数模与物模相结合研究涡流工具携液机理

Numerical Simulation and Physical Modeling on Liquid Carrying Mechanism of Vortex Tool

涡携液机理、影响因素以及适用界限认识不清等问题,制约了涡流排水采气工艺大规模推广应用。为解决这一问题,首先对涡流场受力情况进行分析:在涡流场中,小液滴在垂直方向上额外受到了马格纳斯力和滑移-剪切升力的作用,这两个力的共同作用使得液体随着管壁螺旋向上运动,从而提高了气井携液能力。然后,自行设计制造了实验装置,进行了涡流气-液两相流物理实验和数值模拟分析。物理实验结果表明:涡流工具能够将压力能转换为动能,在高流速下涡流工具可将段塞分层流转变为螺旋流,提高了气体持液率;在低流速下,涡流工具起到挡板作用,阻止液体滑脱;产气量、产水量、井斜角和工具叶轮高度是影响涡旋效果的主要因素。数值模拟分析表明:管壁形成了一层高速螺旋液膜,管道中部为气体,随着管壁和轴线流速逐渐平衡,螺旋流也随之减弱。

Unclear understanding of liquid carrying mechanism, influencing factors and applying limit restricts large scale popularization and application of the technique of gas recovery by water drainage of vortex.In or- der to solve this problem,the forces of droplets in the vortex field were analyzed as follows.In the vortex field,Magnus force and slip-shear lift force were loaded on the small droplets at the vertical direction additionally,which drive the fluid upward spiral along with tubing wall and result in liquid carrying capability improved of the gas wells.Experimental installation was designed and made by ourselves,and physical experiment and numerical simulation analysis were made for vortex gas-liquid two phase fluid.Physical experiment results show that the vortex tool can transform pressure energy into kinetic energy and slug stratified flow into helical flow at high velocity,and liquid holdup may be improved.At low velocity,the vortex tool has the function of baffle to prevent liquid slippage.Gas production,water production,deviation angle and impeller height of the tool are the main influencing factors of vortex.Numerical simulation analysis presents that high- speed spiral liquid membrane may be formed at the tubing wall,gas distributes at the center of the pipe, and the helical flow may be weaker along with the balance between the tubing wall and axial velocity.