| Popis: |
Whether on an aquifer or depleted field storage, the cushion gas represents a substantial, if not major, component of investment required to develop the storage project. The economic advantage of an inert cushion which can be produced at a lower cost than pipeline quality storage gas has been recognized for sometime. This paper presents a complete case study of a gas conversion and inert gas injection in Cerville-Velaine, an aquifer storage operated by Gaz de France. First, for 1986-87 a programmed change from low BTU to high BTU gas is described. Then, in the second stage, part of the cushion is replaced by an inert substitute. The engineering plans for the two equations involved numerical simulation by several different models. The degree of complexity of the simulators ranged from those corresponding to simplified, equal mobility displacements to 3-D with compressibility, miscibility and diffusional transport through porous environment. The conditions related to mixing were characterized by using data from field tests involving hydrogen as a tracer. |
