Subs
Crossover sub is mainly used in oil, gas and geology drilling process to connect with other drill stem parts. It is connected of upper drilling tools and lower drilling tools. It has well structure and well property. Because of the different connecting components, there are different requirments to crossover subs. It has “A”, “B” and “C” type.
Specification：All sizes.
Drill pipe is one of important tools in drilling process. The tool joints are the main components for producing the drill pipe. Weld the tool joints on two sides of drill pipe body by friction welding, the drill pipe are finished producing.
Specification：All sizes.
Circulating sub is installed in the top of drilling stem. The upper thread is connected with circulating system of casing, tubing, and union thread to circulate the drilling fluid. It divided into casing circulating sub, tubing circulating sub, union circulating sub and tee sub.
Wear sub can valid resolve the above mentioned problems in the process of oil and gas drilling. It can reduce the drilling torque and friction between drill stem and casing by rotating drilling. So it can protect the casing and drill pipe.
The oriented sub is used for the bent screw drilling tool getting into orientated. Put the gradiograph in the directional bond. It is used for kicking off in directional well, side tracking and vertical well. It has the advantages of simple structure, easy to use and low cost
