A lower separator located below a submersible well pump intake has a labyrinth flow path, causing a first well fluid separation of lighter components from heavier components as well fluid flowing into the lower separator turns downward to flow toward a lower separator heavier component port. A bypass riser has a bypass riser inlet below the pump intake and a bypass riser outlet above the pump intake. A lighter component conduit communicates the bypass riser inlet with lighter components of the first well fluid separation, causing a second well fluid separation at the riser outlet as a heavier portion of the lighter components flowing up the riser turn to flow downward to the pump intake. A heavier component conduit bypasses the bypass riser inlet and delivers the heavier components of the first well fluid separation to the pump intake.