Abstract: In order to effectively reduce the friction which occurs when running casing in extended-reach wells,and in long sections of horizontal wells,to ensure casing is run into the planed formation,a new casing floating friction reducer was developed.It can effectively reduce the friction generated when running casing,and ensure safer operations.The concept and the procedures were based on the principle that keeps the inside of casing empty by a floating friction reducer,so as to reduce the weight of casing and friction caused by running casing.According to the casing floating technology and requirements of cementing,a main part and four auxiliary components of floating system were developed,which include the floating friction reducer and a drillable float collar used for isolating falling articles,a high pressure whirling float shoe,a shear-pin type casing cleaner and an anti-rotation bump plug.The floating friction reducer was tested at both surface and the Well Sheng 2-Ping 17,Shengli Oilfield,and it showed that each component worked properly and that floating founction was achieved.The successful development of a floating friction reducer for casing can result in successful applications in extended reach wells and in the long section of horizontal wells.