By establishing force equilibrium equations, a mechanical model for calculating the friction on the string is set up, and the analytical formulas for calculating the hook load and wellhead torque when the string is tripped in.

• 通过建立管柱受力平衡方程，推导出水平井管柱入井时摩阻计算的力学模型，分析计算了在稳定和旋转方式下管柱入井时的大钩载荷和井口扭矩等重要技术参数的解析公式。