KR102528170B1 - Offshore Floating Oil Production, Storage and Unloading Methods Using Flotation Structures - Google Patents

Abstract

An offshore floating petroleum production, storage and offloading method includes receiving hydrocarbons from at least one of a FPSO, a production riser, or a subsea wellhead by means of a floating hull; processing the received hydrocarbons to form hydrocarbon products in the floating hull; storing hydrocarbon products in floating hulls; and unloading the stored hydrocarbon product. The floating hull comprises a circle in plan view of the hull, and the floating hull comprises a bottom surface, a top deck surface, connected in series and symmetrical about a vertical axis, and extending from the top deck surface downward toward the bottom surface. It has at least three connected parts. The at least three connected parts include an upper cylindrical part, a lower conical part, a cylindrical neck part, and a set of fins fixed to the hull and configured to provide hydrodynamic performance through linear and quadratic damping.

Description

Offshore Floating Oil Production, Storage and Unloading Methods Using Flotation Structures

This embodiment relates generally to a method for operating a floating platform, storage and offloading (FPSO) vessel.

The present invention relates to a method for operating a floating production, storage and offloading (FPSO) vessel and, in particular, to a hull design and offloading system for a floating drilling, production, storage and offloading (FDPSO) vessel.

The present invention satisfies these needs.

Various embodiments provide a method for offshore floating oil production, storage and offloading, the method comprising: (a) at least one of a FPSO, a production riser, or a subsea wellhead by means of a floating hull; accepting hydrocarbons from; (b) processing the received hydrocarbons to form hydrocarbon products in the floating hull; (c) storing a hydrocarbon product in a floating hull, wherein the floating hull comprises a circular shape when viewed in plan view of the hull, and the floating hull comprises: (i) a bottom surface; (ii) the top deck surface; (iii) at least three connected parts connected in series and configured symmetrically about a vertical axis, extending downward from the top deck surface towards the bottom surface, and comprising an upper cylindrical portion, a lower conical portion, and a cylindrical neck portion. part time job; and (iv) a set of fins secured to the hull and configured to provide hydrodynamic performance through linear and quadratic damping; and (d) unloading the stored hydrocarbon product onto at least one of a tanker or pipeline.

The detailed description will be better understood with the following accompanying drawings.

1 is a top plan view of an FPSO ship and an oil tanker moored to the FPSO ship according to the present invention.
Figure 2 is a side view of the FPSO vessel of Figure 1;
Figure 3 is an enlarged detailed version of the side view of the FPSO vessel shown in Figure 2;
Figure 4 is an enlarged detailed version of the top plan view of the FPSO vessel shown in Figure 1;
5 is a side view of an alternative embodiment of a hull for an FPSO vessel according to the present invention.
6 is a side view of an alternative embodiment of a hull for an FPSO vessel according to the present invention.
7 is a side view of an alternative embodiment of an FPSO vessel according to the present invention, showing the central column received in a bore through the hull of the FPSO vessel.
Figure 8 is a cross-sectional view of the central column of Figure 7 taken along line 8-8;
9 is a side view of the FPSO vessel of FIG. 7 illustrating an alternative embodiment of a central column, in accordance with the present invention.
Figure 10 is a cross-sectional view of the central column of Figure 9 taken along line 11-11.
11 is an alternative embodiment of a center column and mass trap viewed along line 11-11 of FIG. 9, in accordance with the present invention.
12 is a top plan view of a movable rope connection unit according to the present invention.
Fig. 13 is a side view of the movable tether connection of Fig. 12 taken in partial cross section along line 13-13;
Fig. 14 is a side view of the movable tether connection of Fig. 13 taken in partial cross-section along line 14-14;
15 is a side view of a vessel according to the present invention.
Figure 16 is a cross-sectional view of the vessel of Figure 15 taken along line 16-16, which is shown in cross section.
Figure 17 is a cross-sectional view of the vessel of Figure 15 taken along line 17-17 as shown in cross section.
Figure 18 is a cross-sectional view of the vessel of Figure 15 taken along line 18-18 as shown in cross section.
This embodiment is described in detail below with reference to the enumerated figures.

Before describing the device in detail, it will be understood that the device is not limited to a specific embodiment and can be practiced or carried out in various ways.

The present invention provides a floating platform, storage and offloading (FPSO) vessel having multiple alternative hull designs, multiple alternative center column designs and a movable tether system for offloading, wherein the movable tether system allows an oil tanker to operate on a FPSO vessel. This allows it to be oriented over a wide arc.

The present invention particularly relates to methods for producing, storing, and offloading offshore floating oil.

A first step of the method includes receiving hydrocarbons from at least one of a FPSO, a production riser, or a subsea wellhead by means of a floating hull.

The next step involves processing the received hydrocarbons to form hydrocarbon products in the floating hull.

The method then continues with the storage of the hydrocarbon product in the floating hull, which is characteristically circular in plan view of the hull, the floating hull having a bottom surface, a top deck surface, connected in series and on a vertical axis. at least three connected portions configured symmetrically with respect to each other, the connected portions extending downwardly from the top deck surface toward the bottom surface, the at least three connected portions comprising: an upper cylindrical portion, a lower conical portion, a cylindrical neck portion, and a set of fins secured to the hull and configured to provide hydrodynamic performance through linear and quadratic damping, the invention also continuing with offloading stored hydrocarbon products.

Referring now to the drawings, we can see the distinctive hull.

