KR102019267B1

KR102019267B1 - Apparatus for releasing stress of subsea pipeline

Info

Publication number: KR102019267B1
Application number: KR1020120133456A
Authority: KR
Inventors: 박명철; 주영석
Original assignee: 대우조선해양 주식회사
Priority date: 2012-11-23
Filing date: 2012-11-23
Publication date: 2019-09-06
Also published as: KR20140066349A

Abstract

The present invention relates to stress relief of subsea pipes, and more specifically, to reduce the design stress on the pipes by relieving the stresses generated in the seabed pipes, thereby reducing the thickness of the pipes and thus the time and cost required for construction. The stress relief device of the subsea pipe can reduce the
Stress relief device of the subsea pipe according to the present invention includes a body connected to the subsea pipe, the elastic portion is provided to be stretchable to the body and the stress absorbing portion provided to absorb the stress applied to the body.

Description

Apparatus for releasing stress of subsea pipeline}

The present invention relates to a stress reliever of a subsea pipe, and more particularly, to a stress reliever of a subsea pipe configured to reduce construction costs by reducing the thickness of a pipe by relieving stress generated in a subsea pipe.

In general, in the case of steel pipes installed on the sea floor, buckling occurs due to thermal stress generated during shut-in or shut-down. Cause.

In addition, as a kind of subsea pipe, a steel catenary riser used for drilling causes stress on the riser due to the movement of the vessel due to algae or waves. At this time, the stress applied to the riser is largely generated in the part in contact with the bottom of the sea floor.

Conventionally, a method of increasing the thickness of a steel pipe or steel canister riser has been used to withstand the stresses generated in the subsea pipes. However, this conventional method has a problem of incurring the cost of materials and increasing the installation and transportation costs of the subsea pipes.

This problem can be applied not only to risers used for drilling, but also to pipes installed on the seabed for fluid transfer such as oil or deep water.

The present invention is to solve the conventional problems as described above, it is possible to reduce the design stress by releasing the stress generated in the subsea pipes, thereby reducing the thickness of the pipes to reduce the construction cost have.

According to an aspect of the present invention for achieving the above object, as a remover of the stress applied to the subsea pipe, a body connected to the subsea pipe; An elastic part provided on the body to enable expansion and contraction; And a stress absorber provided to absorb the stress applied to the body.

The body is bisected and connected by the expansion and contraction, the connection portion for connecting the subsea pipes are provided on each side, the connection tube of a flexible material for connecting the connection to each other may be installed inside.

The body can be fixed to any one of the two nutrients.

When the stress is released, the body may be provided with an elastic member for providing an elastic force to return to its original length.

The elastic member is made of a coil spring is installed in a plurality along the periphery of the central portion in the body, it can be fixed by mounting both ends in the mounting portion provided on both sides in the body.

The stretchable portion may be fixed to both ends of the bisecting portion of the body, the wrinkles may be formed to stretch.

The stress absorbing unit detects the elastic expansion and contraction of the body and outputs a detection signal; A fluid supply unit for circulating and supplying a fluid for absorbing stress in the body; And a controller configured to receive the detection signal of the stretch detection unit and control the inflow and outflow of the fluid through the fluid supply unit.

The stretch detection unit may be formed of a tension sensor is installed to be pressed to the elastic member installed in the stretch direction in the body.

The fluid supply unit is a storage tank in which the fluid is stored; An inlet line connected to inject fluid from the storage tank to the body and having an inlet valve controlled by the controller; An outflow line connected to outflow the fluid from the body to the storage tank and having an outflow valve controlled by the control unit; And it may include a pump that is installed to provide a pumping force for the inflow of the fluid in the inlet line.

According to another aspect of the present invention, a stress remover applied to a subsea pipe, the body includes a body connected to the expansion and contraction to the subsea pipe, the stress applied to the body is absorbed by the stress absorbing portion so that the subsea pipe A stress reliefr of the subsea pipe is provided which eliminates the stress applied to the undersea pipe.

It may include an elastic portion provided in the body so that the body is stretchable.

The stretchable portion may be divided into two divided parts of the body is fixed at both ends, the wrinkles may be formed to stretch.

According to the present invention, it is possible to lower the design stress for the pipe by relieving the stress generated in the subsea pipe, thereby reducing the thickness of the pipe can reduce the time and cost required for construction.

1 is a cross-sectional view showing a stress canceller of the subsea pipe according to an embodiment of the present invention.
Figure 2 is a cross-sectional view for explaining the operation of the stress relief device of the subsea pipe according to an embodiment of the present invention.

Hereinafter, the configuration and operation of the preferred embodiment of the present invention will be described in detail with reference to the accompanying drawings. In addition, the following examples may be modified in many different forms, and the scope of the present invention is not limited to the following examples.

1 is a cross-sectional view showing a stress canceller of a subsea pipe according to an embodiment of the present invention.

