If I work on a rig in state 1 but live in state 2 and have taxes withheld for both states, will my W2 taxable income for states be twice my Federal taxable income?

No. If you work in a state that is not your resident state you will receive two state W2's, but income amounts reported to both states should be the same (or close). If the majority of your income is from that out-of-state job then you should get a pretty big refund from your home state, because of the credit that you get from your home state for taxes paid to the other state.