FIELD

[0001] Embodiments described herein relate to use of magnetism for leak management in metal piping. More specifically, embodiments described herein relate to methods and apparatus for deploying magnets to stop or control leaks in metal piping.

BACKGROUND

[0002] Drilling for oil is one of the world's largest industries. Unfortunately, bringing critical energy resources to consumers occasionally results in releasing oil and other substances into the environment. As was clearly demonstrated in the summer of 2010 with the massive oil release in the Gulf of Mexico, effective and efficient means for addressing leaking well bores, pipe risers, and other leaking pipes is still needed.

SUMMARY

[0003] Embodiments disclosed herein provide an apparatus for closing a leak from an open pipe with a spool tapered to extend inside the open pipe a magnet configured to produce a magnetic field aligned with a central axis of the pipe, and a valve coupled to the spool.

[0004] Other embodiments provide a method of connecting magnetically susceptible pipes by tapering an end of a first pipe to mate with a second pipe, providing a magnetic field in alignment with a central axis of the first pipe and the second pipe, and configuring the magnetic field to provide an attractive force between the first pipe and the second pipe.

[0005] Other embodiments provide a method of sealing a leaking pipe by providing a ferromagnetic slurry in the leaking pipe, positioning one or more magnets to direct the ferromagnetic slurry toward an inside surface of the pipe, and using the magnetic field to harden the ferromagnetic slurry against leaks in the inside surface of the pipe.

[0006] Other embodiments provide a method of plugging a well bore by providing a slurry of a ferromagnetic material into the well bore, positioning one or more magnets proximate an external surface of the well bore, accumulating the ferromagnetic material inside the well bore at a location adjacent the one or more magnets to form a flow restriction, and providing a plug mixture into the well bore to plug the well bore.

[0007] Other embodiments provide a method of plugging a leaking metal pipe by applying a magnet with a gasket over the leak in the metal pipe, sealing the casket against the metal pipe, and maintaining the seal by the magnetic force of the magnet.

BRIEF DESCRIPTION OF THE DRAWINGS

[0008] So that the manner in which the above-recited features of the present invention can be understood in detail, a more particular description of the invention, briefly summarized above, may be had by reference to embodiments, some of which are illustrated in the appended drawings. It is to be noted, however, that the appended drawings illustrate only typical embodiments of this invention and are therefore not to be considered limiting of its scope, for the invention may admit to other equally effective embodiments.

[0009] Figure 1 A is a schematic side view of an arrestor according to one embodiment .

[0010] Figure 1 B is a cross-sectional detail view of the arrestor of Figure 1 A.

[0011] Figure 2A is a schematic side view of a leak management apparatus according to another embodiment.

[0012] Figure 2B is a schematic end view of a leak stopping apparatus according to another embodiment.

[0013] Figure 2C is a schematic end view of a leak stopping apparatus according to another embodiment.

[0014] To facilitate understanding, identical reference numerals have been used, where possible, to designate identical elements that are common to the figures. It is contemplated that elements disclosed in one embodiment may be beneficially utilized on other embodiments without specific recitation. DETAILED DESCRIPTION

[0015] Figure 1 A is a schematic side view of an arrestor 1 00 according to one embodiment. The arrestor 1 00 of Figure 1 A fits into an end of a leaking pipe to facilitate stopping the leak. The arrestor 1 00 comprises a spool 102 with a block valve 104. The spool 102 is coupled to a tapered fitting 1 06, which is tapered to facilitate mating with an open end of a riser, which is generally the same diameter as the spool 102. It should be noted that the arrestor 100 of Figure 1 A may be sized to fit a particular leaking riser, if desired. The tapered fitting 106 enters the pipe riser, penetrating until the spool 102 contacts the pipe riser at an end 1 10 of the spool 102 that couples to the tapered fitting 106. The spool 102 may contact the pipe riser by abutting an edge of the pipe riser or the end of the pipe riser may nest inside the end 1 10 of the spool 102.

