摘要
可动凝胶深部调驱是微裂缝发育低渗特低渗储层水窜治理的重要手段,但现有可动凝胶渗流主要局限于均匀孔隙介质,微裂缝内流动和复杂储层渗流动力学模型研究均较欠缺.通过可动弱凝胶微裂缝渗流可视化实验,深入认识其在微裂缝这一孔隙结构中的流动特性.实验发现,可动凝胶微裂缝渗流表现出幂律流动形态、临界压力梯度、粘滞吸附、再次水驱潜在重新窜流风险等特点,渗流压力梯度受交联黏度、缝宽影响的敏感性较强.综合实验认识以及孔隙介质可动凝胶非线性渗流、低渗非线性渗流、双重介质渗流等数学模型,建立了微裂缝发育低渗特低渗储层可动凝胶调驱的数学模型,涵盖了流体运动、质量守恒、可动凝胶黏度特性等方程以及大裂缝优先调驱、非牛顿流体剪切、岩石孔渗吸附损伤、调驱过程微裂缝限压等系列附加判定指标,以尽可能贴近矿场调驱实际,为该类复杂储层可动凝胶渗流动力学分析提供基础.
Flowing gel deep plugging is a key method for water channeling treatment in low permeability reservoir developed with a mass of natural micro-fractures.However,available researches about flowing gel treatment are mainly focused on the non-linear seepage of flowing gel in homogeneous porous media or filed tests.An experiment about flowing gel displacement in visual micro-fracture is carried out,in which an insight into the flow characteristics of gel in a particular pore structure is viable.Characters as movable gel micro-seepage flow of power-law flow,critical pressure gradient,sticky adsorption,risks of channeling again in secondary water-flooding are found with the micro fractures.A higher pressure gradient in gel displacement is watched with the higher initial cross-linking viscosity and narrower fracture width.Then,modeling on the flowing gel displacement in the low permeability reservoir developed with natural micro-fractures and wide fractures is attempted.The above experimental recognition are combined with the non-linear seepage of the flowing gel in the homogeneous porous media,the non-linear flow in low permeability reservoir,and the double porosity media flow.Therein considers three phases-water,oil and flowing gel.Motion equation,mass conservation equation and viscous character equation of flowing gel in the matrix,micro-fractures and wide fractures are established.To approaching the actual filed plugging,a series of judgment requirements,as prior plugging in the wide fractures,non-Newton fluid shear thinning in micro-fractures,permeability and porosity damage in the fractures by adsorption and limited displacement pressure against micro-fracture open or propagation,are also append.It may provide a basis for the dynamic explanation for the actual deep plugging and fluid redistribution.
出处
《陕西科技大学学报（自然科学版）》
2016年第1期107-113,共7页
Journal of Shaanxi University of Science & Technology
基金
国家重大科技专项项目(20011ZX05009-004)
国家自然科学基金项目(51274229)
关键词
微裂缝
大裂缝
低渗油藏
可动凝胶
渗流数学模型
micro fractures
wide cracks
low permeability reservoirs
flowing gel
math ematic seepage model
