It was not a "primary reason" they find one or more but
some analyses and congressional statements (like the 2007 Congressional Record entry) discuss the strategic importance of Iraq's oil and the reversion of its oil sales back to U.S. dollars after the invasion, these are interpretations or critiques, not official policy documents. Declassified materials and reports from the time emphasize security and WMD concerns over financial motives like the petrodollar.
Also China last year made a peace agreement and alliance between Iran and Saudi arabia just to detach the petrodollar to their currency as we see now.