Method and apparatus for launching pipeline clearing spheres
AssigneeThe British Petroleum Company p.l.c.
InventorDonald Alan Southgate
Life of this patent
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Abstract
Pipeline tool for closing an open end of a pipeline and which is suitable for use with a pipeline clearing sphere for clearing a pipeline has a tubular member for holding one or two spheres side by side and an aperture in the wall of the tubular member to release gas trapped therein and pipes for supplying compressed air to launch the spheres.
Claims3
An underwater pipeline apparatus for closing an open end of a pipeline and for carrying and launching at least one pipeline clearing sphere for clearing the pipeline, said apparatus comprising in combination:
- i. a tubular member having a given diameter for holding a pipeline clearing sphere and having an open end for inserting in the open end of a pipeline and a transverse closure opposite said open end, said closure being spaced from the open end a distance sufficient to permit the clearing sphere to be positioned therebetween;
- ii. an outwardly radially expanisble gripping and sealing means associated with the tubular member and actuatable by a fluid under pressure to grip the inside of a pipeline and seal thereagainst;
- iii. means for supplying said fluid to actuate said gripping and sealing means;
- and
- iv. means for introducing compressed gas to the interior of the tubular member to displace the pipeline clearing sphere from the interior of the tubular member into the interior of the pipeline wherein the tubular member has an aperture in the wall thereof at a position so that gas can be released therethrough from the space between the location in the tubular member to be occupied by a spere and the transverse closure of the tubular member and the walls thereof, and means for admitting water to the interior of the space, whereby the water in said space acts to overcome sphere distortion when the apparatus is submerged.
A method of clearing a pipeline using a pipeline clearing apparatus which method comprises:
- i. sucking a pipeline clearing sphere into a tubular member having a closed and open end by partly evacuating the member, said sphere and closed end defining a space therebetween;
- ii. admitting water to, and releasing air from, the space between the sphere and the closed end of the tubular member whereby the admitted water in said space acts to overcome sphere distortion when the apparatus is submerged;
- iii. inserting the open end of the tubular member in the open end of a submerged pipeline;
- iv. sealingly engaging the open end of the tubular member to the pipeline;
- and
- v. supplying compressed gas to the space between the sphere and the closed end to displace the sphere into the pipeline and along the inside thereof to thereby clear the pipeline.
Dependencies are inferred from the claim text.