A company W.O.B. Trading Lp-UK, Scotland-provides a complete service for the purchase, sale and refurbishment of used barrels.  

Used barrels-They are recently-emptied oak barrels for decorating and gardening. Different size.

Reconditioned barrels-They are emptied to order and sold air-dried.
The value of these barrels in the wood soaked with the different  flavours of its contents and used for maturing other alcoholic beverages. Drums may very well be used for aging of highly structured wines, which are primarily concerns the micro-bubble!

Sherry barrels. They are very appreciated in famous distilleries from Scotland, Ireland, England and the United States for aging Whiskeys and Bourbon.

Cognac barrels.They are very good for storage of brandy, seeds and other distillates, which are to benefit from the stored cognac. Used by the most famous French distilleries.

Barrels of Oporto
Barrels of Muscatel
Barrels of Brandy