CROSS-REFERENCE TO RELATED APPLICATIONS

[0001] This application claims the benefit of U.S. Provisional Application No. 62/027,564, filed July 22, 2014, which is incorporated herein by reference.

BACKGROUND

[0002] The present disclosure relates generally to leg protectors. More specifically, in certain embodiments, the present disclosure relates to leg protectors for jack-up rigs and associated systems and methods.

[0003] At offshore oil and gas sites, drilling and production top sides are typically supported by an offshore platform. Offshore platforms are large structures that may have facilities to drill wells, to extract and process oil and natural gas, and to temporarily store products until they can be brought to shore for refining and marketing. One type of offshore platform used is a jack-up rig.

[0004] A jack-up rig is a type of mobile platform that may comprise a buoyant hull fitted with a number of movable legs, capable of raising its hull over the surface of the sea. The buoyant hull enables transportation of the unit and all attached machinery to a desired location. The jack-up rig may be maneuvered into location with its legs up and the hull floating on the water. Upon arrival at the work location, the legs may be jacked down onto the seafloor. Then "preloading" may take place, where the weight of the barge and additional ballast water are used to drive the legs securely into the sea bottom so they will not penetrate further while operations are carried out.

[0005] After preloading, the jacking system may be used to raise the entire barge above the water to a predetermined height or "air gap," so that wave, tidal and current loading acts only on the relatively slender legs and not on the barge hull. The legs of such units may be designed to penetrate the sea bed, may be fitted with enlarged sections or footings, or may be attached to a bottom mat.

[0006] While the legs may be designed to handle the tidal and current loading, the legs may still be damaged by external forces such as ice floes or ship impacts. It is desirable to develop an apparatus to protect the jack-up legs from external forces such as ice floes or ship impacts. SUMMARY

[0007] The present disclosure relates generally to leg protectors. More specifically, in certain embodiments, the present disclosure relates to leg protectors for jack-up rigs and associated systems and methods.

[0008] In one embodiment, the present disclosure provides a leg protector for a jack-up rig, wherein the leg protector comprises a body comprising an inner surface and one or more protrusions disposed on the inner surface.

[0009] In another embodiment, the present disclosure provides a jack-up rig comprising: a hull, one or more legs connected to the hull, and one or more leg protectors connected to the one or more legs.

[0010] In another embodiment, the present disclosure provides a method of installing a jack-up rig comprising: transporting a jack-up rig to an offshore location, wherein the jack-up rig comprises a hull, one or more legs connected to the hull, and one or more leg protectors connected to the one or more legs and extending the one or more legs of the jack-up rig to the sea floor.

BRIEF DESCRIPTION OF THE DRAWINGS

[0011] A more complete and thorough understanding of the present embodiments and advantages thereof may be acquired by referring to the following description taken in conjunction with the accompanying drawings.

[0012] Figure 1A is an illustration of a leg protector for a jack-up rig in accordance with certain embodiments of the present disclosure.

[0013] Figure IB is partial cut away view of a leg protector for a jack-up rig in accordance with certain embodiments of the present disclosure.

[0014] Figure 2 is an illustration of leg of a jack-up rig in accordance with certain embodiments of the present disclosure.

[0015] Figures 3 A and 3B are illustrations of jack-up rig system in accordance with certain embodiments of the present disclosure.

[0016] The features and advantages of the present disclosure will be readily apparent to those skilled in the art. While numerous changes may be made by those skilled in the art, such changes are within the spirit of the disclosure.

DETAILED DESCRIPTION

[0017] The present disclosure relates generally to leg protectors. More specifically, in certain embodiments, the present disclosure relates to leg protectors for jack-up rigs and associated systems and methods.

[0018] There may be several potential advantages to the leg protectors discussed herein. In certain embodiments, the leg protectors discussed herein may be able to protect the legs of the jack-up rig from external forces such as ice floes or ship impacts. In certain embodiments, these leg protectors may be easily fixed to different elevations along the legs depending where the most severe external forces could be. The use of the leg protectors may also enable to use of lighter legs and allow the use of lattice legs rather than tubular legs. In addition, the leg protectors described herein may introduce bending (instead of crushing) failure in ice to reduce ice loads and ice induced vibrations. In addition, the interior surfaces of the protectors may comprise portions capable of rotating the protectors in a desired orientation so that the legs can be passed through the protectors until the desired elevation is reached.

