Blowout (well drilling)

As a blowout, an uncontrolled leakage of drilling mud, oil and / or natural gas is called from a borehole of a drilling or production facility. Often the oil or gas ignites.

Until the 1920s there were no concepts to prevent blowouts, which is also called " gusher " called.

Blowout

Oil and natural gas deposits are located under gas-and liquid-tight cap rock. Due to the burden of these rock masses underneath the gas and liquid bubble is under high pressure.

This pressure is compensated in the hole by the drill hole is filled with drilling fluid during the drilling of a high density; the weight of the column of liquid creates a hydrostatic back pressure. In the course of oil or gas wells, it sometimes comes in unexpected pressure increases by nearby gas or oil reservoirs, the press into the well.

This is known as kick and requires an immediate response on the part of the drilling personnel. A kick can be detected by pressure measurements and / or by observing the Bohrflüssigkeitsmenge. The most important element for the control of such pressure increases is the blowout preventer, which is mounted as a series of combined shut-off directly above the borehole.

Failure to stop the kick, it comes to Blowout: gas and / or oil flow freely into the hole and " blow the contents of the well off". The associated displacement of the drilling fluid auflastenden exacerbated the imbalance growing.

The risk of blowouts is that to connect to the explosively urgent outward fluid flow large amounts of natural gas with the ambient air to form a highly explosive mixture; a spark or a hot surface, enough to ignite it. Since oil and gas now flow back freely, there is an erasable only with great technical effort fire. It can be destroyed in a very short time by the explosion and the fire, the entire rig.

Can not stop a blowout, get large amounts of oil and gas in an uncontrolled into the environment, where at least the oil considerable ecological damage caused.

Blowout events

• Elgin wellhead platform (North Sea, 2012)
• Deepwater Horizon ( Gulf of Mexico, 2010)
• Natural gas leak in the North Sea (1990 )
• Ixtoc I ( Gulf of Mexico, 1979)
• Ekofisk Bravo (North Sea, 1977)
• Lakeview Gusher (California, 1910)