浸泡在钻井液中的钻柱 ,会受到钻井液浮力的影响。在钻井施工过程中 ,井眼轨迹预测和控制及钻柱摩阻计算都应考虑浮力的影响。在钻井过程中 ,浮力的计算一般忽略了钻杆的内外加厚影响 ,而对于复合钻柱的浮力计算有不同的观点。文中对直井和斜井两种情况下的钻柱浮力进行了详细分析 ,提出了钻柱浮力的计算新方法 ,并在现场进行了验证。 The drill string immersed in the drilling fluid can be affected by the buoyancy of the drilling fluid. During the drilling process, the influence of buoyancy should be considered in the well trajectory prediction and control and calculation of drill string friction. During the drilling process, the buoyancy calculation generally ignores the inner and outer thickening effects of the drill pipe, but has different viewpoints on the buoyancy calculation of the composite drill string. In this paper, the buoyancy of the drill string in both vertical and inclined wells is analyzed in detail. A new method for calculating the buoyancy of the drill string is proposed and validated in the field.