(EN) An inclined fluid separation system 1 for separating well fluids comprises an inclined section 2 with a plurality of sensors 7a to 7f and an extraction port 6. The well fluids flow up the inclined section 2 to allow water 4 to be separated from the well fluids at the foot of the inclined section 2. Water 4 is extracted from the inclined section 2 by the extraction port 6. The sensors 7a to 7f are used to detect the position of a water tail 8, so that the extraction of water 4 is controlled by the position of the water tail 8.