Seal for a Wellbore

Abstract

A seal apparatus for closing a wellbore, the apparatus being universally deployable and capable of closing the wellbore even in the case of damage located beneath a present blowout preventer. The apparatus is based on the idea of introducing a seal into the wellbore in order to close it off to avoid damage from a rising fluid. For this purpose, the seal has at least one apron, or a capsule. An opening of the apron, or distending of the capsule, causes a non-positive and / or positive connection to be produced in respect to the wall of the wellbore such that the wellbore is closed.

Description

FIELD OF THE INVENTION[0001]The invention relates to a seal for a wellbore in which a fluid, for instance oil or gas, flows up.Prior Art[0002]So-called blowout preventers are known from the prior art. The term blowout preventer is used for various shut-off valves that are fitted directly over the wellbore in the case of a drilling operation. Blowout preventers serve to prevent a fluid from flowing out of the wellbore. This is necessary, in particular, if the drill string is damaged or if the drilling operation encounters a pressurized zone.[0003]While a drilling operation is being performed, the drill string extends through the blowout preventer. If, in this case, there is an outflow of the fluid that cannot be stopped by other means, a two-stage mechanism comes into effect in the blowout preventer. In a first stage, seals are activated, which seal off the outer space around the drill string. Should this not suffice to stop an outflow of the fluid, the drill string is severed inside...

AI Technical Summary

Benefits of technology

The patent describes a device used in wellbore construction that helps to seal the wellbore. It consists of an at least one apron that is folded towards the pipe and can be unfolded away from the pipe and towards the wall. The unfolding of the apron is caused by a pressure applied to the aperon by the fluid rising in the wellbore. The device can be made of flexible material, such as a sack or umbrella, or metal braided fabric. It can also be coated with a protective substance or reinforced with reinforcing ribs. To prevent damage, multiple aprons can be used, with one designated for protecting the others. The device helps to prevent the seal from sliding out of the wellbore and ensures the wellbore remains secure.

Problems solved by technology

This is necessary, in particular, if the drill string is damaged or if the drilling operation encounters a pressurized zone.

In particular cases, however, it is questionable whether the dimensioning of the blowout preventer used is adequate for severing the drill string.

The incident in the Gulf of Mexico has shown that the known methods used have considerable weaknesses and are highly susceptible to faults in respect of deployment and operation.

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