METHODOLOGY FOR DESIGNING, MANUFACTURING AND TESTING OF DRILLING DAMPER ELASTIC POLYURETHANE UNIT

Abstract

In recent years, dampers based on vibration damping units made of urethane prepolymers and hardeners have been widely used in drilling. This is largely due to the efficiency and simplicity of the design in relation to traditional devices with rubber elastic assemblies and devices based on various metal springs. Concerning the efficiency, it can be noted that when using diamond bits in the layout of the drill string, which create low-amplitude high-frequency vibration during their operation, the use of drilling dampers based on rubber or polyurethane elastic nodes is most beneficial. Compared to rubber, polyurethane also has a number of advantages that allow it to be used in a wider range of product requirements. Functional advantages include: high abrasion resistance; greater resistance to tearing compared to rubber; high resistance to fats and oils; wide operating temperature range from minus 70 °С to 120 °С; quick restoration of its original form after prolonged cyclic loads due to its high elasticity; the most optimal ratio of price to durability of the product. Polyurethanes have high stability characteristics throughout the entire service life. It is also important to note that polyurethane products can be produced by free casting, which does not require, unlike rubbers, complex and expensive injection molds and special equipment. This feature, combined with the availability of various types of machining, allows to solve the problem of manufacturing small-scale and experimental products quickly and inexpensively. This article discusses the main stages of designing a vibration damping unit made of polyurethane for a drilling damper. These include designing a unit based on static and dynamic calculations, manufacturing a prototype and testing it on stands. Tests are conducted to determine the static and dynamic performance indicators of the node. Calculations performed for a single polyurethane ring can be interpolated for nodes of a more complex shape. This will allow the use of the proposed technique in the development of multi-axis dampers.