The difference between drill pipe and drill collar

The drill collar, the difference between drill pipe and drill collar, is located in the lower part of the drill string and is a part of the lower drilling assembly. Its characteristics are large wall thickness (generally 38~53mm, which is equivalent to 4~6 times of the wall thickness of drill pipe), and it has great gravity and stiffness. Drill collars are generally divided into three types: spiral drill collars, nonmagnetic drill collars and integral drill collars. Drill pipe is a kind of steel pipe with thread at the tail, which is used to connect the surface equipment of drilling rig with the drilling and grinding equipment or bottom hole installation at the bottom of drilling. The purpose of drill pipe is to transport drilling mud to the drill bit, and to advance, lower or rotate the bottom hole installation together with the drill bit. Difference: the drill collar is thicker than the drill pipe wall and heavier per unit length. The lower part of the drill collar is connected with the drill bit, and the upper part is connected with the drill pipe. The function is similar, the drill pipe is to transmit motion and power, and the drill collar is stronger than the drill pipe, which directly drives the bit operation. Definition of geological drill pipe Geological drill pipe is a geological drilling tool designed and produced by using geological alloy steel pipe through resistance welding process. The rod body is made of geological alloy steel pipes (R780, DZ50), and the geological drill bit is made of high-quality alloy structural steel (42CrMo), which has been treated by vacuum quenching and tempering, greatly improving the fatigue strength and shear strength. Geological drill pipe is produced and processed by advanced resistance welding technology. The drill pipe has the characteristics of high bending strength and strong welding, which can ensure the requirement of straightness during deep hole drilling, and has high fatigue strength and long service life. It is characterized in that the drill pipe is of outer flat structure, and the drill pipe joints with different specifications are welded by steel pipes and processed into tapered threads or rectangular threads, which are used end to end. The advantages of this kind of products are: the rod body is made of high-quality geological alloy steel pipe, and the drill pipe joint is made of high-quality alloy structural steel, which is formed by high-pressure forming, vacuum quenching and tempering and resistance welding. Advanced automatic numerical control processing equipment is selected for thread processing, which effectively ensures the processing accuracy of each product. The advanced production technology of first resisting welding and then stopping thread processing ensures the coaxiality specification of multiple joints of drill pipes during deep hole drilling. Compared with similar products, the product has the characteristics of high bending strength, large rotating torque and stable operation.