Casing drilling : advantages and limitations

Casing drilling technology involves drilling and casing a well simultaneously. It eliminates the conventional drill string by using the casing itself as the hydraulic conduit and means of transmitting energy to the bit. Casing drilling has been employed in many countries as an effective method of reducing the overall drilling costs by lessening drilling time and drill string problems encountered during conventional drilling process such as lost circulation, differential sticking, well control, and wellbore instability. This paper describes development, application area, benefits and limitation of casing drilling technology.