https://en.wikipedia.org/wiki/Enhanced_oil_recovery#Gas_injection   
It`s really interesting, this "enhanced oil recovery" stuff.  It seems mixing SB21 severance tax-free gas liquids , along with an 8 dollar per stuffed barrel subsidy, also severance tax free into TAPS,.. speeds the loss due to severance free barrels down TAPS.  
I would posit under SB21, if we don`t enact a COMPLETE and sustainable fiscal plan going forward, we will be broke shortly, waiting as the Senate seems to want, for any fair severance based on the oil price, to return to the state from the STILL HUGE conventional legacy fields.  The Senate is putting oil industry investor dividends before the health and rights of Alaska`s fiscal state, who`s very health is what our constitution is based on which is the vital importance of sustaining and receiving fair value for the severance of our finite resources.  Exxon`s excuse for not building PT was "we don`t have a gasline".  We sued them and gave it away.