JPS6249520B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an apparatus for transporting crude oil by pipeline to locations where the temperature of the transport route is low, such as the ocean floor or cold regions.

Tankers are generally used as a means of transporting crude oil by sea, and in some cases pipeline transport is also used. If tanker transportation could be replaced with pipeline transportation in these two cases, transportation costs could be reduced. On the other hand, when transporting crude oil over long distances or in cold regions, the pipeline must be heated by electrical means to maintain the viscosity of the crude oil while transporting it.
This requires such construction at sea, making it unsuitable for sea transport, especially in cold regions or over long distances.

From this point of view, the inventor of the present invention has conducted extensive research into an effective method for transporting crude oil on the seabed by pipeline. As a result, we developed a method of making the pipeline a double-tube structure, electrically connecting the inner and outer tubes in series, and heating the inner and outer tubes with Joule heat by directly passing an alternating current through them. I ended up developing it. When this method is implemented, crude oil can be transported under the sea by directly heating the crude oil on the inner tube side, while keeping the inner tube warm on the outer tube side and protecting the inner tube from water pressure, corrosion, etc. In addition, according to this method, it is easy to install cables on the seabed, and since there is no cable wiring in the transportation line, there is no risk of electrical problems occurring on the seabed over time. It is possible to realize pipeline equipment that can be used for ten years.

Examples of the present invention will be described in detail below.

FIG. 1 is a submarine pipeline transport diagram in which the present invention is implemented. Pipeline a, as shown in FIG. The transport steel pipe 1 and the sheath steel pipe 2 are electrically connected 3 at their terminals, and an alternating current is applied to the transport steel pipe 1 via a conductor 5 from an alternating current power supply device 4,
The current passes through the transport steel pipe 1 from the connection 3 to the sheathed steel pipe 2, and passes through the sheathed steel pipe 2 as a return path to the conductor 6.
The configuration is such that the AC current is returned to the AC power supply device 4 from there.

In the figure, 7 is an insulating and heat-insulating layer covering the outside of the transport steel pipe 1, and 8 is a concrete layer covering the outside of the sheathed steel pipe 2, which is intended for laying on the seabed.

Next, to explain the operation of the apparatus according to the present invention, the laying of the pipeline a starts with the sheathed steel pipe 2.
is welded on the ground and laid on the seabed with a concrete layer 8, and then the transport steel pipe 1 is welded on the ground and inserted into the laid outer sheath steel pipe 2 while covering it with the insulation and heat insulation layer 7. and electrically connect 3 at the terminal.

Pipeline a is laid as described above, and the first
Crude oil is pumped from a base 9 to a base 10 shown in the figure using a transport steel pipe 1. In this transportation,
When an alternating current is applied from the alternating current power supply device 4 to the transport steel pipe 1, the current flows through the outer surface of the transport pipe 1 due to its AC electrical characteristics (resistance loss, iron loss), generates heat on the outer surface, and flows inside. Heating crude oil to reduce its viscosity. Further, the alternating current that has passed through the transport steel pipe 1 and flowed from the terminal into the jacket steel pipe 2 flows to the inner surface of the jacket steel pipe 2, and similarly generates heat on the inner surface of the jacket steel pipe 2 due to the AC electrical characteristics. The jacketed steel pipe 2 heats the inside of the jacketed steel pipe 2 by this heat generation, keeps the transport steel pipe 1 warm, and blocks the influence of low temperatures on the seabed.

The present invention heats a pipeline on the seabed as described above, and its main effects are listed below.

(1) The transport steel pipe 1 and the jacketed steel pipe 2 form a double pipe structure, and an alternating current is applied directly to this using the AC current power supply device 4 to coat the outer surface of the transport steel pipe 1 and the inner surface of the jacket steel pipe 2. Generates heat using AC electrical characteristics,
Since the crude oil in the transport steel pipe 1 is heated to reduce its viscosity, it is possible to transport the crude oil by pipeline on the seabed or in cold regions.

(2) Since there are no cables or other electrical wiring in pipeline a, there is no need to worry about electrical failures, making it ideal as an undersea pipeline heating device that cannot be repaired once installed. .

(3) Since the sheathed steel pipe 2 generates heat to keep the transport steel pipe 1 warm, heat escape from the transport steel pipe 1 is almost eliminated.

(4) Since the transport steel pipe 1 is completely surrounded by the sheath steel pipe 2, even if crude oil should leak from the transport steel pipe 1, the sheath steel pipe 2 will prevent the crude oil from leaking into the sea.

(5) When laying a pipeline, first install the jacket steel pipe 2.
Since the transport steel pipe 1 can be welded and then laid while being welded and then inserted into the sheath steel pipe 2 while being welded, insulated, and heat-insulated, the laying work can be carried out on the ground.

(6) Since the current flows only through the inner surface of the sheathed steel pipe 2, there is no need to coat the outer surface of the sheathed steel pipe 2 with an expensive insulating material.

(7) The jacketed steel pipe 2 protects the transport steel pipe 1 from water pressure and external damage.

(8) The device of the present invention can be implemented not only for the submarine pipeline transportation of crude oil, but also for the transportation of other viscous substances on the ocean floor, on land, and in cold regions, and has a wide range of applications.

[Brief explanation of the drawing]

Fig. 1 is an example diagram of the device of the present invention applied to a submarine pipeline, Fig. 2 is an explanatory diagram of a transport pipe and heating method in which the present invention is implemented, and Fig. 3 is a cross-sectional view taken along the line A-A. . 1...Transportation steel pipe, 2...Sheath steel pipe, 3...Connection, 4...Power source, 5, 6...Conductor wire, 7...Insulation and heat insulation layer, 8...Concrete layer, 9, 10...
base.

Claims (1)

[Claims] 1. A transport steel pipe (inner pipe) made of a ferromagnetic material for transporting crude oil, and a ferromagnetic material surrounding this transport steel pipe to form a double pipe structure and electrically connected to the transport steel pipe at the terminal. A crude oil pipe transportation device consisting of a jacketed steel pipe, an insulating and heat-insulating material covering the transport steel pipe, and an alternating current power supply device having power supply terminals connected to the transport steel pipe and the jacket steel pipe, respectively.