DK174388B1

DK174388B1 - Method and apparatus for reproducing the conditions in force when conducting a welding operation on a subsea pipeline operating with a flowing fluid

Info

Publication number: DK174388B1
Application number: DK698588A
Authority: DK
Inventors: Jean-Claude Ancenys; Jacques Farenc
Original assignee: Scs Bv Holdings
Priority date: 1987-12-18
Filing date: 1988-12-15
Publication date: 2003-01-27
Also published as: GB2213276B; DK698588D0; NL8803008A; NO885573L; NO174078B; NO885573D0; NL193348B; DK698588A; NL193348C; GB2213276A; NO174078C; FR2625012B1; GB8829428D0; FR2625012A1

Description

DK 174388 B1 iDK 174388 B1 i

Den foreliggende opfindelse angår en fremgangsmåde og et apparat til at reproducere forhold, der er gældende, nar der skal udføres en svejseoperation på en undervandsrørledning, som er i drift med en gennernstrømmende fluid.The present invention relates to a method and apparatus for reproducing conditions which are applicable when performing a welding operation on an underwater pipeline operating with a flowing fluid.

5 Opfindelsens tekniske område omfatter udstyr, som er egnet til udførelse af offshore-arbejde under vandet.The technical field of the invention comprises equipment suitable for performing offshore work underwater.

For tiden tilvejebringes der for at reproducere de forhold, som er gældende ved udførelse af svejseoperationer på en rørledning, i hvilken der strømmer en fluid, en forsøgsopstilling, der udgøres af et 10 rør med et stykke, der har de samme karakteristika som rørledningen, der etableres et lukket kredsløb i forsøgsopstillingen, og den samme fluid, fx olie eller gas, som strømmer gennem den rørledning, der er i drift, bringes til at strømme rundt i det lukkede kredsløb, hvorefter varmetransmissionsforholdene gennem væggene i den rørledning, der er i 15 drift, og hvori væsken strømmer, opnås under atmosfæreforhold.Currently, in order to reproduce the conditions applicable to performing welding operations on a pipeline in which a fluid is flowing, an experimental set up consisting of a pipe having a piece having the same characteristics as the pipeline provided is provided. a closed circuit is established in the test array and the same fluid, e.g., oil or gas flowing through the operating pipeline, is caused to flow around the closed circuit, whereupon the heat transmission conditions through the walls of the pipeline contained in the operation, and in which the liquid flows, is obtained under atmospheric conditions.

Sådanne rørledninger kan have en stor diameter, fx omkring 1 m, og det er indlysende, at en sådan forsøgsopstilling at dyr at sætte op og relativt voluminøs, og den kan derfor eksempelvis ikke benyttes i et konventionelt højtrykskammer til at reproducere forhold ved svejsning, 20 som skal udføres på en undersøisk rørledning, der er i drift.Such pipelines can have a large diameter, for example about 1m, and it is obvious that such an experimental set-up is expensive to set up and relatively voluminous, and therefore cannot be used, for example, in a conventional high-pressure chamber to reproduce welding conditions. which must be carried out on an underwater pipeline in operation.

Den foreliggende opfindelse søger at afhjælpe disse ulemper.The present invention seeks to overcome these drawbacks.

Formålet med opfindelsen er at tilvejebringe en forsøgsopstilling til en metode og et apparat til ved havbundstryk at reproducere de forhold, som kræves for at udføre en svejseoperation på en undersøisk 25 rørledning, som er i drift med olie eller gas strømmende igennem.The object of the invention is to provide an experimental set-up for a method and apparatus for reproducing at sea bottom pressure the conditions required to perform a welding operation on an undersea pipeline operating with oil or gas flowing through.

