ROI is basically non-existent. The numbers are closely held trade secrets, you won't find the projections published anywhere, but most sources agree, the prospects for demand are bad, which is why no private investors can be found. Industry insiders agree that basically the whole industry is sun-setting, so the majors are just going to ride it into the ground, claim capital losses and declare bankruptcy after the equity is safely transferred elsewhere. Optimistically we're looking at maybe 40-60 years before we even recoup the initial principle.

What it does do, however, is make it basically impossible for Alberta to separate. It catches their nuts in an economic vise. Their debt to Canada because of those two pipes would bankrupt them 100x over if they ever tried to leave.