空钻井筒二维流场的数值模拟及井口压力分析

Numerical simulation of two-dimensional flow-fields of well bore by air drilling and analysis of pressure in wellhead

空气钻井井口压力是控制井筒内气固两相流场的重要参数,本文基于有限体积法,采用多块结构化网格,对川渝地区相关井空气钻进时的井筒二维流场进行了数值模拟,得到了速度、压强沿井深的分布情况。结合最小携岩速度与冲蚀临界速度准则,比选了合理的井口压力值范围,与实际钻井操作参数吻合较好。

Pressure in wellhead is an important parameter for gas-cutting two-phase flow fields of well bore by air drilling.Two-dimensional flow fields in well bore were simulated using finite volume method on a multi-block structure grid system.Distributions of velocity and pressure along the depth of well were obtained.Combined with the minimum velocity of carrying cuttings and critical erosion velocity,reasonable value range of pressure in wellhead was got.The results are in good agreement with the actual operating parameters.