[0016] A magnetic collar 108 disposed around the spool 102 generates a magnetic field within the spool 102 that creates an attractive magnetic force between the spool 102 and the pipe riser. The attractive force increases the contact force between the spool 102 and the pipe riser, improving the seal therebetween. The magnetic collar 108 also generates an attractive magnetic force between the arrestor 100 and the pipe riser. The magnetic collar 108 may be a permanent magnet, or preferably an electromagnet. When using an electromagnet, the arrestor 100 may be positioned with the tapered fitting 106 inside the pipe riser, and then the magnetic collar 108 may be energized to generate an attractive force between the spool 102 and the pipe riser. The attractive force seals the joint between the spool 1 02 and the pipe riser. If desired, the block valve 104 may be opened to admit fluids from the pipe riser into the arrestor 100 to be collected. The block valve may be left open while the arrestor is secured in place by the magnetic force. The magnetic force may also be used to hold the arrestor in place while it is welded to the pipe riser.

[0017] The tapered fitting 1 06 may be formed integral with the spool 102, may be welded to the spool at the end 1 10, or may have a cylindrical insert portion that fits within the spool 1 02 and is welded to an inner wall of the spool 102. The degree of tapering of the tapered fitting 1 06 may be selected to meet the requirements of different embodiments, but in most embodiments, the taper will be slight. In one example, the spool 1 02 has a 6 inch diameter, and the tapered fitting 106 extends beyond the end 1 10 of the spool 102 by about 18 inches. In this embodiment, the degree of tapering is between about 1 /1 0 inch and about ¼ inch reduction in diameter. The tapering is generally linear, but may be non-linear in alternate embodiments.

[0018] Figure 1 B is a cross-sectional detail view of the arrestor 100 of Figure 1 A. In the embodiment of Figure 1 B, the tapered fitting 1 06 is formed integral with the spool 102. In Figure 1 B the arrestor 100 is shown in mating relationship to a blowout preventer 150, which is in turn coupled to a pipe riser 152. In Figure 1 B, the arrestor 100 has a ring 1 12 coupled to the magnetic collar 1 10, the ring 1 12, magnetic collar 1 10, spool 102, and tapered fitting 106 cooperatively forming a recess for accommodating the pipe riser 1 52. Such construction will also accommodate a pipe riser without a blowout preventer. While the arrestor 1 00 is held against the pipe riser 152 and blowout preventer 1 05, the ring 1 1 2 may be welded to the pipe riser 1 52 for improved seal.

[0019] In the embodiment of Figure 1 B, the magnetic collar 1 10 comprises a housing 1 14, a conductor 1 1 6, and a core 1 18. The conductor 1 16 and core 1 18 constitute a magnetic assembly that may be an electromagnet. The core 1 18 is generally a magnetic field enhancing material, such as ferrite. The housing 1 14 may be any suitable structural material, such as metal, which may be lined with a dielectric material if the conductor 1 1 6 carries an electric current.

[0020] The tapered fitting 1 06 and the spool 102 define an angle point 1 16, at which the diameter of the tapered fitting 106 begins to decline. When the magnetic collar 1 10 is placed proximate the pipe riser 152, the magnetic force between the magnetic collar 1 10 and the pipe riser 1 52 pulls the magnetic collar 1 10, along with the spool 1 02, toward the pipe riser 1 52 and the blowout preventer 150, creating a sealing force at the point of contact between the magnetic collar 1 1 0 and the pipe riser 152. The angle point 1 1 6 is generally inside the pipe riser 152 when the magnetic collar 1 10 contacts the pipe riser 1 52 to ensure the best seal. The angle point 1 1 6 may extend into the pipe riser 152 any convenient distance, but in most embodiments, the extension length will be between about ¼ and 1 pipe diameters. For example, in a 6 inch pipe system (i.e. the inner diameter of the pipe riser 152 is 6 inches), the angle point 1 16 will extend into the pipe riser 152 between about 1 .5 inches and about 6 inches, such as about 3 inches.

