Why the Oil reserves in the Gulf of Guinea are the cause that the political course of the US is changing towards Iraq

Not a lot of people know that Africa's oil/gas resources are concentrated in the area of the Gulf of Guinea. Nor do a lot of people know that the main oil-producing area of this region is in the sea, far removed from the center of political and other conflicts.
This means oil production is relatively safe, in addition the quality of the oil is higher because as it contains less sulfur. The advantages don't end here, the low transport cost compared to the Caspian Sea and the Middle East from this region to the US are considered ideal.
Reports say that 7 billion barrels of the globe's newly proven deposit of 8 billion barrels of crude oil in 2001 are produced in the region of the Gulf of Guinea.
Does anyone know that Exxon, Chervron and other companies have invested US$3.7 billion, the largest US investment in Africa to date, in building an oil pipeline leading from Chad to Cameroon?
The reason why murderers like the president of Equatorial-Guinea Obiang are invited to the White House is because of the oil resources before the coast.
And this is why China, which holds 40% of the oil resources in Sudan, shrug their shoulders when accused by the US to ignore the murdering of black Sudanese by Arab Sudanese.

I should add that the US is the largest oil consumption country in today's world, its average daily oil consumption accounts for almost one-third of the world total consumption. Absolutely crazy, this looks to me like ascramble over resources between China and the US.