Dette formål opnås ved fremgangsmåden ifølge opfindelsen, ved hvilken - et første rørledningsstykke, der har de samme karakteristika som den i drift værende rørledning, placeres i et overtrykskammer, - et andet rørledningsstykke, der har samme længde som det første 30 rørledningsstykke og en yderdiameter, som er mindre end inderdiameteren af det første stykke, er placeret inden i det første rørledningsstykke således, at det første og det andet 2 DK 174388 B1 rørledningsstykke er koaks lale og afgrænser et ringformet rum mellem sig, - organer er placeret i det ringformede rum for at generere et turbulent væskeflow, 5 - de to ender af det ringformede rum lukkes, - en fluid ledes ind under tryk via en inløbsåbning, der er beliggende ved den ene ende af det ringformede rum, og der skabes et turbulent fluidflow i det ringformede rum, - den strømmende fluid bringes tilbage via en udløbsåbning, der 10 er beliggende ved den anden ende af det ringformede rum, og fluiden recirkuleres, og - forhold, såsom afstanden mellem de to rørledningsstykkers vægge, organerne til at dannelse af et turbulent fluidflow, temperaturen, trykket og fluidens strømningshastighed, vælges således, 15 at der gennem det første rørledningsstykkes væg opnås en varmetransmission, der svarer til den varmetransmission, som opnås ved fluidflow'et i den undersøiske rørledning, der er i drift.This object is achieved by the method according to the invention in which - a first pipe piece having the same characteristics as the operating pipe is placed in an overpressure chamber, - a second pipe piece having the same length as the first pipe piece and an outer diameter, which is smaller than the inner diameter of the first piece, is located within the first pipe piece so that the first and second pipe pieces are coaxial and define an annular space between them, - means are placed in the annular space for generating a turbulent fluid flow, 5 - the two ends of the annular space are closed, - a fluid is fed under pressure via an inlet opening located at one end of the annular space, and a turbulent fluid flow is created in the annular space. - the flowing fluid is returned via an outlet opening 10 located at the other end of the annular space, and the fluid and conditions such as the distance between the walls of the two pipelines, the means for forming a turbulent fluid flow, the temperature, the pressure and the flow rate of the fluid are selected such that a heat transmission corresponding to the heat transmission is obtained through the wall of the first pipeline piece. which is obtained by the fluid flow in the operating subsea pipeline.

Ved fremgangsmåden gøres der brug af følgende formel: P “ Η x (ledningstemperaturen fiuidtemperaturen) 20 hvor P er varmeenergien og H er transmissionskoefficienten, og formlen anvendes som følger: P “ H' x (forsøgsledningens temperatur - den i opstillingen strømmende fluids temperatur) hvor den i opstillingen strømmende fluids karakteristika og temperatur 25 muliggør en beregning af fluidens gennemsnitshastighed, og den således beregnede hastighed og fluidens strømningshastighed benyttes til at beregne strømningstværsnittet, dvs. det ringformede rum mellem de to stykker af rørledningen, der udgør opstilling,en. og stigningsvinklen for den skrueformede væg, som udgør organet til generering af et 30 turbulent fluidflow.The method uses the following formula: P “Η x (conduction temperature fluid temperature) 20 where P is the heat energy and H is the transmission coefficient, and the formula is used as follows: P“ H ′ x (test line temperature - the temperature of the fluid flowing in the set) the characteristics and temperature of the fluid flowing in the array enable a calculation of the average velocity of the fluid, and the velocity thus calculated and the flow velocity of the fluid are used to calculate the flow cross-section, ie. the annular space between the two pieces of the pipeline constituting erection, one. and the pitch of the helical wall constituting the means for generating a turbulent fluid flow.

Opfindelsens formål opnås ligeledes med et apparat ifølge opfindelsen omfattende en kombination af - et overtrykskammer, i hvilket der er optaget en forsøgsopstilling, som udgøres af DK 174388 B1 3 - et første rørledningsstykke, der har de samme karakteristika som den i drift værende rørledning, • et andet rørledningsstykke, der har samme længde som det første rørledningsstykke og en yderdiameter, som er mindre end 5 inderdiameteren af det første stykke, hvilket første og hvilket andet rørledningsstykke er koaksiale og afgrænser et ringformet rum mellem sig, - et organ til at generere et turbulent væskeflow og beliggende i det ringformede rum, som indbefatter lukkevægge ved sine ender, 10 - en indløbsåbning for fluid under tryk beliggende ved den ene ende af det ringformede rum og en udløbsåbning beliggende ved den anden ende, og - organer til at bringe fluiden til at strømme i det ringformede rum og til at tilpasse og kontrollere dens strømningshastighed, 15 temperatur og tryk på en sådan måde, at der opnås en varmetransmission gennem væggen af det første stykke rørledning svarende til den varmetransmission, som opnås ved fluidflow'et i den i drift værende undersøiske rørledning.The object of the invention is also achieved with an apparatus according to the invention comprising a combination of - an overpressure chamber in which an experimental set-up constituted by DK 174388 B1 3 is taken - a first pipeline piece having the same characteristics as the pipeline in operation; a second pipe piece having the same length as the first pipe piece and an outer diameter less than 5 the inner diameter of the first piece, said first and second pipe pieces being coaxial and defining an annular space between them, - a means for generating a turbulent fluid flow and located in the annular space including closure walls at its ends, 10 - a pressurized fluid inlet opening at one end of the annular space and an outlet opening located at the other end, and - means for bringing the fluid to flowing in the annular space and adjusting and controlling its flow rate; 15 temperature and pressure in such a way that a heat transmission is obtained through the wall of the first piece of pipeline corresponding to the heat transmission obtained by the fluid flow in the operating subsea pipeline.

