How absence of US troops affects Iraqi oil output?

The Iraq War officially ended and remaining U.S. troops are scheduled to withdraw by the end of this year. How the entire withdrawal of foreign troops affect on Iraqi oil production?

Iraq produced about 2.5 million barrels per day of crude oil before the break of Iraq War in March 2003. The country's crude oil output nosedived to nearly zero and recovered to around the 2 million bpd level after major battle was over.
The production, however, was interfered because of the aggravation of the peace until late 2007.

The peace is the important factor for the stable oil production.
Iraq was seen to produce about 2.7 million bpd of crude oil in November 2011. It is close to the nation's current output capacity of 3 million bpd.

Iraq is one of the world richest oil reserve country that have 115 billion barrels of reserve. Iraqi potential crude oil production capability is estimated at 13 million bpd.
Wars and disputes over the past three decades prevented the nation from developing the rich oil resources.

Iraq released its oil field for the international players in 2008 and foreign companies acquired development rights of total 11.1 million bpd of anticipated crude oil output through the bidding in 2009.
Further biddings for the unprospected mining area are also scheduled in early 2012.

Iraqi government is very optimistic following the aggressive investments by foreign companies.
It anticipates 6.5 million bpd of crude oil production in 2014 and 12 million bpd of output by 2017.
But the International Energy Agency forecasts that Iraqi oil production is likely to be about 4 million bpd and won't surge like Iraqi government expects.

Crude oil shipment capacity in the country is also expected to increase from the existing 2.5 million bpd in line with the rising production capacity.
The nationwide peace keeping is required because the country's oil fields are widespread from south to north.

The following chart shows the number of civilian death increased sharply between 2004 and 2007 although the large-scale battles ended within 2003.

The U.S. government says that the increased troops helped to calm the situation in late 2007. But the main reasons for the peace recovery were recognized as that the U.S. and Iraqi government gave funds to anti-Americanism militia organizations and conciliated them for the al-Qaeda-linked organizations annihilation.

Revenge is an important factor for the Middle Eastern disputes. People have to do revenge when their relatives are killed even if the killed person was not justice. People who lost their relatives by the anti-terrorism fights are likely to hate and attack foreign troops.

Withdrawal of foreign troops is likely to reduce opportunities to spread the hate. On the other hand, the confrontation structure among Iraqi people --the Shia and Sunni Muslims, Kurdish, al-Qaeda-linked groups, etc-- deepened in the growing process of the self-warning organizations.

Meanwhile, the stability of the Iraqi society, and favorable oil resource development may ease the global balance of oil supply and demand that lead oil prices lower. It must be an unpleasant situation for Iran that is decreasing oil production due to the absence of resource development caused by the international sanction.