CN102175437A - Buckling test device for deepwater submarine conduit - Google Patents

Abstract

The invention belongs to the technical field of deep-sea oil development and transportation, and relates to a buckling test device for a deep-water submarine pipeline, comprising a pressure chamber composed of a main cabin, a front hatch, and a rear hatch of the cabin, the front hatch and the rear hatch The covers are respectively connected to the two ends of the main cabin body. Sealing rings are provided on the inner sides of the front hatch and the rear hatch. A hydraulic press is fixed on the front hatch. The piston rod of the hydraulic press extends through the front hatch to the main compartment. In the body, the end of the piston rod is provided with a piston rod flange, and a guide rail is provided on the bottom upper surface of the main cabin, and a pulley for transporting the pipeline test piece is placed on the guide rail, and the two ends of the pipeline test piece are connected with the pipe end Flange, the described piston rod flange matches with the pipeline end flange, and the pipeline end flange on the other end of the pipeline test piece matches with the top and bottom flanges fixed on the rear end hatch cover of the cabin body. The invention can simulate the deep-sea high-pressure environment, and carry out buckling tests of pipelines under various loads.

Description

A deep water submarine pipeline buckling test device

technical field

The invention belongs to the technical field of deep sea oil development and transportation, and relates to a buckling test device for a submarine pipeline.

Background technique

The marine environment, especially the deep sea environment, has complex and diverse conditions. Submarine pipelines not only bear self-weight, external hydrostatic pressure, internal pressure, medium temperature, prestress, force of pipeline accessories, force of covering and seabed, force caused by pigging operation, etc. Functional loads, as well as environmental loads such as wind, waves, currents, ice (for riser or landing pipeline sections) and earthquakes, are also challenged by occasional loads such as extreme sea conditions, ship collisions, falling objects, sand liquefaction, and operational failures. Pipelines laid in deep water areas are very likely to fail under the action of external loads, such as yield failure of the spanning section of the pipeline, buckling, collapse, and fatigue failure of the pipeline due to high hydrostatic pressure and axial force in the deep water area. . Once the submarine pipeline is damaged, leaked or broken due to various reasons, it will not only cause huge losses to the national economy, but also cause serious pollution to the marine environment. Therefore, it is necessary to study key technologies such as the structural characteristics of deepwater submarine pipelines.

At present, the research on the structural buckling theory of deepwater pipelines is still in the exploratory stage, and experimental research on the buckling mechanism and conditions of deepwater submarine pipelines is needed to verify and improve the buckling theory. At present, a variety of test devices for studying pipeline buckling have been developed at home and abroad, and the pipeline buckling test technology has been perfected. For example, the bell-shaped pressure chamber in Norway is placed vertically to measure the buckling performance of the upper and lower sides of the plate under the action of hydrostatic pressure difference, but the maximum pressure of the pressure chamber is only 4Mpa; while the domestic 915 pressure cylinder has a working section with a diameter of 1.5 m, the length of the working section is 2.9m, the pressure cylinder is also vertical, and the pipeline buckling test device suitable for longer pipe fittings and considering various load combinations has not yet appeared in China.

Contents of the invention

The purpose of the invention is to provide a device capable of simulating the deep-sea high-pressure environment and performing buckling tests of pipelines under various loads. Technical scheme of the present invention is as follows:

A buckling test device for deep-water submarine pipelines, used for buckling tests on pipeline specimens, the device includes a pressure chamber composed of a main cabin, a front hatch, and a rear hatch of the cabin, the front hatch and the rear hatch They are respectively connected to the two ends of the main cabin body. Sealing rings are arranged on the inner sides of the front hatch and the tail hatch. An oil pressure system is fixed on the front hatch. The piston rod of the oil pressure system extends through the front hatch. In the main cabin, the end of the piston rod is provided with a piston rod flange, and a guide rail is provided on the bottom upper surface of the main cabin, and a pulley for transporting the pipeline test piece is placed on the guide rail, and the two ends of the pipeline test piece are connected with The pipe end flange, the piston rod flange is matched with the pipe end flange, the pipe end flange on the other end of the pipe test piece and the top and bottom flange fixed on the rear end hatch cover of the cabin body matching; the pressure chamber is provided with a pressurization hole, a pressure relief port, a water injection port, an exhaust port, a safety valve, a pressure sensor opening and a test line outlet.

