Abstract：In the process of production and maintenance of oil fields，the pipe network of oil and water treatment stations such as transfer stations，metering rooms，wells and joint stations needs to be emptied.Usually the hose is connected by wire or clamp to the empty pipe，and the other end of the hose is put into the waste water tank or the dirty oil tank.Due to the big liquid pressure，often accompanied by a large number of gas，the gas will lead to vent pipe pressure is big，often leads to vent pipe joint is tension crack or snap，or hose or hose，the phenomenon of the"dragon"，lead to slop spitting everywhere，greatly affected the production and maintenance，but also caused serious environmental pollution.Application is put forward in the process of oilfield emptying a decompression blowout preventer， based on the numerical simulation of stress analysis，found that flow through the device can largely decrease the pressure，after which can effectively reduce due to empty station safe hidden trouble，reduce the pollution of the environment and energy consumption.

Keywords:safety and energy saving；blowout；numerical simulation；emptying device