Dolyk R. Selection of non-steerable bottom hole assemblies for rotary well drilling

The dissertation is devoted to the selection of non-steerable bottomhole assemblies (BHA) in conditions of information uncertainty for rotary well drilling. General task of making technological decisions for drilling vertical and inclined well bore sections has been formulated. The decomposition of general task has been proposed in the form of task sequence of selection drilling fluid, drill bit type, drilling parameters and BHA. A statistical model that takes into account multifunctional requirements, information uncertainty and field data has been proposed for selectionBHA. BHA static and dynamic characteristics have been studied based on field data of well drilling onsome fields of Dnieper-Donets Rift.The statistical estimations of the bit side force, the quality indices of the wellbore quality and the casing columns cementation have been constructed.Selection of non-steerable BHA for drilling vertical and inclined well bore sections has been substantiated. Variants of multi-supported BHA for ensuring the wellbore quality.