非均质多孔介质中剪切稀释流的非混相驱替研究  

Immiscible displacement of a shear-thinning fluid in heterogeneous porous media

作　　者：王盟浩 熊友明[1] 刘理明[1] 彭庚[1] 张政 WANG Menghao;XIONG Youming;LIU Liming;PENG Geng;ZHANG Zheng(State Key Laboratory of Oil and Gas Reservoir Geology and Exploitation,Southwest Petroleum University,Chengdu,Sichuan 610500,China)

机构地区：[1]西南石油大学油气藏地质及开发国家重点实验室,四川成都610500

出　　处：《岩石力学与工程学报》2019年第S02期3783-3789,共7页Chinese Journal of Rock Mechanics and Engineering

摘　　要：地下流体在一定温度压力条件下,会呈现剪切稀释性。剪切稀释性影响流体黏度场,从而改变流体被驱替时的特征。使用植入幂律流变模型的格子Boltzmann两相流模型,编写计算程序,模拟牛顿流体在非均质多孔介质中驱替剪切稀释流的过程。使用非牛顿泊肃叶流验证了数值模型,并从界面推进、驱替效率、速度场、黏度场等方面研究非均质多孔介质中被驱替液的剪切稀释性对驱替过程的影响。模拟结果显示:被驱替液剪切稀释性的增强造成驱替界面推进的加快和驱替效率的提升,使驱替液更能深入驱替非均质多孔介质中残余的被驱替液。该现象的机制为:被驱替液剪切稀释性的增强造成了指进路径上的黏度降低,而非指进区域的黏度升高;驱替过程由指进路径上高流动区域的黏度所主导,因此增强被驱替液剪切稀释性的效果类似于降低黏度,从而提升驱替效率。研究揭示了流体剪切稀释性对多孔介质中驱替过程的影响,对涉及地下非牛顿流体驱替过程的产业具有指导性。The subsurface fluids could show shear-thinning property at certain pressure and temperature.The shear-thinning property affects the viscosity field of the fluid,thus altering the displacement behaviors during immiscible displacement.In this work,a lattice Boltzmann two-phase model implemented with a power law rheological model is adopted to simulate the displacement process of a Newtonian fluid displacing a shear-thinning fluid in heterogeneous porous media.After validating the model with non-Newtonian Poiseuille flow,the effect of the shear-thinning property of the displaced fluid on the displacement process is investigated from various aspects such as interface evolution,displacement efficiency,velocity field and viscosity field.The simulation results show that with stronger shear-thinning property in the displaced fluid,the interface evolves more rapidly and the displacement efficiency is increased,the invading fluid could better displace the residual displaced fluid.The mechanism for this phenomenon is that with stronger shear-thinning property,there are lower viscosities in the fingering paths and higher viscosities in the regions without fingering.The displacement process is dominated by the viscosity in the high mobility regions at the fingering paths.Increasing the shear-thinning property has similar effects to decreasing the viscosity of the displaced fluid,thus increasing the displacement efficiency.This research reveals the influence of the shear-thinning property on immiscible displacement in heterogeneous porous media,and is of guidance for industries concerning displacements of non-Newtonian fluids.

关 键 词：土力学 非均质多孔介质 非混相驱替 剪切稀释流 格子BOLTZMANN方法 

分 类 号：TU43[建筑科学—岩土工程]