均质多孔介质中石油残留与挥发特性

Residual and Volatilization of Oil in Homogeneous Porous Media

将砂样筛分成不同粒径组分,应用室内模拟实验研究多孔介质孔隙大小对其中石油的残留和挥发的影响。结果表明,均质多孔介质中石油最大残留饱和度随着多孔介质颗粒粒径增大而减小,幂函数可表述两者之间的关系,而单位比表面石油残留体积与平均粒径之间呈线性正相关;在连续淋滤过程中,多孔介质中石油的释放呈先快速后慢速的趋势,水淋滤对大粒径的CS1、CS2、CS3和极细粒径的CS6中的石油残留饱和度变化影响较小;多孔介质中石油挥发量随多孔介质颗粒粒径的增大而降低,抛物线模型可表达石油挥发动力学过程;多孔介质中石油极限残留率和石油挥发速率系数与多孔介质颗粒粒径的关系均可采用幂函数描述,且颗粒粒径对石油极限残留率的影响更为明显。

The effects of porous medium＇s pore size on residual oil and oil volatilization of the porous medium were investigated by laboratory simulation through screening the sand sample into different particle size fractions.The results showed that the maximum residual oil saturation in porous medium decreased with the increment of mean grain size of porous medium,and power function could express the relationship between the two parameters.Volumetric retention per unit available surface area increased with the increase of mean grain size of porous medium at a linear rate.Oil release from porous medium was with the trend of firstly fast then slow in the continuous leaching process.The residual oil saturation of porous media with large particle size,such as CS1,CS2,CS3,and CS6 with very small particle size changed a little by water leaching.The loss of oil volatilization decreased with the increase of particle size of porous medium,and parabola model could describe its kinetics process.The relationship of minimum residual oil rate and volatilization rate coefficient of oil in porous medium with the mean grain size of porous medium could be described by power function,and the particle size of porous medium impacted the minimum residual oil rate greatly.