CROSS REFERENCE TO RELATED APPLICATIONS

[0001] This application claims the benefit of U.S. Provisional Application No. 61/911,825, filed December 4, 2013, which is incorporated herein by reference.

BACKGROUND

[0002] The present disclosure relates generally to offshore platforms. More specifically, in certain embodiments, the present disclosure relates to offshore platforms capable of receiving cassette barges 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 may either be floating platforms or fixed platforms. Examples of fixed platforms include gravity based structure. A gravity based structure is a support structure held in place by gravity that rests on the sea floor. Due to their strength and reliability, gravity-based structures have been used extensively in the North Sea offshore Norway and Scotland.

[0004] From time to time, offshore platforms must be re- supplied with equipment and supplies. It is estimated that up to 45,000 tonnes of supplies must be delivered to a single offshore platform annually. There are currently several methods of resupplying these offshore platforms. One such method includes the utilization of supply barges. Typically, the supply barges travel to the offshore platform and then remain alongside the offshore platform while being offloaded by a crane. Unloading these barges in this manner may however be problematic. Severe weather conditions may result in unsafe working environments suspending the offloading operation. This is especially true in arctic conditions where the presence of sea ice is especially problematic. Certain barges may not be intended for operation in ice and thus offshore platforms in arctic conditions may not be able to be supplied during the winters.

[0005] It is desirable to develop a safer and more efficient method of resupplying offshore platforms in arctic environments. SUMMARY

[0006] The present disclosure relates generally to offshore platforms. More specifically, in certain embodiments, the present disclosure relates to offshore platforms capable of receiving cassette barges and associated systems and methods.

[0007] In one embodiment, the present disclosure provides an offshore platform comprising: a hull; a doorway disposed on the hull; and an internal harbor within the hull.

[0008] In another embodiment, the present disclosure provides an offshore platform system comprising: an offshore platform, wherein the offshore platform comprises: a hull; a doorway disposed on the hull; and an internal harbor within the hull; and a topside resting on the gravity based structure.

[0009] In another embodiment, the present disclosure provides a method of resupplying an offshore platform comprising: providing an offshore platform comprising an offshore platform, wherein the offshore platform comprises a hull, a doorway disposed on the hull and an internal harbor within the hull; berthing a vessel at the internal harbor; and unloading the vessel.

BRIEF DESCRIPTION OF THE DRAWINGS

[0010] 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.

[0011] Figure 1 is an illustration of an offshore platform in accordance with certain embodiments of the present disclosure.

[0012] Figure 2 is an illustration of an offshore platform in accordance with certain embodiments of the present disclosure.

[0013] Figure 3 is an illustration of an offshore platform system in accordance with certain embodiments of the present disclosure.

[0014] 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

[0015] The present disclosure relates generally to offshore platforms. More specifically, in certain embodiments, the present disclosure relates to offshore platforms capable of receiving cassette barges and associated systems and methods. [0016] There may be several potential advantages to the offshore platforms discussed herein. In certain embodiments, the offshore platforms discussed herein may be able to provide an internal harbor or dock where a vessel may be driven by passing through a doorway on the offshore platform. Once the vessel is inside the offshore platform, the doorway may be closed to allow the vessel to be completely isolated from the outside environment (wind, waves, currents, ice, freezing temperatures) and offloaded in the relative calm of the artificial harbor that exists within the offshore platform.

[0017] In certain embodiments, the present disclosure provides an offshore platform. In certain embodiments, the offshore platform may be a fixed platform or a floating platform. In certain embodiments, the offshore platform may be a gravity based structure. In certain embodiments, the gravity based structure may be a vertical gravity based structure or a conical gravity based structure.

[0018] Referring now to Figure 1, Figure 1 illustrates an offshore platform 100. As can be seen by Figure 1, in certain embodiments, offshore platform 100 may comprise a conical gravity based structure. In certain embodiments, offshore platform 100 may comprise hull 110, doorway 120, and internal harbor 130.

[0019] In certain embodiments, hull 110 may be constructed out of any material suitable for use as a gravity-based structure. In certain embodiments, hull 110 may be constructed out of steel, concrete, or a combination thereof. In certain embodiments, hull 110 may be constructed out of steel reinforced concrete.

