This is a special downhole multi-layer sand screen for oil and other fluids containing sand. The preferred embodiment of the sand filter includes an outer screen, an intermediate screen and an inner screen although another embodiment may have only an outer and an inner screen. The outermost screen is of larger spacing to retain only the coarser sand particles and the openings in the inner two screens are progressively smaller to retain the less coarse sand material. The coarser sand particles bridge about the larger openings in the outer screens and progressively finer sand materials bridge across the intermediate and inner screens.