An FPSO vessel 10 according to the present invention is shown in a plan view in FIG. 1 and in a side view in FIG. 2 .

The FPSO vessel 10 has a hull 12 and a central column 14 is attached to the hull 12 and may extend downward.

The FPSO vessel 10 floats on water W and is used for the production, storage and/or offloading of earth-mined resources, such as hydrocarbons including crude oil and natural gas, and minerals such as may be mined by solution mining. can be used

The FPSO vessel 10 may be assembled onshore using known methods (similar to ship building) and towed to an offshore location, typically above an oil and/or gas field located below the offshore location. will be in

Anchor lines 16a, 16b, 16c, 16d to be fastened to anchors on the seabed (not shown) moor the FPSO vessel 10 at a desired location. An anchor line is generally referred to as an anchor line 16, and elements described herein that are similarly related to each other will share a common identification number and will also be distinguished from each other by a suffix letter.

In a typical application for an FPSO vessel 10, crude oil is produced from the earth below the seabed below the vessel 10, transferred into the hull 12, temporarily stored therein, and transported to an onshore facility by a tanker ( T) is unloaded. The oil tanker T is temporarily moored to the FPSO vessel 10 by means of a hawser 18 during unloading operations. A hose 20 extends between the hull 12 and the tanker T to transfer crude oil and/or other fluids from the FPSO vessel 10 to the tanker T.

3 is a side view of the FPSO vessel 10. FIG. 4 is a top plan view of the FPSO vessel 10, the angle view being larger and more detailed than the corresponding FIGS. 2 and 1. The hull 12 of the FPSO vessel 10 has a circular top deck surface 12a, an upper cylindrical portion 12b extending downwardly from the deck surface 12a, and a downwardly extending upper cylindrical portion 12b an upper conical portion 12c extending downward from the upper conical portion 12c, a cylindrical neck portion 12d extending downward from the upper conical portion 12c, and a lower conical portion extending downward from the neck portion 12d and diverging outwardly. 12e, and a lower cylindrical portion 12f extending downward from the lower conical portion 12e. The lower conical portion 12e is described here as having an inverted conical shape or as having an inverted conical shape opposite to the upper conical portion 12c, where the upper conical portion is described as having a regular conical shape. The FPSO vessel 10 preferably floats such that the surface of the water intersects the top side conical portion 12c, where it is said that the waterline is on a regular cone shape.

The FPSO vessel 10 is preferably loaded and/or ballasting to keep the waterline at the bottom portion of the top conical portion 12c. When the FPSO vessel 10 is properly installed and afloat, the cross-section of the hull 12 through any horizontal plane is preferably circular.

The hull 12 may be designed and sized to meet the requirements of a particular application, and services may be requested from Marin, the Netherlands, to provide design parameters optimized to meet the design requirements for a particular application. .

In this embodiment, the upper cylindrical portion 12b has approximately the same height as the neck portion 12d, and the height of the lower cylindrical portion 12f is about 3 to 4 times greater than the height of the upper cylindrical portion 12b. The lower cylindrical portion 12f has a larger diameter than the upper cylindrical portion 12b. The upper conical portion 12c has a greater height than the lower conical portion 12e.

5 and 6 are side views showing alternative designs for the hull.

Figure 5 shows a hull 12h with a circular top deck surface 12i (essentially the same as top deck surface 12a) at the top of an upper conical portion 12j, the upper conical portion of which extends downwards. is tapered inward.

A cylindrical neck portion 12k is attached to the lower end of the upper conical portion 12j and extends downwardly from the upper conical portion 12j. A lower conical portion 12m is attached to the lower end of the neck portion 12k and extends downward from the neck portion 12k while flared outward. A lower cylindrical portion 12n is attached to the lower end of the lower conical portion 12m and extends downwardly from the lower conical portion 12m. An important difference between hull 12h and hull 12 is that hull 12h does not have an upper cylindrical portion corresponding to upper cylindrical portion 12b in hull 12 . Otherwise, the upper conical portion 12j corresponds to the upper conical portion 12c, the neck portion 12k corresponds to the neck portion 12d, and the lower conical portion 12m corresponds to the lower conical portion 12e. corresponding, and the lower cylindrical portion 12n corresponds to the lower cylindrical portion 12f.

Each of the lower cylindrical portion 12n and lower cylindrical portion 12f has a circular bottom deck (not shown), except that a central portion 14 extends downwardly from the circular bottom deck. Similar to the top deck surface 12a.

Figure 6 is a side view of a hull 12p, which has a top deck 12q similar to a top deck surface 12a. The upper cylindrical portion 12r extends downward from the top deck 12q and corresponds to the upper cylindrical portion 12b.

An upper conical portion 12s is attached to the lower end of the upper cylindrical portion 12r and extends downwardly while tapering inwardly. Upper conical portion 12s corresponds to upper conical portion 12c in FIG. 1 . Hull 12p in FIG. 6 does not have a cylindrical neck corresponding to cylindrical neck 12d in FIG. 3 .

Instead, the upper end of the lower conical portion 12t is connected to the lower end of the upper conical portion 12s, and the lower conical portion 12t flares outward and extends downward. The lower conical portion 12t in FIG. 6 corresponds to the lower conical portion 12e in FIG. 3 .

