Abstract:The bullheading as an unconventional technique to kill a well is by pumping the kill fluid directly into the wellbore or the annulus during the gas kick, until all the influx is displaced into the exposed open hole formation and the wellbore is filled with a kill fluid of sufficient density to balance the reservoir pressure. For the type of blowouts applied by the bullheading technique, this paper analyzes the invasion fluid characteristics, the formation physical properties, and other parameters for the bullheading, identifies the applicable conditions, the necessary conditions and the required equipment for bullheading, and analyzes the field applications for bullheading to provide some guidelines for engineers. With considerations of the kick and blowout features in recent years, it is shown that the bulheading has a good prospect for the shallow gas well overflow, the high pressure gas well overflow, and other complex well overflows and blowouts.