FR2718665A1 - Submerged jet submerged pipe cutting tool. - Google Patents

Abstract

The present invention relates to a tool for radial or diametrical cutting of pipes, in particular submerged submarine pipes (pipeline) as well as those forming part of the supporting structures of an oil platform, by projection under high pressure of abrasive particles in suspension in a carrier fluid. A tool for radial cutting of pipes (1), by a pressurized abrasive jet is capable of penetrating inside said pipe, which tool comprises a body (2) capable of being immobilized inside said pipe. piping and comprises a rotating head (3) provided with a nozzle (5) for spraying an abrasive mixture, which body comprises a first inflatable positioning ring (6) and a second inflatable positioning ring (7), which rings inflatable are (6, 7) toric, consist of an elastomeric membrane (10) which delimits a sealed cavity (11), the section of which at rest is very flattened, and the thickness (13) of which under pressure is at least equal to twice the thickness (12) at rest. The technical field of the invention is that of cutting tubes, in particular metal tubes.

Description

TOOL FOR CUTTING PIPING IMMERED BY ABRASIVE JET

  The present invention relates to a radial cutting tool

  or diametric piping, especially submerged piping under-

  (pipeline) as well as those forming part of the structures carrying platforms of oil, by projection under a pressure

  high abrasive particles suspended in a vector fluid.

  The technical field of the invention is that of the cutting of

especially metal tubes.

  It is necessary in particular for operations of dismemberment or dismantling of oil rigs after the end of their operation, to cut the base of the piles on which these platforms rest, which piles are generally anchored on the sea floor; this type of operation can in particular be carried out by introducing inside these piles a radial or diametrical cutting tool of the pile (or of said pipe) and of cutting of

  this with an abrasive jet under high pressure.

  Patent Application EP 63940 already discloses an abrasive jet cutting tool that is capable of being introduced inside a pipe, which comprises a body, a head rotatably mounted relative to the body and at least one cutting nozzle which is connected to a source of fluid under pressure and fed by said pressurized fluid mixed with abrasive particles; the device described in this document comprises auxiliary nozzles for moving the tool by a fluid jet, that is to say by reaction, and comprises an inflatable annular collar which makes it possible to position

  the device in the piping during the cutting operation.

  The device described in EP 63940 is intended to cut tubes or stacks, that is to say to perform a cut by a jet of fluid loaded with abrasive particles, in a direction parallel to the axis of the pipework in which it is introduced. For radial or diametrical cutting of piping, it is necessary to obtain a positioning of the tool in the very precise piping, in order to ensure a good cutting of this piping; indeed, if the axis of the tool (particularly the axis of rotation of the head of the tool) is offset with respect to the axis of the pipe, it will be obtained after rotation of the head on a lathe (or 360), a helical cut which prevents a separation of the pipe sections, and does not allow to achieve a real diametrical cut. The problem is therefore to provide a cutting device

  whose positioning is improved.

  The problem is also to provide such a cutting device that can be handled, put in place and emerged quickly and as simply as possible in such types of

  pipelines or piles carrying platforms.

  The solution to the problem consists in providing a tool for radial cutting of pipes, by a jet of abrasive pressure, which tool is likely to penetrate inside said pipe, which tool comprises a body capable of being immobilized to the interior of said pipe and comprises a rotary head provided with a nozzle for blowing a mixture of water and abrasive, which body comprises a first inflatable positioning ring and a second inflatable positioning ring, which inflatable rings. are toric when they are inflated pneumatically or hydraulically, which inflatable rings are constituted by an elastomeric membrane which delimits a sealed cavity whose section at rest is very flattened (having a thickness for example between 25 and 30 mm) and whose thickness

  pressure is at least twice the thickness at rest.

  Where appropriate, said rotating head may be provided with two diametrically opposed jet nozzles which may be used simultaneously or one of which may be used when the other is defective, and supplied by separate means equipped with disconnection whose state can be controlled remotely, which may allow the use of one or other of the nozzles

  in the event of blockage of one of the nozzles without local manual intervention.

  Moreover, in the case for example of tools intended for cutting tubes of very large diameter, it may be advantageous to provide at least a third substantially identical inflatable ring

  said first and second inflatable rings.

