RU83995U1 - VESSEL FOR PRODUCING NATURAL GAS (VESSEL FOR PRODUCING AND PROCESSING NATURAL GAS IN METHANE RECTIFIED AND STORAGE OF METHANOL UNDER CONDITIONS OF INTENSIVE WAVE AND DRIFTING ICE) - Google Patents

Abstract

1. A vessel for natural gas production, having a hull, a technological complex consisting of gas production equipment, an energy complex, a residential unit, an anchor-mooring system, including a turret, the axis of which is shifted in the nose relative to the mid-section of the hull, a gas riser, and the hull the vessel is made with the possibility of rotation relative to the axis of the turret with its nose on the moving beaten ice in the anchored state in the direction of the ice load under its influence and with simplified contours that satisfy the requirements, presenting connected to the hulls of ice navigation vessels, as well as with double sides and a second bottom, characterized in that the technological complex is supplemented by a plant for the production of rectified methanol from natural gas, which includes interconnected reforming units, methanol synthesis and distillation columns, airborne and central cargo tanks for storing the produced methanol-rectified, communicated by the main with the installation for the production of rectified methanol, and the methanol-shipping system associated with the indicated tanks - The certificate for the tanker, and keels are installed on the cheekbones of the hull, while the vessel is equipped with a ballast system connected to the spaces between the double sides and sedation tanks, which are used as mentioned cargo tanks of opposite sides, connected by a highway through a locking device to each other, as well as spaces between double sides of opposite sides with ballast sea water, also connected by a highway through a locking device to each other, and the bow of the vessel

Description

This utility model relates to shipbuilding, namely, to marine complexes that allow producing natural gas, processing it into distilled methanol and storing it under conditions of intense sea waves and drifting ice, as well as shipping methanol to tankers.

A known system for offshore oil and gas production, methanol production from gas and its storage, followed by shipment to tankers. This system includes a vessel containing a hull with an internal turret, as well as technological equipment for oil and gas production, methanol production equipment, a reforming reactor for producing syngas, a methanol synthesis reactor, cargo tanks for storing methanol and a means for feeding methanol to tanker. That’s all

equipment is placed on the ship. (WO 00/23689 dated 04/27/2000, IPC ⁷ ЕВВ 43/34, С07С 29/151).

However, this well-known system cannot be used in an ever-changing and dangerous ice environment. In addition, because of this, it is not possible to rectify methanol on this system during a wave at sea. This is due to the fact that this known system is not able to quickly eliminate and reduce the influence of pitching on the process of rectification of methanol from natural gas. The reason is that the system has a limited scope. It is intended only for the extraction of gas from a sea plume in temperate sea latitudes, in which severe unrest is rarely observed.

A vessel for producing hydrocarbons in ice conditions is known, comprising a hull with a turret, the axis of which is shifted in the nose relative to the mid-section, as well as technological and energy complexes, a residential unit, and an anchor-mooring system associated with the turret, the hull of which is rotatable relative to the axis of the turret with its nose on the moving broken ice in the anchored state in the direction of the ice load under its influence and with simplified contours that satisfy the requirements for the hulls of the ship ice navigation, as well as double sides, and a second bottom (patent RU 2162808 of 10.02.2001, MPK ⁷ V63V 35/44).

This well-known technical solution is selected as a prototype, since it has the largest number of essential features that match the essential features of the claimed technical solution.

However, this device, providing offshore hydrocarbon production under the influence of drifting ice on the vessel, has significant disadvantages:

- this vessel cannot be used for hydrocarbon production with the production of rectified methanol in conditions of intense sea waves, since the pitching negatively affects the methanol rectification process;

- there is a difficulty in releasing the vessel from the anchor-mooring system if the iceberg approaches the extraction site to leave the iceberg's trajectory and re-detach the vessel after the iceberg leaves;

- there may be a low efficiency of spontaneous turning of the vessel under the influence of external, including ice loads;

- unreliable riser protection for transporting hydrocarbons from a subsea well to a vessel from drift ice.

