EP1205629A2 - Method and device for securing an oil well in the event of a defect in the hydraulic control line of its downhole safety valve - Google Patents

Abstract

Safety process for an oil well of the type comprises a production pipe (1), a bottom safety valve called the origin valve (6) which is mounted in a sleeve (5) in the production pipe, and a hydraulic control line outside the production pipe, called the origin control line (4), supplying fluid under pressure to the valve and a fluid inlet through the sleeve to open at the valve. This process is to ensure the safety of the well if the origin control line fails. The origin valve is replaced by a special bottom valve containing hydraulic connectors along its axis on its top part, means of isolating or sealing closed the origin control line at its periphery and a movable blocking device at the bottom part closed by a fluid under pressure arriving axially via a hydraulic connection. A new hydraulic control line, called the concentric control line, is installed inside the production pipe and along its axis, and this line is connected to the special valve. Also the equipment (special valve, airlock, control line, tools) to operate this process.

Description

The invention relates to means for securing an oil well equipped with a bottom safety valve whose line of hydraulic control is faulty. It extends in particular to a new command line and tools for installing or removing the new line ordered.

We know that, for security reasons, oil wells are generally fitted with bottom safety valves which are inserted into a sleeve-receptacle housed in the production tube of the well a few tens or hundreds of meters deep; these valves have the function of allowing automatically stop effluent production if an incident occurs at the head of well or downstream from them. They are hydraulically controlled upon opening from the surface and close automatically with a powerful spring reminder when a hydraulic pressure drop occurs on the line command, whether this fall is commanded or accidental. This line of hydraulic control consists of a pressurized fluid conduit which runs outside the production tube (between the latter and the outer casing) and is connected, on the one hand, at the surface to a fluid supply, on the other hand, at the level of the valve, to a channel which passes through the receptacle sleeve containing the valve for feed it. This type of system is now used in practically all wells, in particular eruptive offshore wells.

This hydraulic control line sometimes faults (leak, blocked or broken line): the safety valve can no longer be supplied with pressurized fluid and no longer plays its role; she stays generally closed by the action of its spring and blocks the passage of the effluent.

Two solutions are currently available to the operator to overcome this deficiency. It can extract the safety valve from the production tube (after installation of a well head airlock) and then close the command line defective by installing an insulation jacket in the production tube provided with seals which isolate the arrival of the control fluid through the receptacle sleeve. The well can work again but it is then outside security standards since it is no longer equipped with basic security. Another solution avoiding this extraordinary operation consists in "killing" the well, that is to say to reconstitute it entirely by balancing the pressure of the effluent with mud, extracting the entire production tube and its equipment and by casing the well again (like a new well) with the installation of a new traditional type control line and a new valve security, just like in a new well. This solution which then allows working according to safety standards is extremely heavy and expensive.

The present invention provides a new solution for restore an oil well with a hydraulic control line defective, without having to kill and retub the well. The object of the invention is to equip the well with a new hydraulic safety system independent of the original command line, respecting the standards of security, and this by implementing a procedure considerably lighter than the second solution mentioned above.

To this end, one of the objects of the invention is to provide various equipment (new command line, tools for installing or removing the new command line) that allow you to implement a new process for restoring the well.

• par "tube de production", le tube situé au centre du puits pour guider les effluents (tubing),
• par "manchon-réceptacle", le manchon qui est intercalé sur le tube de production pour recevoir la vanne de sécurité de fond (nipple),
• par "tubage externe", la gaine tubulaire située autour du tube de production pour l'isoler du terrain (casing),
• par "ensemble de suspension", la partie (hanger) située à l'extrémité supérieure du tube de production et du tubage externe et qui relie mécaniquement ces deux éléments (en anglais "spool" ou "tubing hanger"),
• par "tête de puits", le système de vannes et robinets qui équipe le puits au-dessus de l'ensemble de suspension (well head).

Conventionally, we will designate below (the corresponding English term is indicated in parentheses):

• "production tube" means the tube located in the center of the well to guide the effluents (tubing),
• by "receptacle sleeve", the sleeve which is interposed on the production tube to receive the bottom safety valve (nipple),
• by "external casing", the tubular sheath located around the production tube to isolate it from the ground (casing),
• "suspension assembly" means the part (hanger) situated at the upper end of the production tube and the external casing and which mechanically connects these two elements (in English "spool" or "tubing hanger"),
• by "wellhead", the system of valves and taps which equips the well above the suspension assembly (well head).

The process concerned to restore a well to safety tanker equipped with a bottom safety valve - said original valve - whose line hydraulic control - said original line - is defective, consists of replace the original valve with a special bottom valve comprising, along its axis and in the upper part, hydraulic connection means, at its periphery, means for sealing or sealing the original control line, and, in the lower part, a movable shutter operable when closing by action of a pressurized fluid arriving axially by the connection means hydraulic, to be installed inside the production tube, along its axis, a new hydraulic control line, called the control line concentric, and to connect said concentric control line to the means of hydraulic connection of the special valve.

