RU2747345C1 - Method for marine production, storage and unloading of oil using floating structure - Google Patents

Abstract

FIELD: oil industry.

SUBSTANCE: invention relates to the field of offshore production of hydrocarbons, in particular oil. A method of operating a floating installation for offshore production, storage and unloading of oil includes the following stages. First of all, hydrocarbons are taken into the floating body of a floating installation for offshore production, storage and unloading of oil. After that the received hydrocarbons are processed. A hydrocarbon product is formed in the floating hull. The hydrocarbon product is stored in the floating hull. The stored hydrocarbon product is unloaded. The floating hull is circular in top view and has a lower surface, an upper deck surface, at least three connected sections connected in series and arranged symmetrically around a vertical axis, with the connected sections extending downward from the upper deck surface to the lower surface. These at least three connected sections have an upper cylindrical section, a lower conical section, a cylindrical constricted section, and a set of stabilizers attached to the body to correct fluid dynamics through linear and quadratic damping.

EFFECT: invention makes it possible to optimize the functions of receiving hydrocarbons, processing received hydrocarbons, storing and unloading hydrocarbons as well as the characteristics of a floating installation.

10 cl, 18 dwg

Description

Cross-reference to related claims

[0001] This application is a continuation of US patent application No. 15 / 798,078 filed October 30, 2017 under the name "Floating Rig", which is a partial continuation of US patent application No. 15 / 705,073, filed September 14, 2017 under the name "Floating Rig" structure ", which is a continuation of US patent application No. 15 / 522,076 filed April 26, 2017 entitled" Floating Structure ", which claims priority over national phase application PCT / US2015 / 057397, filed Oct. 26, 2915, which claims Priority to US Patent Application No. 14 / 105,992, filed Oct. 27, 2014 under the title "Floating Structure", which is a continuation of US Patent Application No. 14 / 105,321, filed December 13, 2013 under the name "Floating Structure", which is a patent US No. 8,869,727 October 28, 2014, which is a partial continuation of US patent application No. 13 / 369,600, filed February 9, 2012 titled "Stable e offshore floating storage ", which issued US patent No. 8,662,000 on March 5, 2014, which is a partial continuation of US patent application No. 12 / 914,709, filed October 28, 2010, which issued US patent No. 8,251,003 on August 28, 2012, which claims priority US Provisional Patent Application No. 61 / 259,201, filed Nov. 8, 2009; and US Provisional Patent Application No. 61 / 521,701, filed Aug. 9, 2011, both of which have expired. These references are incorporated herein in their entirety.

The technical field to which the invention relates

[0002] Embodiments of the present invention generally relate to a method of operating a floating storage and discharge installation.

State of the art

[0003] The present invention relates to a floating production, storage and offloading installation, and in particular to hull structures and offloading systems for a drilling, production, storage and offloading installation.

[0004] The proposed options meet these needs.

Disclosure of invention

[0005] According to various embodiments, there is provided a method of offshore production, storage and discharge of oil using a floating unit, comprising the steps of: (a) receiving hydrocarbons into the vessel from at least one of: a floating unit, a production riser, or a wellhead at the bottom of the sea; (b) processing the received hydrocarbons, forming a hydrocarbon product in the floating hull; (c) store the hydrocarbon product in a floating hull, the floating hull comprising: (i) a bottom surface; (ii) surface of the upper deck; (iii) at least three connected sections connected in series and located symmetrically about a vertical axis, with the connected sections extending downwardly from the upper deck surface to the lower surface; wherein these at least three connected sections comprise an upper cylindrical section, a lower conical section and a cylindrical tapered section; and (iv) a set of stabilizers attached to the hull and adapted to adjust the hydrodynamic characteristics through linear and quadratic damping; and (d) discharge the stored hydrocarbon product into a tanker and / or pipeline.

Brief Description of Drawings

[0006] The following is a more detailed description of the present invention with reference to the accompanying drawings, where:

[0007] FIG. 1 is a top view of a floating production, storage and offloading installation (hereinafter, floating installation) according to the present invention and a tanker moored to this floating installation.

[0008] FIG. 2 is a side view of the FPSO of FIG. one

[0009] FIG. 3 is a more detailed, enlarged side view of the floating installation of FIG. 2.

[0010] FIG. 4 is a more detailed, enlarged top view of the floating installation of FIG. one.

[0011] FIG. 5 is a side view of an alternative embodiment of the hull of a floating installation according to the present invention.

[0012] FIG. 6 is a side view of an alternative embodiment of the hull of a floating installation according to the present invention.

[0013] FIG. 7 is a side view of an alternate floating installation of the present invention showing a center column inserted into an opening in the hull of the floating installation.

[0014] FIG. 8 is a cross-sectional view of the central column of FIG. 7 on line 8-8.

[0015] FIG. 9 is a side view of the floating installation of FIG. 7 showing an alternative embodiment of the center column of the present invention.

[0016] FIG. 10 is a cross-sectional view of the central column of FIG. 9 on line 11-11.

[0017] FIG. 11 is an alternate cross-sectional view of the center column and mass manifold taken along line 11-11 in FIG. 9 according to the present invention.

[0018] FIG. 12 is a top view of a movable mooring cable joint according to the present invention.

[0019] FIG. 13 is a side view of the mobile connection with the mooring line of FIG. 12 in partial section along line 13-13.

[0020] FIG. 14. is a side view of the mobile connection with the mooring line of FIG. 13 in partial section along line 14-14.

[0021] FIG. 15 is a side view of a vessel according to the present invention.

