弹性作用对驱油用聚合物扩大波及能力的影响

The influence of elasticity on the sweep efficiency of polymer for oil displacement

元福卿 徐辉 宋敏 孙秀芝

中国石化胜利油田分公司勘探开发研究院，山东 东营 257015 中国石化胜利油田分公司油气开发管理中心，山东 东营 257001

Research Institute of Exploration and Development, Shengli Oilfield Company, SINOPEC, Dongying 257015, China Oil and Gas Development Management Center, Shengli Oilfield Company, SINOPEC, Dongying 257001, China

黏度是影响聚合物扩大波及能力最重要的因素。为了提高聚合物扩大波及能力，最常用的方式是提高聚合物的表观黏度。有关弹性作用对于提高聚合物微观驱油效率的研究比较多，但对于扩大波及能力的研究较少。为此，选择了相对分子质量不同但表观黏度相同的驱油用聚合物进行研究，首先表征了聚合物分子尺寸和微观聚集形态，然后对比了能够反映聚合物弹性大小和弹性占比的弹性模量及相位角，最后通过岩心及可视化驱油实验研究了2个聚合物的阻力系数和驱油效果。结果表明：在黏度相同的条件下，和相对分子质量为1 000×10₄的聚合物相比，相对分子质量为3 000×10⁴的聚合物的弹性模量提升2.6倍，相位角由80°降低至65.5°，表现出更高的弹性和弹性占比，最终阻力系数提升2.5倍，采收率提高近1倍。因此，弹性对于提高聚合物扩大波及能力具有重要作用，新型聚合物的研发需要黏性和弹性并重。

Viscosity is the most important factor to affect sweep efficiency of polymer. In order to improve  sweep efficiency of polymer, the most frequently used method is to improve apparent viscosity of polymer. There are many researches on improving microscopic oil displacement efficiency of polymer by elasticity, while there are few studies on the influence of elasticity on sweep efficiency of polymer. For this reason, polymers for oil displacement with different molecular weight but the same apparent viscosity are selected to study. Firstly, the molecular size and microscopic aggregation morphology of the polymer was characterized. Secondly, elastic modulus and phase angle which can reflect the elasticity and elastic proportion of the polymer were compared. Finally, the resistance coefficient and oil displacement efficiency of the two polymers are studied by core experiment and visual oil displacement experiment. The results show that under the same viscosity, the elastic modulus of 3,000×10⁴ relative molecular weights polymer is increased by 2.6 times compared with that of 1,000×10⁴ relative molecular weights polymer. The phase angle is reduced from 80° to 65.5°, showing a higher elasticity and elastic proportion. The final resistance coefficient is increased by 2.5 times, and the oil recovery is increased by nearly doubled. Therefore, the elasticity plays an important role in improving the sweep efficiency of polymer. The development of new polymers requires that polymers have both viscosity and elasticity.

10.6056/dkyqt202301021