The paper proposes a new technology for fluid production intensification, in particular hydrocarbons, which is implemented via significant increasing of the local wellbore diameter in the interval, where the productive stratum is present. The proposed technology improves the well productivity by increasing the filtration surface area and opening new channels for filtering fluids into the well. The innovative, technical idea is to drill large diameter circular recesses in planes perpendicular to the well axis. After that, the rock mass located between the circular recesses are destroyed by applying static or dynamic axial loads. The required value of the axial force is provided by the weight of the standard drilling tool. As a result of the study, the analytical relations to specify the admissible radius of circular recesses and admissible thickness of rock mass between two adjacent circular recesses from the condition of safe operation are obtained. The numerical analysis carried out for typical reservoir rocks substantiated the possibility of well diameter local reaming twenty times. A special tool for circular recess drilling is developed and the principle of its operation is described. The advantage of the proposed approaches is the low energy consumption for well diameter reaming. Our technology will have special economic expediency for the intensification of production from hydrodynamically imperfect wells and under the condition of fluid filtration according to the expressed nonlinear law.

Currently, drilling of directional oil and gas wells under complex technical-technological and mining-geological conditions requires the use of drill pipes made of various materials. In turn, to choose rational modes of strengthening drill pipes and drill string layouts, information on the contact forces and friction forces of the drill string pipes on boreholes is necessary. Drill pipe curved sections friction with boreholes and drill bit resistance moment changes are the main causes of uneven rotation of a drill string during rotary or combined drilling methods and the occurrence of parametric oscillations. To reduce the cost of mechanical energy for well wiring, it is necessary to take into account the “drill string–borehole rocks” force interaction to estimate the magnitude of the frictional forces and their influence on the technological parameters of the drilling process. To solve this problem, mathematical models of “conventionally vertical and inclined drill string sections–borehole” were built. Based on the industrial data, an analysis of the force interaction of a deformed drill string composed of pipes made of different materials (aluminum, titanium, steel) was carried out. Analytical dependences were obtained for determining the contact forces and friction of the pipes on boreholes. A numerical study of the change of these power factors depending on the depth of the well under conditions of intensive vibration loading was carried out. The amplitude values of these forces, the frequency of their change for good sections, as well as the places for the most rational installation of drill pipes in the layout of the drill string were estimated. It was established that the intensity of contact and friction forces for steel drill pipes is greater than for titanium or aluminum ones. It is shown that the greater impact of a solid steel string on contact forces and frictional forces compared to a layout with sections of titanium or aluminum pipes in the range of vibration frequencies of 8–22 Hz corresponds to a bit rotation frequency of 70–80 rpm. The practical application of the obtained research results will contribute to the improvement of technical and economic indicators of the well drilling process.

Management of wells in the process of their construction is one of the important factors in ensuring the safety of the technological process. Blowout equipment, which includes annular preventers, is used to control the wells. This applies to the construction of oil and gas wells, or wells that provide degassing of coal seams to reduce their gas-dynamic activity. For the purpose of safe and long-term operation of annular preventers on the basis of the theory of thick-walled combined reinforced shells and the carried-out analytical research, the mathematical model for research of a stress-strain condition of a seal of an annular preventer has been offered. Taking into consideration the real design, the seal of the annular preventer is modeled by a rubber shell, reinforced in the circular direction by rubber frames, and in the longitudinal direction by metal stringers. The mathematical model provides for determining the stiffness, internal force factors and stresses in the longitudinal and transverse sections of the combined rubber-metal seal, considering the peculiarities of its operation. At the same time, the model includes the conditions of interaction of the rubber base of the seal with a pipe, as well as the action of sealing pressure under operating conditions. The use of the proposed mathematical model reduces the costs of experimental research and will contribute to ensuring the reliability of simulation modeling results. The advantage of the method is the determination of calculated loads at different points of the combined seal under the existing state of dangerous zones and the influence of operating conditions. In the meantime, prerequisites have been created for expanding the possibilities of simulation modeling and designing structural elements of annular preventers with increased operational characteristics. The practical value of the obtained results is determined by the possibility of using them to ensure the performance of the rubber-metal seal both at the stage of its design and during the operation.

Construction of an improved mathematical model of the axial and lateral oscillations of the riser in the plane of action of the velocity vectors of the fluid flow washing the riser was considered. This model makes it possible to study the stress-strain state of the riser with simultaneous impact on it from the sea and the change in the force of tensioning its upper end. In addition, the model specifies the force effect exerted on the riser by the washing fluid flowing in it.Based on the developed mathematical model, a simulation model of operation of the "drilling ship – rope-type tensioning system of the riser – riser" system was created in the Modelica modeling language and a series of numerical experiments were performed at various levels of seaways. The obtained results show that the proposed model produces 22‒40% higher calculated values of the amplitude of lateral oscillations and 10‒25 % higher calculated values of the bending moments in critical sections compared with the results of the classical model of lateral oscillations. The greatest difference between the simulation results was observed with moderate seaways. With a growth of seaways, the difference between the two models decreases. Proceeding from the obtained results, it is not recommended to neglect the effect of variation in time of the forces tensioning the riser in applied problems of studying riser operation in conditions of slight sea.

Lifting structures are critical components in the automotive industry, yet their excessive weight and bulk often impede mobility and ease of use. This paper presents a comprehensive study on the structural optimization of a scissor lift, focusing on the topological redesign of its lever. The primary objective is to achieve significant mass reduction while preserving structural integrity, load-bearing capacity, and safety. The core hypothesis is that strategic topological modifications can induce favorable stress redistribution, leading to material savings without compromising safety margins. The research methodology, implemented in the spring of 2024, was based on numerical modeling using the Finite Element Method (FEM) in Ansys Workbench. Numerical analysis of the base lever identified a maximum equivalent stress of 152 MPa, corresponding to a safety factor of 2.27. The proposed optimizations yielded a new lever topology that reduces the component’s mass by 39% (to 35 kg) while maintaining a high safety factor of 1.52 under a maximum stress of 226.5 MPa. The results confirm that the proposed design approach successfully enhances the lift’s performance-to-weight ratio, offering a viable solution for developing more efficient and portable automotive lifting equipment.