[0022] FIG. 16 is a cross-section of the vessel according to FIG. 15 on line 16-16.

[0023] FIG. 17 is a side view of the vessel of FIG. 15 in section along the line 17-17.

[0024] FIG. 18 is a side view of the vessel of FIG. 15 in section along the line 18-18.

[0025] The following is a detailed description of embodiments of the invention with reference to the drawings.

Description of preferred embodiments of the invention

[0026] Before proceeding to a detailed description of the proposed device, it should be understood that this device is not limited to specific options and one hundred it can be created or implemented in different ways.

[0027] In accordance with the present invention, a floating storage and discharge unit is provided with several alternative hull designs, multiple alternative center column designs, and a movable unloading mooring system that allows the tanker to feather in a wide arc relative to the floating unit.

[0028] In particular, the present invention relates to a method for offshore oil production, storage and offloading.

[0029] In a first step of the method, hydrocarbons are received into the floating hull from at least one of the floating drilling rig, production risers, or a wellhead on the seabed.

[0030] In the next step, the produced hydrocarbons are processed to form a hydrocarbon product in the floating hull.

[0031] The method then continues by storing the hydrocarbon product in a floating body, the unique floating body having a circular cross-section in top view and comprising: a bottom surface; upper deck surface; at least three connected sections, connected in series and arranged symmetrically about a vertical axis, with the connected sections extending downwardly from the upper deck surface to the lower surface; and at least three connected sections comprise: an upper cylindrical portion; lower conical part, cylindrical tapered section; and a set of stabilizers attached to the body and configured to adjust the hydrodynamic characteristics through linear and quadratic damping; and the stored hydrocarbon product is discharged.

[0032] A unique housing is shown in the drawings.

[0033] The floating installation 10 of the present invention in FIG. 1 is shown in top view and FIG. 2 is a side view.

[0034] The floating installation 10 has a body 12 and a center column 14 that can be attached to the body 12 and project downward.

[0035] The floating unit 10 floats in water W and may be used to extract, store and / or discharge a resource recovered from the earth, such as hydrocarbons, including crude oil and natural gas, and minerals that can be recovered by in situ leaching.

[0036] The floating installation 10 can be assembled in an extraterrestrial plant by known methods similar to those used in shipbuilding, and towed to the desired position at sea, typically over an oil and / or gas field in the ground below this position at sea.

[0037] Anchor lines 16a, 16b, 16c and 16d, which are attached to anchors in the seabed (not shown), anchor the floating installation 10 in position. Anchor ropes will generally be referred to as anchor ropes 16, and similar elements described herein will be identified by a single reference numeral and distinguished from each other by a letter suffix.

[0038] In a typical application of the floating unit 10, crude oil is extracted from the ground below the floating unit 10, transported, temporarily stored in the hull 12, and unloaded onto a tanker T for transportation to onshore facilities. Tanker T is temporarily moored to floating installation 10 for the duration of the unloading operation with mooring line 18. A hose 20 extends between hull 12 and tanker T for pumping crude oil and / or other fluid from floating installation 10 to tanker T.

[0039] FIG. 3 is a side view of the floating installation 10, FIG. 4 is a top plan view of the floating installation, each of these views is enlarged and shows more detail than the corresponding FIGS. 2 and 1, respectively. The hull 12 of the floating installation 10 has a circular upper deck surface 12a, an upper cylindrical section 12b extending downwardly from the upper deck surface 12a, an upper conical section 12c extending downwardly from the upper cylindrical section 12b and tapering inwardly, a cylindrical tapered section 12d extending downwardly from the upper a tapered section 12c, a lower tapered section 12e extending downwardly from the tapered section 12 and widening outwardly, and a lower cylindrical section 12f extending downwardly from the lower tapered section 12e. The lower conical section 12e is described herein as having the shape of an inverted cone or having an inverted conical shape, in contrast to the upper conical section 12c, which is described herein as having a regular conical shape. The floating installation 10 preferably floats so that the surface of the water intersects the regular upper conical section 12c, which is referred to herein as a waterline that is in a regular conical shape.

[0040] The floating installation 10 is preferably loaded and / or ballasted to maintain the waterline at the bottom of the regular upper conical section 12c. When the floating drilling rig 10 is installed and floating correctly, the cross-section of the hull 12 in any horizontal plane is preferably circular.

[0041] Hull 12 may be designed and sized to meet specific operational requirements and Maritime Research Institute (Marin, the Netherlands) may request design optimization services to meet design requirements for specific application.

[0042] In this embodiment, the upper cylindrical section 12b has approximately the same height as the tapered section 12d, while the height of the lower cylindrical section 12f is 3 or 4 times the height of the upper cylindrical section 12b. The lower cylindrical section 12f has a larger diameter than the upper cylindrical section 12. The upper tapered section 12c has a greater height than the lower tapered section 12e.

[0043] FIG. 5 and 6 are side views showing alternative housing designs.

[0044] FIG. 5 shows a hull 12h having a circular upper deck surface 12i that is substantially identical to an upper deck surface 12a at the top of an upper conical section 12j that tapers inward as the height decreases.

[0045] The cylindrical tapered section 12k is attached to the lower end of the upper tapered section 12j and extends downwardly from the upper tapered section 12j. The lower tapered section 12m is attached to the lower end of the tapered section 12k and extends downwardly from the tapered section 12k, expanding outwardly. The lower cylindrical section 12n is attached to the lower end of the lower tapered section 12m and extends downwardly from the lower tapered section 12m. The significant difference between the body 12h and the body 12 is that the body 12h does not have an upper cylindrical portion corresponding to the upper cylindrical portion 12b in the body 12. Otherwise, the upper conical section 12j corresponds to the upper conical section 12c, the tapered section 12k corresponds to the tapered section 12d , the lower tapered section 12m corresponds to the lower tapered section 12c, and the lower cylindrical section 12n corresponds to the lower cylindrical section 12f.