I én udførelsesform udgøres organerne til dannelse af et turbulent 20 væskeflow under tryk af en skrueformet væg, der med en konstant hældning strækker sig over det ringformede rums længde, hvilken væg er i tæt forbindelse med både den indre overflade af det første rørledningsstykke og den ydre overflade af det andet rørledningsstykke. Den skrueformede væg udgøres af båndmetal, der er 25 snoet i en skruelinie omkring det andet stykke rørledning og fastgjort dertil, hvor båndmetallet sammen med den indre overflade og det første rørledningsstykke afgrænser et rum, som udfyldes af en tætnende pakning.In one embodiment, the means for forming a turbulent fluid flow under pressure is constituted by a helical wall extending at a constant slope over the length of the annular compartment, which wall is in close contact with both the inner surface of the first pipeline piece and the outer surface of the second pipeline piece. The helical wall is constituted by band metal twisted in a helical line around the second piece of pipeline and attached thereto, where the band metal, together with the inner surface and the first pipeline, delimits a space which is filled by a sealing gasket.

Denne pakning udgøres af en kant, som er i kontakt med den indre 30 overflade af det første stykke rørledning, og af to læber, der er placeret skrævende over båndmetallet, og pakningen er fastgjort til båndmetallet med lim, og den er fremstillet af højtemperaturbestandig silicone.This gasket is constituted by an edge which contacts the inner surface of the first piece of pipeline, and by two lips located strangely above the band metal and the gasket is attached to the band metal with glue and is made of high temperature resistant silicone. .

DK 174388 B1DK 174388 B1

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Indløbsåbningen for fluid under tryk er fastgjort til væggen af det andet stykke rørledning, og udløbsåbningen for fluiden er fastgjort til væggen af det første stykke.The inlet opening for fluid under pressure is attached to the wall of the second piece of pipeline and the outlet opening for the fluid is attached to the wall of the first piece.

Ifølge opfindelsen omfatter apparatet også en tank indeholdende 5 fluiden; et fluid-tilløbskredsløb, der udgår fra tanken, hvilket kredsløb indbefatter en pumpe til at bringe fluiden under tryk og cirkulere den fra tanken, en flowmåler, et termometer og en trykmåler, og hvilket kredsløb ender ved en forseglet passage, der går gennem høj trykskammerets væg, og med et rør, der strækker sig fra passagen 10 til det andet stykke rørlednings indløbsåbning; og et returkredsløb, der fører tilbage til tanken, og som omfatter et rør, der fører fra den udløbsåbningdel, som er fastgjort til det første rørlcdningsstykke, til en passage, der går gennem overtrykskammerets væg, og dette kredsløb indbefatter etter passagen et termometer og en 15 ventil til at styre og stoppe den strøm af fluid, der vender tilbage til tanken. Den skrueformede væg står vinkelret på stykkerne af rørledning.According to the invention, the apparatus also comprises a tank containing the fluid; a fluid supply circuit exiting the tank, which includes a pump to pressurize the fluid and circulate it from the tank, a flow meter, a thermometer and a pressure gauge, and which circuit terminates at a sealed passage passing through the high pressure chamber. wall, and with a pipe extending from passage 10 to the second piece of pipe inlet opening; and a return circuit leading back to the tank, comprising a tube leading from the outlet opening portion attached to the first pipe solder to a passage passing through the wall of the overpressure chamber, and this circuit includes, after passage, a thermometer and a 15 valve to control and stop the flow of fluid returning to the tank. The helical wall is perpendicular to the pieces of pipeline.

