Disclosed are methods, systems, and computer-readable medium to perform operations including: receiving a real-time density log comprising bulk density readings of a subterranean formation, where a well is being drilled in the subterranean formation; aggregating density readings over a first threshold distance from a current drilling depth in the subterranean formation; calculating a minimum formation density and a maximum formation density in the aggregated density readings; calculating a difference between the maximum formation density and the minimum formation density; in response to determining that the difference is greater than a field threshold, determining whether a previous kick alert occurred at least a second threshold distance from the current drilling depth; and in response to determining that the previous kick alert occurred at least the second threshold distance from the current drilling depth, detecting a kick in the well.