The overseas field application shows that oil base muds with densities greater than 1.6 g/cm3 have lower equivalent circulation density(ECD) if manganese tetraoxide is used as the weighting agent,instead of barite.

• 国外现场应用表明；对于密度在1.；6 g/cm3以上的加重油基钻井液；用四氧化锰代替重晶石粉加重；能降低钻井液的当量循环密度。