Geotechnical Analysis of Long-term Stability of Oil Reservoirs on Water-saturated Sandy and Clayey Soils
The article reports statistical data on total leaks of oil hydrocarbons during their storage and transportation. At present, the assessment of long-term stability of reservoirs is carried out with due consideration of transition of sandy and clayey soils into a quasi-elastic state under the action of cyclic loads. Experience in operating of reservoirs for hydrocarbons storage shows that microbial activity intensifies under favorable conditions such as the presence of water-saturated soil, natural and introduced microbiota in the underground space, contamination by oil product as well as heating of soils under the bottom of the reservoir. It is experimentally proved that this process transforms clayey soils into a quasi-plastic state, and sands - into a quick-sand state. The article presents the statistical data on total leakages of hydrocarbons in the process of their storage and transportation. An example of the analysis of fuel oil tank stability loss after 19.5 years of its operation is considered.. Calculations of the reservoir stability at changed parameters under conditions of negative transformation of the composition and physical-mechanical properties of soils are conducted. Recommendations for improving the safety of long-term operation of hydrocarbon storage tanks are given.