The work is devoted to the analysis of the reasons for the decrease in the intake capacity of horizontal injection wells at the Vostochno-Messoyakhskoye oil and gas condensate field, as well as the development of measures to restore it. A complex of experimental studies has been carried out, including the study of mineralogy, granulometry and component composition of sediments; analysis of the possibility of salt deposition of poorly soluble salts; formation of persistent oil-water emulsions; investigation of the solubility of sediments in acid composition and the development of a formulation with low corrosion aggressiveness and increased solvent capacity for sediments. The presence of calcium carbonate, iron compounds and quartz sand in sediments from filter of modular water injection station, as well as in the bottom-hole zone of the injection well formation, has been established. The reasons for the appearance of calcium carbonate in the deposits are the presence of elevated concentrations of calcium and bicarbonate ions in the raw water of the central pumping station, heating of the raw water on the modular water injection station by CCP pumps, insufficient dosage of the salt deposition inhibitor used to protect against calcium carbonate precipitation. Filtration tests were carried out on the rock of the PK1-3 formation and the selection of compositions capable of increasing the permeability of the formation rock. Compositions for acid bath and injection into the reservoir to restore intake capacity have been developed, and their pilot testing has been carried out. Acid compositions have been developed that effectively dissolve deposits from the modular water injection station and bottom-hole formation zone of horizontal injection wells of the Vostochno-Messoyakhskoye field. A complex technology of hydrochloric acid treatments of the bottom-hole formation zone with the establishment of an acid bath and the injection of an acid composition into the reservoir with a pre-treatment of a mutual solvent is proposed. Field testing of selected compositions for processing of the bottom-hole zone of injection wells was carried out, as a result of which an increase in the well intake capacity coefficient was achieved by 2.05 – 2.61 times.
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