CN110271645B

CN110271645B - Offshore crude oil lightering method

Info

Publication number: CN110271645B
Application number: CN201910554106.9A
Authority: CN
Inventors: 韩先锋
Original assignee: Individual
Current assignee: Individual
Priority date: 2019-06-25
Filing date: 2019-06-25
Publication date: 2021-03-26
Anticipated expiration: 2039-06-25
Also published as: CN110271645A

Abstract

The invention provides an offshore crude oil lightering platform, which belongs to the technical field of offshore crude oil lightering and comprises an ULCC, wherein a plurality of clean ballast tanks are arranged inside a hull of the ULCC; an anchoring structure for fixing the reinforced anchor chain is arranged on a bow deck of the ULCC; and a reinforcing structure for supporting the anchoring structure is arranged below the bow deck. Also provided is an offshore crude oil lightering method comprising the steps of: A. filling ballast water into the clean ballast tank; B. one-trip ship berths for oil supply and simultaneously cleans a ballast water tank to discharge water outwards; C. the two-range ship is moored to receive oil. According to the offshore crude oil transfer platform and the offshore crude oil transfer method, one ULCC is used as transfer of the offshore crude oil, the problem that VLCC (very low-voltage carrier) harbor pressure is serious is solved, and the stability of the transfer platform can be kept.

Description

Offshore crude oil lightering method

Technical Field

The invention belongs to the technical field of offshore crude oil lightering, and particularly relates to an offshore crude oil lightering method.

Background

Along with the continuous development of economy and the improvement of the living standard of people, the crude oil import quantity in China rapidly rises, but the number and the receiving and discharging capacity of VLCC (giant crude oil tanker) wharfs limit, and the VLCC to be discharged at deep water crude oil ports in China seriously presses the wharf. In the prior art, the method for solving the problem of VLCC harbour pressing is to perform offshore crude oil transfer, stop the VLCC in a deep water area, unload the crude oil in the VLCC by using a plurality of two-course ships, and transport the crude oil to each crude oil storage warehouse.

Disclosure of Invention

The invention aims to provide an offshore crude oil lightering method to solve the technical problems that VLCC (very large tank load cell) to be unloaded is pressed port seriously, VLCC directly lightens to waste time and affects safety in the prior art.

In order to achieve the purpose, the invention adopts the technical scheme that: the offshore crude oil lightering platform comprises a ULCC, wherein a plurality of cleaning ballast tanks are arranged inside a hull of the ULCC; an anchoring structure for fixing a reinforced anchor chain is arranged on a bow deck of the ULCC; and a reinforcing structure for supporting the anchoring structure is arranged below the bow deck.

Further, the anchor structure including be used for with the round pin axle that strenghthened type anchor chain is connected and set up in the both ends of round pin axle, be used for supporting the otic placode of round pin axle, the bottom of otic placode with bow deck fixed connection.

Furthermore, the pin shaft is inserted into the lug plate, and locking pins are arranged at two ends of the pin shaft.

Furthermore, the reinforcing structure comprises an additional deck stringer arranged on the lower surface of the bow deck and a strut for supporting the additional deck stringer, wherein the top of the strut is fixedly connected with the additional deck stringer, and the bottom of the strut is fixedly connected with the upper surface of the second deck.

The offshore crude oil lightering platform provided by the invention has the beneficial effects that: compared with the prior art, the offshore crude oil lightering platform utilizes one ULCC as the lightering transfer of the offshore crude oil, reduces the mooring time of the VLCC, is internally provided with a plurality of clean ballast tanks, and keeps the balance of a ship body by injecting and releasing ballast water in the oil receiving and supplying processes; the bow deck of the ultra-huge crude oil tanker is provided with an anchoring structure which is connected with a reinforced anchor chain fixed on the seabed so as to keep the stability of the hull in stormy waves, and a reinforcing structure is arranged below the bow deck and used as a support of the anchoring structure so as to ensure the structural strength of the bow deck.

The invention also provides an offshore crude oil lightering method, which comprises the following steps:

A. injecting ballast water into the clean ballast tank;

B. one-trip ship berths for oil, and simultaneously the clean ballast tank is drained outwards;

C. the two-range ship is moored to receive oil.

Further, in step a, the draft of the ULCC is 9.5m or more.

