What are the wear and tear situations that may occur after using petroleum drill collars?

Fatigue wear is the mechanism of rolling or rolling erosion wear on the surface of rotary excavator drill rods, which is mainly manifested in the form of microcracks and micro cutting during low angle erosion; During high angle erosion, crack propagation and brittle fracture are the main mechanisms. During the operation of the drill string, the rotation speed is relatively high, and the relative velocity with the drilling fluid is also high. If the viscosity and weight of the drilling fluid are high, the sand content is high, and the drilling is carried out for a long time, it will cause significant erosion and wear to the drill string.

Abrasive wear is a phenomenon caused by the relative motion of external hard particles or hard surface micro peaks on the surface of rotary excavator drill rods, resulting in surface abrasion and material detachment. The surface characteristics of rotary excavator drill rod columns are abrasion tearing, longitudinal tensile marks, local peeling, and cracks. The mechanism of abrasive wear is micro cutting, where multiple plastic deformations lead to fracture and micro fracture. The drill string is prone to significant bending under composite stress conditions, resulting in severe friction between the protruding areas and the hard rock layers. The quenching treatment thickness on the surface of the drill string is generally 1mm. After the quenching layer wears off, the wear rate will accelerate in the future. In deep hole drilling, sometimes there are obvious scratches on the surface of the extracted drill rod, which is a manifestation of abrasive wear.

After using the drill collar for a period of time, we will find that there will be varying degrees of wear, and of course, some wear is inevitable. Because in the use of rotary excavator drill rods, there may be friction between various components, so it is not surprising to see wear and tear.