Compressed Air Flow within Aquifer Reservoirs of CAES Plants

• Published in: Transport in porous media Vol. 81; no. 2; pp. 219 - 240
• Main Authors: Kushnir, R., Ullmann, A., Dayan, A.
• Format: Journal Article
• Language: English
• Published: Dordrecht Springer Netherlands 01.01.2010; Springer; Springer Nature B.V
• Subjects: Air flow; Aquifers; Civil Engineering; Classical and Continuum Physics; Compressed air; Critical flow; Discharge; Earth and Environmental Science; Earth Sciences; Earth, ocean, space; Energy storage; Engineering and environment geology. Geothermics; Enlargement; Exact sciences and technology; Exact solutions; Flow velocity; Geotechnical Engineering & Applied Earth Sciences; Hydrocarbons; Hydrogeology; Hydrology. Hydrogeology; Hydrology/Water Resources; Industrial Chemistry/Chemical Engineering; Interface stability; Mathematical analysis; Mathematical models; Parameter identification; Parameter sensitivity; Pollution, environment geology; Pressure distribution; Reservoirs; Sedimentary rocks; Sensitivity analysis; Stability analysis; Stress concentration; Suction; Variations; Water discharge; Partially penetrating well; Water coning; Compressed air energy storage (CAES); Porous reservoirs; Critical flow rates; models; sensitivity analysis; permeability; air-water interface; reservoirs; suction; air; pressure; storage; transport; water; critical flow; Water conking; aquifers; fluctuations; discharge; porous media; Analytical solution; stability; energy
• DOI: 10.1007/s11242-009-9397-y
• ISSN: 0169-3913

A model on the air flow within aquifer reservoirs of Compressed Air Energy Storage (CAES) plants was developed. The design of such CAES plants requires knowledge of the reservoir air pressure distribution during both the charging and discharging phases. Also, it must assure air/water interface stability to prevent water suction during discharge. An approximate analytical solution for the pressure variations within the anisotropic reservoir porous space was developed, subject to the Darcy equation and for conditions of partially penetrating wells. Sensitivity analyses were conducted to identify the dominant parameters affecting the well pressure and the critical flow rate (water suction threshold). It is demonstrated that water coning is a factor that could severely limit the discharge air flow rate. A significant diminishment of that limitation and reduction of the pressure fluctuation can be achieved by enlargement of the air layer height and discharge period. Likewise, aquifers with larger horizontal permeability impose less restrictive critical flows. A conclusion on the preferred screen length could not be merely drawn from technological considerations, but should also involve important economic aspects.