The objective of the proposed invention is the creation of safe and efficient operation of a mobile system in the form of a vessel for the offshore production of natural gas and the production of distilled methanol from it, its storage and shipment to tankers in the conditions of intense waves and drifting ice by moderate rolling of the vessel without reducing the volume of cargo tanks for storage rectified methanol in the entire filling range of cargo tanks from empty to full, achieving maximum utilization of hull volume d I cargo tank and provide guaranteed spontaneous reversal in the direction of the ship's nose as the impact of wind and wave and ice loads.

To do this, in a well-known vessel for natural gas production, having a hull, a technological complex consisting of gas production equipment, an energy complex, a residential unit, an anchor-mooring system, including a turret, the axis of which is offset in the nose relative to the mid-section of the hull, gas riser, moreover, the hull of the vessel is made with the possibility of rotation relative to the axis of the turret with its nose on the moving broken ice in the anchored state in the direction of the ice load under its influence and with simplified contours,

meeting the requirements for hulls of ice navigation vessels, as well as with double sides and a second bottom. The technological complex is complemented by a unit for the production of rectified methanol from natural gas, which includes interconnected reforming units, methanol synthesis and distillation columns, airborne and central cargo tanks for storing the produced methanol-rectified, communicated by the main line with the installation for the production of rectified methanol, and associated with the indicated tanks the methanol-rectified shipping system for the tanker. The sides of the vessel are inclined to the vertical at an angle of 10-15 °, and keels are installed on the cheekbones of the hull. The vessel is equipped with a ballast system connected to the spaces between the double sides and sedimentation tanks, using the cargo tanks mentioned above, connected by a line through the locking device to each other, as well as the spaces between the double sides with ballast sea water, also connected by the line through the locking device to each other . In this case, the bow of the vessel is made in a spoon-shaped form, and the anchor-mooring system is supplemented by a buoy installed on the turrets with a channel under the gas riser, which can rotate relative to the turret, under which a reciprocal receiving chamber is made in the hull for fixing the buoy.

In addition, the axis of the turret in the hull is located aft from the bow perpendicular at a distance of 0.15-0.20 of the length of the vessel.

At the same time, on the ship’s hull in the turret area or on the turret buoy an ice-removing device is placed to protect the gas riser from ice impact.

Moreover, the ice-removing device for protecting the gas riser is installed covering at least half the turret circumference from the bow of the vessel.

In addition, distillation columns are lowered through the upper deck and installed on the second bottom.

Along with this, cargo tanks for storage of rectified methanol are equipped with an elastic partition separating their cavity from a stretchable durable material, hermetically attached from the inside to the walls of the tanks along the perimeter of their longitudinal or transverse section, on one side of which these tanks are connected by a main line with a methanol production unit - rectification, and on the other side - with a ballast system.

At the same time, the cavities of airborne cargo tanks in communication with the ballast system are connected by a highway through a locking device to each other for use as soothing tanks.

In addition, the methanol-rectified shipping system is located in the stern of the vessel and in the midship area.

Equipping the hull with zygomatic keels in combination with soothing tanks ensures a moderate roll amplitude.

Performing the sides of the vessel with an inclination to the vertical at an angle of 10-15 ° allows us to provide an approximate constancy of the initial metacentric height by reducing the width of the vessel along the current waterline while reducing its draft and resulting in smooth rolling over the entire range of changes in vessel draft.

Using the space between the double sides of the vessel to receive ballast sea water allows empty cargo tanks to maintain a sufficient draft of the vessel, preventing a significant increase in the initial metacentric height and, as a result, maintaining smooth rolling.

The installation of distillation columns lowered through the upper deck at the second bottom allows to reduce the levels of acceleration in

distillation columns during pumping, which creates favorable conditions for the distillation of methanol.

