Kayan Casing na Waje

Jerin outer casing wani bangare ne mai mahimmanci a cikin tsarin narkar da double rotary, wanda ke da niyyar tabbatar da tabbatar borehole yayin da ake shiga cikin yanayin kasa mara daɗi a cikin gina shingen gida na karkara da ayyukan injiniyan geotechnical. Wadannan kayan narkar da na musamman suna kafa shafin outer rotating na tsarin double rotary rig, aikin tare da inner drilling assembly don samun ci gaba na borehole mai kima. Jerin outer casing ya yi aiki ne don kare borehole, musamman a cikin ƙasa mara tabbas inda ake amfani da hanyoyin narkar da single-rotation ba.