What Does Casing String Mean?
A casing string is a length of steel pipe assembled together for the purpose of securing the cut sides of a well bore. The individual pipe sections are connected and lowered into the borehole and the resulting space between the casing and the borehole wall is cemented using cement slurry.
The pipe joints are 12 meters in length with each end male threaded and connected using double-female threaded pipes of short lengths called couplings. Casing is very important in a wellbore to isolate the formations that exist adjacent to it. Casing pipes are supported at regular intervals using centralizers that help maintain the spacing between the casing and well bore wall.