Methods and devices for restoring control and resuming production at an offshore oil well following an uncontrolled fluid release after an explosion

Abstract

Methods and devices for restoring control of at an offshore oil well following an uncontrolled fluid release after an explosion include lowering through a riser of successive flow restricting inserts into the oil well to gradually reduce the uncontrolled fluid release. Flow restricting inserts may be inserted in parallel or in series with each other. Following attachment of the riser to the oil well, provisions are made to restore oil production from the well. Flow restricting inserts may further be used to adjust flow resistance from the well in order to optimize oil production. Passages between the riser and the flow restricting inserts may also be used to form a gas lift in order to maximize production of oil from the well.

Description

CROSS-REFERENCE DATA[0001]This application is a continuation-in-part of the co-pending U.S. patent application Ser. No. 13 / 675,975 filed 13 Nov. 2012 entitled “Method and Alignment System for Killing an Uncontrolled Oil-Gas Fountain at an Offshore Oil Platform Using a Telescopic Insert Assembly”; which in turn claims the priority date benefit from a U.S. Provisional Application No. 61 / 681,257 filed 9 Aug. 2012 and entitled “The Method of Killing an Uncontrolled Oil-Gas Fountain at an Offshore Oil Platform Using a Telescopic Insert Assembly”.[0002]This application is also a continuation-in-part of the co-pending U.S. patent application Ser. No. 13 / 184,497 filed 16 Jul. 2011, now U.S. Pat. No. 8,448,709 entitled “Method of Killing an Uncontrolled Oil-Gas Fountain Appeared After an Explosion of an Offshore Oil Platform”; which in turn claims a priority benefit of the U.S. Provisional Patent Application No. 61 / 367,478 filed 26 Jul. 2010.[0003]All cited above patent documents are incorpo...

AI Technical Summary

Benefits of technology

[0013]The object of the present invention is to provide improved methods and devices for restoring control of an oil well and arresting uncontrolled release of fluids into the environment following an explosion.

[0014]Another object of the present invention is to provide novel methods and devices for efficient, expedient, and less expensive processes of regaining control over an oil well after a blowout or an explosion.

[0018]In addition to quickly restoring control over the damaged oil well, the present invention provides for novel methods and devices to return the well to produce oil through the riser. In fact, additional manipulation of the flow restricting inserts (lowering or rising at least some of them or adding / removing more inserts) provides for a convenient way to adjust flow production from the oil well for the remaining portion of the well lifespan.

[0022]Fluid release will be further diminished as a result of positioning additional flow restricting inserts into the oil well. Once the flow of fluids is reduced to a manageable level, the riser may be attached to the oil well to preclude further fluid release therefrom. At this point, the oil well may be sealed off, for example by pumping cement down the annular space between the riser and the biggest flow restricting insert. In other embodiments, the oil production from the oil well may be resumed. In this case, the presence of flow restricting inserts allows for an advantageous adjustment of flow resistance through the riser over the remaining portion of the oil well lifespan.

Problems solved by technology

This may cause a gas explosion that may result in human casualties, environmental pollution and the creation of an uncontrolled fountain.

This uncontrolled fountain is very difficult to suppress, because the wellhead is under enormous pressure.

As offshore drilling on the continental shelves is progressing into deeper and deeper waters, the problem is many times more complicated when the explosion occurs in deep waters.

Suppressing such a well and cleaning of the environment may cost billions of dollars.

This method has proved to be the most rapid, but it can currently only be used in the case of well blowouts in shallow water, i.e. less than 1,000 meters deep.

Inserting such a large string of pipes presents a challenge due to an enormous pressure in the well urging the killing string out of the well.

This method takes a long time (several months) while allowing for the uncontrolled release to continue polluting the waters with large quantity of oil.

This process is also quite expensive.

In addition, there is always an uncertainty present as to the exact location of the well deep down under the sea bottom.

To date, no practical equipment or method is available to the industry for the purpose of regaining control of a deep water abandoned wellhead on the offshore seabed after a blowout causing spilling of reservoir fluids into the sea.

The environmental pollution caused by such outpouring of reservoir fluids and gases can have disastrous consequences, as evident by the 2011 pollution created over a large section of the Gulf of Mexico and adjacent beaches by the erupted BP well off the coast of Mexico.

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