Why not light it? https://en.wikipedia.org/wiki/Gas_flare
Well... careful with estimates on that. From the Door to Hell article:
> It was estimated that the gas would burn out within a few weeks, but it has instead continued to burn for more than four decades.
2) From an environmental standpoint, isn't CO2 in the atmosphere better than methane?
Lighting it would be admitting defeat. I suspect pride is a factor here.
An obvious solution, that I'm sure there is a reason can't be used, that article didn't even mention despite being titled "why engineers can't stop the leak."