The lower cylindrical part 12u is attached at the upper end, for example by welding, to the lower end of the lower conical part 12t, extends downward, and essentially corresponds in size and configuration to the lower cylindrical part 12f of FIG. 3 . A bottom plate 12v (not shown) surrounds the lower end of the lower cylindrical portion 12u, and the lower end of the hull 12 in FIG. 3 and the hull 12h in FIG. 5 are similarly surrounded by the bottom plate. , each bottom plate may be adapted to receive a respective center column corresponding to center column 14 in FIG. 3 .

Referring now to FIGS. 7-11 , an alternative embodiment for the central column is shown. 7 is a side view of the FPSO vessel 10 partially broken away to show the central column 22 according to the present invention. The FPSO vessel 10 has a top deck surface 20a with an opening 20b through which a central 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 top deck surface 20a. When the central column 22 is fully retracted, the FPSO vessel 10 can move through shallower water than if the central column 22 were fully extended. U.S. Patent No. 6,761,508 to Haun provides additional detail relating to this and other aspects of the present invention and is hereby incorporated by reference in its entirety.

7 shows the central column 22 partially retracted, the central column 22 may extend to a depth where the upper end 22a is located within the lowermost cylindrical portion 20c of the FPSO vessel 10. . FIG. 8 is a cross-section of the central column 22 taken along line 8-8 in FIG. 7, and FIG. 8 is a plan view of a mass trap 24 positioned at the bottom end 22b of the central column 22. indicates The mass trap 24 (shown in this embodiment as having a hexagonal shape when viewed in plan view) is formed when the FPSO vessel 10 is suspended in water and subjected to wind, waves, currents and other forces. is weighted with water to stabilize it. In FIG. 8 the central column 22 is shown to have a hexagonal cross-section, but this is a design choice.

9 is a side view of the FPSO vessel 10 of FIG. 7 partially broken away to show the central column 26, in accordance with the present invention. The central column 26 is shorter than the central column 22 of FIG. 7 . The upper end 26a of the central column 26 can move up and down in the opening 20b in the FPSO vessel 10, and with the central column 26, the FPSO vessel 10 is of the central column 26. It can be operated with only two or a few meters protruding below the bottom of the FPSO vessel (10).

To stabilize the FPSO vessel 10, a mass trap 28, which can be filled with water, is fixed to the lower end 26b of the central column 26.

FIG. 10 is a cross-section of the central column 26 taken along line 10 - 10 in FIG. 9 .

In this embodiment of the central column, the central column 26 has a square cross-section, and the mass trap 28 has a pentagonal shape when viewed in plan view of FIG. 10 .

In an alternative embodiment of the center column of FIG. 9 viewed along line 10 - 10, the center column CC and mass trap MT are shown in top plan view in FIG. 11 . In this embodiment, the central column (CC) has a triangular shape when viewed in cross section, and the mass trap (MT) has a circular shape when viewed in a top plan view.

Referring to FIG. 3 , the FPSO vessel hull 12 has a cavity or recess 12x indicated by phantom lines, which is a central opening that goes into the bottom portion of the lower cylindrical portion 12f of the FPSO vessel hull 12. am. The upper end 14a of the central column 14 projects into essentially the entire depth of the recess 12x.

In the embodiment shown in FIG. 3, the center column 14 is effectively cantilevered from the bottom of the lower cylindrical section 12f much like a post anchored in a hole, but the center column 14 is the FPSO vessel hull. (12) extends downward into the floating water. A mass trap 17 for containing water weights to stabilize the hull 12 is attached to the lower end 14b of the center column 14.

Although various embodiments of a central keel have been described, the central column is optional and may be eliminated entirely or replaced with other structures that protrude from the bottom of the FPSO vessel and help stabilize the vessel.

One application for the FPSO vessel 10 shown in FIG. 3 is the production and storage of hydrocarbons and related fluids, such as crude oil and natural gas, and minerals and other resources that may be extracted or obtained from Earth and/or water. As shown in FIG. 3, the production risers P1, P2, and P3 are pipes or tubes, for example, through which crude oil can flow from deep inside the earth to the FPSO vessel 10, the floating drilling rig It has significant storage capacity in tanks inside the hull 12.

In FIG. 3 , product risers P1 , P2 , P3 are shown positioned on the outer surface of hull 12 and product will enter hull 12 through openings in top deck surface 12a. will be. An alternative configuration is available for the FPSO vessel 10 shown in FIGS. 7 and 9, produced inside an opening 20b providing an open passage from the bottom of the FPSO vessel 10 to the top of the FPSO vessel 10. Riser can be positioned. The production risers are not shown in Figures 7 and 9, but may be located on the outer surface of the hull or inside the opening 20b. The upper end of the production riser may end at a desired position relative to the hull, so that the product may flow directly into a desired storage tank inside the hull.

The FPSO vessel 10 of FIGS. 7 and 9 can be used to drill into the earth to find or extract resources, particularly hydrocarbons such as crude oil and natural gas, so the vessel can be used for floating drilling, production, storage and offloading (FDPSO). ) becomes a ship.

For this application, the mass tank (MT) 24 or 28 will have a central opening that runs from the top surface to the bottom surface, through which a drill string can pass, which drill string the production riser into a FDPSO ( It is a structural design that can be used to accommodate inside the opening 20b of 10). A derrick crane (not shown) will be provided on the top deck surface 20d of the FPSO vessel 10 for handling, lowering, rotating and raising the drill pipe and assembled drill string, the drill pipe and assembled drill string The string extends downward from the derrick crane and passes through the opening 20b of the FPSO vessel 10, the interior of the central column 22 or 26, the central opening of the mass tank 24 or 28 (not shown) and water. This will lead you to the bottom of the sea.

