Strengthening and reconstructionof drilling core pipe for engineeringand geological exploration

Abstract

Currently, there is a tendency to increase the depth of gaseous and liquid fossils extraction. Therefore, prospecting and developing new deposits is promising. There is also a need to create new freshwater sources and implement relevant geological work based on this need. It is essential to have information about the characteristics of the explored slabs and the geology of the fields in general. Implementation of engineering and geological core drilling exploration is the most acceptable and provides the necessary data. Here, the peculiarities of the technological schemes of the process implementation make it possible to obtain separate sections of structures at a depth of the drilling equipment. It is essential to use traditional equipment, recommended for decades and provides the necessary results [1–3]. In the drilling process, you can achieve different diameters and depths of wells execution, obtain fossil samples etc. Engineering and geological exploration drilling is now taking on increased use in various industries [3]. Therefore, the problem of providing high- quality drilling tools, the stability of their operating characteristics, and the possibility of usage in different conditions is an urgent need today. Modern drilling problems determine the usage of components of the core set with the appropriate physical and mechanical characteristics. Especially it relates to elements close to the drilling tool and the place of fossil; destruction – drill pipe. It is installed immediately after the crown core drill and receives almost the same loads and effects during working [1–3]. Conditions for the implementation of the process of core drilling are characterized primarily by the effect on the elements of the significant axial and twisted core set forces. There is the influence of the corrosive and active environment of the fossil in the washing and lubricating liquids well, etc. High temperatures are also observed at the drilling sites [3], which negatively affect the working tool and speed up its operation. As a result, there is an intensive shock, and abrasive core pipe wear and operation indicators change their constructive size. As a result, it is necessary to replace the operated drill string periodically. Considering modern technical and economic factors, it may be decided to repair a pipe to its original size in many cases. There are tasks for providing the appropriate characteristics of the core pipe surface. It is possible to model such properties of the new surface that functionally the best meet the conditions of the drilling process of a given geological formation. The peculiarities of applying the therapeutic layer on the surface of the core pipe are investigated in work. The experience shows that using electric arc surfacing under the flux layer is expedient. This provides the necessary adhesion of the applied layer and promotes obtaining resistance to the operation surface of the core pipe. At the same time, there is high-quality protection and the possibility of additional alloying through the flux-slaggy welding bath. Using electrode powder type wires creates conditions for flexibility to achieve the established characteristics of functional layers [4–6]. The filling flux, located in the cross-section of the electrode wire, can be easily changed by chemical composition. At the same time, it is possible to make relatively small parties of a wire with the set characteristics. The technological scheme justification about the core pipe surfacing is performed. It provides the previous displacement of the electrode butt size from the zenith of the core pipe to prevent the welding bath from spreading. The structural pipe size , the requirements for residual deformations, and the conditions of shapping the welded layer show the practicality of welding on a helix.

Ensuring the technological strength when welding the shaft with flange of auto-vehicles

“…The material of the flange (steel grade VSt3ps) belongs to low-carbon steels of ordinary quality. That is, according to [5,6,14], good welding is achieved without additional special heat treatment. Using the data of the chemical analysis of the flange and the recommendations of the special literature [5 -8], the value of the carbon equivalent was determined according to expression (1).…”

“…4. Setting the parameters of the welding regime was carried out according to the recommendations of the specialized literature [7,8] and the construction of the welded structure (annular seam). The following regime parameters are recommended for automated welding of the shaft and flange in shielding gases (Table 2).…”

“…Therefore, when developing the welding technology of the shaft and flange, it is advisable to use methods that limit or eliminate the need for post-welding heat treatment; -limitation of the content of carbide-forming elements and their influence on the formation processes of structural heterogeneity. It was established [4,5,7,8] that structural heterogeneity is manifested depending on the content of alloying elements, their type and thermodynamic activity. In particular, the intensity of the influence increases with the increase in affinity to carbon of the remaining alloying elements.…”

“…In particular, by changing the parameters of the thermal cycle, it is possible to achieve different cooling rates of the metal of the welded joint [9]. As a result, there is a decrease in the content of hardening structures, prevention of the formation of a coarse-grained structure of the seam metal, and a decrease in overheating of the seam areas [8,10]; -in the case when preheating is important from a technological point of view, it should be combined with the parameters of the welding mode with low-power heating sources [10]. This creates conditions for the martensitic transformation to occur in the hightemperature region; -use of welding materials with high plastic properties.…”

“…Obtaining equal-strength welded joints is often difficult when manufacturing this type of welded structures. This is due to the use of high-strength steels, which are mostly supplied in a pre-heat-treated state [8,10]. As a result of welding, there is not only a redistribution of the structural-phase composition, but also the initial thermal strengthening of the base material is levelled [12,14].…”