There are many factors affecting the performance of dri […]
There are many factors affecting the performance of drill pipe wear-resistant belts, and there are three major factors in general:
1. The influence of load force During the drilling process, all factors that increase the contact force between the drill pipe joint and the inner wall of the casing (or well wall) will aggravate the occurrence of wear. For example, in a well section with a large "dogleg" degree, the contact pressure between the drill pipe joint and the inner wall of the casing increases relatively. At this time, whether it is the hardband or the inner wall of the casing (or well wall), the wear phenomenon will increase.
2. The influence of friction coefficient During the drilling process, all factors that increase the friction coefficient between the drill pipe joint and the inner wall of the casing will aggravate the occurrence of wear. If the lubricant type or amount is not suitable, the rotating speed of the turntable is increased, and the temperature is too high or too low, the wear phenomenon will also increase.
3. The influence of wear-resistant belt and casing (or well wall) material properties. According to the theory of "adsorption film" in tribology, it is difficult to form an adsorption film between the friction pair formed by drill pipe steel and rock. The coefficient mainly depends on the surface characteristics of the friction pair material, and the surface characteristics of the friction pair are stable, and the friction coefficient is less affected by the load. For the friction pair formed by the drill pipe and the casing steel, it is easier to form an adsorption film between the two. When a positive pressure is applied, the adsorption film is gradually destroyed, and the surface characteristics of the friction pair contribute more and more to the formation of the friction coefficient. The coefficient of friction is greatly affected by the load. Any material properties that increase the coefficient of friction will aggravate wear.