FR2780751A1 - Process and device for lining a well or channel using inflatable pre formed sections - Google Patents

Abstract

Process for tubing a well or channel (C) using a pre formed sleeve which is flexible and radially expandable and/or unfolding, by inflating it under an internal pressure (P). The wall comprises a filament armor set into a fluid resin which can be hardened in situ by polymerisation, after the pre form is placed in the well or channel The resin is injected after the pre form is inflated and/or unfolded, from a reservoir (3). The means of injecting the resin are a piston and/or a pump (5). Device for carrying out this process, including an extractable dilating tool around which the preform is fixed. The filament armor is made of textile or metal fibers. The pump is designed to carry into the well or channel the ambient liquid and to operate the piston via a pipe which contains a non-return valve. The resin is a thermoset. The reservoir contains two compartments, one containing the resin and the other the hardener or catalyst, allowing the two components to be injected simultaneously. The reservoir is independent of the preform and its inflating system, with connectors to link the reservoir and the preform before it is introduced into the well or channel. The reservoir is fixed to the extractable dilating tool. The reservoir is tubular and is fixed coaxially to one end of the tool.

Description

The present invention relates to a method and a device for

  casing of a well or pipe.

  Flexible tubular preforms, in the form of radially expandable sleeves, have already been proposed for the casing of an oil drilling well, or of a pipeline, in particular for consolidating or repairing it (or inflating it). effect of internal pressure, and curable in situ; such preforms are intended to be placed in the radially folded and / or unexpanded state - state in which they

  have a small radial size - then to be unfolded and / or expanded radially -

  ment by application of an internal pressure, before being hardened in situ, in particular by

polymerization.

  A system of this type is described for example in document WO 94/25655, according to which the wall of the preform comprises a filamentary reinforcement; the latter is formed of braided fibers, for example carbon or glass, the braiding allowing the radial expansion and, correspondingly, the axial retraction of

the assembly during inflation.

  The resin may be a resin of known type, hardening under the effect of the

  heat or under the effect of a chemical reaction, by contacting with a hardener.

  The system which is the subject of the aforementioned document consists of an inflatable internal tool - called a matrix -, around which the preform is initially fixed. This tool is removable. After inflation and hardening of the preform, which comes to line the inner wall of the well or the pipe, and adhere intimately to this wall, the tool

  can be torn off axially and removed from the well or pipeline.

  The document FR-B-2 737 533 relates to a similar improved system, in which a series of frangible compression rings allows inflation

  progressive of the preform, from one end to the other.

  In known systems, the resin is incorporated, in the fluid state, with

  inside the wall of the preform as soon as the latter is manufactured.

  This results in a number of drawbacks.

  Firstly, it being observed that the nature of the resin depends on the well or the pipe for which the preform is intended, each preform must, at the time of its manufacture, be adapted, not only in terms of its dimensions, but also sure

  the plan of the nature of the resin it contains, at the well or the pipe in question.

  This naturally poses a problem of storage, inventory management,

and therefore response time.

  Secondly, the presence of the resin in the wall of the preform necessarily increases the transverse dimensions (diameter) of the preform when it is in the non-swollen state; this goes against the search for good compactness, allowing the preform to pass through restrictions of small diameter at the time of its installation. Third, in the case of a thermosetting resin, storage

  at room temperature over a long period of time may cause the reticula to start.

  tion. This unwanted advance in crosslinking can modify the behavior of the resin, or even prohibit its use. For this it is necessary to keep the product in a temperature-controlled container, including during transport, which

  of course poses practical and cost problems.

  The present invention proposes to solve these difficulties.

  For this, the idea behind this invention is to dissociate the resin from the wall of the preform, at the time of its manufacture, the incorporation of the resin in the

  wall made only on site, after the preform has been introduced and positioned-

  born in the well or the pipeline, using the absolute pressure of the well (or the pipeline) to migrate the resin into the preform and avoid any formation of air bubbles. The invention relates to a preform in the form of a flexible and radially expandable and / or unfoldable sleeve, of the type mentioned above, the wall of which comprises

a filamentary reinforcement.

  The method according to the invention consists in injecting the resin inside the wall, so that it comes to drown the preform, after positioning of the latter

  inside the well, preferably after inflation and / or unfolding of the preform.

  The device which is the subject of the invention is remarkable in that it

  comprises at least one reservoir containing a fluid resin curable by polymerization

  tion, means being provided which make it possible to inject this resin in situ into said

  wall to impregnate the filamentary framework.

