输气管的输气能力和水力摩阻系数是随着时间而变化的，如果是不含硫化氢的干气，气中的固体颗粒对管壁的磨光作用，使投产后的输气管的粗糙度和水力摩阻逐渐减小，输气能力增大。The gas transmission capacity and hydraulic friction coefficient of the delivery pipe change with time. If the dry gas does not contain hydrogen sulfide, the polishing effect of solid particles in the gas on the pipe wall will make the roughness and hydraulic friction of the delivery pipe gradually decrease and the gas transmission capacity increase after the production.