摘要
为了缓解大庆油田复合驱开发区块储层物性变差,表面活性剂损耗量增大、三元体系抗吸附性能减弱的问题,开展表面活性剂浓度优化研究,指导改善复合驱技术经济效果。采用换砂不换液、换液不换砂两种静态吸附实验方法分析段塞不同位置的化学剂损耗,结合动态吸附和物理模拟驱油实验,确定合理的表面活性剂浓度变化方式。研究结果表明,三元段塞驱替前缘吸附严重,应提高表面活性剂浓度;前缘流经后的油砂吸附能力减弱,可降低后续段塞的浓度;被吸附后的表面活性剂存在脱附现象,对后续段塞浓度进行补偿。根据化学剂损耗规律,提出表面活性剂梯度降浓方式,在保持化学剂用量不变的情况下,扩大超低界面张力作用距离,可相对常规恒定浓度方式进一步提高采收率0.91百分点。
In Daqing oilfield,physical properties of reservoir become worse and adsorption loss of surfactant increases,research on surfactant concentration optimization was carried out to improve the technical and economic effect of composite flooding.Two static adsorption experimental methods were used to analyze chemical agent loss at different positions of the slug.One method was to change sand without changing liquid,the other was to change liquid without changing sand.Combined with dynamic adsorption and physical simulation experiment,the reasonable variation mode of surfactant concentration was determined.The result showed that,surfactant adsorption at the front of slug displacement was serious,and surfactant concentration should be increased.Adsorption capacity of oil sand flowing through leading edge was weakened,the concentration of subsequent slugs should be reduced appropriately.The adsorbed surfactant could desorb and compensate subsequent slug.According to the law of chemical agent loss,a gradient injection method of surfactant was proposed,which could enlarge action distance of ultra-low interfacial tension with same chemical dosage.Compared with conventional injection method,EOR could be further improved by 0.91%using the gradient injection method.
作者
刘春天
陆屹
田燕春
李星
王颖
宋志瑞
李欣欣
LIU Chuntian;LU Yi;TIAN Yanchun;LI Xing;WANG Ying;SONG Zhirui;LI Xinxin(Exploration and Development Research Institute,Daqing Oilfield Company Limited,National Energy Continental Sandstone Old Oilfield Sustainable Development Research and Development Center,Daqing,Heilongjiang 163712,P R of China)
出处
《油田化学》
CAS
CSCD
北大核心
2021年第3期499-503,共5页
Oilfield Chemistry
