San Ramon, CA-Based Oil & Gas Co Chevron 4Q 2017 Net Income Was $3.118 Bil, Up 612% or Up By $2.680 Bil From the 4Q 2016 Net Income of $438 Mil .................................................................................. $2.020 Bil or 75% of the $2.680 Bil Net Income Improvement Came From an Income Tax Benefit From the Oil & Gas-Favored Trump Tax Bill, Primarily From the US Federal Income Tax Debt Forgiveness Feature in the Trump Tax Bill