  According to a reference embodiment, the invention provides a tool (underwater in particular) of diametral or radial cutting of pipes (immersed in particular), by a jet of abrasive under pressure, which tool comprises a first part or body said fixed part , that is to say capable of being immobilized inside said pipe, and comprises a second part or head, said movable or rotatable part, that is to say capable of being rotated by relative to said first fixed portion, along an axis substantially coinciding with the longitudinal axis (ZZ) of said pipework, which second movable portion is provided with a nozzle for projecting (or discharging) an abrasive mixture (generally comprising abrasive particles suspended in a fluid, preferably a liquid) which first part comprises a first inflatable ring positioning said tool in said pipe, which tool further comprises a second ring onflable positioning of said tool, which inflatable rings are substantially identical and toric, consist essentially of an elastomer membrane, preferably armed with textile or mineral fibers, which membrane defines a sealed cavity of substantially toroidal or annular shape, the section of which rest (in the uninflated state) is very flattened, and whose thickness under pressure (in the inflated or expanded state, at low pressure, for example at a pressure of the order of a few bars or hundreds of kilograms Pascal ), is at least equal to

double the thickness at rest.

  The invention makes it possible to ensure very accurate positioning (in terms of parallelism and centering or coaxiality), for example with an accuracy of about 5 to 10 mm, of said tool in said pipework, so as to allow (during inflation under pressure) a significant radial expansion or expansion of said positioning rings, and so as to allow said inflatable rings to retract (or to radially shrink) during the implementation.

  placing or removing said tool in said piping.

  Preferably the ratio of the height of said section (at rest) to the thickness of said section (at rest) is greater than 2, for example close to 5 to 15, and the thickness of said section at rest is very low , preferably less than or equal to 100 mm, by

example close to 10 to 50 mm.

  Advantageously, said tool further comprises at least one, for example two inflatable lifting rings of the portion of pipe cut by said tool, which inflatable lifting rings are preferably arranged around a tubular body of a hoist and are

  disposed between flanges surrounding said tubular body.

  Advantageously, said inflatable lifting rings are surrounded by a mattress or deformable ring of generally toroidal shape, for example of substantially rectangular section, whose substantially cylindrical outer surface has a coefficient of

  friction, on the inner face of said pipe, high.

  Advantageously said body (and / or said head) comprises a

  pierced ferrule (with cuts or windows).

  Advantageously, said tool comprises a preferably flexible supply pipe of abrasive of said nozzle, which is fixed relative to said body of said tool; said tool comprises a rotary joint and comprises a rotating flexible duct (supplying said abrasive nozzle) which is connected to the outlet of said rotary joint and to a supply pipe of said nozzle provided in said head, which flexible of supply is able to rotate simultaneously with said head and / or said nozzle, along said axis; said nozzle is preferably movable and capable of moving radially under the action of a jack for example, which head also comprises a rolling stop or roulette wheel capable of rolling on said inner face of said pipe to be cut and said head further comprises means of

recall of said bus.e.

  Advantageously said hoist and said body of said tool are connected by flexible links such as slings, preferably of adjustable length; alternatively said hoist and said body can be rigidly connected to one another or together

rigid mechanics.

  Advantageously the spacing or the distance between the median diametral planes of said first and second inflatable positioning rings is at least equal to the width (or height) of said

  inflatable positioning rings.

  Advantageously, said tool is fed with fluid loaded with abrasive particles under a high pressure, preferably comprising

  between 100 and 2000 bars (or hundreds of kilos Pascal).

  Advantageously, said movable nozzle is subjected to a pressing force, for example exerted by said fluid loaded with abrasive particles, which tends to press said nozzle against the internal face of said pipe, and is preferably also subjected to a restoring force ( or of equilibrium of the same direction but of direction opposite to said support force) exerted by a spring or a jack by

example.

  Advantageously, said inflatable positioning rings surround a thin cylindrical tubular part or ferrule of said body, which ferrule is provided at its periphery with substantially circular flanges located on either side of each of said

  inflatable positioning rings.

  Thanks to the presence and the particular structure of the inflatable positioning rings of a tool according to the invention, the pressure exerted by said inflatable rings, during their inflation allowing the locking in position of the tool in the pipework, which is is exerted by reaction on the structure of the body of the tool, is very reduced because of the large bearing surface between said inflatable rings and the structure of said body of said tool, which allows for a structure of said body lighter and much easier

  to handle, due to low mechanical stresses.