So without changing the production tube and its equipment, this process provides the well with a new bottom safety whose originality is to be controlled by a line internal to the production tube, the original line being disused (line which passes through the receptacle sleeve and goes up towards the surface between the production tube and the external casing). Once in place, the valve special isolates or blocks the arrival lights of this original line through the sleeve socket. The special valve then fulfills exactly the same role than a traditional safety valve and allows operation of the well meets safety standards.

An object of the invention is to provide a new line of hydraulic control, called concentric control line, called to be in place along the axis of the production tube to control the special valve of safety previously defined. According to the invention, this line comprises, on the one hand, a plurality of sections, known as common sections, intended to be arranged end to end along the axis of the production tube, on the other hand, an upper section intended to be disposed at the upper end of the current sections, finally a head system intended to be hung on a well head raising element.

Preferably, each running section of said line comprises, from top to bottom, a male connector, a first hollow connector holder with the upper end of which the male connector is attached, a first centering device arranged around the first connector holder to center it in the tube production of the well, a hydraulic connection tube attached to the lower end from the first connector holder, a second hollow connector holder secured to the lower end of the hydraulic connection tube, a second centering device arranged around the second connector holder to center it in the production tube of the well, and a female connector secured to the lower end of the second connector holder.

The upper section of the line has a sleeve tubular, a male connector and a female connector respectively subject to the upper end and the lower end of said tubular sleeve, and at minus a centering device arranged around the tubular sleeve to center the latter in the well production tube.

Finally, the line head system includes a block of suspension adapted to be housed in the raising element, means for attachment to the upper part of said suspension block in order to its attachment by means of a fitting or removal tool, a socket extending down and secured under the suspension block to slide the tubular sleeve of the upper section, sealing means between socket and tubular sleeve, hydraulic connection means connecting, to through the suspension block, said bush and the means for passage of the raising element, and centering fins secured around the sleeve to center it in the production tube of the well.

According to other features of the invention, the connector male of each line section (current sections or upper section) includes essentially a connector body provided with a penetration nose in a female connector and pierced longitudinally with a hydraulic passage, connector nose anchoring structures in the female connector, a check valve closing of the hydraulic passage, elastic means urging the valve towards its closed position, and a valve stem housed in the connector nose in view push the valve back to the open position when the male connector is connected in a female connector.

The female connector of the line sections is conjugated with the male connector above described and includes a connector body provided with a housing for the nose of a male connector and pierced longitudinally with a passage hydraulic, an anchor movable in the transverse direction between a position anchor corresponding to the locking of the anchor structures of the male connector and an erasing position where it frees said anchoring structures, means elastic biasing the anchoring member towards its anchoring position, a structure internal erasure of the anchoring member under the pressure of the nose of a connector male, a release cam protruding from the periphery of the body connector in order to ensure the erasure of the anchoring member and the unlocking connectors under the pressure of a sliding surface around the connector, a valve for closing the hydraulic passage, means elastics urging said valve towards its closed position, and a rod valve housed in the body for maneuvering the valve to its position when the male connector is anchored in the female connector.

Such connectors, male and female, are capable of cooperating and lock to each other, with a single press, securely, automatically and waterproof. Before locking, they are closed by their valve or flap, which avoids pollution of the sections of the control line (or of the internal tube of the valve special) by the effluent present in the production tube. They are opened in end of locking and allows the passage of control fluid.

In addition, each female connector can be unlocked by the external pressure of a surface on its unlocking cam. The installation of line sections in the production tube can thus be ensured, section by section, using a standard type cable lowering device, equipped with a installation tool provided with such a female connector at the bottom. This connector female will be hooked on the male connector of the line section in order to get off this one. At the end of descent, after locking the female connector of said section on the male connector of the lower section already in place (or of the special valve for the first section installed), a shear pin which is provided with the installation tool is sheared by threshing and releases a sleeve of unlocking equipping said fitting tool: this sleeve acts on the cam unlocking of the female connector of the installation tool and the latter, released, can be reassembled and rearmed by means of a new pin for the installation of the next stretch.

Furthermore, the removal of each section of line can be carried out by means of a similar cable lowering device, equipped with a tool of removal comprising a push tube. The latter will be used to unlock the section line which is to be removed, from the lower section, by acting on the cam unlocking of its female connector (via section centralizers as will be better understood later).

Thus, the invention allows, by simple and type operations usual for oil well professionals, to restore a well to safety tanker respecting safety standards and performing all procedures necessary on the new installation, in particular the removal of the special valve background and that of the concentric command line when needed.

