Lubrication may be especially important on extended reach or horizontal wells where the friction between the drill pipe, drill bit and rock surfaces must be kept to a minimum.

• 对延伸区域或水平油井而言,润滑可能尤为重要,因为在这些地方,钻杆、钻头和岩石表面间的摩擦必须保持在最低水平。