A method for detecting an influx in a wellbore with first and second pressure transmitters arranged in a fixed vertical distance in relation to each other. The method includes calculating an expected density of a return flow between the first and second pressure transmitters, continuously measuring an actual density of the return flow based on a measured pressure at the first and second pressure transmitters, comparing the calculated expected density of the return flow and the measured actual density of the return flow to determine the influx in the wellbore, and predicting a probability of hydrates forming in the well by measuring a temperature via a temperature transmitter arranged in a section of the well adjacent to the first and/or the second pressure transmitter, and using the temperature together with the measurements from the first and second pressure transmitters.