Drilling fluid trip tank is the important part of the auxiliary system. The trip tank should have the adjusted liquid level scaleplate to measure the drilling fluid volume which flow into or outflow. The fluid volume of trip drill string is monitored when start droping the tubular column to ensure formation fluid unadmitted borehole. Amount to when 1bbl drill string of drilling fluid volume is taken from the borehole, should have 1 bbl drilling fluid to trip it to keep the constant liquid level in borehole. If the drill string volume is not be compensated, the fluid liquid level maybe decrease, because of hydrostatic pressure decreased to low enough, the formation fluid can enter into borehole, this is the well kick.
When drop the tubular column to borehole, drilling fluid re-back to drilling fluid trip tank. The redundant drilling fluid in trip tank should return to the circulating system which through drilling fluid shale shaker. Big particles can gush from teh well, if the gushed drilling fluid bypass drilling fluid shale shaker maybe block the hydrocyclone.
Drilling field drilling fluid trip tank obvious reduce the times of inductivity well kick. The obsolete or vintage circulating system drill rig use the number of punchings of drilling pump to calculate the filled drilling fluid. If the pump efficiency of mud pump is considerably below the estimate pump efficiency, it must decreases the drilling fluid liquid colume height and lead to static pressure waterhead decreased. If the stratum pressure is greater than drilling fluid static pressure will produce well kick.