[0020] In certain embodiments, hull 110 may comprise bottom 111, top 112, and side 113. In certain embodiments, bottom 111 and/or top 112 may be generally circular shaped portions. In certain embodiments, bottom 111 and/or top 112 may be multifaceted shaped portions such as regular polygons with from 6 to 30 sides.

[0021] In certain embodiments, bottom 111 may be from 100 feet to 1000 feet in diameter. In certain embodiments, bottom 111 may be from 250-800 feet in diameter. In certain embodiments, bottom 111 may be capable of resting on a sea floor. In certain embodiments, top 112 may be from 75 feet to 900 feet in diameter. In certain embodiments, bottom top 112 may be from 150-600 feet in diameter. In certain embodiments, top 112 may be capable of supporting a topside.

[0022] In certain embodiments, side 113 may be located between bottom 111 and top 112. In certain embodiments, side 113 may comprise keel 114, sloped ice wall 115, neck 116, and wave deflector 117. [0023] In certain embodiments, keel 114 may be a cylindrically shaped portion. In certain embodiments, keel 114 may be a multifaceted portion having the same cross sectional shape of bottom 111. In certain embodiments, keel 114 may have the same diameter of bottom 111. In certain embodiments, the height of keel 114 may be a function of water depth, ice depth, and/or the height of sloped ice wall 115.

[0024] In certain embodiments, sloped ice wall 115 may be a conically shaped portion. In certain embodiments, sloped ice wall 115 may be a multifaceted portion having the same cross section of bottom 111. In certain embodiments, sloped ice wall 115 may have a constant slope or a variable slope. In certain embodiments, the diameter of sloped ice wall 115 may vary from a value equal to the diameter of keel 114 at the bottom of sloped ice wall 115 to a value equal to the diameter of neck 116 at the top of sloped ice wall 115. In certain embodiments, the height of sloped ice wall 115 may be a function of water depth, ice depth, and/or the height of keel 114.

[0025] In certain embodiments, neck 116 may be a cylindrically shaped portion. In certain embodiments, neck 116 may be a multifaceted portion having the same cross sectional shape of bottom 111. In certain embodiments, neck 116 may have a diameter of from 75 feet to 600 feet. In certain embodiments, neck 116 may have a diameter of from 150 feet to 400 feet. In certain embodiments, the length of neck 116 may be a function of water and/or ice depth.

[0026] In certain embodiments, wave deflector 117 may comprise a tapered portion

117a and a vertical portion 117b. In certain embodiments, tapered portion 117a may have a constant taper or a variable taper. In certain embodiments, the diameter of tapered portion 117a may vary from a value equal to the diameter of neck 116 at a bottom of tapered portion 117a to a value equal to the diameter of top 112 at a top of tapered portion 117a. In certain embodiments, tapered portion 117a and vertical portion 117b may be multifaceted portions having the same cross sectional shape of bottom 111.

[0027] In certain embodiments, doorway 120 may be disposed on hull 110. In certain embodiments, doorway 120 may be disposed on side 113 of hull 110. In certain embodiments, doorway 120 may be disposed on sloped ice wall 115 or may span both slope ice wall 115 and keel 114. In certain embodiments, doorway 120 may provide access to internal harbor 130.

[0028] In certain embodiments, doorway 120 may permit one or more vessels to pass through hull 110 and into harbor 130. In certain embodiments, the size of doorway may vary as a function of the vessels entering into the harbor and the size of hull 110. In certain embodiments, doorway 120 may be from 25 to 450 feet wide. In other embodiments, doorway 120 may be from 50 to 300 feet wide. In certain embodiments, doorway 120 may be from 30 to 200 feet tall. In certain embodiments, doorway 120 may be from 50 to 100 feet tall.

[0029] In certain embodiments, doorway 120 may be located at sea level. In certain embodiments, a portion of doorway 120 may be located above the sea level and a portion of doorway may be located below the sea level. In certain embodiments, a top 121 of doorway 120 may be from 25 to about 100 feet above sea level. In certain embodiments, a bottom 122 of doorway 120 may be from 10 to 50 feet below sea level.

