DE2503618A1 - PROCEDURE FOR LAYING PIPELINES AND DEVICE FOR CARRYING OUT THE PROCEDURE - Google Patents

Description

PATENT LAWYERS

DR. ING. A. VAN DERWERTH DR. FRAN Z LE DE RE R

(1934-1974) ^β MÖNCHEN 80

LUCILE-GRAHN-STR. 22 - TEL. I0891472947 "

Munich, January 24, 1975 EN 3654

THE BRITISH PETROLEUM COMPANY LIMITED Britannic House, Moor Lane, London EC2Y 9BU,

England

Method for laying pipelines and apparatus for implementation of the procedure

The invention "relates to a method for laying underwater pipelines, the crude oil from underwater oil wells to the coast; d. H. ashore. The invention also relates to it a device for carrying out the method in lOrm of underwater vehicles that can be used for this purpose.

Conventional underwater pipelines for oil are made from individual lengths made of weight-coated steel tubes that are welded together on a laying bar and lowered into the sea. The greater the depth of the seabed, around the greater the tensile stress that has to be withstood by the pipeline during the laying process, and as a result shows that laying pipelines at depths greater than 30 m created considerable technical difficulties

509831/0826

TELECRAMMEi L E D E R E R P AT E N T MÖNCHEN

and has required the use of relatively thick steel pipes in order to withstand the tensile stresses involved. The difficulty in laying steel pipelines is greatly increased by rough sea conditions, and when the wave heights become greater than a predetermined value for any laying operation, the laying operation must be discontinued. This means that for many months of the year the laying operations are extremely difficult or even impossible in certain sea areas, e.g. B. in the North Sea.

The object of the invention is to create a method for laying underwater pipelines suitable for the transport of crude oil, which method can be carried out largely independently of the sea conditions. Another object of the invention is to create an underwater vehicle which is suitable for laying such underwater pipelines.

The method according to the invention for laying underwater pipelines, which are suitable for conveying crude oil to the coast, is characterized in that a fiber-reinforced pipe made of a thermosetting resin is produced within a submerged underwater vehicle that can move over the seabed manufactured pipe is weight coated inside the vehicle and that the coated pipe is led out of the submerged vehicle.

Procedures for making pipes from thermosetting resins are known per se and they can easily be adapted for implementation within a submerged vehicle . Such working methods are z. B. in Chapter II (Tube and Rod Production) of Glass Reinforced Plastics, 2nd edition, published by Philip Morgan, Verlag Iliffe and Sons Limited,

509831/0826

". Such procedures can be extrusion or Include monofilament winding methods.

A wide variety of reinforcing fibers can be used will. For example, the fibers can be made of inorganic or consist of organic material. Examples of inorganic fibers are glass fibers and metal thread, ζ. B. steel wires. Examples of organic fibers are the numerous polymeric fibers produced by the thermosetting resin used are not attacked, e.g. B. when using unsaturated polyester resin systems, nylon, polyethylene terephthalate (terylene) and carbon thread. Mixtures of different threads "... can produce pipes with the desired properties. The preferred thermosetting resins are unsaturated polyester resins and polyepoxy resins. Advantageously, will the pipe is produced continuously at the same speed, with which the finished pipeline will be transferred to the seabed. Alternatively, the device for manufacturing of the pipe be arranged to move within the vehicle so that a length of pipe is made, which can then be coated. This length of coated pipe is then pushed out of the vehicle when the device producing the pipe in its starting position is moved before making another length of pipe. The pipe produced must be weight coated to ensure its stability on the seabed. The preferred one Weight coating consists of aggregate, which forms a solid coating with a suitable, thermosetting Resin is bound. The use of bound aggregate ' has the advantage that the binder, which gives the finished coating with good impact resistance, is easily available, and that the aggregate has the required compressive strength

509831/0826

"owns to help lay and use pipelines to withstand pressures occurring in deep seas. Advantageously, that is used to bind the aggregate Resin the same resin that was used to make the pipe. This creates a good bond between the pipe and the weight coating ensured.