Further, in step B, a plurality of first-stage ships moor for oil in sequence, and the displacement of the first-stage ship moored first is smaller than the displacement of the second-stage ship moored second.

Further, in step B, the draft of the ULCC is 23m or less.

Further, in the step C, the oil receiving of the two-way ship is single-board oil receiving.

Further, in the step C, the oil receiving of the two-way ship is two-side oil receiving.

The offshore crude oil lightering method provided by the invention has the beneficial effects that: compared with the prior art, the offshore crude oil refuting method utilizes one ULCC as refuting transfer of offshore crude oil, the VLCC of the transported crude oil is docked on one side of the ULCC for oil supply, the VLCC can leave after the oil supply is completed, the docking time of the VLCC is reduced, the ULCC is taken as offshore crude oil transfer storage, the ULCC is fixed in a deep sea area through a reinforced anchor chain, and the crude oil stored in the ULCC is unloaded to each crude oil storage bank through a two-course ship at any time.

Drawings

In order to more clearly illustrate the technical solutions in the embodiments of the present invention, the drawings needed to be used in the embodiments or the prior art descriptions will be briefly described below, and it is obvious that the drawings in the following description are only some embodiments of the present invention, and it is obvious for those skilled in the art to obtain other drawings based on these drawings without inventive exercise.

FIG. 1 is a schematic structural diagram of an anchoring structure of an offshore crude oil lightering platform provided by an embodiment of the invention;

FIG. 2 is a schematic structural diagram of a reinforcing structure of an offshore crude oil lightering platform according to an embodiment of the invention;

wherein, in the figures, the respective reference numerals:

1. a bow deck; 2. a pin shaft; 3. an ear plate; 4. a locking pin; 5. a reinforced anchor chain; 6. enlarging the chain ring; 7. a deck stringer; 8. attaching a deck stringer; 9. a pillar; 10. the second deck.

Detailed Description

In order to make the technical problems, technical solutions and advantageous effects to be solved by the present invention more clearly apparent, the present invention is further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative of the invention and are not intended to limit the invention.

The offshore crude oil lightering platform provided by the invention is explained.

Referring to fig. 1 and 2, the offshore crude oil transfer platform includes a ULCC (ultra large crude oil tanker) having a plurality of clean ballast tanks inside a hull; an anchoring structure for fixing a reinforced anchor chain 5 is arranged on a bow deck 1 of the ULCC; a reinforcing structure for supporting the anchoring structure is arranged below the bow deck 1.

In the ULCC loading and unloading procedure, ballast water needs to be injected into or discharged from a clean ballast tank to maintain the stability of a ship body due to the change of self-loading; the anchor structure is used for fixing the reinforced anchor chain 5, one end of the reinforced anchor chain 5 sinks into the sea bottom and is fixed, the other end of the reinforced anchor chain 5 is connected with the anchor structure, and when the ULCC is disturbed by wind and waves, the reinforced anchor chain 5 strains the ship body, so that the stability of the ship body is kept, and the shaking is reduced. Because the reinforced anchor chain 5 has larger pulling force on the ship body, the arrangement of the reinforced structure can ensure that the bow deck 1 has enough strength and rigidity when bearing larger pulling force.

Compared with the prior art, the offshore crude oil lightering platform provided by the invention utilizes one ULCC as the lightering transfer of offshore crude oil, reduces the mooring time of VLCC, is internally provided with a plurality of clean ballast tanks, and keeps the balance of a ship body by injecting and releasing ballast water in the oil receiving and feeding processes; the bow deck 1 of the ultra-huge crude oil tanker is provided with an anchoring structure and is connected with a reinforced anchor chain 5 fixed on the seabed, so that the stability of the hull in stormy waves is kept, and a reinforcing structure is arranged below the bow deck 1 and is used as a support of the anchoring structure, so that the structural strength of the bow deck 1 is ensured.