• les figures 1 à 10 sont des schémas illustrant les diverses phases du procédé conforme à l'invention de remise en sécurité d'un puits pétrolier,
• les figures 11 et 12 sont des coupes axiales d'une vanne de fond spéciale conforme à l'invention, respectivement en position fermée et en position ouverte,
• les figures 13 et 14 sont des coupes transversales de ladite vanne spéciale par des plans A et B,
• la figure 15 est une vue de détail, en coupe axiale, du connecteur mâle équipant ladite vanne spéciale,
• la figure 16 est une coupe axiale d'un élément de rehausse de tête de puits, fixé sur l'ensemble de suspension du puits, le système de tête de la ligne de commande hydraulique étant représenté en place dans ledit élément de rehausse,
• la figure 17 est une coupe transversale par un plan C de l'ensemble représenté à la figure 16,
• les figures 18, 19 et 20 sont des coupes axiales respectivement du système de tête, du tronçon supérieur, et d'un tronçon courant d'une ligne de commande concentrique conforme à l'invention,
• la figure 21 est une vue de détail en coupe d'un tronçon courant en position de déverrouillage,
• la figure 22 est une vue de détail en coupe axiale du connecteur femelle équipant les tronçons de la ligne,
• la figure 23 est une vue de détail en coupe axiale montrant un connecteur femelle et un connecteur mâle accouplés et verrouillés,
• les figures 24 et 25 illustrent l'opération de mise en place de la vanne spéciale dans le manchon-réceptacle du puits, au moyen d'un outil de pose,
• les figures 26 et 27 sont des coupes transversales par des plans D et E de la vanne spéciale et de l'outil de pose dans la position de la figure 24,
• les figures 28 et 29 sont des vues de détail en coupe d'un outil de pose de ligne de commande concentrique, respectivement en position armée et en position déverrouillée,
• les figures 30, 31 et 32 illustrent les opérations de pose d'un tronçon de ligne de commande dans le tube de production du puits,
• la figure 33 illustre la pose du système de tête de ladite ligne de commande concentrique,
• la figure 34 est une coupe axiale d'un outil de dépose d'un tronçon de ligne de commande concentrique, et la figure 35 en est une coupe par un plan transversal F,
• la figure 36 illustre l'opération de dépose d'un tronçon de ligne de commande concentrique,
• enfin, les figures 37, 38, 39 et 40 illustrent les opérations de dépose d'une vanne spéciale conforme à l'invention.

Other characteristics, objects and advantages of the invention will emerge from the description which follows, with reference to the appended drawings, which present, without limitation, an exemplary embodiment; on these drawings:

• FIGS. 1 to 10 are diagrams illustrating the various phases of the process according to the invention for restoring an oil well,
• FIGS. 11 and 12 are axial sections of a special bottom valve according to the invention, respectively in the closed position and in the open position,
• FIGS. 13 and 14 are cross sections of said special valve by planes A and B,
• FIG. 15 is a detail view, in axial section, of the male connector fitted to said special valve,
• FIG. 16 is an axial section of a well head raising element, fixed to the suspension assembly of the well, the head system of the hydraulic control line being represented in place in said raising element,
• FIG. 17 is a cross section through a plane C of the assembly shown in FIG. 16,
• FIGS. 18, 19 and 20 are axial sections respectively of the head system, of the upper section, and of a current section of a concentric control line according to the invention,
• FIG. 21 is a detailed view in section of a current section in the unlocked position,
• FIG. 22 is a detail view in axial section of the female connector fitted to the sections of the line,
• FIG. 23 is a detail view in axial section showing a female connector and a male connector coupled and locked,
• FIGS. 24 and 25 illustrate the operation of placing the special valve in the sleeve-receptacle of the well, by means of a setting tool,
• FIGS. 26 and 27 are cross sections through planes D and E of the special valve and of the setting tool in the position of FIG. 24,
• FIGS. 28 and 29 are detailed sectional views of a concentric control line fitting tool, respectively in the armed position and in the unlocked position,
• FIGS. 30, 31 and 32 illustrate the operations of laying a section of control line in the production tube of the well,
• FIG. 33 illustrates the installation of the head system of said concentric control line,
• FIG. 34 is an axial section through a tool for removing a section of concentric control line, and FIG. 35 is a section through a transverse plane F,
• FIG. 36 illustrates the operation of removing a section of concentric control line,
• finally, FIGS. 37, 38, 39 and 40 illustrate the operations for removing a special valve according to the invention.

To avoid adding to the description, elements or operations which are already well known to those skilled in the art will be mentioned but not described in detail ; moreover, the English terminology being most often used in this sector, we have given for certain expressions the corresponding English term between quotes to facilitate human understanding of the art.

The process illustrated in Figures 1 to 10 is intended to ensure the restoration of an oil well equipped with a conventional safety valve of bottom with a broken hydraulic control line. We referenced on these figures in 1 the production tube, in 2 the external casing, in 3 the assembly of suspension ("spool" or "tubing hanger"), in 4 the original hydraulic line deficient which crosses the assembly 3, passes between the external casing and the production and passes through the receptacle sleeve referenced in 5 to reach the valve classic background referenced in 6, and in 7 the classic system of valves and taps, designated wellhead.

The first operation of the process (Figure 1), well known in itself professionals, consists in equipping the wellhead 7 with an airlock 8 to through which the cable of a standard descending device 9 passes. To this cable are suspended the tools necessary for the operations to be executed.

The original valve 6 is extracted from the well using a tool traditional recovery 10 (Figure 2).

The production tube 1 is then released and installed successively in it, as shown in FIG. 3, a bottom plug well 11 ("plug"), a conventional bottom valve 12 in the closed position in the sleeve-receptacle 5 of the original valve (this conventional valve 12 can be the original valve 6 itself after verification or a different valve of the same type) and, on the surface, a non-return valve 13 ("BPV: Back Pressure Valve") which is hung in the suspension assembly 3. These operations and tools correspondents are classic.

