Apparatus for collecting oil escaped from an underwater blowout

Abstract

A large diameter conduit extends from a subsea location surrounding a wellhead to an area above the water surface. The conduit is designed to channel escaped oil and gas from the underwater well to a floating collection facility. The conduit has a portion formed from polyvinyl chloride to reduce paraffin solidification and methane gas icing.

Description

BACKGROUND OF THE INVENTION[0001]The present invention relates to an apparatus for collecting oil escaped from an underwater wellhead into a surrounding body of water. More particularly this invention relates to an apparatus for channeling escaped oil from a point near the seabed to a floating oil collection facility.[0002]In recent years, the exploitation of oil and gas deposits in geological layers deep beneath the sea surface has become more and more common. The exploitation of these energy resources comprises several phases from the drilling of test wells up to and including the establishment of production facilities. Test drilling as well as production is often conducted from offshore structures, such as floating rigs, semi-submersible vessel and bottom-secured platforms.[0003]Several problems accompany deep-sea drilling and production, one of which is position of the wellhead a mile or more below the water surface. When the production pipe is damaged, the steel casings and the...

AI Technical Summary

Benefits of technology

[0011]It is a further object of the invention to provide an apparatus for channeling the escaped oil via a tubular conduit that minimizes icing of the methane gas and solidification of paraffin in the collection channels.

[0013]The tubular member has an open top, which facilitates pressure equalization between the water and the interior of the tubular member. Escaped oil and gas ascend to the water surface being guided by the tubular member. To reduce solidification of paraffin and methane icing, a portion of the tubular conduit if formed from polyvinyl chloride.

Problems solved by technology

Several problems accompany deep-sea drilling and production, one of which is position of the wellhead a mile or more below the water surface.

When the production pipe is damaged, the steel casings and the underlying rock formations are leaking oil, under a considerable pressure into the water.

If the BOP fails, a catastrophic blowout can occur, as a result of which the wellhead and the formation around it starts leaking oil.

In the offshore drilling or production of oil and gas, accidents such as equipment malfunctions or the like occasionally result in a condition known as a blowout.

In such instances, the fluids under substantial underground pressure flow uncontrollably to the surrounding body of water.

The contamination caused by a blowout disastrously affects the environment.

A non-checked oil spill can kill every sea inhabitant and wildlife along a nearby shoreline.

However, to control the flow from a burning or damaged well, it is necessary to close the wellbore at a location where the casing and tubing are still undamaged and accessible.

These procedures, however, are hazardous, costly and time consuming.

As the additional wellbores are drilled, which can take several months in an offshore location, the oil continues to flow onto and pollute the surrounding area.

Moreover, in an offshore operation, heavy wave action severely limits the available options.

In spite of advanced technology and substantial safety measures, there is always a risk of accidents caused by e.g. human error, material fatigue, system malfunctioning or the influence of forces of nature.

The escaped oil rises to the surface and disperses with resulting pollution and detrimental effects to bird life and the environment of marine biology.

Furthermore, the blown pipe may have uneven edges, which makes sealing of the pipe even more difficult.

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