Resultatet af opfindelsen er opnåelse af forhold og midler for udførelse af en svejseoperation på optimal vis på en undersøisk 20 rørledning, der er under brug, og i hvilken der strømmer en fluid.The result of the invention is to provide conditions and means for performing a welding operation optimally on an underwater pipeline which is in use and in which a fluid flows.

Fordelene ved opfindelsen ligger for det første i forsøgsopstillingens funktionsforhold i højtrykskammeret, hvor der ved havbundstryk kan udføres forsøg, så funktionsforholdene svarer til den i drift værende undersøiske rørledning, på hvilken der skal udføres svejseoperationer, 25 og for det andet i installationsomkostningerne, som er betydeligt mindre end for de forsøgsopstillinger, der benyttes for tiden, og også i, hvor let fremgangsmåden kan realiseres ved brug af udstyr, der er meget simpelt.The advantages of the invention lie firstly in the experimental setup's operating conditions in the high-pressure chamber, where seabed pressure can be carried out, so that the operating conditions correspond to the operating subsea pipeline on which welding operations are to be carried out, 25 and secondly, the installation costs, which are considerable less than for the experimental setups currently used, and also in how easy the method can be realized using equipment that is very simple.

Andre fordele og karakteristika for opfindelsen vil fremgå af den 30 følgende beskrivelse af et eksempel på en udførelsesform for en forsøgsopstilling, idet der henvises til tegningen, på hvilken fig. 1 viser et skematisk tværsnit gennem et højtrykskammer, i hvilket en forsøgsopstilling ifølge opfindelsen er placeret, og figuren viser DK 174388 B1 5 på skematisk form indretningerne til regulering af opstillingen placeret uden for høj trykskammeret, fig. 2 viser et længdesnit af en forsøgsopstilling svarende til den i fig. 1 viste, 5 Fig. 3 viser et snit langs linien III-III i fig. 2, og fig. 4 viser et delsnit i forstørrelse illustrerende udførelsen af den skrueformede væg, som strækker sig inden i det ringformede rum mellem de to stykker af koaksial rørledning.Other advantages and characteristics of the invention will become apparent from the following description of an exemplary embodiment of an experimental arrangement, with reference to the drawing, in which: FIG. 1 shows a schematic cross-section through a high-pressure chamber in which an experimental arrangement according to the invention is placed, and the figure shows in schematic form the devices for controlling the arrangement located outside the high-pressure chamber; FIG. 2 shows a longitudinal section of an experimental arrangement similar to that of FIG. 1; FIG. 3 shows a section along the line III-III in FIG. 2, and FIG. 4 is an enlarged partial sectional view illustrating the embodiment of the helical wall extending within the annular space between the two pieces of coaxial pipeline.

For at reproducere en undersøisk rørlednings driftsforhold, der er 10 bestemmende for en svejseoperation, dvs. dens indre tryk og dens flow af gas eller olie, skabes der ifølge opfindelsen et flow af en fluid, fx vand, mellem et første stykke af en forsøgsrørledning og et andet stykke rørledning, som er koaksialt med det første stykke og har en skrueformet væg påsvejset. Rummet mellem de to længder af rørledning, 15 stigningen af den skrueformede væg, temperaturen, trykket og vandstrømningshastigheden vælges alle, så at der skabes et turbulent flow, der sikrer, at varmen transmitteres gennem væggen af det første stykke rørledning, på en måde, der svarer til den varmetransmission, som opnås på grund af flow'et af gas eller olie i en i drift værende, 20 undersøisk rørledning.To reproduce a submarine pipeline operating condition that determines a welding operation, i.e. its internal pressure and its flow of gas or oil, according to the invention, a flow of a fluid, e.g. water, is created between a first piece of an experimental pipeline and a second piece of pipeline coaxial with the first piece and having a helical wall welded . The space between the two lengths of pipeline, the rise of the helical wall, the temperature, the pressure and the water flow rate are all selected so as to create a turbulent flow which ensures that heat is transmitted through the wall of the first piece of pipeline in a manner that corresponds to the heat transmission obtained due to the flow of gas or oil in an operating subsea pipeline.

