Experimental Study on Precipitation Regularity of Asphaltene in Underground Water-Sealed Caverns under Varying Temperature and Pressure Conditions

Abstract

Through experimental research, this paper reveals the influence of different storage temperatures and pressures on the amount of asphaltene deposition in Russian ESPO crude oil in underground water-sealed caverns. Based on Stokes' settling theory and the experimental results of asphaltene settling at different temperatures and pressures, the Stokes particle settling calculation formula was optimized for temperature and pressure terms. Finally, a particle settling calculation formula that takes into account different sedimentation systems, different crude oil systems, and different temperature and pressure conditions was achieved. The research results show that the asphaltene precipitation of the crude oil system is more affected by temperature than pressure at 10°C-30°C and 0.12MPa-0.28MPa. The precipitation amount decreases with increasing temperature, and the precipitation amount does not show an obvious correlation trend with pressure changes. The research results can provide important theoretical and practical basis for inhibiting the sedimentation loss of long-term storage of crude oil in underground water-sealed caverns.