[0019] Referring now to Figures 1A and IB, Figures 1A and IB illustrate leg protector 100. In certain embodiments, leg protector 100 may be a buoyant structure capable of floating on a sea surface. In certain embodiments, the leg protector may be filled with water or sand so that it is heavier than its buoyancy force. In certain embodiments, leg protector 100 may be capable of floating on a sea surface while a leg of a jack-up rig is extended through leg protector 100.

[0020] As can be seen by Figure 1, in certain embodiments, leg protector 100 may comprise a body 110. In certain embodiments, body 110 may be hollow. In certain embodiments, body 110 may comprise an outer surface 111, an inner surface 112, and a bottom surface 113. In certain embodiments, outer surface 111, inner surface 112, and bottom surface 113 may define an interior. In certain embodiments, the interior may be filled with air, water, or sand. In certain embodiments, outer surface 111, inner surface 112, and bottom surface 113 may have a thickness of one inch or more.

[0021] In certain embodiments, body 110 may comprise a top opening 114 and a bottom opening 115. In certain embodiments, top opening 114 may be a circular opening with a diameter in the range of from five to 100 feet. In certain embodiments, bottom opening 115 may be a circular opening with a diameter in the range of from five to 100 feet. In other embodiments, top opening 114 and/or bottom opening 115 may have a cross section of any shape, including, but not limited to, rectangular, square, triangular, and hexagon. [0022] In certain embodiments, as shown in Figure 1, body 110 may be conically shaped comprising a number of circular cross sections of decreasing size. In certain embodiments, the diameter of the circular cross sections may range from a diameter of two hundred feet to the diameter of top opening 114. In certain embodiments, body 110 may be from five to 100 feet tall.

[0023] In certain embodiments, body 110 may be constructed out of any material. In certain embodiments, body 110 may be constructed of steel. In certain embodiments, body 110 may have an overall thickness of from one to six inches.

[0024] In certain embodiments, body 110 may comprise a number of protrusions 120 on inner surface 112. In certain embodiments, protrusions 120 may comprise positioners 121 and stoppers 122. In certain embodiments, protrusions 120 may be welded onto inner surface 112. In other embodiments, protrusions 120 may comprise a part of surface 112.

[0025] In certain embodiments, positioner 121 may be a raised edge. In certain embodiments, the raised edge may have a simple geometry. In certain embodiments, (as shown in Figures 1A and IB) the raised edge may have a geometry of that of a non- vertical, nor-horizontal line. In certain embodiments, the line may have an angle of from 20 to 70°. In certain embodiments, the raised edge may be raised by one to ten inches.

[0026] In certain embodiments, protrusions 120 may comprise multiple positioners 121. In certain embodiments, protrusions 120 may comprise two, three, four, five, or six positioners 121 disposed equispaced on a circumference of surface 112. In certain embodiments, protrusions 120 may comprise a pair of positioners 121 or two, three, four, five, or six pairs of positioners 121 disposed equispaced on a circumference of surface 112. In such embodiments, the positioners 121 in each pair of positioners 121 may be from two to twenty inches apart. In such embodiments, each pair of positioners 121 may comprise inside edges 123, first outside edge 124, and/or a second outside edge 125.

[0027] In certain embodiments, positioners 121 are capable of engaging a pin on a leg of a jack-up rig. In certain embodiments, positioners 121 may have a geometry that permits and/or requires leg protector 100 to rotate clockwise when a pin of the leg is engaged with inside edges 123 and/or first outside edge 124 while the leg is lowered relative to leg protector 100. In certain embodiments, positioners 121 may have a geometry that permits and/or requires leg protector 100 to rotate counter-clockwise a pin of the leg is engaged with inside edges 123 and/or second outside edge 125 while the leg is raised relative to leg protector 100. In other embodiments, positioners 121 may have a geometry that permits and/or requires leg protector 100 to rotate counter-clockwise when a pin of the leg is engaged with inside edges 123 and/or first outside edge 124 while the leg is lowered relative to leg protector 100. In certain embodiments, positioners 121 may have a geometry that permits and/or requires leg protector 100 to rotate clockwise when a pin of the leg is engaged with inside edges 123 and/or second outside edge 125 while the leg is raised relative to leg protector 100.

