A method and system for downhole treatment and pumping of well fluids enhances the pumping of viscous fluids to the surface. The first step is to separate the oil and water from the well fluid and then channel the oil to a chamber that encloses the motor. The heat from the motor will increase the heat of the crude oil flowing past the motor, thereby lowering the viscosity of the crude oil. The water flows separately past the motor in another passageway, and remixes with the oil. After the oil and water recombine, the treated well fluid has a lower viscosity, and the fluid is then pumped to the surface more efficiently than without treating the oil.