After drilling is successfully completed, production risers can be installed and resources such as crude oil and/or natural gas can be received and stored in tanks located inside the FPSO vessel. US Patent Application Publication 2009/0126616, of which Srinivasan is the sole inventor, describes the placement of tanks on the hulls of FPSO vessels for the storage of oil and water ballast, and is incorporated herein by reference. In one embodiment of the present invention, a heavy ballast such as a slurry of hematite and water may preferably be used in the outer ballast tank. A slurry is preferred, preferably 1 part hematite and 3 parts water, but a permanent ballast such as concrete may be used. Concrete with heavy aggregates such as hematite, barite, limonite, magnetite, steel punch and steel ball may be used, but preferably a high-density material may be used in slurry form. Thus, while the drilling, production, and storage aspects of the floating drilling, production, storage, and offloading vessel of the present invention have been described, the description of the offloading function of the FDPSO vessel remains.

Returning to the unloading function of the FDPSO vessel of the present invention, FIGS. 1 and 2 show the transport tanker T moored to the FPSO vessel 10 by means of a tether 18 (rope or cable) and a hose 20 is extended from the FPSO ship 10 to the oil tanker T. The FPSO ship 10 is anchored to the seabed through anchor lines 16a, 16b, 16c, and 16d, and the position and orientation of the oil tanker T are affected by wind direction, wind power, wave action and force, and the direction of the current. receive

Accordingly, the oil tanker T is oriented relative to the FPSO vessel 10 because the tanker's bow is moored to the FPSO vessel 10 and the stern is in an alignment determined by the balance of forces. As the forces of wind, waves and currents change, the oil tanker T can move to a position indicated by imaginary line A or a position indicated by imaginary line B. In the case of a change in the net force that causes the tanker T to go toward the FPSO ship 10 rather than away from the FPSO ship 10, a tugboat or temporary anchorage system (neither not shown) may be used to ) at a minimum safe distance from the FPSO vessel 10, so that the tether 18 remains taut.

If wind, wave, tidal forces (and other forces) are held static and constant, the tanker T is oriented to a position where all forces acting on it are in equilibrium and the tanker T is at that position. will be maintained on However, this is generally not the case in natural environments. In particular, the direction and speed or force of the wind changes from time to time, and due to the change in the force acting on the tanker T, the tanker T moves to another position where the various forces balance again. Accordingly, as various forces (eg, forces due to the action of wind, waves, and tidal currents) acting on the oil tanker T change, the oil tanker T moves relative to the FPSO vessel 10 .

Figures 12-14, together with Figures 1 and 2, show a movable tether connection 40 on an FPSO vessel according to the present invention, which connection helps accommodate the movement of the transport tanker relative to the FPSO vessel.

12 shows a plan view of the movable rope connection part 40 in partial cross-section. In one embodiment the movable tether 40 comprises an almost completely enclosed tubular channel 42 having a rectangular cross-section and a longitudinal slot 42a in the side wall 42b; a set of stand-offs 44, including stand-offs 44a, 44b, connecting the tubular channel 42 horizontally to the outer upper wall 12w of the hull 12 of Figs. 1-4; a trolley 46 that is captured and movable inside the tubular channel 42; a trolley shackle 48 attached to the trolley 46 and providing a connection point; and a plate 50 rotatably attached to the trolley shackle 48 via a plate shackle 52 .

The plate 50 has an approximately triangular shape, and the vertex portion of the triangle is attached to the plate shackle 52 via a pin 54 passing through a hole in the plate shackle 50 . The plate 50 has holes 50a adjacent to the other points of the triangle and plate holes 50b adjacent to the final points of the triangle. The tether 18 ends with double connection points 18a and 18b, which connect to the plate 50 through holes 50a and 50b, respectively. Alternatively, the double ends 18a, 18b, plate 50 and/or shackle 52 can be eliminated, tether 18 can be connected directly to shackle 48, and tether 18 is attached to the trolley. Other variations of the method linked to (46) are also available.

FIG. 13 is a side view of the movable tether connecting part 40 shown in partial cross-section as seen along the line 13 - 13 in FIG. 12 . A side view of the tubular channel 42 is shown in cross section. The wall 42b with the slot 42a is a relatively high vertical outer wall, and the outer surface of the opposite inner wall 42c has the same height.

The stand-off 44 is attached to the outer surface of the inner wall 42c by welding, for example. A pair of relatively short horizontal walls 42d, 42e opposed to each other, except that the vertical wall 42b has a horizontal longitudinal slot 42a extending substantially the entire length of the tubular channel 42. It extends between the vertical walls 42b and 42c to completely enclose the tubular channel 42 .

14 is a side view of the tubular channel 42 shown in partial cross-section to show the side of the trolley 46 . The trolley 46 includes a base plate 46a having four rectangular openings 46b, 46c, 46d, and 46e, which rectangular openings are mounted on four shafts 46j, 46k, 46m, and 46n. It is for accommodating the wheels 46f, 46g, 46h and 46i, respectively, and the four axles thereof are attached to the base plate 46a via stand-offs.

