Effect of Annular Gas–Liquid Two-Phase Flow on Lateral Vibration of Drill String in Horizontal Drilling for Natural Gas Hydrate

NGH (natural gas hydrate) is a sort of green energy with huge reserves. When drilling and exploiting NGH, the complex environment will aggravate vibration drill string, which destroy stability reservoir make it decompose to produce large amount gas. Gas flows into annular fluid, filling gas–liquid two-phase flow variation in characteristic parameters pipe flow. The mixed string more intense. In this study, nonlinear mathematical model lateral established by considering influence internal external fluids, gravity, bottom axial force on string. effect fluid velocity content was studied through experiments numerical simulations. This study found that, an increase content, weakened, intensified, so greater than that content.