[0046] Both the lower cylindrical section 12n and the lower cylindrical section 12f have a circular lower deck (not shown) similar to the circular upper deck 12a except for a central portion 14 that extends downwardly from the circular lower deck.

[0047] FIG. 6 is a side view of hull 12p that has an upper deck 12q that looks like an upper deck 12a. The upper cylindrical section 12r extends downwardly from the upper deck 12q and corresponds to the upper cylindrical section 12b.

[0048] The upper conical section 12s is attached to the upper cylindrical section 12r and extends downwardly tapering inward. The upper tapered section 12s corresponds to the upper tapered section 12c in FIG. 1. The housing 12p in FIG. 6 does not have a tapered section that corresponds to the cylindrical tapered section 12d in FIG. 3.

[0049] Instead, the upper end of the lower tapered section 12t is connected to the lower end of the upper tapered section 12s, and the lower tapered section 12t extends downwardly outwardly. The lower conical section 12t in FIG. 6 corresponds to the lower conical section 12e in FIG. 3.

[0050] The lower cylindrical section 12u is attached at an upper end, for example by welding, to the lower end of the lower tapered section 12t and extends downwardly substantially matching the size and configuration of the lower cylindrical section 12f in FIG. 3. A bottom plate 12v (not shown) encloses the lower end of the lower cylindrical section 12u and the lower end of the housing 12 in FIG. 3 and housing 12h in FIG. 5 is also surrounded by a bottom plate, and each of the bottom plates can be adapted to receive a center column corresponding to the center column 14 in FIG. 3.

[0051] FIG. 7-11 show alternatives for the center column. FIG. 7 is a side view of a floating installation 10, partially cut away showing the central column 22 of the present invention. The floating installation 10 has an upper deck surface 20a, which has an opening 20b through which the center column 22 can pass. In this embodiment, the center column 22 can be retracted and the upper end 22a of the center column 22 can be raised above the upper deck surface. If the center column 22 is fully retracted, the floating installation 10 can be moved in shallower waters than if the center column 14 was fully extended. Haun, US Pat. No. 6,761,508, provides other details relating to this and other aspects of the present invention, and this patent is incorporated herein by reference in its entirety.

[0052] FIG. 7 shows a partially retracted central column 22, and the central column 22 can be extended to a depth where its upper end 22a is located in the lower cylindrical portion 20c of the floating installation 10. FIG. 8 is a cross-sectional view of the central column 22 taken along line 8-8 in FIG. 7 and FIG. 8 is a top view of a mass manifold 24 located at the lower end of the central column 22. The mass manifold 24, shown in this embodiment, having a hexagonal shape in top view, is suspended in the water to stabilize the floating installation 10 when it floats in and is acted upon. wind, waves, currents and other forces. The center column 22 is shown in FIG. 8 as having a hexagonal section, but the shape of the section is chosen by the designer.

[0053] FIG. 9 is a side view of the floating installation 10 of FIG. 7 with a partial cutaway showing the center column 26 of the present invention. This center column 26 is shorter than the center column 22 in FIG. 7. The upper end 26a of the central column 26 can be moved up and down in the opening 20b in the floating installation 10, and with such a central column 26 the floating installation 10 can be operated when the central column 26 protrudes below the bottom of the floating installation 10 by a couple of meters or several meters. ...

[0054] A mass manifold 28, which can be filled with water to stabilize the floating installation 10, is secured to the lower end 26b of the central column 26.

[0055] FIG. 10 is a cross-sectional view of the central column 26 taken along line 10-10 in FIG. nine.

[0056] In this embodiment, the central column 26 has a square section and the mass manifold 28 has an octagonal shape in a plan view.

[0057] In an alternative embodiment of the center column of FIG. 9, in section along line 10-10, the central column CC and mass manifold MT are shown in plan view in FIG. 11. In this embodiment, the central column CC has a triangular cross section and the MT stock has a circular cross section.

[0058] Returning to FIG. 3, the floating unit hull 12 has a cavity or recess 12x, shown in dashed lines, which is the center opening in the lower cylindrical section 12f of the floating unit 12f. The upper end 14a of the center column 14 projects substantially to the full depth of the recess 12x.

[0059] In the embodiment shown in FIG. 3, the center column 14 effectively hangs from the bottom of the lower cylindrical section 12f, essentially like a pillar buried in a pit, but such that the center column 14 extends down into the water over which the floating hull 12 floats. A water storage mass manifold 24 for housing stabilization is attached to the lower end of the center column 14.

[0060] Different versions of the center column have been described above, however, the center column is optional and can be completely eliminated or replaced by another structure that protrudes from the bottom of the floating installation 10 and helps stabilize the installation.

[0061] One application of the floating installation 10 shown in FIG. 3 is the production and storage of hydrocarbons such as crude oil and natural gas, as well as associated fluids, minerals and other resources that can be extracted from underground or from water. As shown in FIG. 3, production risers P1, P2 and P3 are pipes through which, for example, crude oil from subterranean formations can flow into a floating unit 10, which has a substantial storage capacity in tanks within hull 12.

