The US has nearly doubled oil production to 9.3 million barrels in the past 4 years and will soon be the second largest producer after Saudi Arabia.
OPEC is attempting the break the US shale industry in a war for market share but they might not be taking on just the US. Exxon just announced its discovered a second shale well in Argentina. It’s beyond naive to think the only shale will be in the US and the technology is advancing rapidly. Even Gulf countries will be pouring capital into exploiting shale.
In 2013, the US EIA estimated that Russia has the largest reserves of shale oil and overall they only estimate the US holds 16% of recoverable shale.
EIA estimate of shale oil and gas
These are all still preliminary estimates and are likely to increase. Low oil prices are probably here to stay.