A method and an arrangement for separating oil and water by means of a two-phase liquid/liquid separator. The oil phase and the water phase respectively are separated over a portion of the length of the separator from an upstream end to a downstream end. The oil phase and the water phase respectively are extracted gradually over a length of the separator, and each of the phases is conducted out of the separator separately. A method and an arrangement for orienting the separator in a well are also described.
