Why does my focus blow white smoke

What is your question?

I changed pcv valve and my thermostat today and was poking around and pulled spark plug wires and discovered my plugs sitting in a pool of motor oil about half of an inch deep guessing and I pulled plug out of all four slots and the oil drained into the cylinder head and I clean plug put back in and started the car and white smoke was blowing out the back but car ran good temp good I also removed the valve cover to check gasket and it was good as well