Referring to FIG. 1, the stress canceller 100 of the subsea pipe according to an embodiment of the present invention includes a body 110 connected to the submarine pipes 10 and 20 so as to be extensible, and the body 110. The stress applied to the submerged pipes 10 and 20 may be removed by the stress absorbing part 130 to be absorbed. For this purpose, the body 110, the elastic part 120, and the stress absorbing part ( 130). Here, the subsea pipes 10 and 20 may be steel pipes, for example, steel catenary risers used for drilling. In addition, the subsea pipes 10 and 20 may be applied as pipes installed on the sea floor for fluid transfer such as oil or deep water. All subsea installation pipes requiring stress relief can be applied.

Body 110 is, for example, in order to be connected to the subsea pipes (10, 20), can be divided by the expansion and contraction portion 120, the connection portion 113 for connecting the subsea pipes (10, 20) are both sides Each of the connection tubes 114 may be provided on the inside of the flexible material, for example, a rubber material having corrosion resistance, and the like. In addition, the body 110 may be made of stainless steel, and in addition, any material that satisfies the stress transmission and corrosion resistance of the subsea pipes 10 and 20 may be used.

The connecting portion 113 may be flanged to the bolt 113b through the flange of the subsea pipe 10 through the O-ring 113a, and the extension 113c extending inwardly of the body 110 is the O-ring 113d. The connection tube 114 may be fixed to the extension part 113c by being fastened to the connection tube 114 via the clamp 113e.

The body 110 may be fixed to the bottom of any one of the divided parts (111, 112) divided into two. Here, the partition 111 fixed to the seabed may be connected to the pipe 10 to prevent stress from being transmitted among the seabed pipes 10 and 20. In addition, the partition 112 that is not fixed to the seabed may be connected to the pipe 20 through which stress is transmitted among the seabed pipes 10 and 20.

The body 110 may be provided with an elastic member 115 to provide an elastic force to return to the original length when the stress is released. Here, the elastic member 115 is made of a coil spring may be installed in a plurality along the periphery of the central portion in the body 110, for example, may be installed in each corner portion in the body 110, both sides in the body 110 Both ends may be fixed to the mounting unit 116 provided in the mounting unit 116. In addition, the mounting portion 116 may have a shape of a groove for mounting by mounting the elastic member 115 inside, as in the present embodiment, or as another example, the protrusion of the protrusion for mounting by mounting the elastic member 115 outside It may have a form.

The stretchable portion 120 is provided to be stretchable in the body 110. For example, the divided parts 111 and 112, which are divided into two parts of the body 110, are fixed to both ends and are reduced when stressed, and under tension. Pleats 121 that can be stretched to extend to their original length can be formed, and for this purpose, a corrugated rubber member having corrosion resistance can be used. On the other hand, the elastic portion 120 is coupled to the partitions (111, 112) to maintain the airtight inside the body 110, for this purpose by tightening the clamp 122 having a ring shape as in this embodiment to the body (110) It may be fixed to be in close contact with each other, for example, using a connecting member such as a bracket or a flange joint member, or using an adhesive method, in addition to this can be coupled to the partitions (111, 112) by various methods. . In addition, the stretching unit 120 may be provided with a sealing member such as an O-ring between the body 110, in order to increase the airtight force.

The stress absorbing unit 130 is provided to absorb the stress applied to the body 110, and the elastic detecting unit 131 and the body 110 to detect the expansion and contraction of the body 110 and output as a detection signal as in this embodiment; The control unit 133 for controlling the inflow and outflow of the fluid through the fluid supply unit 132 receives the detection signal from the fluid supply unit 132 and the elastic sensing unit 131 for circulating supplying the fluid for stress absorption in the) It may include.

The stretch detection unit 131 may be formed of a tension sensor installed to be pressed by the elastic member 115 installed in the stretch direction in the body 110. To this end, the stretch detecting unit 131 is installed in the mounting unit 116 to act on the elastic member 115. To measure the tension. In addition, the elastic sensing unit 131 may be installed in a plurality to correspond to each of the elastic members 115, in which case, the control unit 133 by using the maximum value or the average value from the values received from the elastic sensing unit 131 The inlet valve 132b, the outlet valve 132d, and the pump 132f can be controlled.

The fluid supply unit 132 is connected to the storage tank 132a in which the fluid is stored, and the inflow valve 132b controlled by the control unit 133 to connect the fluid to the body 110 from the storage tank 132a. An inflow line 132e which is installed to be connected to the inflow line 132c installed therein, and a fluid outlet from the body 110 to the storage tank 132a, and an outlet valve 132d controlled by the controller 133 is installed; In addition, the inlet line 132c may include a pump 132f installed to provide a pumping force for the inflow of the fluid. Here, not only the pump 132f but also a power source required for the operation of the controller 133 may be provided through a separate power line from the ship.