A preferred weight coating consists of a mixture of unsaturated polyester resin / aggregate which contains a graded aggregate so that the interstices between the particles of the aggregate are minimized and therefore the required amount of unsaturated polyester resin is reduced. Preferably, ratios of aggregate to resin of 1: 7 to Λ : 15, based on weight, are used. Conventional vibrators can be used to compact the weight coating around the pipe before it hardens.

The outer surface of the weight coating is advantageous made as smooth as possible to avoid the problem of sealing any walls or partitions in the submarine, through which the pipe must pass, and across which there is a differential pressure to make low. this can be achieved by surrounding the pipe produced with a shape which defines a cavity into which the Aggregate and the binder can be introduced. Palis the inner surfaces of the mold are smooth, the finished one is Surface of the weight coating is also smooth and can easily pass through suitable sealing rings. Advantageously During continuous production, the mold moves with the pipe, at the same speed and that thermosetting resin is formulated so that it cures or solidifies to a sufficient extent within time, during the shape of the work surface or station in which the

50 9 8 31/0826

Weight coating is made has passed. if the intermittent pipe production procedure described above is used, it may not be necessary be the mold, since the setting or setting of the weight coating can be adjusted to do so has progressed sufficiently for the pipe to run out of time can be pushed out in which a standard length of pipe has been made.

In an alternative procedure, the produced, glass fiber reinforced tube with an outer collar or a Cuff equipped in the area of the weight cover, this collar or this cuff having a larger inner diameter than the outer diameter of the pipe and ■ is set up, the pipe with the delimitation of a cavity to surround between the tube and the collar or the cuff, with a weight bringing in this cavity Material can be poured and allowed to harden. The collar or the cuff can in his / her position on are left on the pipe and form its outer surface.

Any plastic material can be used to form the collars or cuffs. A plastic material is preferably used which has a high impact strength, ie a plastic material with an Izod impact strength greater than 2 and advantageously between 3 and 5 , "is measured. high density polyethylene and copolymers of ethylene with minor proportions of other monomers such as propylene, butene and hexene are especially preferred. Optionally, the collar or collars may be made of foamed art ¹ materials..

509831/0826

The collars or cuffs can have any internal shape, provided that they are over the pipe under Limiting a cavity between them and the pipe can be placed, with this having a sufficient volume possesses, so that the finished combination has a sufficient weight after filling with the weight-bearing material to ensure that the ear falls to the sea floor and stays there. In some cases it can be beneficial be to use collars or cuffs, which form a cover in their position on the pipe, the one or has several flat surfaces, thereby facilitating the positioning of the underwater pipeline on the seabed will. However, it is generally most convenient to provide collars which have the same shape as that Pipe with which they are to be used. In most cases, the collars or cuffs are therefore from round shape so that they match the round tubes normally used.

The collars or cuffs are preferably arranged closely adjacent, but their position is or they are designed in such a way are that the weight-bearing material in a collar or a cuff is slightly different from the weight-bearing Material in the next collar or cuff is separated or only close to a part of its thickness of the pipe is in contact. In this way a finished product is obtained which can bend more easily than a tube completely covered to a uniform thickness by hardened weighting material. the Collars or cuffs can be designed to be plastic material present between the separate weight-bearing materials in adjacent collars or cuffs is. By. Choosing a plastic material with good springback can · the total space between neighboring, weight-bearing Materials are replenished without the

509831/0826

Flexibility of the pipe is impaired. This will the possibility of damage to the pipe by z. B. trawler lines or cables, which are between "neighboring, Weight-bearing materials could be pinched, while still bowing the pipeline possible during laying on the seabed.

The collars on a tube can be of various lengths along the tube, although preferably all of them should be identical.

Every plastic collar or every plastic sleeve is advantageously made in two or more sections, forming the complete collar or the complete Cuff can be put together around the glass fiber reinforced pipe. Advantageously, they are in two halves are made which are designed to facilitate their assembly around the pipe. As soon as you are assembled around the pipe, separate halves or sections can be held together while the weight-bearing material is added, or they can means an adhesive, welding the plastic, or any other suitable means be attached to each other.