Det første stykke rørledning, som danner ydersiden af forsøgsopstillingen, udgøres af et stykke, der har karakteristika, som svarer til eller er identiske med den i drift værende, undersøiske rørlednings karakteristika (inderdiameter, vægtykkelse og 25 stålkvalitet).The first piece of pipeline forming the outside of the test set-up is constituted by a piece having characteristics which are similar to or identical to the operating subsea pipeline characteristics (inner diameter, wall thickness and steel quality).

Længden af opstillingen følger naturligt af den maksimale størrelse, der er plads til i det højtrykskammer, i hvilket forsøget udføres. Yderdiameteren af det andet rørledningsstykke, som er placeret koaksialt inden i det første stykke, og stigningen af den skrueformede 30 væg, som snor sig over hele opstillingens længde omkring det andet rørledningsstykke, er defineret på følgende måde: - Driftskarakteristika for den ledning, der leder fluiden, gør det muligt at beregne den varmeenergi, som er nødvendig for at nå den vægtemperatur, der er nødvendig for udførelse af svejseoperationen.The length of the arrangement naturally follows from the maximum size that can be accommodated in the high pressure chamber in which the test is carried out. The outer diameter of the second pipe piece coaxially positioned within the first piece and the pitch of the helical 30 wall which spins the entire length of the arrangement around the second pipe piece are defined as follows: - Operating characteristics of the pipe conducting the fluid, it is possible to calculate the heat energy needed to reach the wall temperature needed to carry out the welding operation.

6 DK 174388 B16 DK 174388 B1

Der benyttes følgende formel: P - H x (ledningstemperatur - fluidtemperatur), hvor P er varmeenergien og H er transmissionskoefficienten.The following formula is used: P - H x (conduction temperature - fluid temperature), where P is the heat energy and H is the coefficient of transmission.

Som et eksempel er der benyttet følgende transmissionskoefficient 5 under forsøg:As an example, the following transmission coefficient 5 was used during experiments:

» - o.o, i («Γ W»- o.o, i (« Γ W

10 λ = termisk ledningsevne D - (^S/p) hydraulisk diameter p — densitet V *= hastighed μ — dynamisk viskositet 15 Cp “ specifik varme Når der benyttes den samme varmeenergi på forsøgsopstillingen som på den i drift værende rørledning, er målet at opnå samme temperaturer i svejsezonen,10 λ = thermal conductivity D - (^ S / p) hydraulic diameter p - density V * = velocity μ - dynamic viscosity 15 Cp “specific heat When using the same thermal energy in the experimental set-up as in the pipeline in operation, the aim is to achieve the same temperatures in the welding zone,

For at gøre dette antages den varmeflux, der dissiperer gennem den i 20 drift varende rørledning, at være lig med den varmeflux, der' dissiperer gennem det første rørledningsstykkes væg, som udgør ydersiden af af forsøgsopstillingen: P - H' x (forsøgsledningens temperatur - vandtemperaturen)To do this, the heat flux dissipating through the 20-running pipeline is assumed to be equal to the heat flux dissipating through the wall of the first pipeline which is the exterior of the test array: P - H 'x (the temperature of the test line - water temperature)

Vandets karakteristika og temperatur kan benyttes til at beregne 25 vandets gennemsnitshastighed.The characteristics and temperature of the water can be used to calculate the average velocity of the water.

Når denne hastighed er beregnet, fastlægges det flow-tværsnit (dvs. det ringformede rum mellem de to rørledningsstykker, der danner forsøgsopstillingen, og stigningen af den skrueformede væg), der er nødvendigt for at opnå et turbulent vandflow ved en hastighed på 30 omkring 6 m3/s. Det har vist sig, at dette flow-tværsnit muliggør et jævnt flow.When this velocity is calculated, the flow cross-section (i.e., the annular space between the two piping pieces forming the test array and the rise of the helical wall) is required to obtain a turbulent water flow at a rate of about 6 m3 / s. It has been found that this flow cross section enables smooth flow.

DK 174388 B1 7DK 174388 B1 7

Naturligvis fastlægges tykkelsen af de to endeplader og af det andet, indre rørledningsstykke således, at de kan modstå det indre tryk i opstillingen, hvilket tryk kan være nødvendigt for at undgå, at vandet koger.Of course, the thickness of the two end plates and of the other inner pipe piece is determined so that they can withstand the internal pressure of the set-up, which pressure may be necessary to prevent the water from boiling.

