METHOD FOR BLOCKING OUTFLOW OF PETROLEUM OR THE LIKE DUE TO DAMAGE TO SUBSEA PETROLEUM WELL STELL PIPE OR THE LIKE

Abstract

The present invention relates to blocking a flow of crude oil or natural gas from a steel pipe for extracting the oil or the like that has been installed in the sea when the steel pipe is broken. When damage occurs to a steel pipe 4 for petroleum or natural gas well that has been installed in the sea, in order to send magnetic particles 21 or the like into the seafloor through an carrying pipe 6 that has been installed and suspended inside the steel pipe 4, the outflow of petroleum or the like coming from a lower portion of the carrying pipe 6 is blocked by a gate valve 20 provided at a lower portion of a feeding equipment 12 for feeding magnetic particles or the like attached to an upper opening 7 of the carrying pipe 6. After that, pressurized water is injected into a housing 14 accommodating magnetic particles or the like of the feeding equipment 12 to sweep the magnetic particles 21 or the like in the housing 14 into the carrying pipe 6 and drop the magnetic particles 21 or the like to the lower end of the carrying pipe 6. The magnetic particles 21 or the like are magnetically adhered to an inner surface of the steel pipe 4 so that the magnetic particles 21 or the like form a mass, suppressing the outflow of petroleum or natural gas. As a result, mortar or concrete 27 can be injected to block the outflow of petroleum or the like.

Description

TECHNICAL FIELD

The present invention blocks a flow of crude oil or natural gas from a steel pipe for extracting the oil or the like that has been installed in the sea when the steel pipe is broken.

BACKGROUND ART

As a method to, when oil flows out from a hole caused by damage to a subsea petroleum well steel pipe, block the hole, inserting a carrying pipe from the hole and injecting concrete is conceivable. However, even if this method is carried out, it is not possible to cure concrete because the outflow pressure of oil pushes back the concrete and the concrete is dispersed in the seawater.

Accordingly, the following method may be used as an alternative. A steel pipe is buried near the place where a petroleum well steel pipe has been buried in the seafloor. Then, the steel pipe is connected to the side wall of the damaged steel pipe in the place where it has been buried in the seafloor. Then, a barrier material is charged through the steel pipe so as to suppress the outflow of oil. After that, concrete is injected. This method, however, requires troublesome large-scale work, and it is therefore difficult to complete in a short time.

SUMMARY OF INVENTION

[Technical Problem]

Mere insertion of a carrying pipe into a hole caused by damage to a subsea petroleum well steel pipe results in, even if concrete is injected, the concrete being pushed back by the outflow pressure of oil. Accordingly, an object of the present invention is to provide a method with which the outflow of crude oil is suppressed prior to injection of concrete.

[Method of Solving the Problem]

When damage occurs to a steel pipe 4 for petroleum or natural gas well that has been installed in the sea, magnetic particles 21 or the like are sent deeply into the seafloor through a carrying pipe 6 that has been installed and suspended inside the steel pipe 4. To implement this, the outflow of petroleum or the like coming from a lower portion of the carrying pipe 6 is blocked by a gate valve 20 provided at a lower portion of a feeding equipment 12 for feeding magnetic particles or the like attached to an upper opening 7 of the carrying pipe 6. After that, a switching valve 19 provided at an upper portion of the equipment and the gate valve 20 are opened simultaneously so as to inject pressurized water into a housing 14 accommodating magnetic particles or the like of a rotary disk 13 to sweep the magnetic particles 21 or the like in the housing 14 into the carrying pipe 6 and drop the magnetic particles 21 or the like to the lower end of the carrying pipe 6. The magnetic particles 21 or the like thereby move along the flow of petroleum or the like in the steel pipe 4 and reach a conical metal mesh 11 attached to the carrying pipe 6. The magnetic particles 21 or the like are blocked up by the conical metal mesh 11 and magnetically adhere to an inner surface of the steel pipe 4. The resulting adherent layer gradually grows downward and reaches a circular mesh plate 8 provided at a tip portion of the carrying pipe 6. The magnetic particles 21 or the like then fill the inside of the steel pipe 4 and form a mass due to magnetic force, suppressing the outflow of petroleum or natural gas. After that, mortar, concrete 27 or the like is injected from the upper opening 7 of the carrying pipe 6 and cured to block the outflow of petroleum or natural gas.

