聚合物驱后凝胶与聚合物交替注入参数优化

大庆油田经过聚合物驱后已进入特高含水开发阶段,存在水驱控制程度低、层间矛盾大等问题。为进一步挖潜剩余油,提高采收率,改善大庆油田注采开发现状,在室内实验研究的基础上,针对N5试验区开展了聚合物驱后凝胶与聚合物交替注入参数优化研究。研究结果表明,聚驱后凝胶与聚合物交替注入驱油采用小段塞多轮次的段塞提高采收率效果优于大段塞少轮次的段塞;最佳组合的段塞为凝胶(0.02PV)+聚合物(0.03PV),共计注入11轮次,注入总量为0.55PV;经过凝胶与聚合物交替注入驱油后,其阶段采收率可在聚驱基础上提高10%左右,说明凝胶与聚合物交替注入驱油方法具备进一步开发聚合物驱后剩余油的潜力。

Parameter optimization of gel and polymer alternating injection after polymer flooding

Daqing oilfield has entered the extra high water cut development stage after polymer flooding. There are some problems, such as low degree of water flooding control and big contradictions between layers , etc. In order to further dip remaining oil, improve recovery factor and solve the problem of injection-production exploitation, on the basis of indoor experiment, this paper studied parameter optimization of gel and polymer alternating injection after polymer flooding in view of N5 test area. The results show that the EOR effect of small slug with more rounds of gel and polymer alternating injection after polymer flooding is better than big slug with less rounds; best combination of slug is gel (0.02 PV)+polymer (0.03 PV) and total injection rounds are 11(total 0.55 PV). Under this condition, the stage recovery can increase about 10% than polymer flooding, which indicates that the method of gel and polymer alternating injection has the potential of further developing remaining oil after polymer flooding.