[0030] In certain embodiments, a movable door 125 may cover doorway 120. In certain embodiments, movable door 125 may be moved away from doorway 120 so that one or more vessels may pass through doorway 120 and enter or exit internal harbor 130. In certain embodiments, movable door may be constructed out of steel, concrete, or steel reinforced concrete. In certain embodiments, movable door 125 may attached to hull 110 by one or more hinges 126 or movable door 125 may be a sliding door disposed on a track (not illustrated). In certain embodiments, movable door 125 may be heavily ice strengthened gate to close the port for protection from ice. In certain embodiments, two or more movable doors 125 may cover doorway 120.

[0031] In certain embodiments, internal harbor 130 may be disposed within hull

110. In certain embodiments, internal harbor 130 may be disposed within sloped ice wall 115 and/or keel 114. In certain embodiments, internal harbor 130 may be partially filled with water. In certain embodiments, internal harbor 130 may capable of berthing one or more vessels. In certain embodiments, internal harbor 130 may comprise one or more internal docks 131. In certain embodiments, one or more vessels may be berthed at the one or more internal docks 131 and be unloaded.

[0032] Referring now to Figure 2, Figure 2 illustrates an offshore platform 200. As can be seen by Figure 2, in certain embodiments, offshore platform 200 may comprise a vertical gravity based structure. In certain embodiments, offshore platform 200 may comprise hull 210, doorway 220, and internal harbor 230.

[0033] In certain embodiments, hull 210 may share any of the characteristics discussed above with respect to hull 110. In certain embodiments, hull 210 may comprise bottom 211, top 212, and side 213. Bottom 211 and/or top 212 may share any of the characteristics discussed above with respect to bottom 111 and top 112.

[0034] In certain embodiments, bottom 211 may be from 100 feet to 1000 feet in diameter. In certain embodiments, bottom 211 may be from 250-800 feet in diameter. In certain embodiments, bottom 211 may be capable of resting on a sea floor. In certain embodiments, top 212 may be from 100 feet to 900 feet in diameter. In certain embodiments, bottom top 212 may be from 250 to 700 feet in diameter. In certain embodiments, top 212 may be capable of supporting a topside.

[0035] In certain embodiments, side 213 may be located between bottom 211 and top 212. In certain embodiments, side 213 may comprise toe 214, vertical ice wall 215, and wave deflector 217.

[0036] In certain embodiments, toe 214 may comprise a tapered portion 214a and a vertical portion 214b. In certain embodiments, vertical portion 214b may be a cylindrically shaped portion. In certain embodiments, vertical portion 214b may be a multifaceted portion having the same cross sectional shape of bottom 211. In certain embodiments, vertical portion 214b may have the same diameter of bottom 211. In certain embodiments, tapered portion 214a may have a constant taper or a variable taper. In certain embodiments, the diameter of tapered portion 214a may vary from a value equal to the diameter of vertical portion 214b at a bottom of tapered portion 214a to a value equal to the diameter of vertical ice wall 215 at a top of tapered portion 214a. In certain embodiments, tapered portion 214a and vertical portion 214b may be multifaceted portions having the same cross sectional shape of bottom 211.

[0037] In certain embodiments, vertical ice wall 215 may be a cylindrically shaped portion. In certain embodiments, vertical ice wall 215 may be a multifaceted portion having the same cross-sectional shape of bottom 211. In certain embodiments, the diameter of vertical ice wall 215 may be from 150 to 900 feet in diameter. In certain embodiments, the diameter of vertical ice wall 215 may be from 200 to 600 feet in diameter. In certain embodiments, the height of vertical ice wall 215 may be a function of water depth, ice depth, and/or the height of toe 214.

[0038] In certain embodiments, wave deflector 117 may comprise a tapered portion 117a and a vertical portion 117b. In certain embodiments, tapered portion 117a may have a constant taper or a variable taper. In certain embodiments, the diameter of tapered portion 117a may vary from a value equal to the diameter of vertical ice wall 215 at a bottom of tapered portion 117a to a value equal to the diameter of top 212 at a top of tapered portion 117a. In certain embodiments, tapered portion 117a and vertical portion 117b may be multifaceted portions having the same cross-sectional shape of bottom 211. In certain embodiments, vertical portion 117b may have the same diameter of top 212.

[0039] In certain embodiments, doorway 220 may be disposed on hull 210. In certain embodiments, doorway 220 may be disposed on side 213 of hull 210. In certain embodiments, doorway 220 may be disposed on vertical ice wall 215. In certain embodiments, doorway 220 may provide access to internal harbor 230.

