EP0574326A1 - Apparatus, well drilling and equipment device, system and method - Google Patents

Abstract

The present invention relates to a system for drilling flanking onto a main well (1) cased by a tubular column (4). At least a portion of the tubular column (4) includes a lateral opening (6, 21) designed to allow a flank well (2) to be drilled. A guiding device is positioned in the tubular portion in front of the lateral opening and is controlled from the surface. A lateral tubular column equips the flank well and includes a connector for connecting to the main column. The present invention also relates to a method for drilling and fitting out a flank well drilled from a cased main well. <IMAGE>

Description

The present invention relates to a system adapted to allow drilling and equipping a well drilled laterally to a main well. The main well can be of any inclination, in particular substantially vertical or strongly inclined.

In the technique of exploiting underground deposits, the lateral drilling technique is known from a main well previously drilled. This main well can be in open hole, that is to say not cased, or cased by a tubular column. In the first case, it is generally necessary to plug the well at the level where the lateral drilling should start. This can be achieved by placing a cement plug which will provide the necessary support points for a directional drilling rig to start lateral drilling. This packing is conventionally equipped with a bottom motor and a deflecting tool such as an elbow fitting. There is also the possibility of drilling according to the rotary technique using a deflection device commonly called "whipstock", which is fixed on or in place of the plug mentioned above. This last technique, old, is more difficult to master in open holes where it is difficult to correctly maintain in position the whipstock in the well. In the case of main wells already cased, the identical technique requires an additional operation of milling a window in the casing in order to then be able to use a directional drilling lining through the opening provided. This operation requires a milling tool adapted to the material used to make the casing from which a window must be cut.

These techniques known under the name of "side track", generally have the purpose of abandoning the lower part of the main well being at a level below said plug or "whipstock". In this case the subsequent equipment of the new well will be conventional, that is to say that the casing rises to the surface or is suspended in an existing column by known means, for example the suspension device commonly called "liner hanger ".

Document US-A-4807704 discloses a system and method for carrying out several boreholes from a main well, but the equipment of the main and lateral wells is complex and occupies the interior space of the main well, preventing thus access to the lower part of the main well. In addition, drilling the lateral well requires a milling phase in the tubular column of the main well.

Document US-A-4852666 discloses an apparatus and method for drilling lateral wells to a horizontal drain. However, this document does not disclose a technique which makes it possible to drill lateral wells from a main well which is already cased. In addition, it does not allow the lateral well to be fitted with a casing.

The object of the present invention is in particular to casing a main well with a tubular pipe comprising one or more lateral openings at least partially prepared before the casing operation, then to hang on it a lateral column introduced into a lateral well drilled at from one of the openings.

When the tubular pipe is made up of elements of tubes assembled as it is introduced into the well, use is made of specifically manufactured tubular elements comprising in particular a lateral opening. The casing operation is carried out according to the conventional technique but incorporating in the desired location, the specific elements comprising the lateral opening as well as other drilling devices and equipment. The main well is thus thus equipped with a mixed casing comprising, at the locations provided by the operators, the means allowing the drilling and the equipment of a lateral well ready for use.

The main well being thus prepared, it should be noted that access to the interior space of the casing allows all the interventions that a person skilled in the art may wish to undertake in such a well. Indeed, the interior space of the casing prepared according to the present invention is not blocked. It will thus be possible to have access in particular to the internal part of the casing below the lateral drilling zone with tools of maximum external diameter, substantially conventional with respect to the internal diameter of said main casing. The drilling and the equipment of the lateral wells distributed over the length of the main casing can thus be carried out with tools and equipment of the same dimension since practically no obstacle obstructs the interior passage of the main casing.

In addition, if the exploitation of the deposit considered, from the main casing alone, is of interest, the corresponding production operations can take place in the usual way, for example by the establishment of a production column, or the installation of a pumping installation. Of course, the communication between the producing formation and the interior of the casing must exist. This is the case if the casing is not cemented and if it includes at least one portion of perforated tube. Otherwise, in situ perforation means, well known in the art, are used.

