低渗透油田表面活性剂增注效果预测

Study on the Prediction Method for Injection Increase by Surfactant at the Low Permeability Oilfield

针对低渗透油田在注水开发过程中注入压力高、压力传导慢等问题,室内进行了表面活性剂相对渗透率和天然岩心降低注入压力等实验研究。实验结果表明,在水驱基础上,天然岩心注入浓度为0.5%的NS—1表面活性剂后,后续水驱压力降低25%以上,降压效果明显。根据油水相对渗透率曲线,在油水两相径向稳定渗流条件下,对表面活性剂增注效果、段塞尺寸与增注量的关系等进行了预测。

Water flooding development lead to high pressure in water injection and slow pressure conduction in low permeability oil field.Laboratory study of the relative permeability and to reduce the injection pressure of the natural core are made.Through 0.5% NS—1 surfactant flooding,the follow-up water flooding pressure reduced by 25% or more,step-down effect is obvious.According to the experimental relative permeability curves,under the condition of radial stable seepage flow with two phases of oil and water,the relationship between surfactant slug size and increasing injection volume was predicted.