  Furthermore, according to a certain number of additional, non-limiting characteristics of the invention: - said means for injecting the resin comprise a pressure piston; - Said resin injection means comprise a pump; - The device comprises an extractable dilator tool around which the preform is fixed; the filamentary reinforcement comprises textile or metallic fibers, for example carbon or glass fibers; - Said pump is adapted to withdraw from the well or the pipeline the

  ambient liquid for actuating said piston, via a conduit which is provided with a non-return valve

return;

  - Said resin is thermosetting.

  In a variant of the device, the latter has a reservoir which comprises two compartments respectively containing a resin hardenable by chemical reaction and a hardener or catalyst to which this resin reacts, means allowing

  the simultaneous injection of these two components into the wall of the preform.

  According to an additional characteristic of the invention, the reservoir that it has one or more compartments - is independent of the preform and its inflation system, connection means allowing their mutual assembly before

  introduction into the well or pipe.

  According to another characteristic, at least one valve is provided, through which the resin is injected. Its function is to regulate the differential pressure between the filamentary reinforcement and the interior of the well or of the pipe. In the case where one is dealing with an extractable dilator tool, said reservoir advantageously, is fixed to this tool, so that it is also removed at the same time

than the latter at the end of the operation.

  Preferably this tank has a generally tubular shape, and it is fixed

  coaxially at one of the ends of the dilator.

  Other characteristics and advantages of the invention will become apparent from the

  description and attached drawings which show by way of nonlimiting example, a

  preferred embodiment. In the drawings: - Figure 1 is a general schematic view of a device according to the invention; - Figure 2 shows the preform and its dilator, the upper part of the figure being shown in axial section and the lower part being shown "peeled"; - Figure 3 is a cross section corresponding to the section plane 111-111 of Figure 5; - Figure 4 is an axial sectional view showing the device introduced into a pipe, vis-à-vis a portion of the latter which has a damaged wall, for example pierced, and which one wishes to tubing; - Figure 5 is an axial sectional view of the distal end portion - in this case the lower end - of the device; - Figures 6 to 9 are views similar to Figure 4, which show the different stages of the casing process; - Figure 10 is a schematic view in axial section similar to the figure, which shows a variant of the device, having a tank with two compartments. The device 1 illustrated in FIGS. 1 to 5 comprises a preform 1

  secured to a dilator 10, which it surrounds.

  We have designated by the references 10a and 10b the frustoconical end portions of the tool. This tool is a tubular sleeve with a flexible and elastic membrane containing a longitudinal central channel 100 into which it is possible to introduce a fluid under pressure, either from the well head, or by pumping the liquid present in

the well or the pipeline.

  The wall of the preform consists of two tubular layers

  concentric 11, 12. The outer layer 12 is an outer skin of elastic material

  elastic mother. The layer 11, trapped between the outer layer 12 and the tool 10 - which in a way constitutes the internal skin - is for example a braiding of carbon fibers. The fitting tool has been designated by reference 2; this tool contains the various electronic instruments for controlling the operation and, if necessary, the pump

inflation of the dilator tool.

  This tool is fixed to the proximal end portion 10a of the device, in this case its upper end if we are dealing with a well or a direction pipe.

  vertical, or having a vertical component -.

  As is well known, the entire device is suspended from a rod; it is a tubular rod intended to be connected to an apparatus located at the well head which makes it possible to introduce and lower the assembly into the well or the pipe and to reassemble them except for the preform at the end of the operation. The tubular rod 20 contains the various electrical conductors and possibly conduits of

  appropriate fluids which allow the connection of the device with the well head.

  The distal end 10b is removably connected to a reservoir

  tubular 3 inside which a piston 4 can slide axially.

  The reservoir 3 is extended downwards by a connecting member 6 to which is attached a pump 5. It is an electric pump connected by conductors, not

  shown, which can pass through the body of the tool 10, to the setting tool 2.

  The pump 5 is suitable for withdrawing from the interior of the well or the pipe the ambient liquid - for example water or petroleum to discharge it into the tank 3, below the piston 4, via a longitudinal channel 60 formed in the member 6. The channel 60 communicates with the outside by a non-return valve 61; the latter is oriented so as to allow the passage of the fluid present in the well or the pipe towards the channel 60 if the external pressure is greater than the pressure prevailing in this channel; it does not, however, allow the escape of the fluid from the channel 60 to the outside. In Figure 5 are designated by the reference 40 of the annular seals surrounding the piston 4; they allow the sealed axial sliding of the piston to

  inside the cylindrical wall 30 of the reservoir 3.

  In the same figure, note the presence of a clamp 16, which retains the reservoir 3, and elements 6 and 5 of which it is integral,

the end of the device 1.

