Abstract: A method and system for the combined underground storage and production of petroleum. A wellbore is drilled such that the surface is in fluid communication with an oil bearing and a salt bearing formation. Salt is leached from the salt bearing formation to form a cavern. The oil bearing formation is placed in condition for production. The pressure in the salt bearing formation is maintained below the pressure in the oil bearing formation and oil is collected in the cavern that was formed in the salt bearing formation. Periodically, oil is displaced from the cavern to the surface. The system includes a wellbore connecting the surface, an oil bearing formation and a cavern in fluid communication, a check valve is placed within the wellbore to permit the one way flow of oil from the oil bearing formation to the cavern. A wellhead tree seals the wellbore through which passes a conduit to inject gas into the wellbore.

Abstract: A method and system for the combined underground storage and production of petroleum. A wellbore is drilled such that the surface is in fluid communication with an oil bearing and a salt bearing formation. Salt is leached from the salt bearing formation to form a cavern. The oil bearing formation is placed in condition for production. The pressure in the salt bearing formation is maintained below the pressure in the oil bearing formation and oil is collected in the cavern. Periodically, oil is displaced from the cavern to the surface. The system includes a wellbore connecting the surface, an oil bearing formation and a cavern in fluid communication, a check valve is placed within the wellbore to permit the one way flow of oil from the oil bearing formation to the cavern. A wellhead tree seals the wellbore through which passes a conduit to inject gas into the wellbore. Also passing through the welltree is a conduct which extends into the cavern through which oil may be displaced.