The collars or cuffs must be kept separate from the tube in order to define an internal cavity into which the weighting material can be introduced. Preferably, the collar or the cuff, if the shapes in question permit, are symmetrically arranged around the tube , so that the cured weight-bearing material in the finished product is the same or at least symmetrical

509831/0826

Has strength around the drill. The spacing of the collar or the cuff can be by means of spacer rings or Similar spacers between the glass fiber reinforced pipe and the plastic collar or the plastic sleeve can be achieved. In a preferred embodiment, the plastic collar or the plastic sleeve is with internal Ribs or internal projections made, which serve the collar or the cuff on the Bring the tube into its position and in particular also around the plastic collar or the plastic sleeve in the case of ribs to reinforce. If internal ribs are used, it is essential to provide passageways through them, so that the weight-bearing material easily covers the entire cavity between the tube and the plastic collar or able to fill the plastic sleeve. Ribs or spacer rings are advantageously made at each end of the plastic collar or the plastic sleeve provided to the To limit the ends of the mold cavity which is formed between the collar or the sleeve and the tube. These End ribs or rings can form resilient material that carries the weighting material in adjacent collars or cuffs separates.

The edges of adjacent collars or cuffs can be designed so that they overlap and so one Form a protective cover over any separation that may be required between adjacent sections of weight bearing Materials or indentations should be present in continuous lengths of weight-bearing material. the Collars or cuffs are preferably designed with internal ribs that are undercut or hollowed out, so that when a flowable, hardenable, weight-bearing material is used, the collar or Holds sleeves on the pipe as it hardens. Furthermore you can

509831/0826

reinforcing materials for the weighting material may be attached either between ribs or on the perimeter, both to reinforce the collar "or the cuff and the weight-bearing material as well as the fastening of the Collar or the cuff on the weight-bearing material to support.

Each collar or each cuff can be provided with a hatch which is arranged in such a position that they are is at the top when the collar or sleeve is in place on the pipe. This hatch enables the introduction of the hardenable, weight-bearing material. It is envisaged that these hatches with hatch locks can be provided, which even have smaller hatches. In this way, the mass of the hardenable, weight-bearing Material can be introduced through the large hatch, then the hatch cover can be put on and the filling process be closed by the small hatch, the small hatch either with a lid after completion of the filling or, alternatively, the weighting material is shaped to achieve a smooth surface on the hatch will.

The weight coating of the pipe produced can also be achieved by rolling an outer cover around the pipe while simultaneously or subsequently introducing weight-bearing material between the pipe and the cover. The outer cover can be applied in the form of individual ,. '■ cylindrical sections, but it is preferably wound onto the tube in a spiral manner, which facilitates continuous operation. One

509831/0826

wide variety of materials from thin sheet metal "up to flexible plastic sheet materials can be used to form the cover. A particularly useful material is high density polyethylene, which can easily be made in the form of a continuous strip, the one Cross-section, eliminating each successive winding of the cover engages the previous winding to form a smooth, outer surface. The cross section of the strip may optionally be shaped so that the finished weight coated tube has indentations or others Has indentations on its outer surface, giving the seabed the desired degree of flexibility which it should ultimately be relocated is achieved. The cover strip can be molded with a rib which is shown in FIG Projecting towards the pipe and supporting the holding of the cover at the desired distance from the pipe, so that sufficient weight-bearing material can be introduced. It can also be designed to prevent the weight-bearing or weighting material is supported in its position before it finally hardens, and if necessary ensure that the cover is attached to the weighting or weighing material in the finished pipeline remains bound. The presence of the rib in the weighting or weighing material can be determined by suitable means Design of the rib can be used to increase the flexibility of the finished pipeline.

