IMPROVEMENT OF THE MATHEMATICAL MODEL OF THE SINGLE-SUPPORT NON-DIRECTIONAL BOTTOM-HOLE ASSEMBLIES

Abstract

The article deals with the important issues of increasing technical and economical parameters of oil and gas wells drilling by improving facilities and scientific and methodological bases of their design and choice. The influence of structural parameters of non-directional bottom-hole assemblies on the static characteristics of its interaction with the well bottom hole and walls has been characterized. International experience in solving different issues concerning design, selection, and operation of the non-directional bottom-hole assemblies with one supporting and centering element has been analyzed. In addition, the main approaches and techniques, used for designing of non-directional bottom-hole assemblies with one centralizer, and criteria that are essential when choosing them for different tasks of directional drilling have been determined. The process of impact on the static characteristics of interaction of such non-directional bottom-hole assembly elements as spindle shaft and bottomhole engine has been studied. The results of the analytical studies on the example of single-support constructions of the assemblies have shown that taking into account in the analytical scheme the interaction of the bottom-hole assembly with the well bottom hole and walls, its different-in-size elements, notwithstanding their length, weight, and bending stiffness, influence the static characteristics of their interaction with the borehole walls, in particular deflecting force on the bit, its deflection angle and pressing force of the centering elements to the walls of the well.