BRIEF DESCRIPTION OF DRAWINGS

FIG. 1 is a vertical cross-sectional view showing a state in which a steel pipe including a carrying pipe therein according to an embodiment of the present invention has been cracked.

FIG. 2 is an enlarged vertical cross-sectional view showing a part of FIG. 1.

FIG. 3 is a cross-sectional view taken along the line A-A shown in FIG. 2.

FIG. 4 is a vertical cross-sectional view showing the initial stage of charging magnetic particles into a steel pipe according to an embodiment of the present invention.

FIG. 5 is a vertical cross-sectional view showing the final stage of charging magnetic particles into the steel pipe.

FIG. 6 is a vertical cross-sectional view showing a state in which a feeding equipment for feeding magnetic particles or the like has been attached above a carrying pipe of the present invention.

FIG. 7 is a cross-sectional view taken along the line B-B shown in FIG. 6.

FIG. 8 is a plan view of a magnetic particle composite bar used to carry out the present invention.

FIG. 9 is a cross-sectional view taken along the line C-C shown in FIG. 8.

FIG. 10 is a vertical cross-sectional view of a steel wire rope-reinforced polyethylene carrying pipe used to carry out the present invention.

FIG. 11 is a cross-sectional view taken along the line D-D shown in FIG. 10.

DESCRIPTION OF EMBODIMENTS

When damage occurs to a steel pipe 4 for petroleum or natural gas well that has been installed in the sea, magnetic particles 21 or the like are sent deeply into the seafloor through a carrying pipe 6 that has been installed and suspended inside the steel pipe 4. To implement this, the outflow of petroleum or the like coming from a lower portion of the carrying pipe 6 is blocked by a gate valve 20 provided at a lower portion of a feeding equipment 12 for feeding magnetic particles or the like attached to an upper opening 7 of the carrying pipe 6. After that, a switching valve 19 provided at an upper portion of the equipment and the gate valve 20 are opened simultaneously so as to inject pressurized water into a housing 14 accommodating magnetic particles or the like of a rotary disk 13 to sweep the magnetic particles 21 or the like in the housing 14 into the carrying pipe 6 and drop the magnetic particles 21 or the like to the lower end of the carrying pipe 6. The magnetic particles 21 or the like thereby move along the flow of petroleum or the like in the steel pipe 4 and reach a conical metal mesh 11 attached to the carrying pipe 6. The magnetic particles 21 or the like are blocked up by the conical metal mesh 11 and magnetically adhere to an inner surface of the steel pipe 4. The resulting adherent layer gradually grows downward and reaches a circular mesh plate 8 provided at a tip portion of the carrying pipe 6. The magnetic particles 21 or the like then fill the inside of the steel pipe 4 and form a mass due to magnetic force, suppressing the outflow of petroleum or natural gas. After that, mortar, concrete 27 or the like is injected from the upper opening 7 of the carrying pipe 6 and cured to block the outflow of petroleum or natural gas.

In order to avoid a situation in which it is difficult to feed individual magnetic particles due to adhesion of magnetic particles to each other, a paper-wrapped magnetic particle composite bar 15 is created. The magnetic particle composite bar 15 is an elongated bar in which non-magnetic clay 22 is present between a plurality of magnetic particles. The magnetic particle composite bar 15 is inserted in the housing 14 of the feeding equipment 12 for feeding magnetic particles or the like, and the magnetic particle composite bar 15 is caused to flow into the carrying pipe 6 by the pressurized water. When the magnetic particle composite bar 15 moves from the bottom of the carrying pipe 6 to the steel pipe 4, soluble wrapping paper 23 is dissolved by petroleum or the like, and the magnetic particles 21 are dispersed. The individual magnetic particles 21 firmly adhere to the inner surface of the steel pipe 4. The magnetic particles are sent in this manner.

