A downhole separator has a housing defining an interior cavity divided into a first chamber and a second chamber by a flow restricting bearing housing. A shaft driven impeller pumps production fluid into the first chamber and to the bearing housing. The bearing housing generates a pressure drop in production fluid entering the second chamber, separating gas from liquid. A vortex generator in the second chamber segregates the liquid to the outside and the gas to the inside of the second chamber. A downhole separation method includes pumping production fluid into a first chamber, and generating a pressure drop in the fluid as the fluid enters a second chamber to separate gas and liquid.