The storage tank 132a may be filled with oil that does not cause corrosion as a fluid, and both the iron part and the rubber part may prevent deformation due to external hydro-static force.

The inlet valve 132b and the outlet valve 132d may be control valves operated by a control signal of the controller 133, and may include a check valve for controlling the flow of fluid in one direction or include a check valve. have.

The operation of the stress canceller of the subsea pipe according to the present invention will be described.

As shown in FIG. 2, when the body 110 is reduced by the compression of the elastic part 120 due to the stress generated in the pipe 20, the elastic sensing part 131 is pressed by the elastic member 115. Through the control unit 133 recognizes the length reduction due to the compression through the opening, by opening the outlet valve 132d by the reduced volume of the fluid, such as oil in the body 110 and the expansion portion 120, such as oil to the storage tank 132a Allow spills. At this time, the body 110 prevents the stress transmitted from the pipe 20 from being transferred to the other pipe 10 due to the structure in which the other partition 112 moves from the partition 111 fixed to the seabed.

As shown in FIG. 1, when the stress on the body 110 is released, the controller 133 recognizes the signal through a signal of the elastic sensing unit 131 installed in the elastic member 115, and the pump 132f. By operating the valve and opening the inlet valve 132b, the fluid, such as oil, stored in the storage tank 132a is filled in the body 110.

As described above, according to the present invention, the stress generated in the subsea pipe can be solved to lower the design stress on the pipe, thereby reducing the thickness of the pipe, thereby reducing the time and cost required for construction.

The present invention is not limited to the above embodiments, and various modifications or changes may be made without departing from the technical spirit of the present invention, which will be apparent to those of ordinary skill in the art. It is.

10,20: subsea pipe 110: body
111,112: Partition 113: Connection portion
113a: O-ring 113b: Bolt
113c: Extension 113d: O-ring
113e: Clamp 114: Connecting tube
115: elastic member 116: mounting portion
120: elastic portion 121: wrinkles
122: clamp 130: stress absorbing part
131: stretch detection unit 132: fluid supply unit
132a: storage tank 132b: inlet valve
132c: Inlet line 132d: Outlet valve
132e: Outflow line 132f: Pump
133: control unit

Claims

As a remover of stress applied to a subsea pipe,
A body 110 that is bisected into the divided parts 111 and 112, in which connection parts 113 for connecting the subsea pipes 10 and 20 are provided, respectively;
An expansion and contraction unit 120 coupled between the partitions 111 and 112 so as to maintain an airtight inside the body 110 and provided to be elastic;
A stress absorbing part 130 provided to absorb the stress applied to the body 110;
Is installed in the elastic direction in the body 110, a plurality of elastic members 115 to provide an elastic force to return to the original length when the stress applied to the body 110 is released; includes; and,
The stress absorbing unit 130,
A stretch detection unit 131 which detects the stretch of the body 110 and outputs it as a detection signal;
A fluid supply part 132 for circulating and supplying a fluid for absorbing stress in the body 110; And
And a control unit 133 which receives the detection signal of the stretch detection unit 131 and controls the inflow and outflow of the fluid through the fluid supply unit 132,
The stretch sensing unit 131 is made of a tension sensor that is installed to be pressed by the elastic member 115, it is provided in plurality to correspond to each of the plurality of elastic members 115,
The control unit 133 is a stress relief device of the subsea pipe to control the fluid supply unit 132 by using the maximum value or the average value of the values received from the plurality of stretch detection unit (131).

The method according to claim 1, wherein the body 110,
Stress reliever of the subsea pipe is connected to the connecting tube 114 of a flexible material for connecting the connecting portion 113 to each other.

The method according to claim 2, The body 110,
Stress relief device of the subsea pipe to which one of the divided parts (111, 112) divided into two is fixed to the sea floor.

delete

The method of claim 1, wherein the elastic member 115,
Comprised of a coil spring is installed in a plurality along the periphery of the center in the body 110, both ends are mounted to the mounting portion 116 provided on both sides in the body 110 is fixed by the stress pipe of the subsea pipe.

The method of claim 1, wherein the stretchable portion 120,
The splitter (111, 112), which is divided into two parts of the body (110), is fixed at both ends, and the stress relief device of the subsea pipe is formed with a corrugation (121) to enable stretching.

delete

The method of claim 1, wherein the fluid supply unit 132,
A storage tank in which the fluid is stored;
An inlet line 132c connected to inlet fluid from the storage tank 132a to the body 110 and having an inlet valve 132b controlled by the controller 133;
An outlet line 132e connected to the fluid to the storage tank 132a from the body 110 and having an outlet valve 132d controlled by the controller 133;
And a pump (132f) installed to provide a pumping force for the inflow of the fluid to the inlet line (132c).

delete