The wells will have been traded between multiple companies (and not necessarily with the intent to abandon them so they don't need to pay costs.). A lot of the

The wells will have been traded between multiple companies (and not necessarily with the intent to abandon them so they don't need to pay costs.). A lot of the 'current owners' will be defunct or bankrupt. Because wells can become productive again (due to new technologies or techniques becoming cheaper or price for oil increasing) it would be hard to show any company was playing shell games even if they were, so it will be hard to show who should be stuck with the cost if the current owner can't pay(and of course shareholders are shielded). It would be a costly forensic exercise and while no doubt it would pay off on average there would be a lot of cases where nothing could be done meaning the tax payer has still lost out. Otherwise the only real way to claw back cash would be to retroactively add liability to the company that contracted drilling the well (this of course has the usual draw backs of retroactive laws). Realistically the only thing that could be done to cover this cost efficiently is some form of tax on the industry as a whole going forward. There also absolutely needs to be a law sooner rather than later that no new wells can be drilled without an appropriate bond (Now days this is the case in a lot of places or is a standard part of permitting).