功能单体类型及含量对耐温抗盐聚合物驱油效果的影响

Effect of Monomer Type and Content on the Oil Flooding Performance of Temperature-resistant and Salt-tolerant Polymers

针对高温高盐环境中聚合物稳定性差的问题,在胜利油田III类油藏条件下,系统对比研究了功能单体类型(AMPS、NVP和DMAM)及含量对合成耐温抗盐聚合物增黏能力、长期稳定性、渗流特征和驱油效果的影响。结果表明,在质量浓度为1500~3000 mg/L、温度为25~95℃下,聚合物AM-AMPS/20%溶液的黏度明显高于其他AMPS含量聚合物以及功能单体NVP、DMAM的聚合物AM-NVP、AM-DMAM,具有最好的增黏效果;但是当钙镁离子浓度从874.0 mg/L提高至5296.0 mg/L时,聚合物AM-DMAM/10%溶液具有最高的黏度。单体含量影响方面,AMPS单体含量越高,聚合物溶液黏度越大;而NVP和DMAM单体含量升高,聚合物相对分子质量减小,溶液黏度降低。驱油结果表明,AM-AMPS驱油采收率增幅在21.9%~24.9%,AM-NVP驱油采收率增幅在20.9%~19.8%,AM-DMAM驱油采收率增幅在22.1%~20.2%,AM-AMPS聚合物驱油能力最强(其中AM-AMPS/20%驱替采收率增幅最高为24.9%),是胜利油田III类油藏驱油潜力聚合物。

In view of the poor stability of polymers in high temperature,high salinity environment,the influence of AMPS,NVP and DMAM on the polymer viscosity,long-term stability,seepage characteristics and oil flooding effects were systematically studied under the class III reservoir conditions of Shengli oilfield.The results showed that the AM-AMPS/20%(20%was the AMPS dosage)solution performed the highest viscosity at concentration of 1500-3000 mg/L and at the temperature of 25-95℃compared to polymer prepared with other AMPS content,and AM-NVP and AM-DMAM solutions.However,when the calcium and magnesium ion concentration increased from 874.0 mg/L to 5296.0 mg/L,AM-DMAM/10%solution became the best in viscosification.In terms of the effect of the monomer content,the higher the content of the AMPS monomer,the greater the viscosity of the polymer solution;and the opposite effect occurred when it came to the NVP and DMAM monomer cases due to the correspondingly decreased molecular weight of their polymers.The oil recovery tests showed that the AM-AMPS could enhanced oil recovery by 21.9%-24.9% based on the water flooding,while AM-NVP and AM-DMAM polymers could enhance oil recovery by 20.9%-19.8% and 21.1%-20.2%,respectively.AM-AMPS polymer had the strongest oil flooding capacity,among which AM-AMPS/20%performed the highest incremental oil recovery of 24.9%,which was promising to be used in class III reservoir of Shengli oilfield.