At the end of these operations, the well is equipped with three safety barriers, plug 11, closed valve 12 and valve 13, so that it is possible to disassemble the wellhead 7 in compliance with safety standards. The Figure 4 shows schematically the well freed from surface equipment.

We then put in place an element 14 for raising the head well (Figure 5) which will later be used to secure and supply the new hydraulic control line. This raising element 14 which will be described in detail further, is fixed on the suspension assembly 3 by studs which cross the flange of said assembly (flange conventionally used to fix thereon the head of well).

The wellhead 7 and the airlock 8 are then replaced as illustrated in figure 6. The well head is fixed by studs on the element extension 14.

With the wellhead back in place, it is possible to remove the non-return valve 13, then extract the classic bottom valve 12 as well as the bottom plug 11, as illustrated in FIG. 7. These operations are and are executed using conventional tools.

The production tube 1 is then released as shown in the figure 8.

The special safety valve (overall referenced 15 in FIG. 9) can then be placed in the receptacle sleeve 5 which contained the original valve. The special valve, the fitting operation of this (which is done using the cable lowering device 9) and the pose used will be detailed later.

Once the special valve 15 has been anchored and locked in the sleeve-receptacle 5, a hydraulic control line is put in place for this valve, known as a concentric control line (generally referenced in 16 to the figure 10). This line extends inside the production tube 1 along the axis of this and is hydraulically connected to a control fluid inlet 17 to through the raising element 14. This line, its positioning (which is carried out using of the cable lowering device 9) and the tools used will be detailed below.

A classic pressure test is performed on the line concentric control to check the proper functioning of the special valve.

The airlock 8 can then be removed. The well is again in production situation with a bottom safety valve which guarantees a operating according to safety standards.

The special safety valve 15 is shown in detail in Figures 11 to 15.

In Figure 11, the valve is shown in axial section at closed position in the receptacle sleeve 5 (shown in lines discontinuous). We see in 5a the fluid passage of the receptacle sleeve which supplied the original valve, and in 5b the anchoring groove with which the sleeve-receptacle, with its lower stop shoulder 5c ("no-go"). In the figure 12, the valve is shown in axial section in the open position, the receptacle sleeve not being drawn.

Said special valve comprises a valve body 18 of general tubular shape, conventionally made up of several tubular parts subject to each other; the upper part 18a of the body is subject to the part low 18b by shear screws 19 in order to allow, in a manner known in to unlock the valve when it is removed.

Inside the body is mounted a tubular slide 20 suitable to move longitudinally in the body between a low position (corresponding to the opening of the valve: figure 12) and a high position (corresponding to its closure: Figure 11). This slide is called back to its position high by a return spring 21 and is controlled downward, as will be seen, by pressurizing the concentric control line 16.

In the lower part, the valve body contains a movable member shutter constituted in the example by a valve 22 which is articulated on said body of so as to be able to pivot between an open position where it is retracted to the side by the slide 20 (Figure 12) and a closed position where said valve - released by raising said slide - closes the valve body by applying against a seal carried by it. The valve 22 is returned to the position of closing by a spring arranged around its articulation axis. It is to highlight that this shutter member, well known in itself, may be of another type and in particular a bullet member which obtains the obturation by a spherical part capable of move longitudinally with an associated rotation.

In contrast to this obturation organ, the body contains a mechanical dog anchoring system which can be of any known type and which is intended, during the installation of the valve in the production tube, to ensure anchoring it in the receptacle sleeve 5. This anchoring system can particular be of the type shown in FIGS. 11 and 12, comprising anchor dogs 23 movable radially to be able to penetrate into the throat anchoring 5b of the receptacle sleeve, a socket 24 for locking the dogs, slidingly mounted in the body and having a suitable peripheral cam 24a to be able to repel the dogs radially, and a return spring 25 urging the locking sleeve 24 upwards. These various organs present, during the fitting or removing the special valve, a classic operation that found in most known valves.

Furthermore, the slide 20 defines a sealed volume 29 between its peripheral face and the internal face of the valve body (whose diameter more important for this purpose). This sealed volume, filled with oil, is delimited, in the upper part, by a seal 30 located at the interface between body and slide, and in the lower part, by a seal 31 of the same diameter as the attached 30.

In the example, the return spring 21 of the slide is disposed in the sealed volume 29, bearing, on the one hand, against a stop piece 33 of the valve body, on the other hand, against an annular rib 34 of the slide, which comes protruding into the sealed volume 29. This arrangement makes it possible to protect the spring 21 which is in the oil without contact with the effluent.

The valve further comprises an internal piston 26 extending the along the axis of its tubular body 18. The lower end 32 of the piston is profiled to reduce turbulence at the heart of the effluent called to circulate in the valve. This piston 26, of small diameter compared to the internal diameter of the body, brings to its lower part a pusher 27 constituted by a section of tube arranged in the valve body to be able to slide therein. This section of tube is secured to the internal piston 26 by radial arms 28 (in the example of the number of of them). This tubular plunger 27 is disposed above and in contact with the slide 20 so as to be able to push said slide down during movement descending from the internal piston 26. In the absence of downward force exerted on the piston, pusher 27 leaves the slide free to go up under the action of its return spring 21 (then pushing said pusher), causing the tilting of the valve 22 and closing the valve.

