论文部分内容阅读
为揭示低频振动对地层以及流体流动规律的影响,鉴于储层孔隙体系结构的复杂性,采用细管多孔介质模型,针对单一细管中的单相不可压缩流体,将低频波对流体流动产生惯性力引入圆管层流的Naver—Stokes(N—S)方程,建立了低频振动条件下单相不可压缩流体在细管中流动的微观动力学模型。该模型采用C—N差分格式,对低频振动条件下单一细管中流体流速以及剪切力分布进行模拟计算和定量分析。结果表明,低频振动条件下圆管中的流速随管径呈抛物线型分布,随时间以不振动下速度分布为中心轴线呈周期性变化;黏附层处剪切力也是随时间以不振动下的剪切力为中心轴线呈现周期性变化,当剪切力大于黏附层流动的临界剪切力时,黏附层会部分发生流动。该模型的建立与求解,为进一步揭示低频振动对地层渗透性微观动力学增效机制提供了重要认识。
In order to reveal the influence of low-frequency vibration on the formation and fluid flow, considering the complexity of the reservoir pore structure, a thin-walled porous media model was used to simulate the single-phase incompressible fluid flow in a single tube. The introduction of the Naver-Stokes (N-S) equation for laminar flow in a circular tube leads to the establishment of a micro-dynamic model for the flow of single-phase incompressible fluid in a thin tube under low-frequency vibration. The model uses C-N difference scheme to simulate and quantitatively analyze the fluid flow velocity and shear force distribution in a single thin tube under low frequency vibration. The results show that the velocity of flow in the tube decreases with the diameter of the tube under the condition of low-frequency vibration and changes periodically with the velocity distribution at the non-vibration as a central axis. The shear force at the adhesion layer also changes with time The shear force changes periodically with the central axis. When the shear force is greater than the critical shear force of the adhesion layer, the adhesion layer will partially flow. The establishment and solution of this model provide an important understanding for further revealing the synergistic mechanism of micro-dynamics of formation permeability through low-frequency vibration.