Bashkir Scientific Research Institute of Petroleum Refining

Abstract Preheating is crucial in welding high-strength steels as it reduces the risk of cold cracking, manages residual stresses, and improves the mechanical properties of welded joints. This study examines various preheating techniques and their effects on the temperature field, residual stress distribution, and deformation behavior in high-strength steel welding. The specific procedures for enhancing it are discussed in this paper, focusing mainly on preheating, controlled heat input during welding, and additionally heat treatment of the welded joint. Through experimental analysis, the optimal preheating temperatures and methods for different steel grades, including S960QL and S1100M, are determined. The results indicate that preheating significantly lowers residual stress, prevents brittle fractures, and enhances overall weld quality.

The efficiency of subsurface resource development in the Arctic zone of the Russian Federation (AZ RF) is closely linked to the need to minimize technogenic risks, particularly those arising from the influence of space weather on navigation systems operating at high latitudes within the auroral oval. Previous studies have described the mechanisms and extent of space-weather effects on the increased measurement errors of magnetic inclinometers used in well geophysical surveys. Drawing on data from a reference magnetic station and an assessment of inclinometric measurement quality (i.e., the ratio of low-quality data to the total number of inclinometric surveys) for 2022–2024 from operating wells in the Russian Federation, this study provides a qualitative evaluation of the relative likelihood of disruptions to technological procedures caused by extreme additional errors of measuring instruments. To reduce technogenic risks during oil- and gas-well development in the AZ RF and on the continental shelf, a decision-support framework is proposed that integrates real-time geomagnetic conditions into geophysical survey processes. Statistical relationships are examined, observed deviations are assessed, and an approach to their interpretation is outlined.

The article summarizes new data on core studies and well logging in the Famennian deposits of the Yugomashevskoye field located in the Republic of Bashkortostan (Russia). Structurally, the subject is categorized as a model of a rimmed platform with characteristic organogenic buildups and associated facies. The identified sedimentation cyclicity, the secondary processes, and the analysis of changes in the relative sea level make it possible to identify the most common types of porosity confined to a particular part of the section and facies zonality. Transgressive and regressive parts of the cycles are characterized by their specific set of lithotypes and characteristic types of void space. It is revealed that the formation of a void space is affected by the duration and intensity of secondary processes: leaching, dolomitization, and claying associated with the subaerial exposure. Moreover, this work substantiates the division of carbonate structures of this region into three types that differ in terms position, morphology, and manifestation of hypergene transformations, as reflected in the differentiation of types of void space of host rocks and their potential in terms of reservoir characteristics.

The dynamics of phenol absorption from aqueous solution on AG-3 activated carbon is studied. Breakthrough curves—showing the time dependence of the relative concentration—are determined experimentally for different thicknesses of the immobile carbon layer and flow rates of the phenolic water. The mathematical model proposed to describe these curves is an equation with a hyperbolic tangent. The sorptional equilibrium constant for phenol at activated carbon is found (K = 3.472 × 10–4 m–1). In modeling the dynamic adsorption of phenol, the range of the permissible hypothetical flow rate in the sorption system is determined: 2.9–10.8 m/h. The influence of this factor on the process is demonstrated.

A series of catalysts were prepared from a granulated hierarchical (micro–meso–macroporous) NaYh zeolite: NaYh, H-NaYh, H-Yh, Li-NaYh, K-NaYh, Ca-NaYh, Mg-NaYh, and La-NaYh. Their physicochemical properties were characterized, and their catalytic activity and product selectivity were investigated in the aromatization of isophorone. The highest performance in the synthesis of 3,5-dimethylphenol was achieved in the presence of K-NaYh, the catalyst distinguished both by the highest basicity among the tested samples and by low concentrations of weak Brønsted acid sites and Lewis acid sites. This sample exhibited a 3,5-dimethylphenol selectivity of 78.6% at an isophorone conversion of 98.9%. H-Yh, H-NaYh, Ca-NaYh, Mg-NaYh, and La-NaYh provided the highest possible isophorone conversion (up to 100.0% at 400°C and 1 h–1), with the reaction products mainly consisting of dimethylbenzenes and trimethylbenzenes (their selectivity reached up to 72.9 wt %). In the presence of low-activity samples (NaYh and Li-NaYh), the predominant products were methylbenzenes (dimethylbenzenes and trimethylbenzenes, 26.6–30.9%) and isophorone derivatives (β-isophorone and dihydroisophorone, 30.5–33.0%).

The main aspects, state of the art, and prospects for the development of technologies for solvent-free deoiling of slack waxes are discussed. The limiting factors affecting the development of solvent-free deoiling technologies and their implementation in flowsheets of oil blocks of petroleum refineries are the batch mode of the process and low efficiency of processing high-boiling slack waxes. Thermal deoiling processes become topical owing to the technological flexibility allowing production of a wide range of paraffin wax products, low operation expenditures, and low environmental impact due to the absence of toxic solvents. The use of solvent-free deoiling technologies will allow the range of paraffin wax products to be considerably expanded.

The purpose of this article is to develop an information-measuring complex for studying the influence of mechanical stresses in metal on the parameters of electromagnetic-acoustic conversion. Based on a comparative analysis of existing installations for studying the acoustic and electrophysical properties of metals, the structure and composition of the information-measuring complex have been developed. When developing the complex and planning research, the requirements of current regulatory and technical documents were taken into account. The research results are aimed at improving methods for isolating and processing information contained in the signal of an electromagnetic-acoustic transducer to increase the sensitivity and information content of non-destructive testing and diagnostics of metal structures.

The implementation of Russia’s energy strategy provides for the creation of an intelligent control system for active-adaptive electrical networks of the electric power complex, which contains a system for remote diagnostic monitoring of energy equipment, including metal load-bearing structures of electrical energy generation, transmission and consumption facilities. Promising in this regard is the use of a high-performance electromagnetic-acoustic method, which allows non-contact detection of metal defects and monitoring of their stress-strain state. But existing electromagnetic-acoustic diagnostic tools do not have sufficient sensitivity and information content to solve this problem. The article presents the results of experimental studies aimed at identifying and processing informative parameters of electromagnetic-acoustic transformation for the implementation of remote diagnostic monitoring of the stress-strain state and metal damage of power equipment. Based on the research results, it was proposed to use a frequency model formed as a result of spectral analysis of the electromagnetic-acoustic transducer signal as an integral parameter characterizing the state of the metal.