As a specific embodiment of the offshore crude oil lightering platform provided by the invention, the selected ULCC ship type is a single-engine single-propeller single rudder with double bottoms and double hulls, the ship length is about 369m, the model width is about 61m, the model depth is 32m, and the full-load displacement is about 422000t (the loading is about 335000 t); the power of a main machine is 31000kw, 1 main boiler (110 t/hour is multiplied by 65 mpa); 3 auxiliary machines, about 1800kw for the No. 1 turbine, and 1200kw and 600kw for the diesel generator sets; 3 cargo oil pumps with the discharge capacity of 5000m³At time, about 18-24 cargo holds; the ship grade is ABS.LR.GR or NV ship grade; two sets of 12-inch crude oil pipelines. The platform is a ship which belongs to the aviation crude oil transportation and has the special inspection distance of about 2 years next time, and a host machine, a main boiler, a fan, a generator set, a cargo pump device, an inert gas system, a shaft system, a propeller and a steering engine of the ship are provided with spare parts with the specified quantity by a classification society. The corresponding classification society certificates of equipment and systems such as fire-fighting lifesaving channels and the like are complete and effective.

Referring to fig. 1 and fig. 2 together, as a specific embodiment of the offshore crude oil lightering method provided by the present invention, a selected ULCC is provided with a single-point anchor mooring system, that is, only one set of anchoring system is provided with a reinforced anchor chain 16 with a chain diameter of not less than 149mm, a main anchor is not less than 35t, a set of anchors with the same weight is provided, a breaking force of the reinforced anchor chain 5 is at least 1000t, in order to connect the reinforced anchor chain 5 with a ship body, an anchoring structure arranged on a ship body bow deck 1 of the ULCC includes a horizontally arranged pin shaft 2, two ends of the pin shaft 2 are respectively provided with an ear plate 3, the ear plates 3 are vertically arranged and are welded and fixed on the upper surface of the bow deck 1, the positions of the two ear plates 3 corresponding to the pin shaft 2 are both provided with round holes, and the pin shaft 2 penetrates through the round holes. The diameter of the pin shaft 2 is at least 389mm, the material is 00cr17ni4cu2nb, the pin shaft can bear 700t mooring pulling force, an enlarged chain ring 6 is arranged at the end part of the reinforced anchor chain 5, and the pin shaft 2 can penetrate through the enlarged chain ring 6.

Preferably, the pin shaft 2 is inserted into the ear plate 3, that is, the pin shaft 2 can be separated from the ear plate 3, and locking pins 4 are respectively installed at two ends of the pin shaft 2 to prevent the pin shaft 2 from sliding out of a round hole formed in the ear plate 3 due to sliding. When ULCC mooring, an enlarged chain ring 6 of the reinforced anchor chain 5 is connected to the pin shaft 2; when ULCC needs to be repaired and maintained in a factory, a steel cable is connected to the reinforced anchor chain 5 through a shackle, the steel cable is tightened through an anchor machine, the enlarged chain ring 6 is loosened, the locking pin 4 is detached, the pin shaft 2 is pulled out of the round hole of the lug plate 3, the enlarged chain ring 6 is separated from the pin shaft 2, and the enlarged chain ring 6 of the reinforced anchor chain 5 is fixed on a buoy with a navigation aid function through a floating crane; after repairing and maintaining the ULCC and returning, hoisting a reinforced anchor chain 5 to an anchoring structure of the ULCC by using a floating crane on an original anchor site, sequentially penetrating a pin shaft 2 through a first lug plate 3, an enlarged chain ring 6 and a second lug plate 3, and locking the pin shaft 2 by using a locking pin 4 to finish anchoring and mooring of the ULCC.

Please refer to fig. 2, as a specific embodiment of the offshore crude oil lightering method provided by the present invention, the reinforcing structure includes an additional deck stringer 8 disposed below the bow deck 1 and a strut 9 for supporting the additional deck stringer 8, the lower surface of the bow deck 1 is provided with a deck stringer 7, the additional deck stringer 8 is disposed below the deck stringer 7 and parallel to the deck stringer 7, and includes a web plate disposed perpendicular to the bow deck 1 and a panel disposed perpendicular to the lower edge of the web plate, the top of the web plate is welded and fixed to the deck stringer 7, the top of the strut 9 is welded and fixed to the lower surface of the panel, and the bottom of the strut 9 is welded and fixed to the upper surface of the second deck 10. When the reinforced anchor chain 5 applies pulling force to the anchoring structure, the bow deck 1 is pulled, the additional deck stringers 8 and the pillars are used as reinforcing structures, and the bow deck 1 is guaranteed not to deform.

