The USNews graduate rankings for PetE. Keep in mind, this is only for grad.
1. Stanford University (CA) 4.6
University of Texas–Austin 4.6
3. Texas A&M University–College Station (Look) 4.0
4. University of Tulsa (OK) 3.9
5. Colorado School of Mines 3.8
6. University of Oklahoma 3.3
7. Pennsylvania State University–University Park 3.2
8. University of Southern California (Viterbi) 3.0
9. Louisiana State University–Baton Rouge 2.8
10. Texas Tech University
However, you should understand that you don't need a PetE degree to become a petroleum engineering. The industry hires plenty of people with degrees in related fields such as ME, CivilE, Mining Engineering, Geological/Earth Resources Engineering, Geology, Geophysics, ChemE, and nowadays a lot of computer science/EE (because of all of the computerized reservoir mapping). Hence, I wouldn't turn down a strong school in those fields, but that doesn't have a PetE degree, in favor of some no-name school that does offer PetE.