As a preferred embodiment, the main cabin is made of bundled multi-layer steel plates; the main cabin is made of Q345R material, and the front hatch and tail hatch are made of 20MnMo material.

The present invention has the following advantages due to the adoption of the above technical scheme: 1. The present invention binds high-strength steel plates layer by layer due to the use of advanced binding technology, and each layer of binding will use X-ray flaw detection. The thickness of each layer of steel plate is 1 cm. 24 layers of steel plates are bundled, with a total thickness of 24 cm, which ensures that the cabin has extremely strong compression resistance and high safety performance. The device of the invention can simulate the deep-sea pressure environment with a water depth of 4300 meters (43Mpa), and provides a stable pressure environment for buckling test research of deep-water submarine pipelines. 2. The present invention is equipped with an axial hydraulic press on its front hatch cover, which can be connected to the flange of the internal pipe fittings through the flange on its piston rod, and pushes the piston rod with oil pressure to exert pressure on the pipeline test piece inside the cabin. Axial force, hydraulic pressure and axial force can be applied to pipe fittings at the same time, and the buckling of pipes under load combination conditions can be studied. 3. The present invention has a total length of 11.5 meters, a diameter of 1.6 meters, and an inner diameter of 1.2 meters, which can accommodate a 1:1 true ratio test piece for testing. 4. Small pulleys and high-strength steel guide rails are installed inside the device cabin of the present invention, which is convenient for the transportation and installation of pipeline test pieces. 5. The upper part of the device of the present invention is equipped with a proportional decompression safety valve. When the water pressure in the cabin exceeds the set safety pressure, the proportional decompression safety valve will automatically spray water to achieve the purpose of quickly releasing pressure and ensuring safety.

Description of drawings

Fig. 1 is a schematic diagram of the main structure of the present invention.

Fig. 2 is a sectional view along the line A of Fig. 1 , that is, a structural view of the front hatch.

Fig. 3 is a sectional view taken along line A-A of Fig. 1 .

Fig. 4 is the rear end hatch cover figure of the present invention.

Figure 5(a) and (b) are the side view and top view of the guide rail, respectively.

The main structural parts of the device of the present invention are represented by numbers in the figure, and the accessories of the device are represented by letters, and the meanings are as follows:

1——Hydraulic press at the front end of the cabin

2, 3, 4 - Studs, nuts and washers for installation and connection of hydraulic presses

5, 60 - type washer

7——A total of 16 double-headed large studs used to install and fasten the front hatch cover, each stud has a diameter of 120mm and a length of 1m

8——The hexagonal nut equipped with the large stud of the front hatch cover

9——Spherical Washer

10——Front hatch cover

11—piston rod flange

12——Pipeline test piece end flange

13—Studs connecting the flange of the pipe test piece

14——Pipe fitting flange connection nut

15——Main cabin

16——Inside tackle

17——top and bottom flange

18——Large stud at the end

19——Large nut at the end

20—pipe test piece

21——Stud studs for connecting and fixing the rear end hatch cover

22——The supporting nut of the rear hatch cover stud

23——Assembly washer for end nut

24——Hatch cover at the rear end of the cabin

25——Inner rail

26——Guide track

27——rail sleeper board

28——Front hatch cover lug

a——safety valve

b——exhaust port

c——Water injection port

d——pressure hole

e——Pressure relief port

f——pressure sensor opening

g1, g2, g3, g4, g5 - test line export

h——drain valve

i1, i2——pressure gauge at the tail end of the cabin

j——tail exhaust valve

Detailed ways

The present invention will be described in detail below in conjunction with the accompanying drawings.

