由于空气钻井采用具有极大压缩性的空气作为循环介质,其循环系统的压力变化与传统钻井方式相比有很大区别。从循环系统的压力分布人手,通过优化理论模型等手段,推导出环空压力计算模型,并求解出环空压力随深度变化的通用解。采用C语言编程计算,得到压力P随井深H变化数据,绘制出P-H曲线,归纳出空气钻井中压力随井深变化规律,为空气钻井中主要参数的计算提供理论依据。
Because of the maximal constrictive air as its circulating medium, the pressure change of the circulation system has great difference when compared with the conventional drilling methods. Starting with the pressure distribution, and through optimizing theory model, some useful theoretical expressions for calculation are derived. The general solution of annular pressure changed with depth formulas is first given, which lays a foundation for the following studies. The P-H data is obtained in detail after the calculation analysis via simplified treatment and c language programming. The change law of pressure is discussed by drawing the distribution curve, which is provided theoretical guarantee and technical support for the main parameter calculation in air drilling.