The Middle East's OPEC oil cartel just ramped up its war on the US shale gas industry as new data from Saudi Arabia shows that oil exports in March reached their highest level in 12 years, with production at record levels.

The equivalent of 7.89 million barrels a day was sold overseas by the Saudi kingdom in March, up from 7.32 million in February and 10% higher than a year earlier.

Saudi Arabia produced 10.29 million barrels of oil a day in March, according to the Joint Organisations Data Initiative (JODI). That was more than any other nation in the world.

Saudi Arabia and other OPEC nations are trying to cripple the US shale gas industry by flooding the market with oil and driving down prices to unsustainable levels for the many small operators. So far the tactic seems to be working, with the oil-rig count in the US crashing.