Tubing The innermost tube inside a well
Oil and Gas travels to the surface through the tubing. To support the borehole and seal it off from the surrounding rock layers, steel pipes are inserted into the hole and cemented in place. The pipes are screwed into each other like a telescope, so they decrease in diameter the deeper they go. Once the reservoir has been reached the tubing is installed: it is the narrowest part of the production string and transports the hydrocarbons upwards.