Gas kick behavior in horizontal wells is different from the gas behavior in normal wells (vertical and deviated wells). Gas follows Boyle’s gas law when it moves up to the shallower section of the wellbore. However, in the horizontal section, there is no change in volume because gas will move up to high side of the wellbore and there is no change in pressure.
The gas kick volume will increase when the kick is circulated out of the horizontal section because the reduction in hydrostatic pressure results in expanding of gas as per Boyle’s gas law (see below).