[0062] FIG. 3, the production risers P1, P2 and P3 are shown to be located outside the hull 12 and fluid flows into the hull 12 through openings in the upper deck surface 12a. There is an alternative design for the floating installation 10 shown in FIG. 7 and 9, where production risers can be positioned in an opening 20b that creates an open through passage from the bottom of the floating installation 10 to the top of the floating installation 10. FIG. 7 and 9, the production risers are not shown, but they may be located on the outer surface of the housing or within the opening 20b. The top end of the production riser may terminate in a desired reservoir within the body to allow fluid to flow directly into the desired reservoir within the body.

[0063] The floating installation 10 of FIG. 7 and 9 can also be used to drill wells for exploration or production of resources, in particular hydrocarbons such as crude oil and natural gas, making the vessel a floating rig for drilling, production, storage and offloading.

[0064] For such an application, the bulk reservoir MT, 24 or 28 will have a top surface to bottom center hole through which the drill string can pass, which is a design that can be used to place production risers in hole 20b in a floating installation. 10. On the upper deck of the floating drilling rig, there is an oil rig (not shown) for manipulating, running, rotating and lifting the drill pipes and the assembled drill string that extends down from the rig, through the opening 20b in the floating drilling rig 10, through the interior the central column 14, through a central opening (not shown) in the mass manifold 24, through the water and into the seabed.

[0065] Upon successful completion of drilling, production risers and a resource, such as crude oil and / or natural gas, can be set up to receive and store in reservoirs located in a floating installation. US Published Patent Application No. 2009/0126616, in which Srinivasan is identified as the sole inventor, describes the design of hull tanks for a floating oil and ballast water storage rig, and this application is incorporated herein by reference. In one embodiment of the present invention, heavy ballast such as mud and lignite may also be used, preferably in external ballast tanks. The preferred drilling fluid is 1 part brown iron ore and 3 parts water, but permanent ballast such as concrete can also be used. Concrete with heavy aggregates such as lignite, barite, limonite, magnetic iron ore, steel cuttings and shot can be used, however, a high density slurry material is preferred. Thus, aspects of the present invention have been described related to drilling, production and storage on a floating drilling rig, and to unloading a ship, which leaves the function of unloading from a floating rig.

[0066] Turning to the floating installation unloading function of the present invention, FIG. 1 and 2 show a transport tanker T, moored to the floating installation 10 with a mooring line 18, which is a line or a rope, and from the floating drilling rig 10 to the tanker T a hose 20 is drawn. The floating installation 10 is anchored on the seabed through anchor lines 16a, 16b, 16c and 16d, and the position and orientation of the tanker T is determined by the direction and strength of the wind, the effect of waves, and the strength and direction of the current.

[0067] Therefore, the tanker T is feathered relative to the floating rig 10 because its bow is moored to the floating drilling rig 10 and the stern moves in accordance with the balance of forces. When the forces of wind, waves and currents change, the tanker T can move to the position shown by dashed line A or to the position shown by dashed line B. To keep the tanker T at a minimum safe distance from the floating drilling rig 10 so that the mooring line 18 remains taut, tugs or a temporary anchoring system may be used if the total forces that cause tanker T to move towards and not away from the floating installation change.

[0068] If the forces of wind, waves, currents (and any others) remain calm and constant, the tanker T will move to a position in which all forces acting on it will be balanced and the tanker T will remain in this position. However, this usually does not happen under natural conditions. In particular, the direction, speed and strength of the wind change from time to time, and any change in the forces acting on the tanker T causes the tanker T to move to a different position, in which the various forces will again be balanced. Consequently, the tanker T moves relative to the floating installation 10 when the forces acting on the tanker T change, such as the forces of wind, waves and currents.

[0069] FIG. 12-14 in conjunction with FIGS. 1 and 2 illustrate a movable line connection 40 on a floating rig 10 of the present invention, which helps to accommodate the movements of a transport tanker relative to the floating installation.

[0070] FIG. 12 is a partial sectional top view of the mooring line movable joint 40. The movable connection 40 of the mooring line comprises, in one embodiment, an almost completely closed tubular channel 42 having a rectangular cross section and a longitudinal slot in the side wall of the housing 12b; a set of posts, including posts 44a and 44b, which connect tubular conduit 42 horizontally to the outer top wall 12w of housing 12 in FIG. 1-4; a cart 46 movably inserted into the tubular channel 42; a bogie bracket 48 attached to the bogie 48 and providing a connection point; and a plate 50 pivotally attached to the bogie bracket 48 through the plate bracket 52.

[0071] The plate 50 has a substantially triangular shape, and a plate bracket 52 is attached to the apex of the triangle with a pin 54 passing through the hole in the plate bracket 52. The plate 50 has an opening 50a adjacent to the other apex of the triangle and an opening 50b adjacent to the last apex of the triangle. A mooring line 18 terminating in two connection points 18a and 18b that are connected to the plate 50 passing through holes 50a and 50b, respectively. Alternatively, the two ends 18a and 18b, plate 50 and / or shackle 52 may be omitted, and the mooring line 18 can be connected directly to the shackle 48, and there are other options for connecting the mooring line 18 to the bogie 46.

[0072] FIG. 13 is a side view of a movable connection 40 with a mooring line, partly in section along line 13-13 in FIG. 12. A side view of tubular channel 42 is shown in cross-section. The wall 42b of the tubular channel in which the slot 42a is formed is a relatively high vertical wall, and the outer surface of the opposite inner wall 42c is of equal height.