As shown in Fig. 1, Fig. 2, Fig. 3 and Fig. 4, the interior of the present invention can simulate the deep-sea high-pressure environment for deep-sea test piece test, and the equipped hydraulic machine can be used to apply axial force to the internal test piece, and its pressure bearing capacity is 43Mpa. The total length is 11.5 meters and the diameter is 1.6 meters. It is installed horizontally and uses water as the internal pressure medium. The present invention includes several main parts of the main cabin body 15, the front hatch cover 10, the cabin rear end hatch cover 24, and the cabin front end oil pressure system 1, which are used to simulate the deep sea pressure environment; System 1 applies axial tensile pressure to the pipeline test piece 20 placed in the cabin; in order to ensure the airtightness of the cabin, bolts and nuts such as 7, 8, 9, 18, and 19 are used for connection and sealing; To meet the needs of the test, flanges 11, 17 are equipped with flanges 12 at the end of the pipe test piece to connect and fix, and the cabin trolley 16 and cabin guide rail 25 are used to transport and support the pipeline test piece; The signal line of the data is exported through the g1, g2, g3, g4, g5 test line export, the water pressure test line in the cabin is guided by the f pressure sensor opening; the c water injection port is used to inject water into the cabin, j the tail end exhaust valve and b exhaust port to discharge the air in the cabin; d pressure hole pressurizes the cabin for testing; after the test is completed, the pressure relief port is released by the e pressure relief port, and the h drain valve drains; the device of the present invention also includes a safety valve. When the water pressure is abnormal and exceeds the set safety limit, the valve will automatically spray water, so that the internal pressure of the device of the present invention is rapidly reduced.

Manufacturing and assembly method of the device of the present invention:

The main cabin body 15 of the device of the present invention is manufactured by a multi-layer binding process, that is, a 1 cm thick steel plate is rolled into a cylindrical shell shape on a large-scale plate rolling machine, and then the steel plates are welded layer by layer, and each layer is welded with a X-ray flaw detection, confirm that there are no scars, trachoma, etc. before proceeding to the next layer of welding. A total of 24 layers are bundled, the total thickness of the main cabin reaches 24 cm, and the front end of the main cabin is open, which must be closed by a separately made front hatch; a hole with a diameter of 160mm is opened at the rear end, so that the tail end of the pipe fittings can be fixed and installed during the test. The tail end opening is sealed by the tail end stud 18, the tail end nut 19 and the cabin body tail end hatch cover 24. The main cabin is made of Q345R material.

The front hatch 10 is made by forging to ensure its strength. As shown in Figure 2, the front hatch has 16 large bolt holes. The front hatch should be opened and closed frequently, and the material of 20MnMo is selected.

The hatch cover 24 at the tail end of the cabin body also adopts a forging process, and 16 small bolt holes are opened on it.

Since the interior of the cabin is filled with water and then pressurized, the watertightness of the front and rear end covers under high pressure must be ensured, so a layer of aluminum sealing rings are respectively fastened on the front and rear end covers.

In the bottom of the cabin, the guide rail 25 is welded in the cabin axially along the cabin body. As shown in Figure 5, the guide rail includes two parallel tracks with a length of 8m, and a rectangular pillow plate is welded at every interval of 700mm in the track axial direction. The track is made of steel pipe with a diameter of 68mm and a thickness of 10mm, and the thickness of the pillow board is 16mm. The rails are of sufficient length to transport the pipe specimens, while the rails themselves are strong enough to resist high water pressure and support the pipe fittings.

After each part of the device of the present invention is made and welded, carry out the assembling of hydraulic press, front and rear end covers, each valve and supporting equipment and main cabin body, concrete method is as follows:

Use the hydraulic press to connect the studs 2, nuts 3, and washers 4 to securely connect the hydraulic press 1 to the front hatch cover 10; the front end of the main cabin body is evenly opened with 16 internal thread openings along the circumference, which are the size of the large stud 7 at the front end, If the spacing is corresponding, one of the 16 front end hatch cover double-headed large studs is screwed into the front end of the main cabin body; the a safety valve is installed on the upper part of the main cabin body with the connecting flange, and the matching exhaust valve is connected with the device of the present invention The b exhaust port on the top is connected, the water injection pump is connected with the c water injection port, the booster pump is connected with the d pressurization hole of the device of the present invention, the pressure relief valve is connected with e, and the j tail end exhaust valve is installed at the tail end of the cabin Install i1 and i pressure gauge 2 at the tail end of the cabin body; and pass the pressure sensor test line and the strain data transmission line through the f pressure sensor opening and the g1-5 test line export respectively; put the large stud 18 at the cabin body tail end 1. The large nut 19 at the tail end is placed outside the cabin, and the front and rear end covers are closed at last, and the front and rear end cover nuts are tightened to complete the assembly of the device of the present invention.