  Moreover, thanks to the very high elasticity and deformability of the inflatable positioning rings according to the invention, the introduction and withdrawal of the tool into the pipe (when

  the inflatable rings are deflated) are greatly facilitated.

  In addition, the invention makes it possible to provide cutting tools (for example tubes of diameter ranging from about ten inches to several meters) that can be centered and see their axis of general symmetry almost perfectly aligned with the longitudinal axis. cutting piping, with a precision or tolerance of

  coaxiality between said axes of about 5 mm.

  Moreover, in the preferred embodiment where the tool incorporates a pneumatic or hydraulic hoist, the handling of the tool and the section of pipe previously cut is greatly facilitated by the use of the inflatable lifting rings and is still facilitated. when using peripheral mattresses with a high coefficient of friction, facilitating the

  handling said cut pipe section.

  Thanks to the characteristics of the invention, and in particular thanks to the presence of a fluid supply hose loaded with abrasive particles which is rotatably mounted relative to the primary supply hose, thanks to the presence of a rotary joint and the presence of a radially movable nozzle, a large cutout

accuracy can be obtained.

  The many advantages provided by the invention will be better

  understood through the following description which refers to

  attached drawings, which illustrate without any limiting character, particular embodiments of a cutting tool according to the invention. FIG. 1 is a longitudinal section along a common longitudinal axis of symmetry of the cutting pipe and the apparatus, a cutting tool equipped with a pneumatic hoist according to FIG.

the invention.

  FIGS. 2 and 3 respectively show a diagrammatic view in half section of the operating mode of the inflatable rings of FIGS.

  positioning and lifting of a tool according to the invention.

  Figure 4 illustrates a detail of a particular mode of

  realization of a movable nozzle according to the invention.

  With reference to FIG. 1, a cutting tool according to the invention essentially comprises a body 2 of substantially cylindrical general shape with an axis 4 which, during the cutting of the tube (of the pipe) 1, for example metallic, must be substantially coaxial with the longitudinal axis ZZ of said tube or pipe 1, and comprises a head 3 rotatable relative to said body 2. The tube 1 which can be the base of a support stack of a petroleum platform, can be for example mounted inside an outer pillar 19 for example made of metal and secured thereto by concrete 20 cast between the two tubes 1 and 19, which tube 19 can be anchored or not

in the underwater soil.

  The cutting tool 2,3 is suspended by slings 16 to a hoist 36 itself suspended by slings 15 to the hook of a lifting device (not shown) for example; the assembly consisting of said cutting tool and said hoist 36 has been introduced inside said tube 1 by the upper end thereof and down to the height o the diametral section of said tube 1 (and possibly said tube 19 and the concrete gap) must be performed by the action of an abrasive jet sprayed by a nozzle 5 in a radial direction (with reference to said tubes 1.19), that is to say along an axis XX shown in Figure 1, said nozzle 5 being driven in a rotational movement (at a speed for example of a turn in 4 to 6 hours) around

  of the ZZ axis of said pipe 1 in order to cause said diametrical cut.

  In the position shown in Figure 1, said cutting tool is in the cutting position and is immobilized and centered inside the tube 1 by two inflatable rings 6, 7 located around a cylindrical portion or ferrule 23 (for example sheet metal) forming part of the body

2 fixed of said tool.

  At the lower end of said body 2 is provided a bearing 34 of large diameter allowing a relative rotation of the head 3 relative to the body 2 about said axis ZZ of said pipe substantially coincides with the axis 4 of said body and / or said head. said cutting tool. The rotation can be obtained by means of a hydraulic motor 28 supplied with a fluid by hoses 29, which motor 28 rotates, via a coupling for example, one or more speed reducers 27 whose shaft final output door pinion 26 which meshes with a ring gear 25 rigidly connected to said head 3, and thus causes the rotation of

said head along said axis 4, ZZ.

  Said head 3 comprises a structure, for example metal, consisting of tubes 56 and a metal frame 21, on which is fixed a jack 18 that can cause a displacement of said nozzle attached to the end of a tube 43 defining a conduit or channel Arrival of the fluid loaded with abrasive particles,

  allowing the delivery of fluid to said nozzle.

  It can be seen that said channel 44 is bent, has a substantially longitudinal portion located along said axis 4 and a radial portion extending along said axis XX; the inlet of said tube 43 and / or of said duct 44 is connected to a flexible hose 32 fixed by its lower part to said tube 33, which flexible hose 32 rotates in

  same time as said head 3 thanks to a rotary joint 33.