• En premier lieu, on peut mettre en production le puits principal seul et utiliser toutes les techniques conventionnelles de production, de mise en production ou de mesure puisqu'il n'y a aucun obstacle à l'intérieur du cuvelage.
• Cela jusqu'au moment opportun ou inévitable où il faut de nouveau investir pour conserver un rendement économiquement acceptable de production.
• On peut alors forer un ou plusieurs puits latéraux en utilisant l'équipement spécifique mis en place avec le cuvelage, en utilisant les données de production que l'on a acquises pendant une phase précédente.

The method of equipping the main well according to the invention has great operating flexibility, since it is possible to envisage several production phases:

• First, one can put into production the main well alone and use all conventional techniques of production, production or measurement since there are no obstacles inside the casing.
• This until the opportune or inevitable moment when it is necessary to invest again to maintain an economically acceptable return on production.
• We can then drill one or more lateral wells using the specific equipment put in place with the casing, using the production data that we acquired during a previous phase.

This production scheme is an example among other possibilities offered by the present invention.

This is possible because the initial investment, corresponding to the specific column of the main well, does not represent significant additional costs. This will improve the drainage of the deposit.

In addition, in the present invention, the openings can be plugged in a substantially sealed manner before their introduction into the well, which in particular allows cementing to be carried out according to the rules of the art.

To achieve this closure, it will be advantageous to use bandages, in particular made of thermosetting composite material which may include reinforcing fibers embedded in a matrix, such as glass fibers. A piece of aluminum or other reforable material can be placed as reinforcement on the openings so that the blockage by the bandages can withstand greater pressures. A conventional type drilling tool, used for lateral drilling, is capable of destroying these bandages and their reinforcement without imposing additional operation. Without changing the tool, it will be possible to continue drilling after having perforated the tire.

Thus, when it has been decided to drill at least one lateral well, a preferred method according to the invention can comprise the following steps. Those described below start from the state where a casing comprising at least one specific opening has been put in place in the main well. We descend into the main casing of the guide means comprising a guide ramp similar to that of a whistle deflector or whipstock, using operating rods. Advantageously, these guide means are adapted to be able to be brought and positioned in the vicinity of any of the lateral openings, when there are several. The operator can choose any of the casing openings to perform lateral drilling and improve operations.

The guide means, anchored and oriented with respect to the opening, can be used both as a tool for deflecting the drilling tool and as a means for positioning the tubular column placed in the lateral well.

To perform drilling, the operating rods are removed to then lower the side drill string. The lining is conventionally that which the operators use with a deflecting tool such as a whipstock, that is to say comprising in particular a drilling tool, a downhole motor, drill collars, drill rods.

When the lateral drilling is completed, the operator decides whether or not to equip the lateral well with a perforated casing or not. If the equipment is executed after drilling, as is often the case to limit the risks of blockage of the well by collapse of the formation, the same guide means are preferably used to descend the lateral tubular column into the lateral well. The upper end of the lateral casing and the opening comprise means for ensuring the junction of the lateral casing in the main casing, at the level of the opening. These joining means may include a connecting fitting adapted to cooperate with the opening. This fitting is fixed on the upper end of the lateral casing.

The invention has in particular the advantage of practically not cluttering the interior space of the main casing by the means of junction between the lateral casing and the main casing, which allows access to the other openings more distant from the surface. , even after fitting the side well with the side casing.

In addition, closing means, for example a sliding door, can complete the joining means.

This door is adapted to obstruct practically all the space situated between the connection connection of the lateral casing and the opening, so that the effluent coming from the lateral well flows into the main casing through the interior of the lateral casing and not not through the annular space between the well and the casing. In fact, if this were not the case, the advantage of installing a column in the lateral well would be less, if not zero.

The closing means, for example the sliding door can also serve as a complementary connecting means with the connecting fitting.

Advantageously, the tool for installing the lateral casing can have the function of properly orienting the special connector with respect to the opening and of closing the opening. Of course, these two operations can be carried out using different tools.

• on positionne dans ladite colonne tubulaire des moyens de guidage sensiblement au niveau de ladite ouverture,
• on équipe un puits latéral d'une colonne latérale tubulaire,
• on réalise une jonction de la colonne latérale sensiblement sur la périphérie de la colonne tubulaire.

