降压增注技术在低渗透油田的应用研究

Application of depressure and increasing injection rate technology in low permeability oilfield

罗跃 陈文斌 郑力军 毛紫楠

长江大学化学与环境工程学院，湖北 荆州 434023 长庆油田分公司油气工艺技术研究院，陕西 西安 710021

针对吴旗长2油藏部分注水井注入压力高、注水驱替效率低及套损井不断增加等情况，分析了注水压力升高的原因，开展了新型表面活性剂体系降压增注的应用研究。该体系由单一两性表面活性剂和黏土稳定剂组成。室内实验表明，60 ℃该体系与吴旗长2油样间的界面张力可达到10-2 ～ 10-3 mN·m^-1数量级，且具有较好的界面张力稳定性。岩心驱油降压模拟试验表明，驱替5 ～ 10 PV新型活性剂体系后，岩心水驱降压率达到30%以上，驱油效率的提高值也在7%以上。在吴旗区块吴72-71井进行了单井现场试验，该井见到了活性剂体系较好的降压增注效果。

Aiming at the problem of high water injection pressure and low displacement efficiency, the laboratory research on decreasing
injection pressure by new surfactant system has been in process with analyzing the reasons of high injection pressure. The new
system is made of single amphoteric surfactant and clay stabilizer. Laboratory experimental results indicate the dynamic interfacial
tension between the flooding system and Chang 2 oil sample reaches to 10^-2_{_}10^-3 mN/m at 60℃and the stability is satisfactory.
Core simulation experiments show the pressure of waterflooding can decrease by 30%and the oil recovery increases above 7%. Field
trial of Well Wu72-71 in Wuqi Oilfield is proceeding and the effect on decreasing injection pressure and improved injection
capacity are satisfactory.