Yes I've experienced it, 12 hour straight 'in the zone' sessions etc. Don't do anything to interrupt it or stop it. It's when you'll get your most powerful, 'flow' productivity. Just make sure you're only setting out on projects that will plausibly have a payoff for you.
For the other stuff that needs to get done, schedule it all into an 'off day' when you don't touch the project, and instead just clear those things.
For the other stuff that needs to get done, schedule it all into an 'off day' when you don't touch the project, and instead just clear those things.