The present invention therefore relates to a method of drilling and equipping lateral wells from a main well cased by a tubular column comprising at least one lateral opening. The method comprises the following steps in combination:

• positioning means are positioned in said tubular column substantially at the level of said opening,
• a lateral well is fitted with a tubular lateral column,
• a junction of the lateral column is made substantially on the periphery of the tubular column.

Lateral drilling means can be lowered into the main well and a lateral well can be drilled from said opening.

The means for drilling said lateral well can be guided by said guide means and the introduction of said lateral column into the lateral well can be guided by said guide means.

Junction means can be oriented relative to said opening by the guide means.

The space between said opening and the lateral column can be substantially plugged substantially at the junction means.

It is possible to activate closing means linked to said tubular column substantially at the level of the lateral opening, for blocking said space.

Said guide means can be moved after the lateral column has been joined to the tubular column of the main well.

The lateral column can be introduced into the lateral well by means of operating rods assembled from the surface, said rods being connected to said lateral column by means of a setting tool.

The closing means can be activated by varying the pressure in the interior space of the setting tool.

The installation tool can be released from said lateral column by varying the pressure in the installation tool.

When the main column comprises several portions of tube having an opening, the openings can be oriented relative to each other by rotation of said portions around the axis of the column, and one can control said orientations using a measurement tool lowered into the interior space of said column.

The invention also relates to a system for drilling and equipping at least one lateral well to a main well cased by a tubular column comprising at least one lateral opening, said opening being suitable for the passage of a drilling tool, said system comprising a lateral tubular column housed in said lateral well and guide means positioned relative to said opening. Said system comprises means for joining the lateral column situated substantially on the periphery of the tubular column.

The system may include means for closing the space between said lateral column and said opening, said closing means being situated substantially at the level of the joining means.

The guide means can be adapted to guide said drilling means and said lateral column.

The guide means may include displacement means allowing the displacement of said guide means in the tubular column after the junction of the lateral column.

The system may include a key integral with the main column in the vicinity of said opening, said displacement means may consist of a continuous groove along the guide means, and said anchoring means may consist of another groove and a reversible lock blocking the key in said other groove.

The system may include a tool for installing said lateral column, said tool being linked to the lateral column by a reversible anchor, said tool comprising means for orienting the joining means by cooperation with the guide means and means for d activation of the means of closing, and said tool can be lowered into the well by operating rods.

The activation means may comprise a differential piston and a drive finger in translation said closure means.

The invention also relates to a connecting device between two tubular elements. A first tubular element has a lateral opening of dimension adapted to allow the passage of the second element, and the device comprises means for joining the second element to the first located at the periphery of the first element.

The device may include means for closing the space between the second tubular element and the opening.

Said joining means may comprise a connection fitting integral with the second tubular element by means of a rotary joint.

The end of the connection fitting may comprise a section along an inclined plane with respect to the main axis of the fitting, a portion of the periphery of said section may be in contact with a corresponding portion of the periphery of the opening, and the closing means may comprise a sliding plate adapted to substantially close off the space between the other periphery portions of said section and of the opening.

Said section can be rectangle.

The end of said connection fitting may comprise, on the sides substantially parallel to the axis of the first element, connection means cooperating with the sliding plate when the latter is moved.

The method, system or device according to the invention can be applied to the exploitation of petroleum deposits, said main well being vertical or horizontal.

