Abstract:
Objective In the process of CO2 pipeline transmission, the process parameters of the transmission pipeline network will change under the shutdown and restarting conditions, in which hydrates are easy to generate to block the pipe network. The formation rule of hydrates and water content in CO2 transportation process is predicted and analyzed to ensure the efficiency and safety of pipeline transportation.
Methods Based on the design of 360 000 tons/year transmission pipeline network of Yanchang oilfield, a supercritical impurity-containing CO2 transmission pipeline network model using OLGA software is established. On the basis of hydrate generation under steady-state transmission, the generation location and generation effect of hydrate are predicted and analyzed.
Results The hydrate generation temperature and pressure decrease under the shutdown condition, and 0.18 kg/m3 of hydrate starts to generate at 5 km to the inlet of the pipeline network. The hydrate generation temperature increases under the restarting condition, the hydrate peak generation is 0.9 kg/m3, the section is shorter and location moves back at 20 km to the inlet of the pipeline network.
Conclusion The simulation results can better guide the design of the Yanchang oilfield pipeline network and provide a theoretical basis for the safe operation of the pipe network.
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