Modeling of CO_2 Injection in North Stavropol Underground Gas Storage Reservoir (Russia)

摘要

North Stavropol Underground Gas Storage (UGS) has been established on the basis of sufficiently large depleted gas field (33 × 18 km), intra-structural Pelagiada rise (16 × 11 km) is considered as a reservoir of CO_2 injection. The production horizon is represented by Paleogene sediments of the lower Oligocene with total thickness of 80-95 m. After the establishment of the UGS, the pressure in the horizon stands at 3 MPa. TOUGH2-TMVOC modeling of CO_2 injection in 16 wells was assigned with rates from 16 to 160 kg/s. The modeling results show that no more than 8% - 10% of the injected CO_2 is dissolved in the liquid phase, of which not more than 1.4% is dissolved in the marginal waters. With a maximum rate of injection, the pressure in Pelagiada reservoir remains below the critical value. Modeling proved potential of CO_2 sequestration during 30 years was estimated 0.005 gigaton.