  The upper part of the reservoir 3 has been designated by the reference 31.

  ci has an end portion 310 which is force fitted into a wall recess 10c formed at the lower end of the dilator tool 10; this connection is reinforced

  by the presence of the aforementioned collar 16.

  The part 31 hermetically seals the lower end of the central channel of the tool. This part 31 is pierced by longitudinal channels 32. Opposite each of the channels 32 - only one of which is visible in FIG. 5 - the wall of the tool is pierced with a similar channel 14 which is extended by a groove 15 - visible on the

  FIG. 3 - axially bordering the annular fibrous layer 11.

  In the example illustrated, three sets of channels 32, 14 and grooves 15 are provided, regularly distributed at 120. A different number can of course be expected. These passages make it possible to supply the layer 11 with resin from the reservoir 3 and to distribute the resin suitably within the layer 11 so as to

  impregnate the filamentary structure constituting this layer.

  The channels 32 are provided with a non-return valve 320 with adjustable calibration, which allows the controlled escape of the resin out of the tank, and prohibits a

pass in reverse.

  As shown more particularly in FIG. 1, the parts 2, 1, 3, 6 and extend coaxially, downwards, the tubular rod 20, this in a small transverse dimension, the largest transverse dimension corresponding to the diameter of the

part 1.

  This diameter is of course a function of the diameter of the well or the

tubing.

  As an indication, if it is a pipe having a diameter of mm, the initial diameter of part 1, in the deflated state is for example of the order of

at 100 mm.

  The length of part 1 depends on the length of the area to be tubed.

  Still for information, this length is between a few meters

and a few tens of meters.

  Initially, the device 1 is manufactured and delivered disconnected from the reservoir 3.

  The structure 11 is therefore not impregnated with resin. She is at the

atmospheric pressure.

  The reservoir initially contains the desired dose of resin 7, in the fluid state.

  It is for example a hot polymerizable resin. The piston 4 is in its

  low position pressing against element 6 (position in Figure 5).

  It is therefore possible, depending on orders and needs, to associate with a device 1 different tanks containing resins of different nature and / or volume. The tank 3 can be stored away from heat, in a suitable thermally insulated container, see refrigerated; on the other hand, the set constituted by the

  preform and the dilator can be stored at room temperature.

  The connection of the reservoir 3 (and of the elements 6 and 5 of which it is integral) to the distal end of the device 1 is made on the site, before the preform is placed in the well or in the pipeline, this after fitting of part 31 in part

and fitting the collar 16.

  In the example illustrated, it involves tubing a cylindrical pipe

  vertical C of which an area Z has deteriorated (see Figure 4).

  We start by introducing and lowering the assembly into line C, in correspondence with zone Z. Generally, a liquid is present inside the line, by

  example of petroleum, if it is an oil pipeline.

  As a result of the negative pressure differential prevailing between the fibrous layer 11 and this liquid, the latter can penetrate via the non-return valve 61 in the channel and push the piston 4 upwards, expelling a certain amount of resin to

  the interior of the layer 11 by the channels 14 and the grooves 15.

  This initial supply of resin, under the effect of ambient pressure, is generally between 0 and 30% of the volume of resin 7 initially contained in the tank. This volume is a function of the setting value of the valves 320 as well as

of the frame structure 11.

  It should be noted that during the introduction of the device into the pipe, and during the descent, the pressure of the liquid therein increases, which creates an increasing pressure differential between the structure and the liquid. This differential

  negative is maintained via valve 320.

  The preform is then inflated, in a known manner, by

  supply of a pressurized fluid P inside the channel 100.

  The tool or the preform are advantageously provided with frangible rings as taught by the aforementioned FR-B-2 737 533. So the inflation is done

  gradually from the bottom to the top of the preform (compare Figures 6 and 7).

  Preferably, reliefs resulting from annular grooves 120 provided in the end portions of the outer skin 12 ensure good anchoring of the

  preform against the internal wall of line C during inflation.

  Of course, as a result of this inflation, there is a retraction of the

  preform in the axial direction (shortening).

  The resin injection is done at the end of inflation.

  To do this, pump 5 is started (via a control system incorporated in part 2). This takes the ambient liquid present in the pipeline

  C, and discharges it into the tank 3, under the piston 4.

  The latter is therefore pushed upwards (arrow F, Figure 7), driving back

  in turn all of the resin 7 in the fibrous layer 11.

  The curing of the resin can then take place, by adding heat.

  As explained in WO 94/25655, this heating can be done in particular by the Joule effect, some of the threads constituting the braiding of the layer 1 1 being

  heating wires which are supplied with electrical energy from the control tool 2.