5 En udførelsesform for apparatet ifølge opfindelsen til udøvelse af fremgangsmåden er vist skematisk i fig. 1.5 An embodiment of the apparatus according to the invention for carrying out the method is shown schematically in FIG. First

Forsøgsopstillingen 1, som beskrives i det følgende, er placeret inden i et højtrykskammer 2, i hvilket trykket er det samme som det havbundstryk, som den i drift værende rørledning udsættes for.The test set-up 1, described below, is located within a high-pressure chamber 2 in which the pressure is the same as the seabed pressure to which the pipeline in operation is subjected.

10 Når forsøget skal udføres, bringes vandet i cirkulation i et kredsløb på følgende måde: Der pumpes vand fra en beholder eller tank 3 af en pumpe 4, der er indsat i et rør 5, i hvilket der ligeledes er placeret en flowmåler 6, et termometer 7 og en trykmåler 8. Røret 5 ender ved en passage 9 til højtrykskammeret 2. Vandet løber fra passagen 9 til 15 opstillingens indløbsåbning ved hjælp af et rør 10, som eksempelvis kan være fleksibelt.10 When the test is to be carried out, the water is circulated in a circuit as follows: Water is pumped from a container or tank 3 by a pump 4 inserted into a pipe 5, in which is also a flow meter 6, a thermometer 7 and a pressure gauge 8. The pipe 5 ends at a passage 9 to the high-pressure chamber 2. The water flows from the passage 9 to 15 the inlet opening of the set-up by means of a pipe 10, for example, which can be flexible.

Efter at vandet på turbulent vis er strømmet gennem opstillingen 1, bringes det tilbage til kredsløbet. Der er fastgjort et andet fleksibelt rør 11 til opstillingens udløbsåbning og det strækker sig 20 til en anden passage 12 i kammeret 2. Et rør 13 leder vandet tilbage til tanken 3, og dette rør indeholder et termometer 14 og en ventil 15 til indstilling og standsning.After the water has turbulently flowed through the array 1, it is returned to the circuit. Another flexible tube 11 is attached to the outlet port of the set-up and it extends 20 to a second passage 12 in the chamber 2. A tube 13 directs the water back to the tank 3, and this tube contains a thermometer 14 and a valve 15 for setting and stopping. .

Fig. 2-4 viser mere detaljeret udformningen af forsøgsopstillingen til udøvelse af fremgangsmåden ifølge opfindelsen. 1 2 3 4 5 6FIG. 2-4 show in more detail the design of the test set for carrying out the method according to the invention. 1 2 3 4 5 6

Som vist i fig. 2 og 3 omfatter den nævnte forsøgsopstilling et første 2 rørledningsstykke 16, som har de samme karakteristika som den i drift 3 værende undersøiske rørledning. Et andet rørledningsstykke 17 er 4 placeret inden i og koaksialt med det første stykke. Som det fremgår 5 af tegningen, har det andet stykke en yderdiameter, der er klart 6 mindre end inderdiameteren af det første stykke 16, hvorved der dannes et ringformet rum 18 mellem de to stykker 16 og 17.As shown in FIG. 2 and 3, the said test arrangement comprises a first 2 pipeline piece 16 having the same characteristics as the subsea pipeline in operation 3. A second pipeline piece 17 is 4 positioned within and coaxially with the first piece. As can be seen from the drawing 5, the second piece has an outer diameter that is clearly 6 smaller than the inner diameter of the first piece 16, thereby forming an annular space 18 between the two pieces 16 and 17.

8 DK 174388 B18 DK 174388 B1

En væg 19 er snoet i skrueform inden i det ringformede rum over hele opstillingens længde, og rummet mellem de to stykker 16 og 17 og stigningen af skruelinien er defineret som forklaret i det ovenstående.A wall 19 is twisted in screw form within the annular space over the entire length of the arrangement, and the space between the two pieces 16 and 17 and the rise of the helix is defined as explained above.