[0073] The posts 44 are attached, for example by welding, to the outer surface of the inner wall 42c. A pair of opposite, relatively short horizontal walls 42d and 42e extend between the vertical walls 42b and 42c to completely enclose the tubular channel 42, except that the vertical wall has a horizontal longitudinal slot that extends almost the entire length of the tubular channel 42.

[0074] FIG. 14 is a side view with tubular channel 42 in partial section to show a side view of carriage 46. Carriage 46 comprises a base plate 46a which has four rectangular openings 46b, 46c, 46d, 46e for receiving four wheels 46f, 46g, 46h and 46i, respectively, which are mounted on four pivots 46j, 46k, 46m and 46n, respectively, which are attached via posts to the base plate 46a.

[0075] Tanker T is moored to the floating installation of FIG. 1-4 by means of a mooring line 18, which is attached to the movable carriage 46 through plate 50 and brackets 48 and 52. When the tanker T is exposed to wind, waves, currents and / or other forces, the tanker T can move in an arc around the floating installation 10 with a radius determined by the length of the mooring line 18, since the bogie 46 can roll freely in a horizontal plane within the tubular channel 42. As best seen in FIG. 4, the tubular channel 42 extends in an arc of approx. 90 degrees around the hull 12 of the floating installation 10. The tubular channel 42 has opposite ends 42f and 42g closed to provide an abutment for the cart. The tubular channel 42 has a radius of curvature that matches the radius of curvature of the outer wall 12w of the housing 12, since the struts 44a, 44b, 44c, 44d are of the same length. The carriage 46 is free to roll back and forth in the closed tubular channel 42 between the ends 24f and 42g of this tubular channel 42. The posts 44a, 44b, 44c, 44d keep the tubular channel away from the outer wall 12w of the housing 12, and the hose 20 and anchor rope 16c pass through the space defined between the outer wall 12w and the inner wall 42c of the tubular channel 42.

[0076] Typically, the forces of wind, waves and currents position the tanker T in a position relative to the floating installation 10, hereinafter referred to as the leeward position relative to the floating installation 10. The mooring line 18 is pulled when the wind, waves and current apply force to the tanker, which is trying to deflect the tanker T from the leeward side of the stationary floating drilling rig 10. The cart 46 is stopped in the tubular channel 42 due to the balance of forces, which counteracts the movement tendency of the cart 46.

[0077] When the wind direction changes, the tanker T can move relative to the floating installation 10, and when the tanker T moves, the cart 46 rolls inside the tubular channel 43 and the wheels 46f and 46g are pressed against the inner surface of the wall of the tubular channel 42. When the wind continues to blow in this new in a fixed direction, the carriage 46 stops in the tubular channel 42 where the forces causing the carriage 46 to roll will be neutralized.

[0078] One or more tugs may be used to prevent tanker T from getting too close to the offshore drilling rig 10 or twisting around the floating drilling rig 10, for example when there is a significant change in wind direction.

[0079] For flexibility in adapting to the direction of the wind, the floating unit 10 preferably has a second movable mooring line connection 60 opposite the line connection 40. Tanker T may moor to either movable joint 40 or movable joint 60, whichever is better for locating tanker T on the leeward side of floating installation 10.

[0080] The mooring cable joint 60 is substantially identical in design to the mobile joint 40 and has its own slotted tubular bogie that has a bracket protruding through the slot in the tubular channel. Each mooring line movable 40 and 60 is believed to be able to adapt to the movement of the tanker T within an arc of approx. 270 degrees, so a high degree of flexibility is achieved, both in a single unloading operation (due to the movement of the bogie in one of the movable connections with the mooring cable) and during the transition from one unloading operation to another (due to the ability to choose between opposite movable joints with the mooring cable).

[0081] The effects of wind, waves and currents can exert a great force on the tanker T, in particular during a storm or squall, which in turn exerts a great force on the cart 46, which in turn exerts a great force on the cut wall (Fig. 13) of the tubular channel 42. The slot 42a weakens the wall and if a sufficient force is applied, the wall may bend, possibly opening the slot 42a wide enough for the carriage 46 to be pulled out of the tubular channel. The tubular channel 42 needs to be designed and constructed to withstand the expected forces. Internal reinforcing corners can be formed in the tubular channel 42 and spherical wheels can be used. The tubular channel is only one means for creating a flexible connection with the mooring line. Instead of a tubular channel, an I-beam can be used as a guide, having opposite flanges attached to the central wall, with a cart or other rolling or sliding device attached to and moving along the outer flange. The movable mooring cable connection is similar to a gantry crane, except that the gantry crane is adapted to resist vertical forces and the mooring cable movable connection must be adapted to resist the horizontal force applied by the mooring line 18. The following patents are incorporated herein by reference in that part , which describe how to design and manufacture flexible joints.

US Patent Nos. 5,595,121, "Amusement Ride and Self-Propelled Cabin Therefor," issued by Elliott et al .; No. 6,857,373, Variable Curvature Rail Mounted Ride issued by Checketts et al .; No. 3,941,060, "Monorail System", issued by Morsbach; No. 4,984,523, "Self-propelled carriage and support rail structure" issued by Dehne et al. and No. 7,004,076 "Closed Rail Material Handling System" issued by Traubnkraut et al., all of which are incorporated herein in full and for all purposes. As described here and in these patents, incorporated by reference, to resist a horizontal force, such as that acts on the floating drilling rig 10 via the mooring line 18 from the tanker T, many lateral movement means can be used, for example, by means of a carriage 46. moving forward and backward, being captured in the tubular channel 42.