An advantage of a high density polyethylene cover is that it can be designed to form part of the finished pipeline; however, other covering materials can also be used which disintegrate on the seabed during a certain period of time, provided that the material

509831/0826

adequate resistance for weight coating compared to the underwater environment. ·

The one previously described is a preferred, hit-hardening one Resin for use both in the manufacture of the ear and for setting the aggregates to form the weight coating is an unsaturated polyester resin. Such resins are generally formulated or can be so formulated can easily be formulated against crude oil or other natural materials passing through an underwater pipeline could be directed, are persistent.

In the description, the term "unsaturated polyester" used in its normal sense, referring to the polycondensation products of dicarboxylic acids or anhydrides with dihydroxyl alcohols if one of the reactants present during the polycondensation reaction is a polymerizable one Has double bond. Unsaturated polyesters can be caused by the presence of monocarboxylic acids, monohydroxyl alcohols and modifying small amounts of polycarboxylic acids or polyhydroxyl alcohols in the polycondensation reaction mixture be. Particularly valuable unsaturated polyesters are esterified by saturated, dihydric alcohols such as ethylene glycol, Diethylene glycol, triethylene glycol, trimethylene glycol, α-propylene glycol, 1,3-butylene glycol and the bisphenol A adducts with ethylene oxide and propylene oxide, with a-unge saturated en, α, β-dicarboxylic acids such as maleic acid, fumaric acid, itaconic acid and citraconic acid. That type of unsaturated Polyester can be modified by adding a small proportion of the unsaturated, dibasic acids to an equivalent Amount of a saturated dicarboxylic acid, e.g. B. amber, adipine, sebacic, phthalic, isophthalic, azelaic, tetrahydrophthalic, Endomethylene tetrahydrophthalic or hexachloroendomethylene tetrahydrophthalic acid, is replaced. Unsaturated polyester -

509831/0826

are generally in the presence of an unsaturated Monomer hardened or cured that is capable of copolymerization with the unsaturated polyester. Examples such monomers are styrene, which is most commonly used, vinyl toluene, α-methyl styrene, methyl methacrylate, Ethylene glycol dimethacrylate, ethyl acrylate, acrylonitrile, vinyl acetate, Diallyl phthalate, diallyl maleate and triallyl cyanurate.

The rate of hardening of unsaturated polyesters and their mixtures with copolymerizable monomers is increasing usually increased by the presence of polymerization catalysts, which organic peroxides such as benzoyl peroxide, Lauryl peroxide, isopropyl "benzene hydroperoxide, methyl ethyl ketone peroxide and 1-hydroxycyclohexyl hydroperoxide. The curing speed the polyester resin can also be modified by adding suitable inhibitors, e.g. B. of hydroquinone, oc-naphthol, tert-butylcatechol, benzaldehyde oder'Tetrahydroquinone, as well as by adding promoters such as certain amines, e.g. B. Dimethylaniline, Diethylaniline, Din-propylaniline, Dimethyl-para-toluidine, diethyl-a-naphthylamine, para-dimethylaminoazobenzene and dimethyl-meta-aminophenol, as well as by adding metal salts such as vanadium, cobalt and manganese naphthenate. The use of such curing catalysts and promoters enable curing of the polyester resin to be induced at ambient conditions and in a period of time that coincides with the speed of movement of the tube through the underwater vehicle, provided that a continuous working process is applied.

The weight coated pipe can be led out of the underwater vehicle directly from the weight coat station

509831/0826

provided that an adequate seal can be provided between the "coated bore" and the wall of the submersible. However, it is preferred to pass the coated pipe through a series of pressure chambers within the submersible, each of which can be maintained at an elevated pressure, so that the pressure differentials between any two chambers and the last chamber and the sea water outside the submersible do not pose too much of a sealing problem pump back. Advantageously out the weight coated pipe directly _ from the submerged underwater vehicle on the seabed when the underwater vehicle is moving.

The invention also relates to an underwater vehicle for Laying underwater pipelines, with the vehicle too a controlled movement on or just above the seabed is able and facilities for the production of a glass fiber reinforced plastic pipe, facilities for weight coating the pipe and means for guiding the weight coated pipe out of the submerged one Vehicle covered out.

