Abstract: The main problem area this invention is solving, is concerning reservoirs containing gas with to low well-head pressure. It is therefore desirable to increase the well-head pressure by applying downhole pumps, however this is not possible if gas is present. The core idea in this present invention, is to place a pump (5) in a “bath” of oil (14), in which oil “bath” (14) makes a gas seal (11), assuring the pump only to be imposed to oil without gas. Oil and gas from the reservoir (1) flows trough perforations (2), into a ring-space (3). This creates a significantly pressure drop of the mixture, in which creates turbulence so the gas content will separate from the oil. The pressure drop is regulated by the gas pressure valve (4).