Abstract: This paper introduces the principles; technical features, application scope and field application effects of the 4 newly developed technologies in Henan oilfield based on fluid jetting theories. They are negative pressure unplugging, depressurized acid flushing without moving string, depressurized water mixing at wellhead of producers, and negative pressure blowdown at bottom of sewage settling tanks. Field application over 200 times shows that the fluid jetting technology can significantly unplug the formations without any damages can rapidly and completely remove acid; can lower wellhead back - pressure and improve producer operation conditions when mixing hot water at wellhead; and can improve mud remove effects and sewage disposal quality when performing blowdown.