摘要
三元复合体系渗流过程中,聚合物的剪切降解和表面活性剂的吸附、滞留等导致体系驱油性能动态变化,影响其到达油藏深部的实际驱油能力。为了探讨驱油过程中复合体系性能的变化及其对复合驱采收率的影响,考察了渗流速度和运移距离对三元复合体系黏度的影响及体系油水界面张力在运移方向上的动态分布特征,研究了复合体系性能变化对采收率的影响。结果表明,渗流速度和运移距离对三元复合体系黏度和油水界面张力的影响较大。随渗流速度的增大复合体系黏度显著降低,渗流速度大于10 m/d时体系黏度变化较小;复合体系的剪切降解主要发生在注入端或近井地带,到达模型或油藏深部后运移距离的增大不会造成体系黏度的显著降低;复合体系界面张力随运移距离的增大显著升高,注入量较小时仅能在注入端或近井地带形成超低界面张力,注入量达到3.0 PV时可在填砂模型深部形成超低界面张力;渗流过程中复合体系界面张力对体系驱油能力的影响较黏度的影响更为显著,使复合体系达到油藏深部后仍保持超低界面张力是复合驱提高采收率的关键之一。
During the seepage of ternary compound system in reservoir,displacing capacity of the system dynamically changed due to the shear degradation of polymer and the adsorption and retention of surfactant,which affected the actual displacing ability of compound system as it reached deep reservoir. In order to determine the property variations of compound system and its effect on oil recovery during flooding process,the effect of seepage velocity and migration distance on the viscosity of compound system and the dynamic distribution characteristic of oil/water interfacial tension along the flow direction were investigated. The influence of property variation of compound system on oil recovery was also studied. The results showed that seepage velocity and migration distance had great effect on viscosity and oil/water interfacial tension of compound system. The viscosity decreased obviously with increasing seepage velocity. When the seepage velocity was greater than 10 m/d,the viscosity decrease became inconspicuous. The shear degradation of compound system mainly occurred in inlet or near wellbore,and the increased migration distance did not cause a significant viscosity decrease after entering deep model or reservoir. The interfacial tension of compound system increased significantly with increasing migration distance. The compound system could only form ultra-low interfacial tension on the injection end or near wellbore when the injection volume was small,while it could reach ultra-low interfacial tension on deep model when 3.0 PV compound system was injected. The influence of interfacial tension variation of compound system on oil recovery was more significant than that of viscosity. And it was the key of chemical combination flooding to keep ultra-low interfacial tension as the system reached deep reservoir.
作者
陈权生
丁名臣
陈静
王业飞
李织宏
严佳城
CHEN Quansheng;DING Mingehen;CHEN Jing;WANG Yefei;LI Zhihong;YAN Jiaeheng(Research Institute of Experiment and Detection, Xinjiang Oilfield Branch Company, PetroChina, Karamay, Xinjiang 834000, P R of China;College of Petroleum Engineering, China University of Petroleum, Qingdao , Shandong 266580, P R of China)
出处
《油田化学》
CAS
CSCD
北大核心
2018年第1期125-130,共6页
Oilfield Chemistry
关键词
聚合物/表面活性剂/碱三元复合驱
渗流速度
运移距离
黏度
界面张力
采收率
polymer/surfactant/alkali combination flooding
seepage velocity
migration distance
viscosity
interracial tension
oil recovery