An oil tanker T is moored to the FPSO vessel 10 of FIGS. 1-4 via a tether 18, which is attached to a movable trolley 46 via a plate 50 and shackles 48, 52. As the trolley 46 rolls freely back and forth in a horizontal plane within the tubular channel 42, as wind, waves, currents, and/or other forces act on the tanker T, the tanker T will It can move while drawing an arc around the FPSO vessel 10 with a radius determined by its length. As best seen in FIG. 4 , the tubular channel 42 extends in an arc of about 90 degrees around the hull 12 of the FPSO vessel 10 . The tubular channel 42 has opposite ends 42f and 42g, each of which is enclosed to provide a stop for the trolley 46. Since the stand-offs 44a, 44b, 44c and 44d are equal in length, the tubular channel 42 has a radius of curvature that matches the radius of curvature of the outer wall 12w of the hull 12. The trolley 46 rolls freely back and forth between the ends 42f and 42g of the tubular channel 42 within the enclosed tubular channel 42 . The tubular channels are spaced from the outer wall 12w of the hull 12 by the stand-offs 44a, 44b, 44c and 44d, and the hose 20 and anchor line 16c are tubular with the outer wall 12w. It passes through the space formed between the inner wall 42c of the channel 42.

In general, wind, waves and tidal forces will position the oil tanker T in a position relative to the FPSO vessel 10 (herein referred to as a downwind position relative to the FPSO vessel 10). As the force that moves the tanker T in the downwind direction away from the stationary FPSO ship 10 is applied to the tanker T by the action of wind, waves and currents, the rope 18 is tensioned taut. to be in a state of being Because of the balance of forces that counteract the tendency of the trolley 46 to move, the trolley 46 comes to rest inside the tubular channel 42 .

When the wind direction changes, the tanker T can move relative to the FPSO vessel 10, and as the tanker T moves, the wheels 46f, 46g, 46h, 46i move against the wall of the tubular channel 42 ( Pressed against the inner surface of 42b), the trolley 46 will roll inside the tubular channel 42. As the wind continues in its new fixed direction, the trolley 46 will settle inside the tubular channel 42 and the force causing the trolley 46 to roll is neutralized.

Restricting the movement of the tanker T using one or more tugboats to prevent the tanker T from moving too close to or wrapping around the FPSO vessel 10, e.g. due to a substantial change in wind direction can do.

For flexibility in accommodating the wind direction, the FPSO vessel 10 preferably has a second movable tether 60 located opposite the movable tether 40 . The tanker T may be moored to either the movable tether 40 or the movable tether 60, depending on which better accommodates the tanker T downwind of the FPSO vessel 10.

The movable tether connection 60 is essentially the same in design and construction as the movable tether 40, and uses a caught free rolling trolley car having its own slotted tubular channel and a shackle passing through a slot in the tubular channel. Have. Each movable tether joint 40, 60 is considered capable of accommodating the movement of the oil tanker T within an arc of about 270 degrees, so that a single unloading operation (movement of the trolley occurring inside one of the movable tether connections) Great flexibility is provided during) and during changeover from one loading operation to another (by being able to choose between movable tether connections that are opposite to each other).

The action of wind, waves and currents can exert large forces on the tanker T, especially during storms or gusts, which exert a large force on the trolley 46 and the slots of the tubular channel 42. A large force is applied to the mold wall 42b (FIG. 13). The slot 42a weakens the wall 42b, and when sufficient force is applied, the wall 42b can bend, so that the slot 42b is wide enough for the trolley 46 to squeeze out of the tubular channel 42 ( 42a) can be opened. The tubular channel 42 will need to be designed and made to withstand the expected forces. The inner corner within the tubular channel 42 may be reinforced for reinforcement, and a spherical wheel may be used. The tubular channel is only one means for providing a movable tether connection. I-beams (with mutually opposing flanges attached to the center web) could be used as rails instead of tubular channels, and a trolley car or other rolling or sliding device could be caught on the outer flanges and moved on them. The gantry crane is similar to its gantry crane, except that the gantry crane is adapted to receive vertical forces, and the movable tether linkage needs to be adapted to accept horizontal forces applied through the tether 18. . Any kind of rail, channel or track may be used for the movable tether, provided that the trolley or any kind of rolling or sliding device is capable of moving longitudinally on the rail, channel or track and is otherwise held. The following patents are incorporated by reference for all of the teachings of these patents, particularly the teachings of how to design and make movable joints. U.S. Patent 5,595,121 entitled "Amusement Ride and Self-propelled Vehicle Therefor" issued to Elliott et al.; 6,857,373 entitled "Variably Curved Track-Mounted Amusement Ride" assigned to Checketts et al.; 3,941,060 (titled "Monorail System", assigned to Morsbach; 4,984,523 (titled "Self-propelled Trolley and Supporting Track Structure", assigned to Dehne et al.); and 7,004,076 (titled "Material Handling System Enclosed Track"). Arrangement", to Traubenkraut et al.) are all incorporated by reference for all purposes as a whole. As described herein and in the patents to which they are incorporated by reference, the horizontal orientation while being held inside the tubular channel 42 Various means may be used to resist horizontal forces, such as those applied to the FPSO vessel 10 from the tanker T through the tether 18 while providing lateral movement, for example by the trolley 46 rolling back and forth on the can

Wind, waves and currents exert many forces on the FDPSO or FPSO vessel of the present invention, which, in addition to other movements, causes vertical up-and-down movement or up-and-down rocking. A production riser is a pipe or tube that extends from a wellhead on the seabed to an FDPSO or FPSO (collectively referred to herein as an FPSO). The production riser is anchored to the seabed and can also be anchored to the FPSO. Tension and compression forces are alternately applied to the production riser by the up and down motion of the FPSO vessel, and thus fatigue and damage may occur to the production riser. One aspect of the present invention is to minimize the pitching of FPSO vessels.