[0040] In certain embodiments, doorway 220 may permit one or more vessels to pass through hull 210 and into harbor 230. In certain embodiments, the size of doorway may vary as a function of the vessels entering into the harbor. In certain embodiments, doorway 220 may be from 25 to 450 feet wide. In other embodiments, doorway 220 may be from 50 to 300 feet wide. In certain embodiments, doorway 220 may be from 30 to 200 feet tall. In certain embodiments, doorway 220 may be from 50 to 100 feet tall.

[0041] In certain embodiments, doorway 220 may be located at sea level. In certain embodiments, a portion of doorway 220 may be located above the sea level and a portion of doorway may be located below the sea level. In certain embodiments, a top 221 of doorway 220 may be from 25 to about 100 feet above sea level. In certain embodiments, a bottom 222 of doorway 220 may be from 10 to 50 feet below sea level.

[0042] In certain embodiments, a movable door 225 may cover doorway 220. In certain embodiments, movable door 225 may be moved away from doorway 220 so that one or more vessels may pass through doorway 220 and enter or exit internal harbor 230. In certain embodiments, movable door may be constructed out of steel, concrete, or steel reinforced concrete. In certain embodiments, movable door 225 may attached to hull 210 by one or more hinges 226 or movable door 225 may be a sliding door disposed on a track (not illustrated). In certain embodiments, movable door 225 may be heavily ice strengthened gate to close the port for protection from ice. In certain embodiments, two or more movable doors 225 may cover doorway 220.

[0043] In certain embodiments, internal harbor 230 may be disposed within hull 210. In certain embodiments, internal harbor 230 may be disposed within vertical ice wall 215. In certain embodiments, internal harbor 230 may be partially filled with water. In certain embodiments, internal harbor 230 may capable of berthing one or more vessels. In certain embodiments, internal harbor 230 may comprise one or more internal docks 231. In certain embodiments, one or more vessels may be berthed at the one or more internal docks 231 and be unloaded.

[0044] Referring now to Figure 3, Figure 3 illustrates an offshore platform system 1000 in accordance with certain embodiments of the present disclosure. In certain embodiments, offshore platform system 1000 may comprise offshore platform 1100, a sea floor 1200, sea level 1300, and topsides 1400.

[0045] In certain embodiments, offshore platform 1100 may comprise a fixed platform or a floating platform. In certain embodiments, offshore platform 1100 may comprise any combination of features discussed above with respect to offshore platforms 100 and 200. In certain embodiments, gravity based structure 1100 may rest on sea floor 1200 and support topsides 1400.

[0046] In certain embodiments, topsides 1400 may comprise any conventional top side. In certain embodiments, topsides 1400 may comprise a drilling rig and/or production facilities.

[0047] In certain embodiments, offshore platform system 1000 may further comprise one or more vessels 1500. In certain embodiments, vessels 1500 may comprise a barge. In certain embodiments, one or more vessels 1500 may comprise cassette barges. In certain embodiments, the cassette barges may be generally box-shaped. In certain embodiments, cassette barges may be from 50-200 feet long, from 25-100 feet wide, have a depth of from 10-60 feet, and have a draught from 5 to 40 feet. In certain embodiments, each cassette barge 1500 may be capable of storing three months of supplies. In certain embodiments, the cassette barges may be pulled by tugs. In certain embodiments, the one or more vessels 1500 may be berthed within offshore platform 1100.

[0048] In certain embodiments, the present disclosure provides a method of resupplying an offshore platform comprising: providing an offshore platform wherein the offshore platform comprises a hull, a doorway disposed on the hull, and an internal harbor within the hull; berthing a vessel at the internal harbor; and unloading the vessel.

[0049] In certain embodiments, the offshore platforms structure may comprise any combination of features discussed above with respect to offshore platforms 100, 200, and/or 1100. In certain embodiments, the vessel may comprise any combination of features discussed above with respect to vessel 1500.

[0050] In certain embodiments, berthing the vessel at the internal harbor may comprise opening a door covering the doorway, allowing the vessel to pass through the doorway, closing the door, and berthing the vessel at a dock at the internal harbor. [0051] 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.

[0052] 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.