Geological steel pipe is a steel pipe used by geological departments for core drilling. It is a long steel pipe for geological drilling with a hollow cross-section and no joints around it.It consists of drill pipe, drill collar, casing, casing pipe, well sedimentation pipe and other parts. Among them, the basic functions of the drill pipe are: (1) to lower the drill bit; (2) to apply drilling pressure; (3) to transmit power; (4) To transport drilling fluid; (5) To carry out special operations: squeeze cement, deal with underground accidents, etc.
The drill collar mainly plays the following roles in the drilling process: (1) applying drilling pressure to the drill bit; (2) ensuring the necessary strength under compression conditions; (3) reducing the vibration, swing, and beating of the drill bit to make the drill bit work smoothly; (4) controlling the well slope.
As an important part of the borehole, casing has the following functions: (1) To prevent the collapse of the borehole wall, isolate different formations to prevent liquid convection between formations, and then play a role in controlling formation liquid and pressure during drilling.；
(2) Assist ground well control equipment and underground production equipment to realize their respective functions.