In the upper part, the internal piston 26 slides in a socket axial 36 which is secured to the valve body by radial arms 37, in the example two in number. Seals 38 at the sleeve / piston interface allow a sealed telescopic movement of the internal piston in the sleeve between a high position corresponding to the closing of the valve 22 (FIG. 11) and a position low corresponding to its opening (figure 12). The upper end of the socket axial is provided with an external thread 35.

At its upper part, a male connector 39 is screwed onto the thread of the axial socket 36. This male connector is adapted to cooperate with a conjugate female connector fitted to the concentric control line 16 in view to carry out a watertight automatic locking by simply pressing both connectors.

FIG. 15 represents an exemplary embodiment of such a male connector 39. (The conjugated female connector will be presented in detail in reference to figure 21 when describing the command line concentric). This male connector comprises a connector body 40 made in two parts 40a, 40b screwed into each other, with interposition of a seal sealing 40c. The part 40a is itself screwed by its thread 35 onto the end of the sleeve 36, while, on the other hand, the part 40b forms a nose elongated 41 intended to penetrate into a conjugate female connector. This nose has of anchoring structures 42 in this female connector, in the example a rib annular having a conical access ramp 42a and a stop shoulder 42b. The parts 40a, 40b forming the connector body are hollow and delimit a hydraulic passage for the control fluid. A valve 43 is arranged in this hydraulic passage to close it when the male connector is not in taken with a female connector. To this end, a spring 44 resiliently biases the valve to its closed position; the valve 43 is extended by a rod 45 housed in the nose 41 in order to push said valve towards the open position when the male connector is connected in the female connector.

Furthermore, the body 18 of the special valve carries, on its face external, two sets of seals 46 and 47, in particular of the rafters, which are arranged to be positioned on either side of the passage of the fluid 5a of the receptacle sleeve when the valve is anchored therein. These toppings isolate the original command line which no longer has any effect.

Of course, the special valve according to the invention includes or may include any other known means which are generally provided with bottom safety valves (in particular profile 48 for hooking the installation and removal tool, which can be seen in Figures 11 and 12 in the section valve body).

When the special bottom valve described above is anchored in the receptacle sleeve of the production tube, its operation is similar to that of a conventional bottom valve, with the exception of the displacement control down the slide 20. When the concentric control line 16 is out pressure, the slide 20 is returned by its spring 21 to its high position where it is set back from the valve 22 (Figure 11): the valve 22 is free and is closed by its own spring. The valve is closed and the effluent pressure increases sealing by pressing the valve on its seat. If we pressurize the line of control, the internal piston 26 is actuated downwards and its tubular plunger 27 causes a displacement down the slide 20 until it abuts against the lower valve nose (figure 12): said slide pushes back the shutter valve 22 and keeps it in its open position. Any drop in line pressure concentric control (voluntary or accidental) generates a release of the valve and its pivoting towards the closed position.

Figures 16 and 17 show the head enhancement element 14 well, which secures and supplies the concentric control line down to the special valve along the axis of the production tube.

This raising element comprises a body 49 called to be attach to the suspension assembly 3. This body has, on its lower underside, tapped blind holes (not visible) for screwing studs through the flange of the suspension assembly. The same fixing means are provided on the face upper part of the body 49 for fixing it to the well head flange 7.

The body 49 is provided with a central bore of diameter at less equal to that of the production tube 1 (preferably equal to the bore of the head well 7) and a lateral channel 50 opening into said bore for the passage of the control fluid. This channel is intended to be connected, in a conventional manner, with the control fluid inlet pipe symbolized at 51.

In addition, the body 49 is provided with line retaining means. concentric control (means for retaining the suspension block than the latter has at its upper end and which can be seen at 56 in Figure 16). These retaining means include, in the example, stop screws such as screws 52 and screws 53 arranged at two levels in the body. Each level includes at least three stop screws regularly distributed around the body (three 120 ° screws have been shown in Figures 16 and 17). Each screw passes through the body in order to protrude in end of tightening in the bore thereof by a stop end 52a, 53a; she can be erased by unscrewing. Sealing means such as rafter joints 54 seal along the screws. At the end of tightening, a shoulder 55 achieves a metal / metal sealing.

The two levels of stop screw are offset in height to ability to position themselves below and above suspension block 56 to retain it, while authorizing its rapid release during the removal of the ordered.

The concentric command line 16 called to hang on the raising element 14 is shown in FIGS. 18 to 23.

This line is constituted by a head system represented in axial section in FIG. 18, by an upper section represented in axial section in the Figure 19 and by common sections as shown in axial section in Figure 20.

The head system includes a suspension block 56 already mentioned, adapted to be housed in the raising element 14 so as to be retained by the stop screw 52 and 53 thereof. This block has at its upper part a profile attachment 57 intended to cooperate with combined means of a setting tool or of removal.

