低渗砂岩油藏纳米乳液渗吸驱油效率影响因素研究

Study on the Influencing Factors of Nanofluid Imbibition Oil Recovery Efficiency in Low-Permeability Sandstone Reservoirs

摘要: 伴随石油开采技术的持续革新，渗吸采油技术因开发低渗油藏的优势渐成研究热点。但纳米乳液在低渗储层的吸附行为及吸附改性效果的主控因素尚不明确，制约其应用。本研究通过渗吸驱油实验，探究了不同条件下纳米乳液在低渗储层的吸附特性及其对驱油效率的影响规律，明确了其影响因素。研究结果表明：影响纳米乳液吸附性能的因素包括温度、纳米乳液浓度、岩心长度、边界开放程度等因素，温度增大10℃，渗吸驱油效率增加幅度达到3%；相同实验条件下，0.3%浓度的纳米乳液要比0.1%浓度的纳米乳液渗吸驱油效率高4%；岩心长度越短，渗吸速率反而最快，最终采出程度最高；边界开放程度越高，渗吸速率越快，其最终采出程度按大小排序为：全开放 > 两端封闭 > 两端开放。

Abstract: With the continuous innovation of petroleum extraction technologies, imbibition oil recovery technology has become a research hotspot due to its advantages in developing low-permeability reservoirs. However, the adsorption behavior of nanoemulsions in low-permeability reservoirs and the factors influencing their adsorption modification effects remain unclear, which restricts their application. This study investigates the adsorption characteristics of nanoemulsions under different conditions and their impact on oil displacement efficiency through imbibition experiments. It identifies the main influencing factors. The results show that factors affecting the adsorption performance of nanoemulsions include temperature, nanoemulsion concentration, core length, and boundary openness. A temperature increase of 10˚C improves the imbibition oil displacement efficiency by 3%. Under the same experimental conditions, a 0.3% nanoemulsion concentration yields a 4% higher imbibition oil displacement efficiency compared to a 0.1% concentration. Shorter core lengths result in faster imbibition rates and higher ultimate oil recovery. Higher boundary openness also leads to faster imbibition rates. The ultimate oil recovery, in descending order, is fully open > both ends closed > both ends open.