Væggen 19 ( fig. 4) udgøres af båndmetal 19a, der strækker sig 5 vinkelret på den inderste rørledning 17 og yderrøret 16. For at lette fremstillingen af opstillingen er båndmetallet 19a ikke så højt som rummet 18 mellem de to stykker 16 og 17. Den skrueformede væg 19 er tætnet ved hjælp af en pakning 19b, der omfatter en kant 19b,, som ligger an mod indersiden 16a af det første stykke rørledning 16's væg, 10 og som er monteret skrævende over båndmetallet 19a. Pakningen 19b indbefatter således to læber 19b2 og 19b3, der strækker sig i det væsentlige parallelt med hinanden over det samme stykke, og pakningen er fastgjort til båndmetallet ved hjælp af lim. Pakningen er fordelagtigt af den type, der er fremstillet af højtemperatur-i5 bestandigt silicone.The wall 19 (Fig. 4) is constituted by band metal 19a extending 5 perpendicular to the inner tubing 17 and the outer tube 16. In order to facilitate the preparation of the arrangement, the band metal 19a is not as high as the space 18 between the two pieces 16 and 17. helical wall 19 is sealed by means of a gasket 19b comprising an edge 19b, which abuts on the inside 16a of the wall of the first piece of conduit 16, and mounted slantingly over the band metal 19a. The gasket 19b thus includes two lips 19b2 and 19b3 extending substantially parallel to one another over the same piece, and the gasket is attached to the band metal by glue. Advantageously, the gasket is of the type made from high temperature-resistant silicone.

Det ringformede rum 18 er lukket i begge ende af opstillingen af vægge 20 og 21, sotn er svejset til rørledningsstykkerne 16 og 17, og væggene rager længere ud end dc nævnte stykker og er kvadratiske. Deres centrale dele er åbne og strækker sig ind til inderperiferien af det 20 inderste rørledningsstykke 17 for at muliggøre adgang til det indre af dette.The annular space 18 is closed at both ends of the array of walls 20 and 21, the soot is welded to the piping pieces 16 and 17, and the walls extend beyond the said pieces and are square. Their central portions are open and extend into the inner periphery of the innermost pipeline piece 17 to allow access to the interior thereof.

Opstillingen indbefatter ligeledes en vandindløbsåbningdel 22, der er fastgjort til det andet rørledningsstykke 17, og en udløbsåbningdel 23, der er fastgjort til det første rørledningsstykke. Disse åbninger 25 er udformet i centralt-gevindskårne fortykkelser, for at væskekredsløbets rør 10 og 11 kan forbindes dertil.The arrangement also includes a water inlet opening portion 22 attached to the second pipeline piece 17 and an outlet opening portion 23 attached to the first pipeline piece. These openings 25 are formed in centrally threaded thicknesses so that the tubes 10 and 11 of the liquid circuit can be connected thereto.

I modsætning til den i fig. 1 viste opstilling omfatter opstillingen i fig. 2 og 3 en grenforbindelse 24, der udgøres af et skørt, der under svejseforsøg på opstillingen er svejset til mellemdelen af stykket 16. 1In contrast to the one shown in FIG. 1, the arrangement of FIG. 2 and 3 are a branch connection 24 which is constituted by a skirt which is welded during the welding tests on the set to the middle part of the piece 16. 1

Det er indlysende, at en fagmand på området kan erstatte de ovenfor beskrevne og eksemplificerende dele med ækvivalente dele, der kan udføre samme funktion, uden at man derved fjerner sig fra sigtet med opfindelsen.It is obvious that one skilled in the art can replace the above-described and exemplary parts with equivalent parts capable of performing the same function, without thereby departing from the scope of the invention.

Claims

A method of reproducing the conditions required to perform a welding operation on an operating subsea pipeline, in which a fluid 5 is characterized, comprising the following steps: * a first pipeline piece (16) having the same characteristics as the pipeline in operation are placed in an overpressure chamber (2); located within the first tubular piece (16) such that the first and second tubular pieces (16, 17) are coaxial and delimit an annular space (18) therebetween, means (19) located in the annular space (18). ) to generate a turbulent fluid flow, - the two ends of the annular space (18) are closed, - a fluid is fed under pressure via an inlet opening (22) located at one end of the annular space (18) and a turbulent fluid flow is created in the annular space, - the flowing fluid is returned via an outlet opening (23) located at the other end of the annular space (18) and the fluid is recirculated, and conditions such as the distance between the walls of the two piping pieces (16, 17), the means (19) for forming a turbulent fluid flow, the temperature (7, 14), the pressure (8) and the flow rate (6) of the fluid are selected so that through the wall of the first pipeline piece (16) achieves a heat transmission corresponding to the heat transmission achieved by the fluid flow in the subsea pipeline in operation.

