Specific features and prospects of well recovery by sidetracking based on the example of the Stynava field
Authors:   Ivano-Frankivsk National Technical University of Oil and Gas, Ukraine, Stavychnyi Yevhen , Piatkivskyi Stanislav ,   Ivano-Frankivsk National Technical University of Oil and Gas, Ukraine, Vytiaz Andrii ,   Ivano-Frankivsk National Technical University of Oil and Gas, Ukraine, Femiak Vasyl ,   Ivano-Frankivsk National Technical University of Oil and Gas, Ukraine, Kovbasiuk Mykhailo ,   Ivano-Frankivsk National Technical University of Oil and Gas, Ukraine
Published: February 2025

"The article provides a brief overview of the recovery of well No. 47 of the Stynava field by horizontal sidetrack drilling. Based on the analysis of the works, it is established that successful implementation of sidetracking projects with a complex profile can only be achieved through clear interaction of all involved contractors, based on the experience, results, and analysis of carried works, in close cooperation with specialists in the research industry, to implement leading technical and technological solutions. It presents the results of a detailed analysis of geophysical surveys and correlates the geological structure of the field with neighboring wells, which allowed us to design the optimal architecture and spatial placement of the sidetrack. The main technological stages of work on sidetracking and the technical difficulties that occurred are briefly described. The reasons for their occurrence and ways to overcome them are analyzed. The influence of a wide range of loads experienced by a drill string during operation in a directional section is considered, taking into account its geometric characteristics limited relative to the diameter of the sidetrack. The operability of the drill string before the onset of the limit state is calculated and the peak criteria beyond which emergency situations can potentially occur are determined. The influence of the applied drilling mud on the reservoir properties of the productive horizon of the Vygoda formation of the Eocene sediments of the Folded Carpathians (impact evaluation on the core permeability recovery factor) is analyzed. The structural, rheological, tribotechnical, inhibitory, and filtration properties of the drilling mud are presented, which ensure the stability of the near-borehole rock mass and accident-free deepening of the well sidetrack. On the basis of system analysis and calculations, the risks that arise during the lowering of the filter-liner in the complex spatial architecture sidetrack with a nonlinear indicator of the intensity of the zenith angle change are identified. On the basis of the calculations, generalized conclusions are drawn and ways to solve problematic issues regarding the possibility of successful descent of the liner to the bottom hole are presented. A graphical interpretation of the study of the plugging fluid and its formulation are presented. The necessity of using extensive stabilized plugging materials and specialized buffer fluids is established. The main practical criteria of the applied buffer systems are described. The example of the implementation of the project of the sidetracking in well No. 47 of the Stynava field and the initial oil production rate obtained confirms the need to carry out work on the well recovery by drilling a sidetrack in the late stage of exploitation of Ukrainian fields to increase hydrocarbon production.