Published June - July 2026, Pg. 36-43

Section: Oil and gas preparing and transportation

UOT: 622.27:622.69

DOI: 10.37474/0365-8554/2026-06-07-36-43

Risk of hydrate formation on oil and gas submarine pipelines in the Caspian Sea conditions

N.E. Abdullazade - Azerbaijan State Oil and Industry University

This article is devoted to the assessment of the risk of hydrate formation in oil and gas submarine pipelines along the Sangachal-Shahdeniz route in the southwestern sector of the Caspian Sea. The structural-mechanical modeling determined the vertical stability parameters, optimal burial depth and soil stability of the pipeline along the route, and the results showed that the mechanical stability of the pipe is more sensitive to hydrodynamic and thermal fluctuations, especially in segments dominated by silt-clay sediments. Based on the MATLAB-OLGA-GIS integrated model, the probability of hydrate formation was assessed along the route, considering temperature, pressure and gas composition, and the results were presented with maps and graphs. 
The analysis shows that the initial segment of the route is assessed as a stable zone, there is a medium risk in the medium-depth zone, and in the direction of the Shahdeniz field, deep segments dominated by silt-clay layers constitute a high-risk zone. Calculations show that the risk of hydrate formation is directly related to the depth of the pipeline, soil type, temperature and pressure distribution. To reduce the risk of hydrates, it is recommended that the flow temperature not fall below 15 oC, the insulation thickness not less than 30–40 mm, the application of thermodynamic inhibitors and the installation of local thermal control systems. In addition, the study separately analyzed the impact of seasonal temperature changes and sea currents on the probability of hydrate formation. The study results emphasize the need to apply a risk-based approach at the pipeline design stage. Overall, the results provide practical recommendations for the safe and sustainable operation of subsea pipelines in the Caspian Sea.

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