The underwater vehicle should be able to move in a controlled manner on or just above the seabed. . Therefore, the vehicle must be equipped with either wheels or chains, which allows it to move along the seabed Caused, can, or there must be nozzles, propellers or similar facilities exist that make it through

509831/082 6

Water, if it is in a sufficiently floating state. The setting of the submerged levitation state can be carried out by conventional means, e.g. B. Use of flood tanks and the like can be achieved. A controlled movement of the vehicle can also be achieved by a combination of mechanical and hydraulic devices. A combination of guide devices in contact with the seabed to stabilize the vehicle and hydraulic devices to move it can exert a constant pull on the emerging pipeline, which ensures that it is not damaged during the laying process.

The production of the pipe and its weighting or adding weight can be done in the same station or in separate ones Stations are carried out. These can be done inside the underwater vehicle in a similar way to workshops be laid out on land, taking special care to control any fumes, given off by the thermosetting resins used could. Preferably, separate stations are used and facilities are provided to feed the pipe produced into the Transfer coating station.

The means for transferring the coated tube to the sea bed, as previously described, preferably comprise a series of pressure chambers. In one embodiment according to the invention, the device should be made adjustable for leading out of the weight coated RoTires from the vehicle to the sea directed towards the end, so that the passing out pipe can be directed upwards on the sea surface. In this way, riser pipes etc.

509831/0826

be formed by using buoys or other floating devices attached to the emerging pipe ".

The underwater vehicle must have all the necessary facilities have to enable a life there, so that a work team on or near the seabed for a can be long enough to allow the pipeline to be laid. The use of iron Nuclear power is particularly valuable in this regard. The underwater vehicle is therefore advantageously equipped with an or provided several connection openings to which supply lines or supply submarines can be connected. The underwater vehicle can be supplied with fresh raw materials through such openings, which are used for production the weighted pipeline is required, as well as food, Fuel and other supplies necessary for crew survival.

In one embodiment, a sealed tube is in the Underwater vehicle manufactured, coated with weight or weighted and transferred to the seabed, further pipe being made at the speed with which the Pipe is laid on the sea bed when the submarine moves from the starting point. ¥ enn the oath point is reached, the pipe can be closed within the vehicle ■ and transferred to the sea floor, where it with the coast or the drilling platform under application of the conventional working methods can be combined.

Normal safety measures for underwater vehicles must be be observed during the design of the underwater vehicle. The risk of flooding in the vehicle as a result of any Collapse or a weak point in the laid pipe can be reduced. putting a mandrel inside the tube is provided for sealing the pipe located within the submersible in response to any inside the pipe through a burst pipe, outside the

509831/0826.

Vehicle caused pressure increase can be expanded.

In the drawing is a schematic cross section of an inventive Underwater vehicle shown. The underwater vehicle 1 has rollers 2, with the help of which it is on the seabed can be moved. In a first station 3, unsaturated polyester resin is extracted from the tank 4- together with glass strands out of the supply 5 to the pipe making machine. This machine is of standard construction a glass fiber reinforced polyester pipe, which is passed through a second station 7, in which aggregate from the storage container 8 and unsaturated polyester resin from the storage container 9 are fed to a mold 10 for a weight coating or to form a weighting coating around the tubes. The polyester resin systems used in stations 1 and 2 are adjusted so that the pipe produced is sufficiently hardened at the point in time at which it is in the second station is run to allow it to weigh the weight of aggregate / resin mixture resists, and the weight coating is sufficiently cured that it forms an effective seal between the second station and the first pressure chamber 11 is able to form. The coated tube then occurs through further pressure chambers 12 and leaves the underwater vehicle through the seal 13 and is deposited on the seabed, when the submersible is moving in the opposite direction, at the speed with which the coated pipe is ejected therefrom.

