Watch CNBC's full interview with Pioneer Natural Resources CEO Scott Sheffield and Exxon Mobil CEO Darren Woods

Pioneer Natural Resources CEO Scott Sheffield and Exxon Mobil CEO Darren Woods join 'Squawk Box' to discuss Exxon Mobil's deal to acquire Pioneer Natural Resources, an all-stock merger valued at $59.5 billion or $253 a share, how the deal came about, potential regulatory hurdles, and more.