This block is hollowed out with a blind internal channel 58 along its axis and a lateral channel 59 putting this internal channel 58 into communication with the channel lateral 50 of the raising element. Two ring seals such as 60 seal between the two channels at the block / riser interface.

The suspension block 56 carries a socket 61 which extends towards bottom and has centering fins such as 62 toward its bottom end to center said socket in the production tube of the well. In the example three fins at 120 ° are provided around the socket.

The upper section of line (Figure 19) includes a tubular sleeve 63 of diameter suitable for sliding housing in the bushing 61. Sealing means such as seals 64 seal the the interface between these elements. The length of the sleeve 63 is adjusted as a function of the height of the production well so that said sleeve, positioned above the common sections (of standardized length), enters the socket 61 at the end of establishment of the line.

At its upper end, the sleeve 63 is provided with a male connector 65 identical to that already described for the special valve, for allow the upper section to be installed or removed.

At its lower end, the sleeve 63 is provided with a female connector 66 identical to those of the current sections (described below) in view of being able to connect with the male connector of the current section below.

In addition, two centralizers 67 and 68 are slidably mounted at friction around the sleeve 63 to center it in the production tube. The upper centering device 67 will be pushed back by the sleeve 61 when the line to remain, through the play of friction, below the lower end of it. The lower centering device 68 is similar to the lower centering device fitted each current section described below, in order to fulfill, in addition to the function of centering, a function for unlocking the female connector of the section during the removing the line.

Each standard section (figure 20) of standardized length, for example of the order of seven meters, includes an upper male connector 69 (identical to that of the special valve) screwed to the upper end of a connector holder hollow 70. This connector holder 70 is provided with a centralizer 71 mounted at friction around it to be able to slide. This centralizer can be constituted by a tubular element around which are welded three fins at 120 °. Seals annulars such as 72 at the connector holder / centering interface ensure efforts of appropriate friction to avoid spontaneous displacement of the centering device in the absence of pushing force, while allowing such a downward movement when it is subjected to a pushing force when removing the section. Stop structures, such as shoulder 73, limit the upward movement of the centering device and define its normal position when the line is in place.

The connector holder 70 is screwed by its lower end in a hydraulic connection tube 74 which makes it possible to give the section the desired standard length. This tube 74 is itself screwed in the lower part on a hollow connector holder 75 similar to the previous one; this last door, to his other end, a female connector 76, screwed thereon.

The connector holder 75 is provided with a centralizer 77 having fins similar to the centering device 71 and mounted frictionally in the same way in order to be able to, when pushed down, slide along the connector holder 75 and the female connector 76. An upper shoulder 78 of the connector holder defines the normal working position of the centering device, while a stop shoulder 79 limits downward movement of the centering device and defines a corresponding stop position when the female connector 76 is unlocked. FIG. 20 shows the centralizer in its normal working position (high position). The detail figure 21 shows the centering device in its stop position for which its tubular element produces the unlocking the female connector by pressing on the cam to unlock it.

Figure 22 is a detail axial section of the connector female 76, called to cooperate with the male connector 39 already described. This connector female includes a connector body 80 (made in two hollow parts as the male connector) which is provided with an interior housing for the connector nose male. A movable anchor member 81 is disposed in this housing to be able cooperate with the anchoring structures of the male connector.

This anchoring member 81, movable in the transverse direction, is biased towards its anchoring position by a spring 82 and has a structure of erasure such as inclined ramp 81a which allows its erasure under the thrust from the nose of the male connector. It can thus be placed in position anchoring by simple pressure, its anchoring structure cooperating with the member anchor 81 of the female connector; locking is effected by a stop shoulder 81b that includes the anchoring member.

In addition, the anchoring member 81 carries a cam unlocking 83 slightly protruding outside the body 80 in order to ensure a clearing of the anchoring member and its unlocking under the effect of pressure of a surface on the cam. Thus, unlocking can be ensured automatically, during removal, through the cylindrical surface of the centering device 77 of the connector holder when said centering device reaches its low position.

In addition, the female connector 76 includes a valve 84 of closing of its internal passage, associated with a spring 85 which urges it towards the closed position. This valve has a rod 86 which is called cooperate with the valve stem 45 of the male connector to operate the valve towards its open position when the male connector is anchored in the connector female. Thus, the connectors when they are free are sealed and are able to be locked mechanically to each other, automatically, by simple pressure, to create a continuous and watertight hydraulic passage. Figure 23 shows schematically a male connector and a female connector in the connected position.

Figures 24 to 27 illustrate the valve installation operation special according to the invention. This operation is carried out, as already indicated in the general description of the process (Figure 9), by means of a standard type cable descent which is fitted with an installation tool 87 known per se. This known tool will not be described in detail: it is provided with means for hooking the valve (fingers 88 cooperating with the attachment profile 48 of the valve) and means to keep its shutter valve in the open position (tube sector 89 which extend the tool down: in English "prong"). This tube sector 89 has a section adapted to be able to pass and slide in the space separating the two arms radials 28 of the special valve as shown in figure 26 (section at this level). Similarly in the upper part, the tubular part 90 of the tool ("probe"), which is called move the valve sleeve 24 downwards during installation in order to release the anchor dogs 23, is shaped into two tube sectors 90a, 90b, so to authorize its passage at the level of the radial arms 37 of the special valve, as the shows figure 27 (section at this level). Apart from these adaptations, the installation tool 87 is a conventional tool, in particular provided with a shear pin (not visible) which is broken during installation.

