Abstract
This article systematizes the causes, development mechanisms, and prevention technologies of corrosion damage to wells and downhole equipment in oil and gas fields based on domestic and international literature. The aim of the study is to identify the major corrosion risks affecting production tubing, casing, and wellhead equipment and to comparatively assess effective methods for managing these risks. The methodology is based on a targeted review of scientific articles, regulatory documents of the Republic of Kazakhstan, and ISO, ASTM, API, and AMPP/NACE standards using comparative analysis and systematization methods. The major threats to well equipment were identified as CO₂ corrosion, sulfide stress cracking and hydrogen damage caused by exposure to H₂S, pitting and under-deposit corrosion, microbiologically influenced corrosion (MIC), and erosion-corrosion damage. These processes are affected by the presence of a free-water phase, pH, the partial pressures of CO₂ and H₂S, salinity, temperature, flow velocity, sand content, biofilm formation, and the microstructure of the metal. Studies conducted at the Uzen oil field confirm the significant role of high water cut and acid gases in the corrosion of downhole equipment. The main corrosion prevention methods proposed include the selection of corrosion-resistant alloys and protective coatings, corrosion inhibitor treatment, cathodic polarization, optimization of operating conditions, and the implementation of corrosion monitoring systems. The results obtained can serve as a basis for developing a comprehensive corrosion protection program aimed at extending the service life of well equipment and preventing emergency situations.