I'd look at dealing with your fans head on before delidding your CPU.
If your case fans are the nosiest part of your setup, deliding your CPU isn't going to do much of anything. Depending on your setup you could simply reduce the fan speed in BIOS and set up a custom fan profile. Depending on your climate (and of course your setup), most people never really need to be running their case fans at full throttle. If you do need high air flow through the case, look in to better performing fans. Most stock case fans leave a lot to be desired.
If your CPU fan is the noisy one, look at a better cooling. Either a new cooler or a new fan for the existing cooler. You're running a k chip, so you already had to buy a 3rd party cooler so chances are you can swap the fan out. Moving to a better fan may be all you need. If not, going with a more efficient cooler would help. If you decide to delide and you're already OCing, you'd want a solid cooler anyway so maybe look at some big air coolers that would fit in your case.