Liquid-gas separator is a special degassingequipment for gas-migration drilling liquid. lt is mainlyused in removing the large bubbles with diameter at 3~25mm in gas migration drilling liquid. These largebubbles refer to the expansion gas in drilling liquld whlchfill up the annulus hollow section of borehole,such gascan cause well kick.even spraying out of the drillingtable surface if it is not removed.