  The inlet of said rotary joint 33 is connected to a hose 31 for supplying fluid loaded with abrasive particles at high pressure. At the tangential or external radial end of said tube 43, close to said nozzle 5, there is provided a wheel 45 capable of resting and rolling on the inner surface 40 of said tube 1 and ensuring positioning or separation between the end of said nozzle 5 and the wall, which is compatible with the work to be carried out, thanks to said jack 18 which tends to push said nozzle radially and to press said roller 45 against said internal wall 40

said tube.

  Said jack 18 may be constituted by a single-acting jack with spring return or by accumulator; alternatively, as described below in relation to FIG. 4, said jack may be constituted by a spring-loaded mechanical jack or a hydraulic jack instead.

  allows to eliminate a hydraulic supply hose from the jack 18.

  Said inflatable positioning rings 6, 7 are fed with an inflation fluid conveyed by partially represented supply hoses, each of said inflatable rings 6, 7 wedged between two circular flanges 24 fixed to the external surface of said ferrule 23 and now in position said inflatable rings 6,7 whose outer surface is plate on the inner face of said tube 1 under the effect of inflation and deformation of said

  rings due to the pressure of the fluid injected by said hoses 30.

  It can also be seen in the upper part of FIG. 1 that said hoist 36 can consist essentially of a tubular body 35 whose inner part is hollow and which receives on its external surface three flanges 41, for example circular, which delimit between them two annular spaces. in each of which is located an inflatable lifting ring 8,9 which can be fed in the same way as said inflatable positioning rings 6,7 (but of which

  the inflation ends have not been shown).

  Advantageously, said inflatable lifting rings 8, 9 themselves are surrounded by a mattress 37, 38 respectively, also of annular shape, substantially compact and relatively non-compressible but whose external face 39 has a high coefficient of friction with the internal face 40. said tube 1 so as to facilitate the locking of said hoist in said tube, which hoist can be used, when the cutting operation is completed, to go up to the surface both said cutting tool and the sectioned tube by force pressure exerted by said lifting rings 8, 9 which are then inflated and which cause pressure contact of the outer face of said mattress 38, 37 against the inner wall of the tube and thus allows the lifting of the cut tube. With reference to FIG. 2, said ferrule 23 constituting an essential part of the framework of said body of said cutting tool can be lightened by virtue of the presence of cuts or windows 28 provided therein and comprises at its periphery said rings.

Inflatable positioning 6,7.

  Each of said rings has a toroidal shape and consists essentially of a membrane 10 which may preferably be of elastomer reinforced with mineral or textile fibers so as to give it a high elasticity and a capacity for radial expansion, and so as to allow have a good memory for the return to the initial position or rest during each deflation of the inflatable rings, which membrane delimits a sealed cavity 11 provided with an orifice or valve 57 allowing the connection of said cavity and / or said inflatable ring to inflating tubing (reference numeral 30 of FIG. 1), which allows the

  inflating and deflating said rings 6,7.

  Each of said rings extends at the periphery of said shell 23 between two circular flanges 24 whose height 12 substantially corresponds to the height at rest (that is to say in the absence of inflation pressure) of said inflatable rings 6 , 7 which is very small compared to the height (or width) 14 at rest of said

inflatable rings.

  With reference to FIG. 3 in which is illustrated an inflatable ring 6, 7 which has therefore been pressurized and a part of the outer face of which membrane 10 is in contact with the inner face 40 of said tube 1, it can be seen that thanks to its radial elasticity said inflatable ring 10 has deformed under the effect of the fluid injected into said cavity 11 so as to come into contact under pressure and to crash against the inner face 40 of the tube 1, in which position the height 13 or thickness in the radial direction of said rings 6, 7 is important relative to said height 12 at rest (Figure 2),

  preferably at least twice that of it.

  With reference to FIG. 4 illustrating a preferred embodiment of a mobile nozzle of a device according to the invention, it can be seen that said nozzle 5 can be kept close to the internal face 40 of the tube 1 thanks to the mounting shown in FIG. this figure; the assembly comprises a tube 431 whose rear end 434 is connected for example to said rotating hose (reference 32 of FIG. 1) which allows the arrival along the arrow 49 of said fluid charged with

  abrasive particles in the channel provided inside said tube 431.

