This paper reviews the achievements of the scientific school of Academician of the Academy of Sciences of the Republic of Bashkortostan, Professor of the Ufa State Petroleum Technological University USPTU) D.L. Rakhmankulov in the field of applied and oilfield chemistry. Having achieved fundamental results during theoretical and experimental research into the structure, properties and mechanisms of transformations of substituted cyclic acetals and heteroanalogues, D.L. Rakhmankulov and his colleagues proposed to apply this knowledge in various sectors of the national economy, in particular, in the oilfield chemistry. An analysis of copyright certificates obtained by the researchers from the 1970s to the 1990s, which were related to the development of reagents of the class of cyclic acetals intended for use in the oilfield chemistry, showed that the obtained reagents can be effectively used as components of drilling fluids, inhibitors of hydrogen sulphide corrosion of oilfield equipment, bactericidal reagents that inhibit the growth of sulphate-reducing bacteria. The efficiency of such reagents significantly exceeded that of well-known industrial reagents. It was noted that aqueous compositions containing 1,3-dioxacycloalkanes dissolve and keep in volume particles of resins and asphaltenes in the form of microemulsions, which makes it possible to increase oil recovery and use cyclic acetals as reagents-solvents of asphalt-resin-paraffin deposits. It was found that the use of cyclic acetals, e.g. 4,4-dimethyl-1,3-dioxane, in the composition of drilling fluids can significantly improve their lubricating, antiwear and anticorrosive properties. By-products of petrochemical industries were often used as a raw material for the production of compounds of the class of cyclic acetals, which at the same time solved the problem of their recycling. It was found that the bottom residue of industrial production of 4,4-dimethyl-1,3-dioxane, containing oxymethy1-1,3-dioxanes, can be successfully used for dissolving gypsum hydrocarbon fuels deposited in oil wells. In order to expand the range of reagents that inhibit the growth of sulphate-reducing bacteria, D.L. Rakhmankulov and his colleagues proposed to use aqueous solutions of 1,3-dioxacycloalkanes as bactericides.