15 is a side view of an FDPSO or FPSO vessel 80 according to the present invention. The vessel 80 has a hull 82 and a circular top deck surface 82a, the cross section of the hull 82 passing through any horizontal plane when the hull 82 is floating and stationary is preferably circular. Upper cylindrical portion 82b extends downwardly from circular top deck surface 82a, and upper conical portion 82c extends downwardly from upper cylindrical portion 82b and also tapers inwardly. The vessel 80 may have a cylindrical neck portion 82d extending downwardly from the upper conical portion 82c (so more similar to the vessel 10 in FIG. 3), but does not have such a cylindrical neck portion. don't Instead, lower conical portion 82e extends downwardly from upper conical portion 82c and flares outward. The lower cylindrical portion 82f extends downward from the lower conical portion 82e. The hull 82 has a bottom surface 82g. The lower conical portion 82e is described herein as having an inverted conical shape or as having an inverted conical shape as opposed to the upper conical portion 82c, where the upper conical portion is described as having a regular conical shape.

The FPSO vessel 80, when loaded and/or ballasting, is shown floating such that the surface of the water intersects the upper cylindrical portion 82b. In this embodiment, the upper conical portion 82c has a substantially greater vertical height than the lower conical portion 82e, and the upper cylindrical portion 82b has a slightly greater vertical height than the lower cylindrical portion 82f. .

To reduce heave and otherwise stabilize the vessel 80, as shown in FIG. 15, a set of fins 84 are attached to the lower outer portion of the lower cylindrical portion 82f. there is. FIG. 16 is a cross-section of the vessel 80 seen along line 16 - 16 in FIG. 15 . As can be seen in FIG. 16, the pin 84 includes four fin portions 84a, 84b, 84c, and 84d, which fin portions are defined as gaps 86a, 86b, 86c, and 86d (collectively, gaps). (86)) are separated from each other. Gap 86 is the space between fin portions 84a, 84b, 84c, 84d, which provides a location to receive production risers and anchor lines outside of hull 82 without contact with fin 84. do. Anchor lines 88a, 88b, 88c and 88d in FIGS. 15 and 16 are received in gaps 86a, 86b, 86c and 86d, respectively, and anchor the FDPSO and/or FPSO vessel 80 to the seabed. Production risers 90a, 90b, 90c, 90d, 90e, 90f, 90g, 90e, 90g, 90h, 90i, 90j, 90k, 90m are received in gaps 86 and contain crude oil, natural gas and/or leached minerals. transfers resources such as from the earth below the seafloor to a tank in the vessel 80. A central portion 92 extends from the bottom 82g of the hull 82.

FIG. 17 is a side view of FIG. 15 in vertical cross section, showing a simplified view of the tank in hull 82 in cross section. Produced resources flowing through the production riser 90 are stored in the internal annular tank 82h. A central vertical tank 82i may be used as a separator vessel for separating and/or storing, for example, oil, water and/or gas. An outer annular tank 82j having an outer wall conforming to the shape of the upper conical portion 82c and the lower conical portion 82e may be used to hold ballast water and/or store produced resources. In this embodiment, the outer ring-shaped tank 82k has an irregular trapezoidal cross-section defined at the top by a lower conical portion 82e and by a lower cylindrical portion 82f having a vertical inner wall and a horizontal lower bottom wall. , but the tank 82k may be used for ballast and/or storage. An annular tank 82m shaped like a washer or donut having a square or rectangular cross section is located at the lowermost outermost part of the hull 82. Tank 82m may be used for storage of produced resource and/or ballast water. In one embodiment, tank 82m holds a slurry of hematite and water, in another embodiment tank 82m contains about 1 part hematite and about 3 parts water.

A pin 84 for reducing up and down motion is shown in cross section in FIG. 17 . Each section of the fin 84 has the shape of a right triangle in vertical section, and the 90° angle is located adjacent to the lowermost outer wall of the lower cylindrical portion 82f of the hull 82, so that the bottom edge of the triangle ( 84e) is co-planar with the bottom surface 82g of the hull 82, and as can be seen in FIG. 17, the hypotenuse 84f of the triangle is the distal end 84g of the bottom edge 84e of the triangle. ) and attaches to the outer wall of the lower cylindrical portion 82f at a point slightly higher than the lowermost edge of the outer wall of the lower cylindrical portion 82. Experimentation may be necessary to determine the size of the fins 84 for optimum effect. The starting point is that the bottom edge 84e extends radially outward at a distance that is approximately half the vertical height of the lower cylindrical portion 82f and the oblique side 84f extends from the bottom 82g of the hull 82 to the lower cylindrical portion ( 82f) is attached to the lower cylindrical portion 82f at a point approximately 1/4 of the vertical height. Another starting point is that if the radius of the lower cylindrical portion 82f is R, the bottom edge 84e of the pin 84 is radially outward by an additional 0.05 to 0.20 R, preferably about 0.10 to 0.15 R, more preferably. It extends by about 0.125 R.

FIG. 18 is a cross-section of the hull 82 of the FDPSO and/or FPSO vessel 80 taken along line 18 - 18 in FIG. 17 . Radial support members 94a, 94b, 94c, 94d provide structural support for the inner annular tank 82h, which tank is shown having four compartments separated by radial support members 94. . Radial support members 96a, 96b, 96c, 96d, 96e, 96f, 96g, 96h, 96i, 96j, 96k, 96m provide structural support for outer annular tank 82j and tanks 82k, 82m. . The outer annular tank 82j and the tanks 82k and 82m are partitioned by a radial support member 96.

