Exxon Mobil is likely to increase exploration spending, targeting high-potential frontier basins to rebuild its reserve base and sustain production growth over the next decade. Major oil giants are shifting strategy after years of underinvestment, reprioritizing upstream exploration to address declining reserves and growing oil and gas demand. Shell has added exploration blocks in Angola, South Africa and the U.S. Gulf of Mexico as part of a broader push to discover large-scale reservoirs akin to Guyana.