An object of the disclosure is to determine the remaining saturation of existing fluids in naturally fractured and/or homogeneous reservoirs, considering an unconventional tracer test, using the double tracer test method with pressure monitoring (PDTcMP®), which also integrates unused technical elements, in order to estimate more accurately the value of the remaining oil saturation (ROS) in naturally fractured reservoirs, unlike conventional methods used most commonly in homogeneous media. The disclosure substantially modifies the conventional tracer test, as it uses innovative technical elements, which reduce the uncertainty and/or ambiguity associated with conventional tracer tests, when they are applied in naturally fractured reservoirs.