| 摘要 |
<p>An improved oil well fire suppressing method is shown. A specific mixture of a high vapor pressure and low vapor pressure halogenated alkane, such as Halon 1211 and Halon 1301, is injected into and below the Blowout Preventor (B.O.P.) in an existing oil well in the event of a fire. In as much as the injection is of a liquid, existing pumping and valving apparatus are capable of injecting against considerable back pressure. In addition, the method contemplates an alternate venturi for injection within and beneath the B.O.P. so as to reduce the back pressure seen by the fire suppression injections and to increase the flow of the suppressant during a major flow as would happen during a blowout. In a preferred embodiment, a mixture of Halon 1301 and Halon 1211, in a percentage having a higher vapor pressure than is customary with such a mixture, is injected in liquid form into and immediately beneath the B.O.P. into the drill string and the drill string annulus during an oil well fire. The mixture rises as a liquid with the liquid component of the fluid within the drill string annulus, and due to its increased vapor pressure with respect to that of methane or inflammable gasses found entrapped in the fluid during an oil well blowout, vaporizes to a fire suppression state selectively and jointly with the entrapped gasses within the fluid within the drill string. As a result, the mixture is preferentially vaporized with the most explosive and flammable components of the overall fluid within the drill string, providing an enhanced fire suppression capability and sufficient suppression by said mixture to prevent re-ignition from occurring.</p> |