The use of airborne cargo tanks as sediment tanks for storing methanol-rectified and the space between the double sides with ballast sea water allows us not to reduce the volume of cargo and ballast tanks to accommodate separate sediment tanks and to moderate the rolling of the vessel as if in cargo when cargo airborne tanks are used with rectified methanol, and in ballast, when the spaces between double sides with ballast sea water are used.

The execution of the bow of the vessel in a spoon-shaped form and the location of the axis of the turret in the hull aft of the bow perpendicular at a distance of 0.15-0.20 of the length of the vessel together guarantees a spontaneous turn of the ship with its nose on the oncoming ice and waves under their influence. The indicated location of the turret axis in the hull was justified by the results of model tests conducted in the ice pool of FSUE TsNII im. Acad. A.N. Krylova "in the conditions of drifting ice.

The addition of the anchor-mooring system with a buoy mounted on a turret, which is fixed in the reciprocal receiving chamber in the hull of the vessel and can rotate relative to the turret, reduces the complexity of the process and the duration of the release of the vessel for emergency removal in the case of approaching the iceberg to the extraction site and re-detaching after leaving iceberg, as well as when the ship moves to a new natural gas production site.

The installation in cargo tanks for the storage of rectified methanol separating their cavity of an elastic partition made of stretchable durable material makes it possible to receive sufficient sedimentation tanks to maintain constant operation and operation of sedimentation tanks in the absence of a pure volume of rectified methanol in cargo tanks

liquid ballast without reducing the capacity of cargo tanks to accommodate additional ballast tanks.

The proposed utility model solves a very urgent problem, the solution of which is occupied by many specialists from different countries. For example, the well-known project of WERNER OFFSHORE, Inc to create a plant for the production of synthetic oil from natural gas (Werner N., Wilkins P. GAS EXTRACTION AND CONVERSION TO SYNTHETETIC FUELSON RUSSI'SARCTIC SHELF. // Transactions of RAO-97, p. 127-130). The plant is proposed to be installed on the coast in the lagoon of about. Novaya Zemlya on 18 barges 120 × 40 m in size, approximately 75 km from the place of extraction.

A well-known Canadian project for the development of the Terra Nova field (Bue O. O. TERRA NOVA FLOATING PRODUCTION. // Transactions RAO-03, p.214), which is based on:

- an underwater system consisting of wellheads and manifolds in protected recesses

- a floating production unit equipped with a turret, which allows you to quickly (in 20 minutes) disconnect from the underwater system.

Data on the projects of vessels in Russia for processing gas into methanol under conditions of sea waves and the possible occurrence of ice formations have not been established by the author and applicant.

The author is aware of the development of options for ship-building plants for liquefying produced gas at the field by lowering its temperature to minus 160 ° С, which requires special gas carrier ships for its transportation, the cost of which is much higher than the cost of ordinary tankers. At the same time, certain difficulties arise in ensuring the reliability of systems for loading liquefied gas in sea conditions.

With a small distance of deposits from the shore or gas processing from onshore fields, pipelines can be used for the transportation of methanol, the amount of capital and

operating costs for the sale of which are several times less than in the case of gas transportation.

In relation to these well-known production of gas production, its processing into rectified methanol and transportation, its claimed utility model has significant differences.

In view of the foregoing, the proposed utility model can be considered new.

The practical applicability of the claimed utility model is illustrated below by the drawing and the corresponding description.

The inventive utility model is a device from which Fig. 1 shows a longitudinal section of a mobile vessel for the offshore production of natural gas and production of rectified methanol from it, its storage and shipment to tankers under conditions of intense waves and drifting ice, and Fig. 2 is a section A -A in figure 1, figure 3 is a view of B in figure 1 and figure 4 is a spoon-shaped shape of the bow of the vessel.

