Compressor oil everywhere

Your A/C unit should be hermetically sealed and there should be no oil coming out. If there is a leak in your unit then the first thing you will notice is a hissing sound followed be a foam of oil coming out where that leak may be. The solution is to first find the leak and seal it, usually be soldering it with high temperture solder (Silver/Bronze) with a tourch that will go to at least 1000 degrees. Once it is sealed you will need to go to the production line coming ont of the compressor and open it up, usually be breaking it and then soldering on a copper line and then attaching a valve to the end of it. Once this is done you will need to have a vaccuum pump connected to the production line and draw a vaccuum as close to 30 degrees down. Once this is done you must let it sit for at least a half hour to make sure everything holds at the vaccuum level. If this works then you need to fill the unit with the appropert refridgerant and cappella oil if necessary and pinch off the production line and braze the end. Check for leaks and if none then your good to go.
Good luck,
Marty