ROTARY SUB AND OTHERS

Lift Sub 

A lift Sub enables safe and efficient handling of straight OD tubulars  such as drill collars, shock tools, jars, directional equipment and  other tools by using the drill pipe elevators. 

Saver Sub 

When rods is added to increase the depth of drilling, the loosening of  the threads are now performed at the bottom end of the Saver Sub  as opposed to the bottom of the Kelly which is the most valuable part  of the drill string. This means that the connection between the top  end of the Saver sub and Kelly is seldom used, and suffers minimal  wear and tear, whereas the lower connection is used in almost  all cases displacing the most wear and tear from the rotary head connection to the much cheaper Saver Sub which is expendable and  reduce cost.  

Straight OD Sub 

Straight OD Sub is used to connect drill stem members that have a similar outside diameter. The drill bit, downhole tools, heavy weight  drill pipe and drill pipe can be crossed over using a straight OD sub. 

Reduced Section Sub 

Reduced Section Sub is used to connect drill stem parts that have different diameters. This sub can be used to crossover large OD  drilling tools or a tapered drill collar string. Saver Sub Straight OD Subs.