As shown in FIG. 6, a non-magnetic receiving frame 16 is provided in the housing 14 of the feeding equipment 12 for feeding magnetic particles or the like. Four paper-wrapped magnetic particle composite bars 15 are inserted into the receiving frame 16. The magnetic particle composite bars 15 are elongated bars in which the clay 22 is present between a plurality of magnetic particles. The rotary disk 13 is rotated to move the magnetic particle composite bars 15 to the position of the carrying pipe 6. When the switching valve 19 and the gate valve 20 are opened, the four magnetic particle composite bars 15 are simultaneously fed by the pressurized water delivered by a pump or the like to respective four sections of the carrying pipe 6 defined by a partition 31, with the receiving frame 16 left in place. The rotary disk 13 includes eight housings 14, and the magnetic particle composite bars 15 loaded in housings 14 are fed in sequence. Accordingly, a large amount of magnetic particles 21 can be continuously fed to the carrying pipe 6.

When feeding of the magnetic particle composite bars 15 has finished, the switching valve 19 for pressurized water is switched to a secondary conduit 36, and the gate valve 20 of the housing 14 is closed. Consequently, the pressurized water flows into the carrying pipe 6 through the secondary conduit 36. Therefore, the magnetic particle composite bars 15 that have been sent previously are smoothly swept downward.

As the carrying pipe 6, pipes made of nonmagnetic material can be used such as a polyethylene pipe, a steel wire rope-reinforced polyethylene pipe, an impact resistant vinyl chloride pipe and a stainless steel pipe. It is most appropriate to use a steel wire rope-reinforced polyethylene pipe 29 as the carrying pipe 6. As used herein, “steel wire rope-reinforced polyethylene pipe 29” refers to a pipe reinforced with a plurality of flexible steel wire ropes 30 in order to resist breakage of the steel pipe 4. The plurality of flexible steel wire ropes 30 are circumferentially disposed and buried inside the pipe wall and each extends in the axial direction thereof. There are projections and depressions in the surface of a steel wire rope 30 and thus the steel wire rope 30 can be firmly adhered to and integrated with polyethylene resin. A pipe connector 32 for connecting the pipes includes a reinforcing metal mesh 33 buried near the outer circumference surface and a nichrome wire 34 buried near the inner circumference surface. The pipe connector 32 is produced by injection molding. An end of the steel wire rope-reinforced polyethylene pipe 29 is inserted into a receptacle in the inner circumference of the pipe connector 32, and electric current is applied to nichrome wire terminals 35 so as to fuse the steel wire rope-reinforced polyethylene pipe 29 and the pipe connector 32. The fusion can provide sufficient resistance to external tensile force.

The magnetic particles 21 have a size ranging from several to several tens of millimeters. The shape can be rectangular bar-shaped, round bar-shaped, plate-shaped or the like. The magnetic particles 21 may be wrapped in clay or soluble paper. Alternatively, the magnetic particles 21 may form a longitudinal shape with the clay 22 sandwiched therebetween, and the resultant is wrapped in the soluble paper 23, thereby forming a bar. Iron particles having a spherical shape, round bar-shape, cube-shape or the like are used. Powdered iron may be mixed with pebbles, sand or the like and used. The powdered iron and sand or pebbles may be fed into the carrying pipe 6 from another feeding port other than the magnetic particles feeding equipment 12.

The circular mesh plate 8 has a structure in which it is suspended by a hanger bar 9 made of copper alloy or stainless steel. The conical metal mesh 11 is made of copper alloy or stainless steel. The conical metal mesh 11 is sized such that its outer circumference is contact with the inner circumference of the steel pipe 4. Instead of the conical metal mesh 11, a tea whisk-shaped metal obtained by finely splitting and flaring the top half of a thin-wall cylinder may be used.

INDUSTRIAL APPLICABILITY

This method that uses magnetic particles can be widely used in the event of an emergency such as the pipe being damaged.