[0028] In certain embodiments, stoppers 122 may be a raised edge. In certain embodiments, the raised edge may have a complex geometry comprising multiple edges. In certain embodiments, the raised edge may have geometry of that of multiple lines. In certain embodiments, the raised edge may be raised from one to ten inches. In certain embodiments, each stopper 122 may comprise first outside edge 126, first inside edge 127, second inside edge 128, and/or second outside edge 129.

[0029] In certain embodiments, a stopper 122 may be disposed above each positioner 121. In certain embodiments, a stopper 122 may be disposed above each pair of positioners 121. In certain embodiments, each stopper 122 may be disposed eight to sixty inches above each positioner 121 or pair of positioners 121.

[0030] In certain embodiments, stoppers 122 are capable of engaging a pin on a leg of a jack-up rig. In certain embodiments, stoppers 122 may have a geometry that permits and/or requires leg protector 100 to rotate counter-clockwise when a pin of the leg is engaged with first outside edge 126 while the leg is lowered relative to leg protector 100. In certain embodiments, stoppers 122 may have a geometry that permits and/or requires leg protector 100 to rotate clockwise when a pin of the leg is engaged with second outside edge 129 while the leg is lowered relative to leg protector 100. In certain embodiments, stoppers 122 may have a geometry that permits and/or requires leg protector 100 to rotate clockwise when a pin of the leg is engaged first inside edge 127 while the leg is raised relative to leg protector 100. In certain embodiments, stoppers 122 may have a geometry that permits and/or requires leg protector 100 to not rotate when a pin of the leg is engaged with second inside edge 128 while the leg is lowered relative to leg protector 100.

[0031] In other embodiments, stoppers 122 may have a geometry that permits and/or requires leg protector 100 to rotate clockwise when a pin of the leg is engaged with first outside edge 126 while the leg is lowered relative to leg protector 100. In certain embodiments, stoppers 122 may have a geometry that permits and/or requires leg protector 100 to rotate counter-clockwise when a pin of the leg is engaged with second outside edge 129 while the leg is lowered relative to leg protector 100. In certain embodiments, stoppers 122 may have a geometry that permits and/or requires leg protector 100 to rotate counter-clockwise when a pin of the leg is engaged first inside edge 127 while the leg is raised relative to leg protector 100.

[0032] In certain embodiments, positioners 121 and stoppers 122 may have a geometry and a location that allow for a pin of a leg of a jack-up rig to be placed into a "locked position." As used herein, the term locked position refers to an engagement of the pin and the stopper such that the leg protector can only move in one direction relative to leg protector 100. In certain embodiments, the pin may be in a locked position when it contacts first inside edge 127 and/or second inside edge 128.

[0033] In certain embodiments, the pin of a leg of the jack-up rig may be placed into a locked position by several different steps. In certain embodiments, the pin of a leg of the jack-up rig may be placed into a locked position by first raising leg of a jack-up rig relative to leg protector 100 so that a pin engages positioner 121, then raising the leg of a jack-up rig relative to leg protector 100 while a pin on the leg is contacting inside edges 123, then raising the leg of the jack-up rig relative to leg protector 100 until the pin makes contact with stopper 122, and then raising the leg of the jack-up rig relative to leg protector 100 while a pin on the leg is in contact with first inside edge 127 until the leg is in the locked position. In other embodiments, the pin of a leg of the jack-up rig may be placed into a locked position by first raising the leg of a jack-up rig relative to leg protector 100 while a pin on the leg is contacting inside edges 123, then raising the leg of the jack-up rig relative to leg protector 100 until the pin makes contact with stopper 122, and then raising the leg of the jack-up rig relative to leg protector 100 while a pin on the leg is in contact with first inside edge 127 until the leg is in the locked position. In other embodiments, the pin of a leg of the jack-up rig may be placed into a locked position by first raising the leg of the jack-up rig relative to leg protector 100 until the pin makes contact with stopper 122 and then raising the leg of the jack-up rig relative to leg protector 100 while a pin on the leg is in contact with first inside edge 127 until the leg is in the locked position. In other embodiments, the pin of a leg of the jack-up rig may be placed into a locked position by raising the leg of the jack-up rig relative to leg protector 100 while a pin on the leg is in contact with first inside edge 127 until the leg is in the locked position.

