By KELIN DILLON In the recently released 2022 edition of Brand Finance’s Oil & Gas 50, Mexico’s state-owned oil company Petróleos Mexicanos (Pemex) fell from 16th to 20th place in the rankings of the world’s 50 largest oil companies. The drop stems from Pemex’s 6 percent reduction in valuation from 2021 to 2022; while the Pemex brand was valued at