A. ballast water is injected into the clean ballast tank.

Under the initial state of marine crude oil lightens, ULCC is in the idle load state, and the draft is lighter, and direct injection into crude oil can lead to the hull to take place great rocking, need pour into the ballast water into earlier, increases hull draft, guarantees to award oily in-process hull stability.

B. One ship berths for oil supply and simultaneously cleans the ballast tank to discharge water outwards.

The method comprises the steps that a ship is anchored at one side of the ULCC, the VLCC loaded with crude oil is anchored with the ULCC through a cable, an electrostatic cable between the ship and the ULCC is connected, an oil pipeline is connected with the ship and the ULCC respectively through a crane, a gas return pipe between the ship and the ULCC is connected, after the tightness of the oil pipeline and the gas return pipe between the ship and the ULCC is confirmed, oil supply operation is executed, when oil supply is carried out, the loading of the ULCC is increased, the draft is increased, the oil supply is carried out while a ballast tank is cleaned, and water is discharged outwards, so that the draft of the ULCC is kept within a safety range.

C. The two-range ship is moored to receive oil.

After the ULCC is fully loaded, the oil storage tank is used as a temporary oil storage tank, crude oil is transported to each crude oil storage warehouse by a two-way ship, when the two-way ship receives the oil, the two-way ship is tied with the ULCC firmly through a cable, an electrostatic cable between the two is connected, then an oil pipeline is respectively connected with the ULCC and the two-way ship through a crane, a gas return pipe between the two-way ship and the ULCC is connected, and after the tightness of the oil pipeline and the gas return pipe between the two-way ship and the ULCC is confirmed, the oil receiving operation is executed.

Compared with the prior art, the offshore crude oil refuting method provided by the invention has the advantages that one ULCC is used as refuting transfer of offshore crude oil, VLCC of transported crude oil is docked on one side of the ULCC for oil supply, the VLCC can leave after the oil supply is finished, the anchoring time of the VLCC is reduced, the ULCC is used as offshore crude oil transfer storage, the ULCC is fixed in a deep sea area through a reinforced anchor chain, and crude oil stored in the ULCC is unloaded to each crude oil storage bank through a two-way ship at any time.

As a specific embodiment of the offshore crude oil lightering method provided by the invention, 6-8 clean ballast tanks are arranged, the total volume is not less than 95000 cubic meters, when ballast water is injected into the clean ballast tanks, the maximum injected amount is 96 percent of the total volume, about 91000t of ballast water, and the draft of ULCC is not less than 9.5m, and the draft of less than 9.5m can influence the stability of ULCC.

As a specific implementation manner of the offshore crude oil lightering method provided by the invention, a plurality of one-pass ships are berthed in sequence for oil teaching, and the method is divided into two conditions:

a first-pass ship with 110000 load tons is dispatched in advance, berthed and oiled, after the first-pass ship with 110000 load tons finishes the oil-dispatching, the first-pass ship with 220000 load tons berths and oils, and the ballast water removing operation of cleaning the ballast tank is carried out in the second half of the first-pass ship oil-dispatching operation, namely the first-pass ship oil-dispatching operation with 220000 load tons. The safety principle of the crude oil refuting and oil feeding process is that the first ship with small water displacement is berthed firstly, and then the second ship with large water displacement is berthed.

The other is that three 110000 tons of first ship are sequentially filled with oil, and when the second ship is filled with oil, the ballast water discharging operation for cleaning ballast tank is carried out.

As a specific implementation mode of the offshore crude oil lightering method provided by the invention, the draft of the ULCC is ensured to be not more than 23m by discharging ballast water in the oil-feeding process of a ship so as to ensure the strength and the operation safety of the ULCC.