  Said tube 431 comprises in its central part a thin tube 433 fixedly mounted relative to said tube 431 by its upstream part (on the left in FIG. 4), around which can slide a mobile tube 432 provided with sealing joints 50, thanks to a bore 55 provided in said tube 431; the downstream end of said tube 432 (on the right in FIG. 4) carries said nozzle 5 for the discharge of the fluid charged with abrasive particles, is fixed to a flange 51 to which is fixed on the one hand a wheel 45 which can press and roll on said inner face 40 of said tube 1 as and when said head of said tool rotates along said longitudinal axis of said tube 1, said flange 51 also carrying an ultrasound sensor 46 for cutting control

performed.

  Said flange 51 also receives the end of threaded rods 47 which pass through a flange 52 fixed with respect to said head of said tool and whose second end is connected to a flange 53 capable of sliding around said arrival tube 431 abrasive fluid; a helical compression spring 48 is provided around said tube 43 and rests between said fixed and sliding flanges 52; the operation is as follows: under the effect of the pressure of the fluid loaded with abrasive particles, said pressure tends to push the nozzle against the inner wall 40 of the tube 1 until the wheel is brought against the wall, which causes by means of said flange 51, said rods 47 and said flange 53, the compression of the spring 48 and consequently the exercise of a restoring force of said nozzle; said tube 431 is also pushed back (to the right of FIG. 4) under the effect of the pressure of said abrasive particles-laden vector fluid, which tube 431

  is retained by a shoulder which bears on said flange 52.

  There is thus a system to overcome the slight coaxiality defect between the axis of the head of the tool and the axis of the

  cutting tube and a device for ensuring a substantially constant contact pressure of said wheel on the inner wall of the tube and therefore to ensure a constant spacing5 between the outlet of said nozzle and said wall to be cut.

  As illustrated in FIG. 1, it can be seen that said first and second inflatable rings (positioning and / or lifting) are

  superimposed, their respective plane of symmetry being substantially parallel to each other (and perpendicular to said axis ZZ).

Claims (10)

  1. Tool for radial cutting of pipes (1), by a jet of abrasive under pressure, which tool is likely to penetrate inside said pipework, which tool comprises a body (2) capable of being immobilized at interior of said pipe and comprises a rotating head (3) provided with a nozzle (5) for blasting an abrasive mixture, which body comprises a first inflatable positioning ring (6) and a second inflatable ring (7) of positioning, which inflatable rings are (6, 7) toric, are constituted by an elastomeric membrane (10) which delimits a sealed cavity (11), whose rest section is very flattened, and whose thickness (13) under pressure is at least twice the the thickness (12) at rest.   2. Tool according to claim 1 further comprising at least one inflatable ring (8, 9) arranged around a body tubular (35) of a hoist (36).   3. Tool according to claim 2 wherein said inflatable lifting rings (8, 9) are surrounded by a deformable ring (37) whose outer surface (39) has a coefficient of friction, on   the inner face (40) of said pipe, elevated.   4. Tool according to any one of claims 1 to 3 in   which said body and / or said head comprises a ferrule (23) perforated.   5. Tool according to any one of claims 1 to 4   comprising an abrasive supply pipe (31) which is fixed with respect to said body of said tool, comprising a rotary joint (33) and comprising a rotating flexible pipe (32) supplying said nozzle connected to the outlet of said joint rotating (33) and a supply pipe (43) provided in said   head, and wherein said nozzle (5) is radially movable.   6. Tool according to any one of claims 2 to 5 in   said hoist (36) and said body of said tool are connected by flexible links (16).   7. Tool according to any one of claims 1 to 6 in   which the center distance (59) between the median diametral planes of said first and second inflatable positioning rings is at less equal to their width (14).   8. Tool according to any one of claims 1 to 7 which   is fed with fluid loaded with abrasive particles under a pressure above 100 bar.   9. Tool according to any one of claims 1 to 8 in   said movable nozzle is subjected to a bearing force against the inner face (40) of said tubing and to a restoring force of   same direction and opposite direction to that of said support force.   10. Tool according to any one of claims 1 to 9 in   wherein said inflatable positioning rings (6, 7) surround a thin cylindrical tubular portion or ferrule (23) of said body (2), which ferrule (23) is provided at its periphery with substantially circular flanges (24) on the sides and other of each of those   inflatable positioning rings.