There could be something in that too - if the sanctions may have...

There could be something in that too - if the sanctions may have that effect on Russia? But I don't believe the US government would be killing off its own energy independence with Shale oil deliberately to hurt the Russians. If there is a conspiracy here it is OPEC trying to maintain their dominance by heavy over production.

This is why the Saudis have not reduced their production as yet and have tried to only heavily discount into the USA. If I where the yanks I would be telling the Arabs that if they don't cut it out they will start exporting oil and petroleum at a discount targeting the OPEC higher price markets. Basically there would be a world wide discount war with the consumers as the winners.
The Yanks could ask the Major oil companies to do that a a national security basis if it really starts to hurt the American oil industry. The problem for other oil producers would be surviving the fallout.