充气钻井井筒压力分布规律研究

Study on wellbore pressure distribution rule in aeration drilling

以多相流理论和欠平衡钻井基本原理为基础,研究了充气钻井的压力控制问题,建立了适合充气欠平衡钻井的物理模型,同时给出了井筒压力计算的多相流理论模型和数值求解方法。结合现场资料,计算了充气钻井时井筒压力随回压和注气量的变化情况,并对其变化情况进行了解释。得出的结论为进行合理的欠压值设计提供了理论依据,对指导和实施欠平衡钻井作业和研究具有一定的理论参考。

Based on the theory of multiphase flow and underbalanced drilling, this paper describes the pressure control issue during aeration drilling. The physical model of aeration drilling, which is fit for the aerated underbalance drilling, has been established. The paper gives the theoretic model of the muhiphase flow of calculating wellhole pressure and the numerical calculation method. Furthermore, the paper shows the influence of the bottomhole pressure on the various wellhead pressure and gas inflow rate, and gives the reasons for the influence results. The study conclusions can be used to revise the bottomhole pressure difference and can provide an important reference for the field applications.