The vehicle has hatches 14, 15, 16 and 17? which to the various storage containers and through which fresh supplies via a second submersible supply vehicle can be delivered, which is equipped with suitable discharge openings, which with the vehicle laying the pipe

509831/0826

can be connected, or via pipes · from a surface craft can be fed. The submersible is also equipped with other hatches through which the crew it can leave while the underwater vehicle is still is under water if a carrier vehicle is connected to the hatch. The underwater vehicle also still owns other fiefdominal maintenance systems which are conventional and not shown in the schematic drawing became.

5 0 983 1/082 6

Claims (20)

Claims Method of laying underwater pipelines through which crude oil can be brought to the coast, thereby gekennz eichnet that a glass fiber reinforced pipe made of a thermosetting resin within a submerged Underwater vehicle, which can move over the seabed, is manufactured that the manufactured Weight coated pipe inside the vehicle and that the coated pipe is led out of the submerged vehicle. 2. The method according to claim 1, characterized in that the glass fiber reinforcement consists of glass fibers and / or metal wires. 3. Method according to claim 1 or 2, characterized in that that the thermosetting resin is an unsaturated polyester or a polyepoxide. 4. The method according to any one of the preceding claims, characterized characterized in that the weight coating is made of aggregate which is bonded with a thermosetting resin. 5. The method according to claim 4-, characterized in that the thermosetting resin used to bind the aggregate is the same resin that was used to make the pipe. 6. The method according to any one of the preceding claims, characterized in that the fiber reinforced tube with a is surrounded by an outer collar or cuff, 5Q9831 / 0826 to create a cavity between the pipe and the collar or of the cuff in which the material for the weight coating is molded. 7. The method according to claim 6, characterized in that the collar or cuff made of plastic material is molded with an Izod impact strength greater than 2. 8. The method according to claim 6 or 7 _5, characterized in that a series of collars or collars are used and arranged and designed so that the coating material does not have a uniform thickness along the pipe with the result that the coated pipe has increased flexibility . 9. The method according to claim 6, 7 or 8, characterized in that that the collar or the cuff is equipped with internal ribs or projections. 10. The method according to claim 6, 7j 8 or 9, characterized in that that the edges of adjacent collars or cuffs overlap and a protective cover over the Form weight-coated tube. 11. The method according to any one of claims 1 to 5, characterized in that an outer cover is rolled up around the tube and that weighting material is introduced between the tube and the cover. 12. The method according to claim 11, characterized in that the outer cover is made of high density polyethylene. 509831/0826 13. Method according to one of the preceding claims, characterized in that the "coated pipe" passes through a series of pressure chambers within the underwater vehicle, which are kept at increasing pressure so that the pressure differences between any two chambers and between the last chamber and the seawater be reduced outside of the underwater vehicle. 14. Underwater pipeline laid according to the method according to one of the preceding claims. 15 underwater vehicle for laying underwater pipelines, characterized in that the vehicle for a controlled movement on or just above the seabed in the Is able and facilities for the production of a glass fiber reinforced plastic pipe, facilities for weight coating the pipe and means for extracting the weight coated pipe from the submerged vehicle having. 16. Underwater vehicle according to claim 15 »characterized in that that the pipe is manufactured in a first station, and that the vehicle has facilities to the produced pipe to a second, facilities for weight coating the pipe having station to lead. f ■ 17. Underwater vehicle according to claim 15 or 16, characterized characterized in that the means for transferring the weight-coated pipe from the vehicle to their towards the sea end are adjustable, so that the emerging pipe is directed upwards towards the sea surface can be. 509831/0826 18. Underwater vehicle according to claim 15? 16 or 17, thereby characterized in that it is powered by nuclear power. 19. Underwater vehicle according to claim 15, 16, 17 or 18, characterized in that it is provided with one or more connection openings to which supply lines or supply underwater vehicles are connected can be. 20. Underwater vehicle according to claim 15, 16, 17, 18 or 19, characterized in that a mandrel within the drill is provided that can be expanded to seal the pipeline. 509831/0826 Blank page