Application of polymer compositions in repair and insulation works in wells

The state of Russia's resource base has a downward trend. In the light of the need to keep the economic indicators not lower than the achieved ones, the emerging problems in the production of hydrocarbons require to solve them are use of new methods. Reducing the volume of associated water, maintaining the environmental safety of oil production while maintaining and even reducing the cost of oil production, due to new technologies and materials, are urgent tasks. For issues of reliable restoration of the technical condition of wells and the limitation of water inflow are this work is devoted. The technology based on the use of a modified polymer water-insulating composition is presented. Analytical and field studies were conducted. The technology and the polymer composition have shown the possibility of application during water inflow restriction and repair and insulation works. Keywords: repair and insulation works; water shutoff; polymer composition; modification of the composition

CATALYTIC SYSTEMS OF BASIC PETROCHEMICAL PROCESSES

Доля каталитических процессов в нефтехимической промышленности ежегодно возрастает. Более 70% разнообразных химических процессов протекают в присутствии катализаторов, в мировой технологии их доля составляет около 90%. Это связано с расширением функциональных возможностей современных катализаторов. Начиная от повышения эффективности и экологичности производства, расширения номенклатуры товарной продукции, получения продуктов с заданными свойствами, до упрощения технологий в некоторых случаях. Кроме этого использование катализаторов существенно определяет уровень энергетических, капитальных и материальных затрат, новизну технологий и их конкурентоспособность. В связи с этим совершенствование индустрии катализаторов и технологий с их использованием относятся к перспективным задачам развития химического и нефтехимического комплексов мировых промышленных лидеров. В числе приоритетных направлений катализа рассматриваются нанокатализ, катализ в сверхкритических растворителях, катализ ионными жидкостями. Основными инструментами совершенствования катализаторов являются модифицирование состава и дизайн структуры. Это определяет обновление ассортимента и рост рынка катализаторов. Последние годы отличаются интенсивностью научных исследований в сфере разработки и изучения катализаторов различных процессов. С целью обобщения информации по разработкам каталитических систем для основных крупнотоннажных нефтехимических процессов подготовлена данная обзорная статья. Систематизированы сведения исследований состава, структуры, способов приготовления, эффективности новых катализаторов процессов гидрирования, дегидрирования, алкилирования, окисления и полимеризации, которые широко применяются в промышленности органического и нефтехимического синтеза. Для разных процессов проведено сравнение новых и используемых катализаторов по критериям экологичности, регенерируемости, а также по выходу и характеристике целевых продуктов. The share of catalytic processes in the petrochemical industry is growing every year. More than 70% of various chemical processes take place in the presence of catalysts; their share in world technology is about 90%. This is due to the expansion of the functionality of modern catalysts. Starting from increasing the efficiency and environmental friendliness of production, expanding the range of commercial products, obtaining products with desired properties, to simplifying technologies in some cases. In addition, the use of catalysts significantly determines the level of energy, capital and material costs, the novelty of technologies and their competitiveness. In this regard, the improvement of the industry of catalysts and technologies with their use are among the promising tasks of the development of chemical and petrochemical complexes of world industrial leaders. Nanocatalysis, catalysis in supercritical solvents, and ionic liquid catalysis are considered among the priority areas of catalysis. The main tools for improving catalysts are composition modification and structure design. This determines the renewal of the assortment and the growth of the catalyst market. Recent years have been distinguished by the intensity of scientific research in the development and study of catalysts for various processes. In order to generalize information on the development of catalytic systems for the main large-scale petrochemical processes, this review article has been prepared. The data of studies of the composition, structure, preparation methods, efficiency of new catalysts for the processes of hydrogenation, dehydrogenation, alkylation, oxidation and polymerization, which are widely used in the industry of organic and petrochemical synthesis, are systematized. For different processes, a comparison was made between new and used catalysts in terms of environmental friendliness, regenerability, as well as the yield and characteristics of target products.

In Situ Alloying of a Modified Inconel 625 via Laser Powder Bed Fusion: Microstructure and Mechanical Properties

This study investigates the in situ alloying of a Ni-based superalloy processed by means of laser powder bed fusion (LPBF). For this purpose, Inconel 625 powder is mixed with 1 wt.% of Ti6Al4V powder. The modified alloy is characterized by densification levels similar to the base alloy, with relative density superior to 99.8%. The material exhibits Ti-rich segregations along the melt pool contours. Moreover, Ti tends to be entrapped in the interdendritic areas during solidification in the as-built state. After heat treatments, the modified Inconel 625 version presents greater hardness and tensile strengths than the base alloy in the same heat-treated conditions. For the solution annealed state, this is mainly attributed to the elimination of the segregations into the interdendritic structures, thus triggering solute strengthening. Finally, for the aged state, the further increment of mechanical properties can be attributed to a more intense formation of phases than the base alloy, due to elevated precipitation strengthening ability under heat treatments. It is interesting to note how slight chemical composition modification can directly develop new alloys by the LPBF process.

CALCULATION OF THE CONSTANTS OF COPOLYMERIZATION OF METHACRYLAMIDE WITHN-VINYLCAPROLACTAM

In this work, a copolymer of methacrylamide with N-vinylcaprolactam was synthesized for the first time by the method of radical copolymerization, based on the obtained values of the copolymerization constants, the dependence of the instantaneous and average composition of the copolymer was calculated. The relative activity constants r1 and r2 of methacrylamide and N-vinylcaprolactam monomers in the reaction of radical copolymerization have been calculated. The probability of the formation of different sequences of units during the formation of the copolymer was investigated. The variance of the compositional distribution was found to have a minimum at the azeatropic point.Key words:copolymerization, methacrylamide, N-vinylcaprolactam, monomer, copolymer, instant composition, average composition, modification, compositional heterogeneity, dispersion

Multivariate Design of 3D Printed Immediate-Release Tablets with Liquid Crystal-Forming Drug—Itraconazole

The simplicity of object shape and composition modification make additive manufacturing a great option for customized dosage form production. To achieve this goal, the correlation between structural and functional attributes of the printed objects needs to be analyzed. So far, it has not been deeply investigated in 3D printing-related papers. The aim of our study was to modify the functionalities of printed tablets containing liquid crystal-forming drug itraconazole by introducing polyvinylpyrrolidone-based polymers into the filament-forming matrices composed predominantly of poly(vinyl alcohol). The effect of the molecular reorganization of the drug and improved tablets’ disintegration was analyzed in terms of itraconazole dissolution. Micro-computed tomography was applied to analyze how the design of a printed object (in this case, a degree of an infill) affects its reproducibility during printing. It was also used to analyze the structure of the printed dosage forms. The results indicated that the improved disintegration obtained due to the use of Kollidon®CL-M was more beneficial for the dissolution of itraconazole than the molecular rearrangement and liquid crystal phase transitions. The lower infill density favored faster dissolution of the drug from printed tablets. However, it negatively affected the reproducibility of the 3D printed object.