Main features of drilling operations while constructing curved wells

Abstract

Objective is to develop theoretical basis, design schemes, and methods to calculate technological support of the processes of directional wells construction of a particularly oil-and-gas group (reliable spatial orientation – irrespective of the values of axial load and rock hardness). Research methodology. Analytical and laboratory studies of the functioning features of a device for directional drilling have been performed by means of modern methods of analytical analysis and experimental studies, i.e. by using general principles of mathematical and physical modelling, methods of processing the research results in the EXCEL and МАТНСАD environment as well as control and measuring devices and materials. The drilling processes within a well were modelled in terms of experimental wells of training drilling ground of Dnipro University of Technology with the use of drill rig УКБ-4П and corresponding auxiliary tools. Research results. Basic principles and certain structural elements of the technology of directional well constructions in terms of the available complex lithological rock-mass features have been considered. Central principles of the design of a directional drilling cycle have been developed; certain parameters of the technology of wellbore profiling have been calculated. A design of the directional-drilling device has been proposed; the device consists of the links, which are capable of going beyond the case contour while drilling, and toothed discs, being mounted coaxially with the corresponding increase in their diameter towards the external case wall. Difference in the diameters of the toothed discs has positive effect on the bottomhole rock-breaking processes and creates the conditions for the most efficient breaking, i.e. chipping. Originality. The improved geological information content and reliability of the performance of drilling and accompanying operations while constructing oil-and-gas and other wells is based on the comprehensive use of advantages of directional drilling and corresponding wellbore profiling. Practical implications. Certain components of the improved technical and technological methodology of operations during the directional well construction have been developed and substantiated, basing on the advanced industrial principles and high economic indices. Principles of the efficient profiling system for oil-and-gas wellbores have been elaborated. The obtained data are the basis for further developments to improve quality and reliability of drilling and accompanying operations while constructing wells of different purposes.