Method for maintaining a gas volume in an underground geological reservoir by nitrogen injection

摘要

The method involves selecting treatment gas i.e. nitrogen, that is lighter than gas to be maintained in an underground geological formation (RES) located under a mantle rock (COUV), where the treatment gas generates interfacial tensions with aqueous or hydrocarbon liquids and wets the rock lesser, than the gas to be maintained. Volume of the treatment gas to be injected is determined according to geological characteristics of the formation and volume of the gas to be maintained. The determined volume of the treatment gas is injected into the formation.