The valve installation operation is carried out according to a procedure known: the tool is hung on the valve, then introduced into the airlock 8 and lowered into well. When the valve is in place in its receptacle sleeve 5 (valve installed on the "no-go" 5c of the receptacle sleeve, anchor dogs 23 located opposite the groove for anchoring said receptacle sleeve: FIG. 24), threshing downwards the tool is operated to break the shear pin thereof. Ways of the tool is released from the valve hooking profile, and the tool is released and can be reassembled (figure 25). Part 90 ("probe") releases socket 24 which goes back under the action of its spring and locks the anchor dogs 23 in the anchoring groove 5b of the receptacle sleeve. In addition, sector 89 ("prong") frees the shutter valve 22 which closes under the action of its spring.

Once the special valve has been placed in the production, we install the concentric command line which ensures the hydraulic maneuvers thereof. The tools for installing it and the operations installation are illustrated in Figures 28 to 33 (operations shown schematically on the Figure 10, already commented on in the general description of the process).

The installation tool shown in Figures 28 and 29 is called equip the standard cable lowering device to lay a running section of line or upper section. This tool which is represented in figure 28 in position army, ready to seize a section, includes a hooking head 91 provided with a profile adapted for its attachment to the descent device, a mandrel 92 bearing in the lower part, a female connector 93 of the type already described, and a sleeve unlocking 94 which is screwed into the head 91 and which carries the mandrel 92 by through a shear pin 95.

As shown in Figure 29, the shear of pin 95 allows the release sleeve 94 to move down relative to the mandrel 92: the tubular lower part 94a of this sleeve which is arranged around of the female connector 93 then ensures the unlocking of this connector by pressing its release cam 83.

Figure 30 shows the descent of a current section of line in the production tube by means of the aforementioned tool, the section having been, in surface, hooked and locked by its male connector to the female connector of the tool.

The descent continues until hooking and locking of the female connector located at the bottom of the section with the male connector of the lower section already in place (or with the male connector of the special valve in the case of the installation of the first section of line). A hype down of the setting tool is then produced to generate shearing of its safety pin (figure 31).

The female connector of the tool is unlocked by the lowering of the sleeve 94 and the male connector of the line section is released. The tool can be reassembled (figure 32) and reset using a new locking pin shear for the establishment of the next section. This rearming, carried out on the surface, is operated after partially unscrewing the sleeve 94 relative to the head 91 to clear the pin hole.

Figure 33 illustrates the installation of the head system of the command line, with a classic tool 96 which is hooked to the profile for hanging the suspension block 56 of said system. The set went down to cable until the sleeve 61 of the system engages around the tubular sleeve 63 of the upper section and that the block 56 comes into abutment with the abutment screws lower 52 (previously arranged in internal projection in their position detention). The upper stop screws 53 can be screwed to block the block of suspension, and the installation tool can be released and reassembled in a conventional manner.

When the concentric control line is installed, a pressure test is performed to check the correct operation of the valve special, and the airlock can be dismantled on the well head. The well is restored security.

To remove the special valve if necessary, first the removal of the concentric command line: the head system of this line is removed by unscrewing the stop screws and reassembled to the cable, then the sections of line are deposited, section after section.

Figures 34 and 35 show the removal tool which is called to equip the standard cable device to deposit each section of line.

This tool includes a head 97 for attachment to the descent, a female connector 98 of the aforementioned type, secured under the head hook 97, and a push tube 99 secured to said head 97 and passing around the female connector 98 with a light 99a at the unlocking cam of this connector in order to leave it free.

The push-tube 99 extends downwards over a length adapted to be able to slide around a section of line and repel centralizers from it to the level of the cam for unlocking the female connector of said section. Towards its lower end, the push-tube 99 has fins of centering 100, in the example of three at 120 °, in order to center the push tube in the production tube when it is lowered into it.

Figure 36 illustrates the operation of removing a section of line using the tool defined above. The tool is lowered to the cable until that its push tube 99 engages around the line section. The descent is continued and the push-tube 99 pushes down the centralizers 71 and 77 of the line section. Lower centering device 77 reaches its unlocked position in which it clears the unlocking cam of the female connector 76 of the section: this female connector is released from the male connector of the line section lower (or special valve for the last section), but only in part high, the female connector 98 of the tool locks onto the male connector 69 located at the upper end of the line section.

The removal tool can then be reassembled with the section of line hung under its female connector 98. On the surface, the line section is released and removed by pressing the cam of said female connector through the lumen 99a. The removal tool is then ready to extract another section of line.

Finally, Figures 36 to 39 illustrate the removal of the valve special, once deposited its concentric command line as we just mentioned to describe. This removal is carried out in a conventional manner using a recovery tool. 101 fitted to the standard cable lowering device.

