HOUSTON (Reuters) - U.S. shale producers have added millions of barrels to global crude supply in recent years, but that does not mean they can quickly replace barrels lost from weekend attacks on Saudi Aramco facilities, energy experts said on Sunday.

Shale producers this year have been cutting budgets and workers and trimming production goals after years of heavy spending. They remain under intense pressure from investors to restrain spending and return money to shareholders through buybacks and dividends rather than expand drilling.