水平井岩屑床层移运动的规律分析

在环空紊流场作用下岩屑床呈具有特定本构关系的浓缩流动介质．本文由岩屑床层移（剪切）运动的内在机理与物理模型出发，研究层移颗粒微观运动的能量平衡与交换，得到了层移床的本构关系和流动速度场方程，以及层移床转静止床的临界水力条件，层移岩屑床的最大厚度，岩屑床的流动能力与流动阻力．阻力方程中考虑了层移床的承压特点及其与环室内外壁的不同摩擦特性．结果表明层移床的结构应力导致其运动失去关于环空几何中心的对称性，流动中心向钻具侧偏移及层移岩屑床的显著增阻效应．

The Rules of Bed-Load Cuttings Trandport in Horizontal Well

In turbulent flow of horizontal annulus,the cuttings bed is a concentrated fluid with special constitutive featrues. Starting from the mechanism and physical model of shared cuttings transport, the constitutive relationship and velocity field of bed-load cuttings transport are established through the study of the energy transfer and equilibrium of the microscopic motions of bed-load particles. From these equations,the critical hydraulies of cuttings motion into static beds, the maximum thickness.of bed-load cuttings layer,and the capability and resistance of cuttings transport are thus derived. In the resistance equation, the factors of fluid pressure in bed and the different frictions of inside and outside walls are also considered. The conclusions show that the yield stress makes the zero shear point of bed-load cuttings flow deviate the inside of annulus, and that the transport of bed-load cuttings increases greatly flow resistance.