[0021 ] Figure 2A is a schematic side view of a leak management apparatus 200 according to another embodiment. The apparatus 200 comprises an electromagnet 202 positioned proximate a riser pipe 204 for a well. The electromagnet 202 is positioned proximate a leaking portion (not shown in Figure 2A) of the riser pipe 204 to facilitate plugging the leak. The leaking portion may be a side portion or an end portion of the riser pipe 204. A ferromagnetic fluid is provided to the interior of the riser pipe 204, and the electromagnet 202 is energized. The electromagnet 202 generates a magnetic field inside the riser pipe 204, at least a portion of which is substantially perpendicular to a central axis 206 of the riser pipe 204. The lines of magnetic force propel the ferromagnetic material in the riser pipe 204 toward a leaking wall, for example the external wall, of the riser pipe 204, creating a layer of magnetically hardened material lining the interior wall of the riser pipe 204 and covering the leaking portion. In an embodiment wherein the riser pipe 204 is leaking from an end portion thereof, the electromagnet 202 may be positioned proximate the end portion, or at any point along the pipe spaced apart from the end portion, and when energized will accumulate the ferromagnetic fluid inside the riser pipe 204 to stop or reduce the leak from the end portion.

[0022] Figure 2B is a schematic end view of a leak stopping apparatus according to one embodiment. A magnet 206, which may be an electromagnet or a permanent magnet, is positioned proximate a leaking portion 208 of a pipe riser 21 0, which may be a well bore. The magnet 206 may have a core 21 2, for example ferrite, for amplifying a magnetic field formed therein, and a coil 214 for generating a magnetic field 216 perpendicular to a central axis 218 of the pipe riser 210. Magnetically active material, such as a slurry of ferromagnetic material for example hematite or iron filings or fragments in oil or drilling fluid, is injected into the riser pipe 210, and the magnetic field 216 propels the magnetically active material toward the wall 220 of the pipe riser 210, covering and sealing the leaking portion 208 thereof.

[0023] In one embodiment, the magnetically active material accumulates in the pipe riser 210 at a location adjacent the magnet 206 to form a flow restriction or plug inside the pipe riser 210. The plug is formed and held in place by magnetic force from the magnet 206. Such a flow restriction may enable a plug or kill mixture to be pumped into the pipe riser 210 without being ejected from the pipe riser 210 by the pressure of the fluid flowing therein.

[0024] In another embodiment, a side wall leak may be magnetically sealed by providing a magnet, which may be an electromagnet or permanent magnet, shaped to follow an outside surface of a pipe riser such as the pipe riser 210. A seal or gasket may be attached to an edge of the magnet such that the seal or gasket continuously contacts the outside surface of the pipe when the magnet is in proximity to the pipe. The magnet may be placed over the side wall leak, with the seal gasket surrounding the leak. The magnetic force between the magnet and the pipe wall attracts the magnet toward the pipe wall, creating a sealing force between the seal or gasket and the pipe wall. Such a device may be used to stop a leak in a gas, oil, water, or other pipe quickly until a permanent repair can be made.

[0025] Figure 2C is a schematic end view of a leak stopping apparatus according to another embodiment. The embodiment of Figure 2C features a semi-circular magnet 250 disposed around a partial circumference of a pipe riser 260. The pipe riser 260 may have a side wall leak that is desirous of sealing, as described above, or may be desirous of plugging or killing. The magnet 250 may be used to provide a side wall seal using an edge gasket and/or a magnetically active slurry, or to provide a flow restriction or plug of magnetically active material inside the pipe riser 260, as described above.

[0026] It should be noted that the magnetically active material to be provided to the interior of the pipe for magnetically sealing a leak is preferably not magnetized, or has only a weak magnetic moment, before it is pumped into the pipe. The magnetic moment of the material should be less that than required to immobilize the material inside the pipe so that the material will flow to the point in the pipe at which the magnet is activated.

[0027] While the foregoing is directed to embodiments of the invention, other and further embodiments of the invention may be devised without departing from the basic scope thereof.