FPSO vessels according to the present invention, such as FPSO vessels 10, 20 and 80, can be built onshore, preferably in a shipyard, using conventional shipbuilding materials and techniques. The FPSO vessel preferably has a circular shape in plan view, but a polygonal shape is advantageous in terms of construction cost, so that a flat and flat metal plate can be used without bending the plate to a desired curvature. An FPSO vessel hull having a polygonal shape with facets when viewed in plan view, as described in U.S. Patent 6,761,508 to Haun and incorporated by reference, is included in the present invention. If a polygonal shape is chosen and a movable tether is desired, the tubular channel or rail can be designed with an appropriate radius of curvature and mounted with appropriate standoffs to provide a movable tether. If the FPSO ship is made according to the description of the FPSO ship 10 in FIGS. 1-4, the FPSO ship is moved to its final destination without a central column, the FPSO ship is anchored at its desired location, and the FPSO ship is moved to It may be desirable to install the center column offshore after it has been settled in place. In the case of the embodiment shown in FIGS. 7 and 9, the central column is installed when the FPSO vessel is on land, the central column is retracted to the uppermost position, and the FPSO vessel is transported to its final destination with the central column fully retracted and installed. It would be preferable to tow up to . After the FPSO vessel is positioned in its desired location, the center column can be extended to the desired depth and the mass trap at the bottom of the center column can be filled to help stabilize the hull against the action of wind, waves and currents. there is.

After the FPSO vessel is anchored and the installation of the vessel is otherwise complete, the floating drilling rig may be used to drill exploration or production wells, if a derrick crane is installed, and may also be used for production or storage of resources or products. To unload the fluid cargo stored on the FPSO vessel, a carrier tanker is sent near the FPSO vessel.

Referring to Figures 1-4, messenger lines may be stored on reels 70a and/or 70b. One end of the messenger line is shot from the FPSO vessel 10 to the tanker T by a pyrotechnic gun and is grabbed by a person on the tanker T. The other end of the messenger line can be attached to the tanker end 18c of the tether 18 (FIG. 2), and a person on the tanker can pull the tether end 18c of the tether 18 towards the tanker T. It may be attached to an appropriate structure of the tanker (T) at its end in the tanker. The person on the tanker T can then shoot one end of the messenger line to the person on the FPSO vessel, who then attaches that end of the messenger line to the tanker end 20a of the hose 20 (FIG. 2). will bet on A person on the tanker can then pull the tanker end 20a of the hose 20 onto the tanker and engage it in an appropriate connection on the tanker for fluid communication between the FPSO vessel and the tanker. Typically, cargo will be offloaded to the tanker from storage on the FPSO vessel, but the reverse is also possible, in which case the tanker's cargo is offloaded to the FPSO vessel for storage.

The hose may be as large as, for example, 20 inches in diameter, but hanging and unloading the hose may take a long time, typically many hours, but less than a day. During this time, as the wind direction changes, the tanker T will typically be oriented downwind of the FPSO vessel and moved slightly around it, which is accommodated in the FPSO vessel via a movable tether connection, allowing the tanker to can move significantly relative to the FPSO vessel, possibly over a range of 270 degree arcs. In the event of a major storm or gust of wind, the unloading operation can be stopped and, if desired, the tanker can be disconnected from the FPSO vessel by untethering the tethers 18. After a typical and smooth unloading operation has been completed, the hose end 20a can be disconnected from the tanker and the hose reel 20b is used to reel the hose 20 onto the hose reel 20b on the FPSO vessel. can A second hose and hose reel 72 are provided on the FPSO vessel for use with the second movable tether connection 60 on the opposite side of the FPSO vessel 10 . The tanker end 18c of the tether 18 can then be disconnected, allowing the tanker T to move away and deliver the received cargo to an onshore port facility. The message line can be used to pull the tanker end 18c of the tether 18 back towards the FPSO vessel, the tether can float in the water adjacent to the FPSO vessel or the tanker end 18c of the tether 18 ) can be attached to a reel (not shown) on the deck 12a of the FPSO vessel 10, and the double ends 18a, 18b (FIG. 12) of the tether 18 are attached to the movable tether connection 40. While remaining connected, the tether 18 can be wound onto a reel for storage on the FPSO vessel.

The present invention relates to an offshore floating petroleum production, storage and offloading method, which method comprises first receiving hydrocarbons from at least one of a FPSO, a production riser or a subsea wellhead by means of a uniquely shaped floating hull; include that

The next step involves processing the received hydrocarbons to form hydrocarbon products in the floating hull.

The method continues with the storage of hydrocarbon products in a specially shaped floating hull, the floating hull having a circular shape in plan view of the hull, the floating hull having a bottom surface; normal deck surface; and at least three connected portions connected in series and configured symmetrically about a vertical axis, the connected portions extending downwardly from the top deck surface toward the bottom surface, the at least three connected portions comprising: an upper cylindrical portion, a lower cylindrical portion; It includes a conical portion, a cylindrical neck portion, and a set of fins secured to the hull and configured to provide hydrodynamic performance through linear and quadratic damping.

