Shale oil extraction Energy estimates that the "ex-situ" processing would be economic at sustained average world oil prices above $54 per barrel and "in-situ" processing would be economic at prices above $35 per barrel. These estimates assume a return rate of 15%. Royal Dutch Shell announced in 2006 that its Shell ICP technology would realize a profit when crude oil prices are higher than $30 per barrel ($190/m), while some technologies at full-scale production assert profitability at oil prices even lower than $20 per barrel ($130/m). To increase the efficiency of oil shale retorting and by this the viability of the shale oil
Keg brewers sell beer in barrels of 15.5 gallons, barrels of 7.75 gallons, and barrels of 5.17 gallons. Since keg sizes are not standardized, the keg cannot be used as a standard unit of measure for liquid volumes. This size standard varies from country to country and brewery to brewery with many countries using the metric system rather than U.S. gallons. A "keg", or half-barrel is a 15.5 U.S. gallon vessel. A quarter-barrel has a volume of 7.75 U.S. gallons. Generally a keg is a vessel smaller than a barrel; thus, it is 30 gallons or smaller. In the U.S. the