润湿性对模拟原油微尺度流动和渗流的影响

Influence of wettability on micro-scale flow and seepage characteristics of simulated crude oil

考察了流体在不同润湿性条件下在低渗透多孔介质微米量级孔喉中流动的渗流特性,实验研究了模拟原油(航空煤油与胜利油田原油以5∶1的体积比配制)在内径为14.9μm、5.03μm、2.05μm的亲水和憎水微圆管中的流动特性。结果表明,模拟原油在5.03μm和2.05μm亲水和憎水微管中的流动均出现了明显的微尺度效应,流动规律均偏离经典理论,且模拟原油在亲水微管中的流量高于其在憎水微管中的值。根据微管实验数据,利用毛管束模型分析了润湿性对模拟原油在多孔介质中渗流特性的影响。在考虑微尺度效应的条件下,模拟原油在低渗透多孔介质中的流动为非线性渗流,润湿性显著影响。在其他条件相同时,模拟原油在亲水模型中的视渗透率大于其在憎水模型中的值。

The seepage characteristics of fluid flowing in the countless micro-sized pores were investigated under the different wettability condition.The simulated crude oil mixed by the aviation kerosene and crude oil from Shengli Oilfield with a volume ratio of 5∶1 were experimentally studied to flow in the hydrophilic and hydrophobic microtubes with diameters of 14.9μm,5.03μm and 2.05μm respectively.The flow characteristics of the simulated crude oil flowing in the hydrophilic and hydrophobic microtubes with diameters of 5.03μm and 2.05μm significantly departed from the prediction of conventional theory,which were influenced strongly by the wettabilities of the microtubes,and the flow rate in the hydrophilic microtubes was larger than that in the hydrophobic microtubes with the same diameters and pressure gradients.Based on the experiment data of microtubes,the influence of wettability on seepage characteristics of the simulated crude oil flowing in the porous media was analyzed with the capillary bundle model.The flows of the simulated crude oil in low-permeability porous media are nonlinear and influenced by the wettability of microtubes when the micro-scale effect is considered.The apparent permeability of simulated crude oil in the hydrophilic model is larger than that in the hydrophobic model.