The killing method of exceptional operating conditions well

During the process of drilling, overflow happens when the waterhole blocks, drilling tool breaks off and drops into the well, or empty hole occurs after hoisting completed. In course of the workover operation, overflow happens while oil tube fracturing, blocking up, and occurring empty well or can't flow. As it is difficult to establish effective fluid cycling for such type of well when overflow occurs, conventional killing well method cannot handle the problem of overflow for the well in special operating conditions. The so-called special operating conditions well have intact well head control equipment, but unable establish cycling after the overflow well shut in. The paper is aimed at finding out the non-routine well control procedure to deal with the overflow of the well in special operating conditions. Study the well killing technology in four situations. The situation included the well is full of natural gas, lower of the well is liquid column and upper of the well is natural gas, the wellbore blocks and unable establish cycling for containing liquid column, besides the wellbore holds fish where the fish is intact and doesn't block the wellbore, the fish blocks the wellbore or the fish is breakup and blocks the wellbore. Discuss the principles, steps, calculation procedure and formulas of killing well in volumetric control mode. The result is applied in one of the non-conventional wells' workover operation in the eastern of Sichuan. This paper simulates the calculation of killing well and reveals the killing well curves and form design. © (2012) Trans Tech Publications.