The bulk of the US's imported oil comes from us??
There is a small interesting clause in the NFTA agreement that states that exports from Canada can not be reduced and have to stay at the same rate per month as the past three months averaged. Right now the USA makes up 2/3's of our production.
I have have a feeling the Chinese portion of oil shipped will partially come out of the US Portion as Beijing has leveraged the US controlled debt on Washington. Or something of that nature.