  Once curing is complete, the tool is deflated, and it is extracted from the cured preform, which remains adhered to the pipe C, as described in the

document already cited.

  The reservoir of FIG. 10 is essentially distinguished from that which has just been described by the fact that it comprises two parallel compartments 34a, 34b, containing

  each a movable piston 4a, respectively 4b.

  The reservoir 34a contains a resin 7a, the hardening of which takes place by chemical reaction when it is mixed with a reactive component (hardener or

  catalyst) 7b contained in the tank 34b.

  The channel 60 connecting the pump 5 to the reservoir 3 has a bifurcation whose branches 60a, 60b are associated, respectively, with the pistons 4a, 4b; the outlet channels 32a, 32b of each reservoir meet to form the outlet channel 32 which

connects to the aforementioned channel 14.

  It is thus understood that when the pistons 4a and 4b are moved upwards under the effect of the liquid coming from the valve 61 or from the pump 5, they simultaneously discharge the resin and the hardener, the mixture of these two components being

  distributed in layer 11 to impregnate the filamentary reinforcement.

  Curing therefore takes place after injection of these two components. The reaction can be activated by a heat supply provided by the setting tool, or by the

only well temperature.

  However, as long as the two components are isolated in their compart-

  respective, there is no risk of mutual reaction and therefore does not arise

  no problem related to the aging of the resin, nor to the storage of the tank.

  It would not go beyond the scope of the invention to provide a device equipped with a pump capable of being used both for inflating the preform and for injecting the resin. Furthermore, it would be possible to fix the reservoir at the proximal end,

  that is to say in the upper part of the preform, and not at its distal end.

  Finally, in the case of a thermosetting resin, it is not always necessary for the device to include heating means; in some cases this is the

  temperature of the well itself which is sufficient to carry out the polymerization.

Claims (11)

  1. Method of casing a well or a pipe (C) by means of a preform in the form of a flexible and radially expandable and / or unfoldable sleeve, by inflation under the effect of an internal pressure (P) , and whose wall comprises a filamentary reinforcement (11) embedded in a fluid resin (7) hardenable in situ by polymerization, characterized in that this resin (7) is injected into said wall also in situ,   after placing the preform inside the well or the pipe (C).   2. Method according to claim 1, characterized in that the   resin after inflation and / or unfolding of the preform.   3. Device for casing a well or a pipe (C) by means of a preform in the form of a flexible and radially expandable sleeve, inflatable under the effect of internal pressure (P), and the wall of which comprises a filamentary reinforcement (11), characterized in that it comprises at least one reservoir (3) containing a fluid resin (7) curable by polymerization, means (32; 14) being provided which make it possible to inject in situ this resin (7) in said wall to impregnate the frame filamentary (7).   4. Device according to claim 3, characterized in that said   resin injection means (7) comprise a pressure piston (4).   5. Device according to one of claims 3 or 4, characterized in that   that said means for injecting the resin comprise a pump (5).   6. Device according to one of claims 3 to 5, characterized in that   that it comprises an extractable dilator tool (10) around which the preform is fixed.   7. Device according to one of claims 3 to 6, characterized in that   that the filamentary reinforcement (11) comprises textile or metallic fibers.   8. Device according to claims 4 and 5 taken in combination,   characterized by the fact that said pump (5) is adapted to withdraw ambient liquid from the well or pipe and to actuate said piston (4), via a conduit (60) which   is provided with a non-return valve (61).   9. Device according to one of claims 3 to 8, characterized in that   that said resin is thermosetting.   10. Device according to one of claims 3 to 8, characterized in that   that said tank (3) comprises two compartments (34a, 34b) respectively containing a resin (7a) hardenable by chemical reaction and a hardener or catalyst (7b) to which this resin reacts, means (5; 4a; 4b; 32a, 32b ; 32; 14) allowing   the simultaneous injection of these two components into the wall of the preform.   1 1. Device according to one of claims 3 to 8, characterized in that   that the reservoir (3) is independent of the preform and its inflation system, connection means (31, 1OC, 16) allowing their mutual assembly before introduction   tion in the well or pipeline (C).   1 2. Device according to one of claims 3 to 8, characterized in that   that it comprises at least one valve (320) through which the resin is injected.   1 3. Device according to claims 6 and 11 taken in combination,   characterized by the fact that said reservoir (3) is fixed to said extractable dilating tool (10).   14. Device according to claim 12, characterized in that said reservoir (3) has a generally tubular shape, and is fixed coaxially to one of the tool ends (10).