REFERENCE SIGNS LIST

1 Sea Surface

2 Seafloor

3 Seawater

4 Steel Pipe for Petroleum or Natural Gas Well

5 Broken Point in Petroleum Well Steel Pipe

6 Carrying Pipe

7 Upper Opening of Carrying Pipe

8 Circular Mesh Plate

9 Hanger Bar of Circular Mesh Plate

10 Fixing Bolt of Hanger Bar

11 Conical Metal Mesh

12 Feeding Equipment for Feeding Magnetic Particles or the Like

13 Rotary Disk

14 Housing Accommodating Magnetic Particles or the Like of Rotary Disk

15 Magnetic Particle Composite Bar

16 Receiving Frame for Magnetic Particle Composite Bar

17 Axial Face of Rotary Disk

18 Motor for Driving Rotary Disk

19 Switching Valve for Pressurized Water

20 Gate Valve of Housing

21 Magnetic Particles

22 Clay

23 Soluble Wrapping Paper

24 Powdered Iron

25 Sand/Pebbles

26 Steel Balls

27 Mortar or Concrete

28 Base

29 Steel Wire Rope-Reinforced Polyethylene Pipe

30 Reinforcing Steel Wire Rope

31 Partition inside Polyethylene Pipe

32 Reinforced Polyethylene Pipe Connector

33 Reinforcing Metal Mesh

34 Nichrome Wire

35 Nichrome Wire Terminal

36 Secondary Conduit

Claims

1. A method for blocking an outflow of petroleum or the like due to damage to a subsea petroleum well steel pipe or the like, the method comprising:

when a steel pipe for petroleum or natural gas well that has been installed in the sea is damaged, in order to send magnetic particles or the like into the seafloor through an carrying pipe that has been installed and suspended inside the steel pipe, blocking an outflow of petroleum or the like coming from a lower portion of the carrying pipe by a gate valve provided at a lower portion of a feeding equipment for feeding magnetic particles or the like attached to an upper opening of the carrying pipe;

after the outflow of petroleum or the like has been blocked, simultaneously opening a switching valve provided at an upper portion of the feeding equipment for feeding magnetic particles or the like and the gate valve, whereby pressurized water is injected into a housing accommodating magnetic particles or the like and provided in a rotary disk 13 to sweep the magnetic particles or the like in the housing into the carrying pipe and drop the magnetic particles or the like to a lower end of the carrying pipe, and the magnetic particles or the like move along the flow of petroleum or the like in the steel pipe, reach a conical metal mesh attached to the carrying pipe, are blocked up by the conical metal mesh and magnetically adhere to an inner surface of the steel pipe, and a resulting adherent layer gradually grows downward so that the magnetic particles or the like reach a circular mesh plate provided at a tip portion of the carrying pipe, fill inside of the steel pipe and form a mass due to magnetic force, suppressing the outflow of petroleum or natural gas; and

after the outflow of petroleum or natural gas has been suppressed, injecting mortar, concrete or the like from the upper opening of the carrying pipe and curing the mortar, concrete or the like.

2. The method for blocking an outflow of petroleum or the like due to damage to a subsea petroleum well steel pipe or the like according to claim 1, comprising:

providing a non-magnetic receiving frame including several compartments in the housing of the feeding equipment for feeding magnetic particles or the like, placing the magnetic particles in the compartments, and causing the magnetic particles in the compartments to simultaneously flow into sections of the carrying pipe by the pressurized water, the sections being formed by dividing the carrying pipe into the same number as the compartments by a partition.

3. The method for blocking an outflow of petroleum or the like due to damage to a subsea petroleum well steel pipe or the like according to claim 1, comprising:

in order to prevent the carrying pipe from breaking at the same time when the steel pipe is broken, using a steel wire rope-reinforced polyethylene carrying pipe in which a plurality of flexible steel wire ropes are circumferentially disposed and buried inside a wall of the polyethylene pipe and each extends in an axial direction thereof, and that is capable of sinking in the sea due to weight of the steel wire ropes, as the carrying pipe.

4. The method for blocking an outflow of petroleum or the like due to damage to a subsea petroleum well steel pipe or the like according to claim 2, comprising:

in order to prevent the carrying pipe from breaking at the same time when the steel pipe is broken, using a steel wire rope-reinforced polyethylene carrying pipe in which a plurality of flexible steel wire ropes are circumferentially disposed and buried inside a wall of the polyethylene pipe and each extends in an axial direction thereof, and that is capable of sinking in the sea due to weight of the steel wire ropes, as the carrying pipe.