[0034] In certain embodiments, positioners 121 and stoppers 122 may have a geometry and a location that allow for a pin of a leg of a jack-up rig to be removed from the locked position. In certain embodiments, the pin of a leg of the jack-up rig may be removed from the locked position by first lowering the leg of a jack-up rig relative to leg protector 100 while a pin on the leg is in contact with second inside edge 128, then lowering the leg relative to leg protector 100 until it contacts fist outside edge 124 of positioner 121, and then further lowering the leg relative to leg protector 100 until the pin is no longer contacting first outside edge 124. In such embodiments, the leg of the jack-up rig is then placed into an "unlocked position." As used herein, the term "unlocked position" refers to an engagement of the pin and the protrusion such that the leg may be lowered and raised relative to leg protector 100 so that the pin passes through the protrusions 120 without contacting inside edge 123, first inside edge 127, and second inside edge 128. In such embodiments, the pin may not be placed into the locked position by simply raising or lowering the legs relative to leg protector 100.

[0035] Referring now Figure 2, Figure 2 is an illustration of a leg 200 of a jack-up rig in accordance with certain embodiments of the present disclosure. In certain embodiments, leg 200 may comprise outside surface 210, one or more pins 220, and a spud can 230.

[0036] In certain embodiments, leg 200 may be any type of leg for a jack-up rig. In certain embodiments, leg structure 200 may have a cylindrical shape or a lattice structure with a width of from five to 100 feet. In certain embodiments, leg 200 may be constructed of steel. In certain embodiments, leg 200 may comprise an outside surface 210. In certain embodiments, leg 200 may have a cross sectional geometry similar to opening 114 (not illustrated in Figure 2) of leg protector 100 (not illustrated in Figure 2). In certain embodiments, leg 200 may have a diameter equal to the diameter of opening 114 (not illustrated in figure 2) of leg protector 100 (not illustrated in Figure 2).

[0037] In certain embodiments, a number of pins 220 may be disposed on outside surface 210 of leg 200. In certain embodiments, pins 220 may be welded onto outside surface 210. In other embodiments, pins 220 may comprise a part of outside surface 210.

[0038] In certain embodiments, leg 200 may comprise one, two, three, four five or six pins 220 may be disposed equispaced on a circumference of outside surface 210. In certain embodiments, leg 200 may comprise a pair of pins 220 or may comprise, or two, three four, five or six pairs of pins 220 disposed equispaced on a circumference of outside surface 210. In certain embodiments, the pins 220 in each pair of pins 220 may be two to twenty inches apart.

[0039] In certain embodiments, leg 200 may comprise a vertical array of pins 220. In certain embodiments, leg 200 may comprise from two to ten rows of pins 220. In certain embodiments, pins 220 are capable of engaging a positioner and a stopper on a leg protector.

[0040] In certain embodiments, spud can 230 may comprise any conventional spud can.

[0041] Referring now to Figure 3, Figures 3 A and 3B are illustrations of a jack-up rig system 300. In certain embodiments, jack-up rig system 300 may comprise a jack-up rig 310 floating on a sea surface 320 above a sea floor 330.

[0042] In certain embodiments, jack-up rig 310 may comprise any type of jack-up rig. Examples of suitable jack-up rigs are disclosed in United States Patent Application Publication No. 2012/0128426, the entirety of which is herby incorporated by reference. In certain embodiments, jack-up rig 310 may comprise a hull 313 and one or more legs 311. In certain embodiments, the one or more legs 311 may comprise any combination of features discussed above with respect to leg 200. In certain embodiments, the one or more legs 311 may comprise one or more spud cans 315. In certain embodiments, the one or more legs 311 may comprise one or more leg protectors 312. In certain embodiments, the one or more legs protectors 312 may comprise any combination of features discussed above with respect to leg protector 100.

