Googling for thoughtful analyses of the Iraq invasion brought me to a two-article BONANZA at
http://www.fpif.org/indices/topics/energy/index.php?sort=authorMichael Renner of the Worldwatch Institute makes sense of the invasion as naked conquest for US "energy security" in a January 2004 article, "Fueling Conflict". His assertions are backed with detailed statistics in an article written a year before, "Post-Saddam Iraq: Linchpin of a New Oil Order".
Here are some excerpts:
"The rate of oil discoveries over the last few decades tells a clear story. In the 1960s, an average of 47 billion barrels per year were discovered. ... the annual rate plummeted to 35 billion barrels in the 1970s, 24 billion in the 1980s, and a mere 14 billion in the 1990s. The United States has gone to great lengths to maintain its domination over world oil during the past half-century. Washington has made particularly heavy investments in keeping the immensely oil-rich Persian Gulf region in its geopolitical orbit. It has done so by propping up client regimes with arms and credits, acquiring military bases, overthrowing or marginalizing those that stand in the way, influencing the routing of oil export pipelines... Securing oil supplies has consistently trumped the pursuit of peace, human rights, and democracy.
... invasion took place for a number of reasons, though not the ones publicly advertised by the Bush administration. Iraqi oil is plentiful, cheap to produce, and high quality, making it lucrative spoils of war. ... A major increase in Iraqi oil production following reconstruction would accommodate the rise in oil demand projected by the Bush administration and reinforce the oil-centered world energy system. ... a pro-U.S. Iraq would help reduce U.S. dependence on Saudi Arabia. Although Washington and Riyadh have had close relations since the 1940s, Saudi Arabia is seen as a less than fully reliable ally in the wake of Sept. 11, 2001 terror attacks on the World Trade Center and the Pentagon. The Saudis receive red marks for supporting extremist Islamic groups and for domestic instability. ...
by achieving Security Council Resolution 1483 in May 2003, the occupiers gained broad control over the Iraqi oil industry and sole decision-making power until December 2007 over the use of oil revenues.... The occupation regime is pushing for a broad privatization of Iraqs economy in accordance with Bush administration goals. Before the start of the war, the administration drafted sweeping plans for asset sales, concessions, leases, and management contracts across the Iraqi economy, including the oil sector. The plans stipulated that the first year of occupation would be spent building consensus for privatization, to be followed by asset transfers over a three-year period. ... who will get preferential access to Iraqs riches? To what extent will existing contracts concluded by Russian, French, and Chinese companies with Husseins regime be upheld? Before the war, there were thinly veiled threats that companies whose home governments refused to support an invasion would be shown the door. By implication, the big winners in such a reshuffling would likely be the U.S. and British companies, such as ExxonMobil, Chevron-Texaco, BP, and Shell..."
All these assertions are supported with detailed statistics at
http://www.fpif.org/pdf/reports/PRoil.pdf , in an article written months before the US invasion even took place.