The vessel for the extraction of natural gas has a hull 1, on which the technological complex is located, consisting of equipment for the extraction of natural gas 2, the energy complex 3, the residential block 4, the anchor-mooring system, including anchor-mooring links 5, connected to the nose hull 1 turret 6 with a gas riser 7, on which a buoy 8 is mounted, fixed in the reciprocal receiving chamber 9 in the ship’s hull and rotatable relative to the turret 6. The ship has simplified contours (not shown) satisfying e requirements for enclosures ice ships, as well as double bead 10 and second bottom 11 (Figure 2). The technological complex includes an installation for the production of rectified methanol from natural gas, which includes interconnected reforming units 12, methanol synthesis units 13 and distillation columns 14, which are lowered through the upper deck and installed on the second day (Fig. 1). Onboard are placed side 15 and center 16

cargo tanks for storing produced rectified methanol (Fig. 2), which are communicated by the main line (not shown in the figure) with the installation for the production of rectified methanol and the methanol-rectified 17 dispatch system connected to tanks 15 and 16 to the tanker located in the stern of the vessel ; a variant of the arrangement of the said system 17 is also provided in the midship region of the vessel (Fig. 1). The sides of the vessel 10 are made with an inclination to the vertical at an angle of 10-15 °, and keels 18 are installed on the cheekbones of the hull (Fig. 2). The vessel is equipped with soothing tanks and a ballast system connected to the spaces between the double sides (10 not shown). Airborne cargo tanks for storing rectified methanol 15 connected by highway 19 through a locking device 20 to each other, as well as the spaces between double sides 10 with ballast water, also connected by highway 21 through a locking device 22 to each other, were used as soothing tanks on the vessel. The nasal tip 23 of the vessel is made in a spoon-shaped form (Fig. 4). The axis of the turret 6 with a channel 24 for the passage of the riser 7 is located aft from the bow perpendicular at a distance of 0.15-0.20 of the length of the vessel, and on the hull of the vessel in the area of the turret there is an ice-removing device 25 for protecting the gas riser 7, covering at least half the circumference turrets from the bow of the vessel (figures 1, 4). It is possible to place an ice-removing device on a turret buoy (Figs. 5, 6).

Cargo tanks for storage of rectified methanol 15 and 16 are equipped with a flexible partition 26 separating their cavity (Fig. 2) made of stretchable durable material that is hermetically attached from the inside to the walls of the tanks around the perimeter of their longitudinal or transverse section. On one side of partition 26, tanks are connected through valve 27 and a line (not shown) with a plant for the production of rectified methanol, and on the other side of partition 26, through valve 28 with a ballast system. The cavities of the airborne cargo tanks 15, which are in communication with the ballast system, are connected by a line 29 through

locking device 30 between them for use as sedimentation tanks.

The work of the proposed vessel for the production of natural gas is as follows.

An auxiliary mooring system with a turret 6 and a buoy 8 mounted on it is installed at the field with the help of auxiliary vessels. A mobile vessel is towed to the field, a buoy 8 is put into the receiving chamber 9 of the vessel’s hull 1, which is fixed in it (Fig. 1). In the case of installing an ice-releasing device on a turret buoy, the vessel, when installed on an anchor-mooring system, is oriented relative to the buoy with an ice-releasing device (Figs. 5 and 6).

When the cargo tanks 15 and 16 are not fully loaded with rectified methanol, into the space between the double sides 10 and / or into the cavities of the cargo tanks communicated with the ballast system, separated by an elastic partition 26, outboard ballast water is accepted (Fig. 2).

In conditions of intense excitement, to moderate rolling of the vessel, in order to create favorable conditions for the production of rectified methanol, sedative tanks are activated. Moreover, in the case of airborne cargo tanks 15 filled with methanol-rectified, it is used as a working fluid, and shut-off devices 20 are opened (Fig. 2), and in the absence of rectified methanol in the mentioned cargo tanks, ballast is used as working fluid sea water located in the space between the double sides 10 and / or in the cargo tanks in the cavities separated by the elastic partition 26, which are in communication with the ballast system, and the locking devices 22 and 30 are opened (Fig. 2).