[0082] Wind, waves and current are applied to a drilling, production, storage and shipping vessel or a floating installation of the present invention, various forces that result in vertical up and down movements in addition to other movements. A production riser is a pipe extending from a wellhead on the seabed to a drilling, production, storage and shipping vessel or to a floating installation, which is referred to herein as a floating installation. The production riser can be fixed to the seabed and attached to the floating installation. The heaving of a floating installation can create alternating tensile and compressive forces on the production riser, which can cause fatigue and fracture. One aspect of the present invention is to minimize the heave of the floating installation.

[0083] FIG. 15 is a side view of a floating drilling rig 80 of the present invention. The offshore drilling rig 80 has a hull 82 and a circular upper deck 82a, the cross-section of the hull 82 in any horizontal plane when the hull 82 is afloat and at rest is preferably circular. The upper cylindrical section 82b extends downwardly from the circular upper deck 82a, and the upper conical section 82c extends downwardly from the upper cylindrical section 82b and tapers inwardly. The vessel 80 may have a cylindrical tapered section 82d extending downwardly from the upper conical section 82c, which would make it more like the floating drilling rig 10 of FIG. 3, but it does not have it. In the locally tapered section, a lower tapered section 82e extends downwardly from the upper tapered section 82c, expanding outwardly. From the lower tapered section 82e downwardly extends the lower cylindrical section 82f. The body has a bottom surface of 82g. The lower tapered section 82e is described herein as having an inverted cone shape, as opposed to the upper tapered section 82c, which is described herein as having a regular tapered shape.

[0084] The FOA 80 is shown floating such that when loaded and / or ballasted, the water surface crosses the upper cylindrical section 82b. In this embodiment, the upper tapered section 82c has a substantially greater vertical height than the lower tapered section 82e, and the upper cylindrical section 82b has a slightly higher vertical height than the lower cylindrical section 82f.

[0085] A set of stabilizers 84 is attached to the bottom and outer portions of the bottom cylindrical section 82f to reduce heave and other stabilization of the floating unit 80, as shown in FIG. 15. In FIG. 16 is a cross-sectional view of floating installation 80 taken along line 16-16 in FIG. 15. As shown in FIG. 16, stabilizers 84 comprise four sections 84a, 84b, 84c, and 84d, spaced apart from each other by spaces 86a, 86b, 86c, and 86d, collectively referred to as "spaces 86"). Gaps 86 are spaces between stabilizer sections 84a, 84b, 84c, and 84d that provide space for service risers and anchor lines to be routed on the outer surface of housing 82 without contacting stabilizers 84. Anchor lines 88a, 88b, 88c, and 88d in FIG. 15 b 16 pass through gaps 86a, 86b, 86c and 86d, respectively, and anchors the floating unit 80 to the seabed. Production risers 90a, 90b, 90c, 90d, 90f, 90g, 90h, 90i, 90j, 90k, and 90m are skipped at intervals 86 and feed a resource such as crude oil, natural gas and / or leached mineral from the earth under the seabed to reservoirs in the floating drilling rig 10. The center section 92 extends from the bottom 82g of the hull 82.

[0086] FIG. 17 is a vertical sectional view of the floating installation 10 of FIG. 15, illustrating in a simplified view the group of reservoirs in the housing 82 in cross section. The produced resource flowing through the production risers 90 is stored in the inner annular reservoir 82h. The center vertical tank 82i can be used as a separator, for example, for separating oil, water, and / or gas, or as a storage facility. An outer annular reservoir 82j having an outer wall conformal to an upper conical section 82 and a lower conical section 82e can be used to store ballast water and / or to store a mined resource. In this embodiment, the outer annular tank 82k is a cavity having an irregular trapezoidal cross-section defined at the top by a lower conical section 82e and a lower cylindrical section 82f, with a vertical inner side and a horizontal bottom wall of the bottom, although the tank 82k can be used for ballast and / or storage. A torus-shaped reservoir 82m in the shape of a gasket or donut with a square or rectangular cross-section is located in the lowermost and outermost portion of the housing 82. The reservoir 82m may be used to store a mined resource and / or ballast water. In one embodiment, reservoir 82m holds the brown iron ore mud, and in another embodiment, reservoir 82m contains approx. 1 part brown iron ore n approx. 3 parts water.

[0087] Stabilizers 84 for reducing heaving in cross section are shown in FIG. 17. Each section of stabilizers 84 in vertical section has the shape of a right-angled triangle, where an angle of 90 ° is adjacent to the lower outer side wall of the lower cylindrical section 82f of the housing 82 so that the lower side 84e of the triangle is in the same plane with the lower surface 82g of the housing 82, and the hypotenuse 84f of the triangle extends from the distal end 84g of the lower side 84e of the triangle up and inward to connect to the outer sidewall of the lower cylindrical section 82f at a point that is only slightly higher than the lower edge of the outer sidewall of the lower cylindrical section 82f, as can be seen in FIG. 17. Sizing stabilizers 84 for optimum performance may require some experimentation. The starting point is the lower side 84e extending radially outward at a distance equal to approximately half the vertical height of the lower cylindrical section 82f, and the hypotenuse 84f connects to the lower cylindrical section 82f about one quarter of the height of the lower cylindrical section 82f from the bottom 82 of the housing 82. Another starting point is that if the radius of the lower cylindrical section 82f is equal to R, then the underside 84e of the stabilizer 84 extends radially outward by an additional 0.05-0.20 R, preferably 0.10-0.15 R and more preferably approx. 0.125 R.

