drillstems

A drillstem is a critical component of a drilling rig, forming the conduit through which drilling fluid is circulated and torque is transmitted to the drill bit. It is typically composed of a series of connected pipes, known as drill pipe, which are joined together by specialized connectors called tool joints. These tool joints are designed for repeated make-up and break-out operations and are manufactured from high-strength steel alloys to withstand the immense pressures and stresses encountered during drilling.

The primary function of the drillstem is to allow the drill bit to penetrate the subsurface formations. As the drillstem rotates, it turns the drill bit, which grinds and breaks up rock. Simultaneously, drilling fluid is pumped down through the hollow interior of the drillstem. This fluid serves multiple purposes, including cooling and lubricating the drill bit, carrying rock cuttings to the surface, and maintaining hydrostatic pressure to prevent wellbore instability and blowouts.

Other components can be attached to the drillstem, such as drill collars, which are heavy-walled pipes placed near the bit to provide weight and stiffening, and specialized measurement-while-drilling (MWD) or logging-while-drilling (LWD) tools that transmit data about downhole conditions to the surface. The integrity and proper functioning of the drillstem are paramount for safe and efficient drilling operations.