砾岩油藏聚合物驱注采耦合调控方法及参数优化

砾岩油藏微观孔隙结构复杂、宏观非均质性强，并且注采井距较小导致优势通道发育，聚窜矛盾突出，聚合物驱开发效果较差。以克拉玛依七东₁区砾岩油藏为例，提出了小井距条件下聚合物驱注采耦合理论及方法。针对注采敏感井组通过注采耦合调控方法，拉大注采井距、变化流线，以控制聚合物窜流，有效启动优势通道屏蔽型剩余油，实现砾岩油藏聚合物精细化驱替，精准调控。结果表明，处于聚合物驱中后期的砾岩油藏在实施注采耦合方法调控策略后，整体含水回返趋势得到有效控制，油井聚窜得到抑制。针对目标油藏开展注采耦合参数优化，采用时间比例为1∶1对称型结构，注采耦合半周期为60 d时采出程度提高1.89%，效果最好。研究结果对砾岩油藏聚合物驱中后期提高采收率的有效开展具有指导意义。

Injection-production coupling control method for polymer flooding of conglomerate oil reservoir and its parameter optimization

Conglomerate oil reservoirs are microscopically characterized by complex pore structures and macroscopically by strong heterogeneity, and smaller injector-producer spacing leads to the development of dominant pathways. As a result, polymer channeling is severe and the development effect of polymer flooding is poor. In this paper, the injection-production coupling theory and method for polymer flooding under the condition of small well spacing was put forward with the conglomerate oil reservoir in District 7E₁ of Karamay as the example. The injection-production coupling control method was adopted in injection/production sensitive well groups to enlarge the injector-producer spacing, change the flowline, control the polymer channeling and effectively activate the remaining oil screen by dominant pathways, so as to realize the fine polymer flooding of conglomerate oil reservoir and its precise control. It is indicated that after the conglomerate oil reservoir in the middle and late stage of polymer flooding is treated by means of injection-production coupling method, the return trend of its overall water cut is under effective control and the polymer channeling is inhibited. The injection-production coupling parameters of the target oil reservoir were optimized by adopting the symmetric structure with time scale of 1∶1. When the half period of injection-production coupling is 60 d, the degree of reserves recovery is increased by 1.89%, which is the best effect. This method is of great significance to guide the enhanced oil recovery of conglomerate oil reservoirs in the middle and late stage of polymer flooding.