气体钻井是以空气、天然气等作为介质携带岩屑的钻井技术,因其机械钻速快,成本低,对储层伤害小,杜绝井漏等特点备受人们关注.基于流体的动力学原理,采用CFD软件,对垂直和倾斜井筒环空气固两相流动进行三维数值模拟研究.模拟发现,对于垂直井筒,空气和岩屑的流速、浓度沿轴向呈对称性分布,最大流速,最大浓度都位于环空的中心区域,越靠近壁面,空气和岩屑的速度,浓度越小.对于倾斜井筒,空气和岩屑的流速、浓度沿轴向并不对称,环空区域空气和岩屑的速度、浓度明显大于近壁面处.%The gas drilling is a drilling technology that uses air or gas as medium to carry drilling cuttings. Because the technology has fast machinery drilling speed, low cost, less damage to the reservoir and so on, it has gained much attention. In this paper, based on the fluid dynamic principle, 3-D numerical simulation of gas-solid two phase flow in vertical and tilt wellbore was carried out by CFD software. The simulation results show that for the vertical shaft, flow velocity and concentration of air and debris are symmetry distribution along the axial, the maximum velocity and the largest concentration are located in the central area of the annular space; the nearer wall, the smaller speed and concentration of air and cutting. For tilt wellbore, flow velocity and concentration of air and debris are asymmetric distribution along the axial, speed and concentration of air and cutting in annular space are bigger than that near wall.
展开▼