This fishing tool is equipped with snap fingers 102 coming to cooperate with the attachment profile 48 of the valve. When the snap is realized (figure 36), a threshing upwards by percussions is implemented to break the shear screws 19 of the special valve: the upper part 18a of the body valve is moved up (Figure 37) and drives the sleeve 24 of locking dogs that are released (Figure 38). The valve can then be reassembled, its socket 24 driving the lower part 18b of the valve body.

Claims (7)

Hydraulic control line intended to be installed along the axis of an oil well production tube, with a view to restoring the well, characterized in that it comprises a plurality of sections, known as current sections, intended for be arranged end to end along the axis of the production tube, each current section comprising, from top to bottom, a male connector (69), a first hollow connector holder (70) at the upper end of which is secured the male connector, a first centralizer (71) arranged around the first connector holder to center the latter in the production tube of the well, a hydraulic connection tube (74) secured to the lower end of the first connector holder, a second hollow connector holder (75) secured to the lower end of the hydraulic connection tube, a second centering device (77) arranged around the second connector holder to center the latter in the production tube of the well, and a connector female (76) secured to the lower end of the second connector holder. Hydraulic control line according to claim 1, characterized in that it comprises an upper section intended to be disposed at the upper end of the current sections, said upper section comprising a tubular sleeve (63), a male connector (65) and a female connector (66) respectively secured to the upper end and to the lower end of said tubular sleeve, and at least one centralizer (67, 68) arranged around the tubular sleeve to center the latter in the production tube of the well . Hydraulic control line according to claim 2, comprising a head system comprising a suspension block (56) adapted for be housed in a raising element (14), fastening means (57) integral of the upper part of said suspension block for attachment by means a fitting or removal tool, a socket (61) extending downwards and secured under the suspension block (56) to slide the tubular sleeve (63) of the upper section, sealing means (64) between the sleeve and the sleeve tubular, hydraulic connection means (58, 59) connecting, to through the suspension block, said bush (61) and means for passage of fluid that includes the raising element (14), and centering fins (62) secured around the bushing (61) to center the latter in the production tube of the well. Hydraulic control line according to claims 1, 2 or 3, characterized in that : the male connector (69, 65) of each current section or of the upper section comprises a connector body provided with a penetration nose in a female connector and pierced longitudinally with a hydraulic passage, anchoring structures of the connector nose in the female connector, a valve for closing the hydraulic passage, elastic means urging the valve towards its closed position, and a valve stem housed in the connector nose in order to push the valve towards the open position when the male connector is connected in a female connector, the female connector (76, 66) of each current section or of the upper section comprises a connector body (80) provided with a housing for the nose of a male connector and longitudinally pierced with a hydraulic passage, a member for anchor (81) movable in the transverse direction between an anchoring position corresponding to the locking of the anchoring structures of the male connector and an erasing position where it releases said anchoring structures, elastic means (82) urging the anchoring member towards its anchoring position, an internal structure (81a) for erasing the anchoring member under the pressure of the nose of a male connector, an unlocking cam (83) projecting at the periphery of the connector body in order to ensure the erasure of the anchoring member and the unlocking of the connectors under the effect of the pressure of a sliding surface around the female connector, a valve for closing the hydraulic passage (84 ), means ela stiques (85) urging said valve towards its closed position, and a valve stem (86) housed in the body in order to maneuver the valve towards its open position when the male connector is anchored in the female connector. Hydraulic control line according to claim 4, characterized in that each centering device (71, 77) of a current section is friction mounted around the corresponding connector holder (70, 75), with stop structures (73, 78) limiting the upward movement of said centering device relative to the connector holder, the second centering device (77) of the section being able to slide around the connector holder (75) and the female connector (76) to a position d 'stop where it pushes the unlocking cam (83) of said female connector. Tool for installing a hydraulic control line according to claim 5, said tool being intended to equip a standard cable lowering device and being characterized in that it comprises: an attachment head (91) comprising, in the upper part, means for attaching the tool to the lowering device, a mandrel (92) carrying, at the bottom, a female connector (93) conjugated with male connectors of the control line sections, and an unlocking sleeve (94), secured in the lower part of the hooking head and connected to the aforementioned mandrel (92) by a shear pin (95) in order to allow, after shearing, a downward movement of said sleeve unlocking with respect to the mandrel, said unlocking sleeve (94) having a lower part (94a) arranged around the female connector (93) carried by the mandrel so as to be able to generate an unlocking of said connector after moving down the sleeve. Tool for removing a hydraulic control line according to claim 5, said tool being intended to equip a standard cable lowering device and being characterized in that it comprises a hooking head (97) of the tool to the lowering device, a female connector (98) conjugated with the male connectors of the line sections, secured under the attachment head, a push tube (99) attached to the attachment head and passing around the female connector with a light (99a) at the level of the unlocking cam thereof, said push tube (99) extending downward and comprising towards its lower end fins (100) for centering in the production tube of the well, said push tube being adapted to be able to slide around a section of line so as to push the centralizers of the latter up to the level of the cam for unlocking the female connector of said section.

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