The method of claim 1, wherein the following formula is used: P - H x (conduction temperature - fluid temperature) where P is the heat energy and H is the coefficient of formula and formula 35 is used as follows: DK 174388 B1 P - H 'x ( the temperature of the test arrangement - the temperature of the fluid flowing in the set) where the characteristics and temperature of the flowing fluid in the set enables the calculation of the average velocity of the fluid, 5 characterized in that the means for generating a turbulent flow are constituted by a helical wall (19) and thus calculated velocity and fluid flow rate are used to define a flow cross section, i.e. the annular space (18) between the two pieces of pipeline (16, 17) constituting the arrangement (1) and the pitch angle of the helical wall (19) so as to obtain a turbulent fluid flow.

Apparatus for reproducing conditions in performing a welding operation on a subsea pipeline in operation in which a fluid is flowing, characterized in that it comprises a combination of - an overpressure stove (2) in which a test arrangement is recorded. (1) comprising: - a first pipeline piece (16) having the same characteristics as the pipeline in operation, 20. a second pipeline piece (17) having the same length as the first pipeline piece (16), and an outer diameter smaller than the inner diameter of the first piece, said first and second tubular pieces (16, 17) being coaxial and defining an annular space (18) therebetween, a means (19) for generating a turbulent fluid flow and located in the annular space (18) which includes closure walls (20, 21. at its ends) - a pressurized fluid inlet opening (22) located at one end of the annular space (18) and an outlet opening (23) 3 0 located at the other end, means (4) for causing the fluid to flow in the annular space (18) and to adjust and control its flow rate (6, 15), temperature (7, 14) and pressure (8) ) in such a way that a heat transmission is obtained through the wall of the first piece of pipeline corresponding to the heat transmission obtained by the fluid flow in the operating subsea pipeline. DK 174388 B1

Apparatus according to claim 3, characterized in that the means for forming a turbulent liquid flow under pressure are constituted by a helical wall (19) extending at a constant increase over the length of the annular space (18), the wall being close connection with both the inner surface (16a) of the first pipeline piece (16) and the outer surface of the second pipeline piece (17).

Apparatus according to claim 4, characterized in that the helical wall (19) consists of 10 strip metal (19a) twisted in a helical line around the second piece of pipe (17) and attached thereto, the band metal together with the inner surface. (16a) of the first pipeline piece (16) defines a space which is filled by a sealing gasket (19b).

Apparatus according to claim 5, 15, characterized in that the gasket (19b) is formed by an edge (19b) which is in contact with the inner surface (16a) of the first pipe piece (16) and of two lips (19b2). , 19b3), which is disposed strangely over the band metal (19a), the gasket (19b) being attached to the band metal (19a) with glue.

Apparatus according to claim 5 or 6, characterized in that the gasket (19b) is made of high temperature resistant silicone.

Apparatus according to claim 3, characterized in that the inlet opening (22) for fluid under pressure is fixed to the wall of the second pipe piece (17) and the outlet opening (23) for the fluid is fixed to the wall of the first piece (16). ).

Apparatus according to any one of claims 3 to 8, characterized in that it comprises a tank containing the fluid (3); a fluid supply circuit exiting the tank, including a pump (4) for pressurizing and circulating the fluid from the tank, a flow meter (6), a thermometer (7) and a pressure gauge (8), and circuit terminates at a sealed passage (9) passing through the wall of the high-pressure chamber (2) and with a pipe (10) extending from the passage (9) to the inlet opening (22) of the second pipe piece (17); and a return circuit leading back to the tank (3), comprising a tube (11) leading from the outlet port 5 (23) attached to the first pipeline piece (16) to a passage (12), passing through the wall of the overpressure chamber (2), and this circuit includes, after passage (12), a thermometer (lying) and a valve (15) for controlling and stopping the flow of fluid returning to the tank.

Apparatus according to claim 4 or 5, characterized in that the helical wall (19) is perpendicular to the pipeline pieces (16, 17).