Both linear damping and quadratic damping are empirical approaches to quantify the hydrodynamic behavior of floating bodies in incompressible, homogeneous Newtonian fluids. In various embodiments, each of the fin and hull of a floating drilling rig is designed and constructed to provide hydrodynamic performance through linear and quadratic damping, which is a numerical method (either linear or non-linear) for determining an accurate estimate of viscous damping. ), including numerical evaluation and experimentation.

Compared to conventional circular floaters that do not include fin features, the hull described herein that includes a set of fins may contribute to better hydrodynamic performance (related to damping) of the FPSO. The shape and/or size of the fins can also have a positive effect, contributing to better hydrodynamic performance (related to damping). However, fins of different shapes and/or sizes may respond differently in water embodiments where algae may affect flows and pressures that may vary greatly depending on the shape and/or size of the fins.

The method continues with offloading the stored hydrocarbon product to at least one of the tanker or pipeline.

In an embodiment, the method contemplates mooring a floating hull to the seabed.

In an embodiment of the method, the floating hull has an upper truncated conical side portion engaging the cylindrical neck portion, the upper cylindrical side portion extending downward from the main deck, and the upper truncated conical side portion below the upper cylindrical side portion. located and maintained above the waterline to the delivery depth of an oil drilling, production, storage and offloading vessel and partially below the waterline to the working depth of the vessel, the upper truncated conical side portion is the diameter of the upper cylindrical side portion has a diameter that gradually decreases from

In an embodiment, the method includes installing a side surface extending from the bottom surface of a hull.

In an embodiment, the method includes using a plurality of fin portions separated from each other by gaps providing a location for receiving production risers and anchor lines outside the hull without contacting the fins. there is.

In an embodiment, the method includes using a pin of a set of pins for reducing heave motion, which pin has the shape of a right triangle when viewed in vertical cross section.

In an embodiment, the method includes using a fin having a bottom edge, the triangle being coplanar with the bottom surface of the hull.

In an embodiment, the method is such that the hypotenuse of the triangle of the fin extends upwards and inwardly from the distal end of the bottom edge of the triangle, at a point slightly higher than the lowermost edge of the outer wall of the hull, the outer wall of the lower cylindrical portion. Includes pins attached to

In an embodiment, the method includes using a uniquely shaped hull with a center column, a center column with a square cross section, and a pentagonal mass trap.

In an embodiment, the method comprises using at least three connected segments which may be connected in series and configured symmetrically about a vertical axis, the connected segments extending downwardly from the top deck surface towards the bottom surface. has been

The specific structural and functional details disclosed herein are not to be construed as limiting, but merely as a basis for the claims and as a representative basis for instructing those skilled in the art to implement the various uses of the present invention.

Although these embodiments have been described with emphasis on the embodiments, it is to be understood that within the scope of the appended claims, the embodiments may be practiced otherwise than as specifically described herein.

Claims (10)

As a method,
a. receiving hydrocarbons from at least one of a FPSO, a production riser, or a subsea wellhead by the floating hull of an offshore floating oil production, storage and offloading vessel;
b. processing received hydrocarbons to form hydrocarbon products in the floating hull;
c. storing a hydrocarbon product in the floating hull, wherein the floating hull comprises a circular shape when viewed in plan view of the hull, and
The floating hull,
i. floor surface;
ii. normal deck surface;
iii. at least three connected portions connected in series and configured symmetrically about a vertical axis, extending downwardly from the top deck surface toward the bottom surface, and comprising an upper cylindrical portion, a lower conical portion, and a cylindrical neck portion;
iv. a set of fins secured to the floating hull and configured to provide hydrodynamic performance through linear and quadratic damping; and
v. having a square cross-section and comprising a retractable central column; and
d. A method comprising unloading a stored hydrocarbon product onto at least one of an oil tanker or a pipeline, operative for an offshore floating oil production, storage and offloading vessel. According to claim 1,
The method of claim 1, wherein the floating hull is moored to the seabed. According to claim 1,
The floating hull has an upper truncated conical side portion engaging with the cylindrical neck portion, the upper cylindrical portion extending downward from the main deck, the upper truncated conical side portion positioned below the upper cylindrical portion and also oil drilling , remaining above the waterline for the delivery depth of a production, storage and offloading vessel and partially below the waterline for the working depth of the vessel, the upper truncated conical side portion progressively decreasing from the diameter of the upper cylindrical portion. having a diameter of According to claim 1,
A method comprising installing a side extending from a hull bottom surface. According to claim 1,
using a plurality of fin portions, wherein the plurality of fin portions are separated from each other by a gap providing a location for receiving the production riser and anchor line outside the hull without contacting the set of fins. How to be. According to claim 1,
The method of claim 1 , wherein a pin of the set of pins for reducing up and down motion has a right triangle shape when viewed in a vertical section. According to claim 6,
wherein a fin of the set of fins has a bottom edge of the right triangle shape, the bottom edge being co-planar with the bottom surface of the hull. According to claim 7,
The hypotenuse of the right triangle shape of the fins of the set of fins extends upwards and inwardly from the distal end of the bottom edge of the right triangle shape, at a point slightly higher than the lowermost edge of the outer wall of the hull, the lower cylindrical portion. Attached to the outer wall of the method. According to claim 1,
The method of claim 1, wherein the hull includes a pentagonal mass trap. According to claim 1,
wherein the at least three connected portions may be connected in series and configured symmetrically about a vertical axis, the at least three connected portions extending downwardly from the top deck surface toward a bottom surface.

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