Review and analysis of historical leakages from storage salt caverns wells
Laboratoire de Mécanique des Solides, Ecole Polytechnique, route de Saclay, 91128 Palaiseau, France
2 Geostock SAS, 2 rue des Martinets, 92500 Rueil-Malmaison, France
3 British Geological Survey, Nicker Hill, Keyworth, Nottingham NG12 5GG, England
4 UGS, Berliner Chaussee 2, 15749 Mittenwalde, Germany
* Corresponding author: firstname.lastname@example.org
Accepted: 29 November 2018
Twelve incidents involving well casing and/or cement leaks in the salt caverns storage industry are described. These incidents occurred at the following storage sites: Eminence salt dome, Mississippi; Elk City, Oklahoma; Conway, Kansas; Yoder, Kansas; Mont Belvieu, Texas; Teutschenthal/Bad Lauchstädt, Germany; Clute, Texas; Mineola, Texas; Hutchinson, Kansas; Magnolia, Louisiana; Boling, Texas; Epe, Germany. Mechanisms leading to a casing leak and consequences are discussed. In most cases, a breach in a steel casing occurred at a depth where a single casing was isolating the stored product from the geological formations. The origin of the breach was due in most cases to poor welding/screwing conditions and corrosion, or excessive deformation of the rock formation. In this, the age of the well is often influential. In many cases, the leak path does not open directly at ground level; fugitive hydrocarbons first escape and accumulate in the subsurface prior to migrating through shallower horizons and escaping at ground surface. A pressure differential between hydrocarbons in the borehole and fluids in the rock mass favours fast leak rates. A wellhead pressure drop often is observed, even when the stored product is natural gas. The incidents described suggest that thorough monitoring (tightness tests) and a correct well design would lessen considerably the probability of a casing leak occurring.
© P. Bérest et al., published by IFP Energies nouvelles, 2019
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