In this Dec. 5, 2012 photo, the sun sets behind an oil pump jack and the Rocky Mountains near Fredrick, Colo.

Oil prices have dropped by half since this summer -- and in response, drillers are slashing budgets for the coming year. Noble Energy plans to cut capital investment in Colorado to about $900 million -- down from $2 billion last year.

The company said it would maintain four drilling rigs working north of Denver and would finish about half as many new wells as last year. Noble Energy produced nearly 11 million barrels of oil in Colorado last year.

Anadarko, the state’s largest oil producer, said it would also announce cutbacks in coming weeks.

The cutbacks are effecting workers in the industry. NPR's John Ydstie reported Thursday that more than 100,000 layoffs have been announced so far worldwide.