The site, known as Well 4 lies in the Fauqa Oil Field, part of a number of of fields Iraq unsuccessfully put up for auction to oil companies for drilling rights back in June. It's also roughly 500 yards from an Iranian border fort, although it clearly falls on the Iraqi side of a border:
"There has been no violence related to this incident and we trust this will be resolved through peaceful diplomacy between the governments of Iraq and Iran," a US military spokesman told AFP at Contingency Operating Base Adder, just outside the southern Iraqi city of Nasiriyah.
"The oil field is in disputed territory in between Iranian and Iraqi border forts," he said, adding that such incidents occur quite frequently.
This is mere muscle flexing by Iran. The real push will come during the elections, when the Iranian backed majority Shi'ite bloc who have already dumped Maliki push for one of their own to take over just as we're pulling out.
Iran intends to Lebanonize Iraq and make it a colony.That's their ultimate goal.