As a specific implementation mode of the offshore crude oil refuting method provided by the invention, the two-way ship adopts single-board oil unloading in the oil receiving process, a full-revolving wheel with a fire-fighting function is used for towing a VLCC two-way ship for receiving and unloading crude oil to be stably parked at one side of the ULCC, after all mooring strong cables are tied on the two-way ship, an electrostatic cable between the two is connected, then an oil pipeline and the VLCC two-way ship are connected by a crane, a gas return pipe between the two ships is connected, after the confidentiality of the ULCC and the VLCC two-way ship and all safety items are confirmed and mutually checked, the two parties sign the oil pipeline, and a pump starting command is sent by the captain of the ULCC to execute the oil receiving operation.

The two-stroke ship can also adopt two-side oil discharge in the oil receiving process, two VLCC two-stroke ships are respectively and stably berthed on two sides of the ULCC by the full-revolving wheels with the fire-fighting function according to the sequence, generally berthed on the port side of the ULCC and berthed on the starboard side of the ULCC, and the wiring, connecting pipes and safety inspection procedures among the three ships are the same as those of the single-side oil receiving. When receiving oil, the crude oil in the ULCC bow crude oil tank is unloaded firstly, then the crude oil in the ULCC bow crude oil tank is unloaded, and finally the crude oil in the ULCC stern crude oil tank is unloaded.

The above description is only for the purpose of illustrating the preferred embodiments of the present invention and is not to be construed as limiting the invention, and any modifications, equivalents and improvements made within the spirit and principle of the present invention are intended to be included within the scope of the present invention.

Claims

1. The offshore crude oil lightering method is characterized in that: the offshore crude oil lightering platform comprises a ULCC, wherein a plurality of cleaning ballast tanks are arranged inside a hull of the ULCC; an anchoring structure for fixing a reinforced anchor chain is arranged on a bow deck of the ULCC; the anchoring structure comprises a pin shaft used for being connected with the reinforced anchor chain and lug plates which are arranged at two ends of the pin shaft and used for supporting the pin shaft, and the bottoms of the lug plates are fixedly connected with the bow deck; the pin shaft is inserted into the lug plate, and two ends of the pin shaft are provided with locking pins; when ULCC mooring, an enlarged chain ring of the reinforced anchor chain is connected to the pin shaft; when ULCC needs to be repaired and maintained in the factory, the ULCC is connected to the reinforced anchor chain by a steel cable shackle, the steel cable is tightened by an anchor machine, the enlarged chain ring is loosened, the locking pin is dismounted, the pin shaft is pulled out of the round hole of the lug plate, the enlarged chain ring is separated from the pin shaft, and the enlarged chain ring of the reinforced anchor chain is fixed on the buoy with the navigation aid function by the floating crane; after repairing and maintaining the ULCC and returning, hoisting a reinforced anchor chain to an anchoring structure of the ULCC by using a floating crane on an original anchor site, sequentially passing a pin shaft through a first lug plate, an enlarged chain ring and a second lug plate, and locking the pin shaft by using a locking pin to finish anchoring and mooring of the ULCC; a reinforcing structure for supporting the anchoring structure is arranged below the bow deck, the reinforcing structure comprises an additional deck stringer arranged on the lower surface of the bow deck and a strut for supporting the additional deck stringer, the top of the strut is fixedly connected with the additional deck stringer, and the bottom of the strut is fixedly connected with the upper surface of the second deck;

by using the offshore crude oil lightering platform, the offshore crude oil lightering method comprises the following steps:

A. injecting ballast water into the clean ballast tank;

B. one-trip ship berths for oil, and simultaneously the clean ballast tank is drained outwards; sequentially berthing and refueling a plurality of first-range ships, wherein the displacement of the first-range ship berthed first is smaller than the displacement of the second-range ship berthed second;

C. the two-range ship is moored to receive oil.

2. Offshore crude oil lightering process according to claim 1, characterized in that: in step A, the draft of the ULCC is more than or equal to 9.5 m.

3. Offshore crude oil lightering process according to claim 1, characterized in that: in step B, the draft of the ULCC is less than or equal to 23 m.

4. Offshore crude oil lightering process according to claim 1, characterized in that: and C, the oil receiving of the two-stroke ship is single-board oil receiving.

5. Offshore crude oil lightering process according to claim 1, characterized in that: and C, the oil receiving of the two-stroke ship is carried out on a double board.