In the presence of drifting ice and waves under their influence, the vessel, together with the buoy fixed in its hull, carries out

spontaneous rotation about the axis of the turret 6 with your nose in the direction of the external load.

In the event of a collision threat with the iceberg, the ship undocks from buoy 8, it, along with the turret 6 and anchor-mooring links 5, is sunk to a safe depth, and the ship is towed from the iceberg's trajectory. After the passage of the iceberg, the docking operation of the vessel with the anchor-mooring system is performed in the reverse order.

When moving to a new natural gas production site, the vessel is undocked from buoy 8, the anchor-mooring system is dismantled, the vessel and the anchor-mooring system are moved to a new production site, where they are installed in the above order.

Thus, it was possible to combine the advantages of production from vessels on the shelf of natural gas with its processing into rectified methanol, storage and transportation using tankers. In fact, a factory-built marine mobile complex for the production of rectified methanol on the sea shelf was created.

Claims (10)

1. A vessel for natural gas production, having a hull, a technological complex consisting of gas production equipment, an energy complex, a residential unit, an anchor-mooring system, including a turret, the axis of which is shifted in the nose relative to the mid-section of the hull, a gas riser, and the hull the vessel is made with the possibility of rotation relative to the axis of the turret with its nose on the moving beaten ice in the anchored state in the direction of the ice load under its influence and with simplified contours that satisfy the requirements, presenting connected to the hulls of ice navigation vessels, as well as with double sides and a second bottom, characterized in that the technological complex is supplemented by a plant for the production of rectified methanol from natural gas, which includes interconnected reforming units, methanol synthesis and distillation columns, airborne and central cargo tanks for storing the produced methanol-rectified, communicated by the main with the installation for the production of rectified methanol, and the methanol-shipping system associated with the indicated tanks - A certificate for the tanker, and keels are installed on the cheekbones of the hull, while the ship is equipped with a ballast system connected to the spaces between the double sides and sediment tanks, which are used as mentioned cargo tanks of opposite sides, connected by a highway through a locking device to each other, as well as spaces between double sides of opposite sides with ballast sea water, also connected by a highway through a locking device to each other, and the bow of the vessel a spoon-shaped flax, and the anchor-mooring system is supplemented by a fitted channel installed on the turrets under the gas riser buoy, which can rotate relative to the turret, under which a reciprocal receiving chamber is made in the hull for fixing the buoy, the turret axis in the hull located aft from the bow perpendicular at a distance of 0.15-0.20 the length of the vessel. 2. The vessel according to claim 1, characterized in that the sides of the vessel are inclined to the vertical at an angle of 10-15 °. 3. The vessel according to claim 1, characterized in that on the hull of the vessel in the turret area an ice-removing device is placed to protect the gas riser from ice. 4. The vessel according to claim 1, characterized in that the ice-removing device for protecting the gas riser from ice is placed on a turret buoy. 5. The vessel according to claims 3 and 4, characterized in that the ice-removing device for protecting the gas riser is installed covering at least half the turret circumference from the bow of the vessel. 6. The vessel according to claim 1, characterized in that the distillation columns are lowered through the upper deck and installed on the second day. 7. The vessel according to claim 1, characterized in that the cargo tanks for storing rectified methanol are equipped with an elastic partition separating their cavity from a stretchable durable material, hermetically attached from the inside to the walls of the tanks around the perimeter of their longitudinal or transverse section, on one side of which tanks communicated with the main installation for the production of methanol. 8. The vessel according to claim 6, characterized in that the cavities of the airborne cargo tanks for storage of rectified methanol, communicated with the ballast system, are connected by a line through a locking device to each other for use as soothing tanks. 9. The vessel according to claim 1, characterized in that the methanol-rectified shipping system is located in the stern of the vessel. 10. The ship according to claim 8, characterized in that the methanol-rectified shipping system is located in the middle of the ship.