viscosity decreased and the volume factor increased，however，the effect of injecting CO2 was better. The sweep efficiency of steam and average temperature of reservoir increased with the increase of stimulation cycle. The sweep efficiency and average temperature of the gas assisted steam stimulation was higher than that of the routine steam stimulation in the same cycle. The development effect of adding air and CO2 was obvious in the middle and late period of routine steam stimulation，which increased the return water rate，oil steam ratio and injection production ratio. Compared with the routine steam stimulation，the air assisted steam stimulation and CO2 assisted steam stimulation could greatly improve the recovery degree，and the development effect of CO2 assisted steam stimulation was the best.