污水配制聚合物溶液稳定性及改进方法研究

罗锋 孙刚

摘 要：以大庆萨南油田南二西和南三西区块为研究平台，首先通过研究由油田新鲜污水和曝氧污水配制的聚合物溶液的粘度稳定性受WDJ-1稳定剂的影响，分析了稳定剂的作用机理；随后，在60 cm长岩心上开展传输运移实验，研究了稳定剂对聚合物溶液在多孔介质里的流动性和传输性能的影响。实验结果表明，在大庆油田45 ℃低温油藏条件下，使用油田污水配制的聚合物溶液存在明显的化学降解作用；HPAM聚合物的热氧降解是因为自由基O·攻击聚合物造成聚合物链发生断裂，导致溶液粘度急剧降低；在新鲜污水和曝氧污水配制聚合物溶液中添加100～120 mg/L稳定剂，能明显提高聚合物粘度在油层条件下的长期稳定性，改善聚合物溶液在岩石多孔介质中的流动性和传输性能，进而确保污水聚合物驱具有较好的驱油效果。

关 键 词：聚合物；污水；粘度；稳定性；流动性；提高采收率

中图分类号：TE 357 文献标识码： A 文章编号： 1671-0460（2016）04-0661-04

Abstract： Taking Nanerxi and Nansanxi blocks of Daqing Sanan oilfield as the research platform. Effect of WDJ-1 stabilizer to the viscosity stability of the polymer solution prepared with fresh water or aeration wastewater was investigated， and the mechanism of stabilizing agent was analyzed. the transport experiments were carried out on a 60 cm core， and effect of the stabilizer on the mobility and transport properties of the polymer solution in porous media was studied. The experimental results show that the chemical degradation of the polymer solution prepared with oil field wastewater under the condition of 45 ℃ reservoir in Daqing oilfield is obvious； The thermal degradation of HPAM polymer is due to the free radical O· attacking polymer， which causes the polymer chains to break down， resulting in a sharp decrease of the solution viscosity； In addition，putting100～120 mg/L stabilizer in the preparation of the polymer solution with fresh water and aeration wastewater， it can significantly improve the long-term stability of the polymer viscosity under the condition of oil layer， improve the flow and transport properties of polymer solution in porous media， And then make sure that the sewage polymer flooding has good oil displacement effect.

Key words： Polymer； Wastewater； Viscosity； Stability； Mobility； Enhanced oil recover

高温和高矿化度（特别是Ca2+、Mg2+离子含量高）条件下，部份水解聚丙烯酰胺聚合物（HPAM）会发生明显的化学降解现象（自由基降解和水解作用），使HPAM溶液粘度下降[1，2]，驱油效率降低。为了约束和减少HPAM溶液的粘度损失，通常采用控制氧含量和添加稳定剂的手段， 如加入少量脲类、酚类物质和醇类物质，以改善HPAM溶液的长期稳定性能[3-8]。

一般认为，大庆油田45 ℃低温油藏条件下，聚合物化学降解作用不明显。近期的实验研究结果表明，45 ℃油藏条件下不同水质配制的聚合物溶液，都存在明显的化学降解作用，添加稳定剂能够使聚合物的粘度保留率大幅度提高。……