The method of use of the device of the present invention is as follows:

The device of the invention is mainly used for simulating the deep-sea high-pressure environment, and can apply an axial force load to an internal test piece to carry out buckling tests of deep-sea submarine pipelines. It can be divided into the following steps:

1. Lift the pipe specimen 20 that has been processed with auxiliary tools such as a crane. At this time, the end flange 12 has been welded at both ends of the pipe fitting. The flange 17 is connected and fastened with matching studs and nuts. Slide block 16 in the cabin to the front port of the cabin body, and then ride the tail end of the pipe fitting and the connection of the large stud on the block in the cabin by means of tools such as a crown block.

2. The flange 12 at the end of the pipeline test piece is connected to the flange 11 on the piston rod of the hydraulic press and fastened with supporting studs and nuts. To ensure the alignment of the two flange faces, the nuts on the flange are diagonally Tighten sequentially.

3. The data acquisition line on the pipe fitting is exported from the g1-5 test line export port.

4. Send the connected front hatch cover 10, pipe test piece 20, and tail stud 18 into the cabin as a whole by means of auxiliary tools such as cranes or trailers. Guide rail 25 slowly slides to the cabin body afterbody.

5. Make sure that the large studs 18 at the end pass through the opening at the rear of the cabin. The 16 large bolts that have been pre-installed at the front of the cabin can also pass through the bolt holes of the front hatch. When the large studs at the end pass through , the tail end big nut 19 is contained on the tail end big stud and tightened, then buckle the cabin body tail end hatch cover 24, with supporting studs 21,22,23, nuts and washers the cabin body tail end is sealed.

6. Spherical washers 9 and large nuts 8 are placed on the large studs of the front hatch cover at one time, and the large nuts are tightened with the help of tools such as hydraulic tensioner or hydraulic wrench to complete the fastening of the front hatch cover.

7. Check whether each valve is closed, then open the exhaust valve at the j tail end and the exhaust port b, and then fill the cabin with water through the water injection port c. Gas is exhausted, close the exhaust valve. When it is observed that water flows out from the exhaust port on the upper part of b, the air in the whole cabin has been exhausted, and the exhaust port is closed, and then the water injection port is closed. The water filling in the cabin is completed.

8. Open the pressurization port d to pressurize the inside of the cabin. Since the cabin is sealed, the water pressure in the cabin will continue to rise by pumping water into the cabin through the pressurization pump, and the test data will be collected through the external system until the end of the test. .

9. After the test, open the e pressure relief port to reduce the water pressure in the cabin to 0, then open the h drain valve at the lower part of the cabin to drain water, open the rear hatch and front hatch of the cabin in turn, remove the pipe test piece, and complete a test.

Claims (3)

1. deep water submarine pipeline buckling test device, be used for the pipeline test specimen is carried out buckling test, this device comprises by main cabin body, the front end hatchcover, the pressure chamber that cabin body tail end hatchcover constitutes, front end hatchcover and tail end hatchcover are connected to the two ends of main cabin body, inboard at front end hatchcover and tail end hatchcover is provided with O-ring seal, on the front end hatchcover, be fixed with oil press, the piston rod of oil press passes the front end hatchcover and extends in the body of main cabin, the end of piston rod is provided with the piston rod flange, upper base surface at main cabin body is provided with guide rail, on guide rail, be placed with the coaster that is used for the transport pipeline test specimen, the two ends of pipeline test specimen are connected with the pipe end flange, described piston rod flange and pipe end flange are complementary, and the pipe end flange on the other end of pipeline test specimen is complementary with the top and bottom process orchid that is fixed on the body tail end hatchcover of cabin; Pressure chamber is provided with pressurization hole, pressure relief opening, water filling port, exhausr port, safety valve, pressure transducer opening and measurement circuit export mouth.

2. deep water submarine pipeline buckling test device according to claim 1 is characterized in that described main cabin body is tied up by multilayer steel plates and made.

3. deep water submarine pipeline buckling test device according to claim 1 is characterized in that described main cabin body is selected the Q345R material for use, and front end hatchcover and tail end hatchcover are selected the 20MnMo material for use.

Images