[0043] In certain embodiments, hull 313 may be a buoyant hull. In other embodiments, hull 313 may not be a buoyant hull. In certain embodiments, hull 313 may comprise one or more cavities 314. In certain embodiments, as shown in Figure 3A, one or more leg protectors 312 may be disposed within the one or more cavities 314. In other embodiments, as shown in Figure 3B, one or more leg protectors 312 are not disposed within the one or more cavities 314.

[0044] In certain embodiments, one or more legs 311 may be attached to hull 313 by any conventional means. In certain embodiments, one or more legs 311 may be attached to hull 313 a jacking and locking mechanism. In certain embodiments, the one or more legs 311 may be movable legs that can be extended above and/or below the hull 313. In certain embodiments, the one or more legs 311 may be extended above and/or below the hull by a rack and pinion mechanism.

[0045] In certain embodiments, as illustrated in Figure 3A, the one or more legs 311 may not be extended to sea floor 330. In such embodiments, the one or more leg protectors 313 may be disposed within the cavities 314 and rest on top of the one or more spud cans 315. In other embodiments, as illustrated in Figure 3B, the one or more legs 311 may be extended to sea floor 330. In such embodiments, hull 313 may be located above the sea surface 320 and the one or more leg protectors 312 may be positioned on the one or more legs 311 at sea surface 320. In such embodiments, the one or more leg protectors 312 may be in a locked position on the one or more legs 311.

[0046] In certain embodiments, the present disclosure provides a method of installing a jack-up rig comprising: transporting a jack-up rig to an offshore location, wherein the jack-up rig comprises a hull, one or more legs connected to the hull, and one or more leg protectors connected to the one or more legs and extending the one or more legs of the jack-up rig to the sea floor

[0047] In certain embodiments, the jack-up rig may comprise any combination of features discussed above with respect to jack-up rig 310. In certain embodiments, the hull may comprise any combination of features discussed above with respect to hull 313. In certain embodiments, the one or more legs may comprise any combination of features discussed above with respect to legs 311 and/or leg 200. In certain embodiments, the one or more leg protectors may comprise any combination of features discussed above with respect to leg protectors 312 and/or leg protector 100.

[0048] In certain embodiments, transporting a jack-up rig to an offshore location may comprise transporting a jack-up rig to an offshore location while the one or more legs are retracted into the hull. In such embodiments, the one or more leg protectors may be disposed within one or more cavities of the hull. In such embodiments, the one or more leg protectors may be resting on top of the one or more spud cans.

[0049] In certain embodiments, extending the one or more legs of the jack-up rig to the sea floor may first comprise extending the legs to the sea surface. In certain embodiments, the one or more legs of the jack-up rig may be extended to the sea surface such that the leg protectors may be lowered to the sea surface. Once the leg protectors are lowered to the sea surface, the legs may then be further extended to the sea floor. In certain embodiments, when the legs are further extended to the sea floor, the leg protectors may float at the sea surface. In such embodiments, the leg protectors may swivel clockwise and counter-clockwise as the one or more protrusions contact the pins of the legs.

[0050] In certain embodiments, extending the one or more legs of the jack-up rig to the sea floor may further comprise locking the leg protectors. In certain embodiments, locking the leg protectors may comprise retracting the legs of the jack-up rig once the legs first contact the sea floor. By retracting the legs, the leg protectors may then rotate and be placed into the locked position. Once in the locked position, the legs may then be extended to the sea floor while remaining in the locked position.

[0051] In certain embodiments, the method may further comprise retracting the legs to the jack-up rig. In certain embodiments, by retracting the legs, the leg protectors may be placed into the unlocked position, permitting the legs to be further retracted to the jack-up rig without the pins of the legs contacting the protrusions of the leg protectors.

[0052] While the embodiments are described with reference to various implementations and exploitations, it will be understood that these embodiments are illustrative and that the scope of the inventive subject matter is not limited to them. Many variations, modifications, additions and improvements are possible.

[0053] Plural instances may be provided for components, operations or structures described herein as a single instance. In general, structures and functionality presented as separate components in the exemplary configurations may be implemented as a combined structure or component. Similarly, structures and functionality presented as a single component may be implemented as separate components. These and other variations, modifications, additions, and improvements may fall within the scope of the inventive subject matter.