[0088] FIG. 18 is a cross-sectional view of the hull 82 of a floating rig and / or floating drilling rig 80 taken along line 18-18 in FIG. 17. Radial support members 94a, 94b, 94c, and 94d provide structural support for the inner annular reservoir 83h, which is shown as having four compartments separated by radial support members 94. Radial support members 96a, 96b, 96c, 96d, 96e, 96f, 96g , 96h, 96i, 96j, 96k and 96l provide structural support for the 82j outer ring tank and 82k and 82m tanks. The outer annular reservoir 82j and the reservoirs 82k and 82m are subdivided by radial support members 96.

[0089] A floating drilling rig of the present invention, such as rig 10, 20, or 80, may be manufactured onshore, preferably in a shipyard, using known ship building materials and techniques. The floating installation is preferably circular in plan view, but construction costs can be lower with a polygonal shape so that flat, planar metal sheets can be used instead of bending such sheets to the required curvature. A floating drilling rig hull having a polygonal faceted shape such as that described in US Pat. No. 6,761,508 to Haun and incorporated herein by reference is within the scope of the present invention. If a polygonal shape is chosen and if a flexible connection to the mooring line is required, the tubular channel or rail can be designed with an appropriate radius of curvature and positioned with appropriate posts so as to create a movable connection with the mooring line. If the floating drilling rig is constructed in accordance with the description of the rig shown in FIG. 1-4, it may be preferable to move the floating drilling rig to its final destination without a center string, and to set the center string at sea after the floating drilling rig has been brought to site and anchored. For the embodiment shown in FIG. 7 and 9, it may be preferable to install the center string onshore, retract the center string to its highest position, and tow the floating drilling rig to its final destination with the center string fully retracted. Once the floating rig is in position, the center string can be extended to the required depth and the mass manifold at the lower end of the center string can be filled to stabilize the hull from wind, waves and currents.

[0090] Once the floating installation is anchored and completed, it can be used to drill exploration or production wells if a rig is installed and can be used to extract and store resources or products. To unload the fluid cargo stored on the floating drilling rig, a transport tanker is brought to it.

[0091] As shown in FIG. 1-4, toe ends may be stored on drums 70a and / or 70b. The end of the dropping end can be fired by a pyrotechnic device from the floating drilling rig 10 to the tanker T and captured by the crew of the tanker T. The other end of the dropping end can be attached to the end 18c of the mooring cable 18 intended for attachment to the tanker (Fig. 2) and the crew of the tanker can retract the end 18c the mooring line 18 to the tanker T, where it can be secured to the corresponding structure of the tanker T. The tanker personnel can then shoot one end of the toe end at the floating drilling rig, the crew of which attaches this end of the toe end to the tanker end 20a of the hose 20 (FIG. . 2). The crew of the tanker then pulls the tanker end of the hose 20 onto the tanker and attaches it to a suitable connection on the tanker to create fluid communication between the offshore drilling rig and the tanker. Typically, the cargo is unloaded from the offshore drilling rig storage facility to the tanker, but the reverse operation can also be carried out when the cargo from the tanker is unloaded to the floating drilling rig for storage.

[0092] Because the hose can be large, for example 20 inches (508 mm) in diameter, the connection and unloading operation can take a long time, typically many hours, but less than a day. At this time, tanker T typically feathered downwind relative to the floating drilling rig, and moves around it when the wind changes direction, which is compensated by the floating drilling platform using a movable connection with a mooring line, which allows significant movement of the tanker relative to the floating drilling rig, possibly in an arc of 270 degrees without interrupting the unloading operation. In the event of a severe storm or squall, the unloading operation can be stopped and, if necessary, the tanker can be moored from the floating drilling rig by releasing the mooring line 18. After a typical and trouble-free unloading operation, the end of the hose can be detached from the tanker and the hose reel 20b can be used to wind the hose. 20 back to be placed on a drum 20b on a floating installation. The offshore rig has a second hose and reel 72 for use in conjunction with a second movable mooring line connection 60 on the opposite side of the offshore drilling rig 10. The tanker end 18c of the mooring line 18 can then be disconnected, allowing the T to move away and transport the resulting cargo to the onshore port. an object. A drop end can be used to pull the tanker end 18c of the mooring line 18 back onto the floating unit, and the line 18 can either float in the water adjacent to the floating unit, or the tanker end 18c of the line can be secured to a drum (not shown) on the deck 12a of the floating unit. while the double end 18a, 18b (FIG. 12) of the mooring line 18 remains attached to the movable line connection 40.

[0093] The present invention relates to a method for offshore production, storage and offloading of oil, which firstly comprises the step of receiving hydrocarbons from at least one of a floating installation, production risers or a wellhead on the seabed into a uniquely shaped floating hull.

[0094] In the next step, the produced hydrocarbons are processed to form a hydrocarbon product in the floating hull.

[0095] The method continues with the step of storing the hydrocarbon product in a uniquely shaped floating hull, wherein the floating hull is circular in plan view, and the floating hull has a bottom surface, an upper deck surface, at least three connected sections connected in series and located symmetrically about a vertical axis, with the connected sections extending downwardly from the upper deck surface to the lower surface; the at least three connected sections are composed of an upper cylindrical section, a lower conical section, a cylindrical constricted section, and a set of stabilizers attached to the body and configured to correct the hydrodynamic characteristics through linear and quadratic damping.

