Dynamic Analysis in Gas Well Drilling

Underbanlanced drilling is a process of forming negative pressure difference at the bottom of the well through which the pressure in the well bore is made lower than strata pressure by the effect of natural condition or artificial means,under controllable conditions.The process can enhance the drilling speed greatly;shorten the period of well establishment and lower drilling cost.Underbanlanced drilling can also lighten or eliminate the damage to hydrocarbon reservoir that drilling fluid has done.Fine pay formation show that underbanlanced drilling can be help to the prospecting success ratio.The appearance of air drilling is the sign of underbanlanced drilling technique.According to the analyzing of the floating air stability in the well,this article set up a mathematic model to stimulate the process of air drilling.