Abstract:In recent years, with the work of deep-seated reservoir gas testing has been increasing year by year, the work of killing well increases quickly as well. How to select killing fluid density is the key point of killing well engineering. High killing fluid density can lead to high loss rate of killing fluid and high dosage, thus results in high cost of killing well. But it would bring hidden dangers for well control safety, even accidents of blowout happen because of the low killing fluid density. This paper experiments the law of the loss rate of killing fluid and influence factors for deep-seated reservoir fracturing. The selection method of gas reservoir killing fluid density after fracturing was established on the basis of experiments, full consideration of the original formation pressure coefficient and pressure formation coefficient of additional stress, and the degree of pressure-depleted and current wellhead pressure. Field application shows that after fracturing, the selection method of gas reservoir killing fluid density is suitable for xushen gas reservoir, it effectively reduces loss rate of killing fluid, reduces the dosage of liquid and the pollution of gas layer, thus this method can be widely used in exploration and exploitation.