[0096] Both linear damping and quadratic damping are empirical approaches to quantifying the hydrodynamic behavior of a floating body in an incompressible homogeneous Newtonian fluid. In the context of the various options, both the stabilizer and the offshore rig hull are configured to correct the hydrodynamic behavior through linear and quadratic damping, which entails numerical evaluation and experimentation by applying numerical methods (linear and non-linear) to accurately estimate viscous damping.

[0097] Compared to prior art circular floating units lacking stabilizers, a hull with a set of stabilizers described herein may have improved hydrodynamic characteristics (related to damping) of the floating unit. The shapes and / or sizes of stabilizers can also have a positive effect, thereby improving the hydrodynamic performance (associated with damping). However, stabilizers with different shapes and / or sizes can react differently in an aqueous environment, where flow can affect flow and pressure, which can be quite different depending on the shape and / or size of the stabilizer.

[0098] The method continues with the step of unloading the stored hydrocarbon product onto a tanker and / or into a pipeline.

[0099] In various embodiments, the method provides for the floating hull to be anchored to the seabed.

[0100] In various embodiments of the method, the floating hull has an upper truncated-conical section connected to a cylindrical tapered section and an upper cylindrical section extending downward from the main deck, and the upper truncated-conical section is located under the upper cylindrical section and is held above the waterline during transport draft of the floating installation, and partially below the waterline at the working draft of the floating installation for drilling, production, storage and unloading, while the upper truncated-conical section has a gradually decreasing diameter from the diameter of the upper cylindrical section.

[0101] In various embodiments, the method comprises installing a side wall extending from the bottom surface of the housing

[0102] In various embodiments, the method comprises using a plurality of stabilizer sections that are spaced apart from each other by clearances that allow for production risers and anchor ropes to extend outside the hull without contacting the stabilizers.

[0103] In various embodiments, the method comprises the step of using a stabilizer from a set of stabilizers to reduce heave, which has a vertical section in the shape of a right-angled triangle.

[0104] In various embodiments, the method comprises the step of using a bottom edge stabilizer in which the triangular shape lies in the same plane with the bottom surface of the body.

[0105] In various embodiments, the method comprises a stabilizer, wherein the triangular-shaped hypotenuse of the stabilizer extends from the distal end of the triangular-shaped underside upward and inward for attachment to the outer side wall of the lower cylindrical section at a point that is only slightly above the lower edge of the outer side wall of the housing ...

[0106] In various embodiments, the method comprises the step of using a uniquely shaped casing with a central column, wherein the central column is square in cross section and the mass manifold is octagonal.

[0107] In various embodiments, the method comprises the step of using at least three connected sections that are connected in series and arranged symmetrically about a vertical axis, and the connected sections extend downward to a lower surface.

[0108] The specific structural and functional details disclosed herein are not to be construed as limiting, they are merely the basis for the claims and a representative basis for teaching specialists the various ways of using the present invention.

[0109] Although the present invention has been described in terms of specific options, it should be understood that within the framework of the appended claims, these options can be implemented in ways other than described.

Claims (18)

1. A method of operating a floating installation for offshore production, storage and unloading of oil, containing the stages at which: a. accept hydrocarbons into the floating hull of a floating installation for offshore production, storage and unloading of oil; b. process the received hydrocarbons, forming a hydrocarbon product in the floating hull; c. store the hydrocarbon product in a floating hull, while the floating hull is circular in top view and contains: i. bottom surface; ii. upper deck surface; and iii. at least three connected sections, connected in series and arranged symmetrically about a vertical axis, with the connected sections extending downwardly from the upper deck surface to the lower surface; moreover, at least three connected sections consist of: an upper cylindrical part; lower conical part and cylindrical tapered section; and iv. a set of stabilizers attached to the floating hull and made with the ability to adjust the hydrodynamic characteristics through linear and quadratic damping; and d. unload the stored hydrocarbon product into a tanker and / or pipeline. 2. The method of claim 1, wherein the floating hull is anchored to the seabed. 3. The method according to claim 1, wherein the floating hull has an upper truncated-conical section connected to a cylindrical tapered section and an upper cylindrical section extending downward from the main deck, wherein the upper truncated-conical section is located below the upper cylindrical section and is held above waterline for the transport draft and partly under the waterline for the working draft of a floating installation for drilling, production, storage and unloading of oil; while the upper truncated-conical section has a gradually decreasing diameter from the diameter of the upper cylindrical section. 4. The method according to claim 1, comprising the step of using a plurality of stabilizer sections separated from each other by clearances that provide space for the production risers and anchor ropes to pass outside the floating hull without contacting the set of stabilizers. 5. The method according to claim 1, wherein the stabilizer from the set of stabilizers for heaving reduction has the shape of a right-angled triangle in vertical section. 6. The method according to p. 1, in which the stabilizer from the set of triangular shaped stabilizers has a lower side; moreover, the lower side of the triangular shape lies in the same plane with the lower surface of the floating hull. 7. A method according to claim 6, wherein the triangular-shaped hypotenuse of the stabilizer set of stabilizers extends from the distal end of the triangular-shaped lower side upward and inward to attach to the outer side wall of the lower cylindrical section at a point that is only slightly above the lower edge of the outer side wall of the floating housing. 8. The method according to claim 1, wherein the floating hull comprises a central square column and an octagonal mass collector. 9. A method according to claim 1, wherein at least three connected sections are connected in series and are symmetrically located about a vertical axis, with at least three connected sections extending downwardly from the upper deck surface to the lower surface. 10. The method of claim 1, wherein the step of receiving the hydrocarbons includes the step of receiving the hydrocarbons from a wellhead on the seabed or from a production riser extending from the wellhead on the seabed.

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