• La figure 1 représente un puits principal et un puits latéral équipés de colonnes tubulaires.
• Les figures 2A et 2B représentent en coupe partielle la portion tubulaire de la colonne principale comportant l'ouverture, le dispositif de guidage et le raccord de liaison de la colonne latérale.
• Les figures 3A, 3B et 3C représentent l'extrémité inférieure du dispositif de guidage.
• Les figures 3D et 3E représentent une autre réalisation de l'ancrage du dispositif de guidage.
• Les figures 4A, 4B et 4C représentent en trois vues, la portion tubulaire comportant l'ouverture.
• La figure 4D représente la porte d'obturation autour du raccord de liaison.
• Les figures 5A et 5B représentent l'extrémité supérieure du dispositif de guidage.
• Les figures 6A et 6B représente le raccord de liaison.
• Les figures 6C, 6D et 6E représentent une autre réalisation du raccord de liaison.
• La figure 6F montre en perspective le raccord de liaison assemblé avec l'outil de pose.
• Les figures 7A, 7B et 7C représentent schématiquement et respectivement, le déplacement dans la colonne principale du dispositif de guidage, le forage latéral, et la descente de la colonne latérale dans le puits latéral.
• Les figures 8A et 8B illustrent des applications préférentielles selon l'invention.
• La figure 9A illustre l'outil de pose de la colonne latérale.
• La figure 9B montre le système d'accrochage de l'outil de pose dans le raccord de liaison.
• Les figures 10A, 10B et 10C représentent le dispositif de fermeture de la porte.
• Les figures 11A, 11B et 11C montrent un exemple d'obturation de la portion tubulaire comportant une ouverture.
• La figure 12 montre un principe de verrouillage d'une porte coulissante après la fermeture.
• La figure 13 illustre une réalisation d'un joint flexible et tournant de liaison entre le raccord de liaison et les tubes de la colonne latérale.
• La figure 14 décrit un moyen de connexion entre une portion tubulaire comportant une ouverture et les autres tubes de la colonne principale.
• Les figures 15A, 15B et 15C montrent une réalisation préférentielle de la portion tubulaire comportant une ouverture et une porte.
• Les figures 16A et 16B montrent schématiquement une variantes des moyens de fermeture.

The invention will be better understood and its advantages will appear clearly on reading the description illustrated by the appended figures among which:

• Figure 1 shows a main well and a side well equipped with tubular columns.
• FIGS. 2A and 2B show in partial section the tubular portion of the main column comprising the opening, the guide device and the connection fitting of the lateral column.
• Figures 3A, 3B and 3C show the lower end of the guide device.
• Figures 3D and 3E show another embodiment of the anchoring of the guide device.
• Figures 4A, 4B and 4C show in three views, the tubular portion having the opening.
• Figure 4D shows the shutter door around the connection fitting.
• Figures 5A and 5B show the upper end of the guide device.
• Figures 6A and 6B show the connection fitting.
• Figures 6C, 6D and 6E show another embodiment of the connecting fitting.
• Figure 6F shows in perspective the connection fitting assembled with the installation tool.
• FIGS. 7A, 7B and 7C show schematically and respectively, the displacement in the main column of the guide device, the lateral drilling, and the descent of the lateral column in the lateral well.
• Figures 8A and 8B illustrate preferred applications according to the invention.
• FIG. 9A illustrates the tool for installing the lateral column.
• Figure 9B shows the attachment system of the installation tool in the connection fitting.
• Figures 10A, 10B and 10C show the door closing device.
• Figures 11A, 11B and 11C show an example of sealing the tubular portion having an opening.
• Figure 12 shows a principle of locking a sliding door after closing.
• Figure 13 illustrates an embodiment of a flexible joint and rotating connection between the connection fitting and the tubes of the lateral column.
• Figure 14 describes a connection means between a tubular portion having an opening and the other tubes of the main column.
• Figures 15A, 15B and 15C show a preferred embodiment of the tubular portion having an opening and a door.
• Figures 16A and 16B schematically show a variant of the closure means.

In FIG. 1, the references 1 and 2 designate the main well and the lateral well in which tubular columns 4 and 3 have been placed respectively. The assembly 5 mainly comprises a lateral opening 21 in the column 4, a fitting connecting 7 between the main column 4 and the lateral column 3, a joint 8 intermediate between the connecting fitting 7 and the column 3, means 9 for closing the space existing between the fitting 7 and the opening 21. The details, as well as the other components will be illustrated by the following figures.

FIGS. 2A and 2B show in partial section the main column 4 in which the guide means 10 are positioned such that the system must be configured for the drilling or equipping operation of the lateral well. The connection fitting 7 is shown in this figure fixed by the stop and retaining means 14 and a sliding door 12 closes the lateral opening 21 around the fitting 7. The details of the door and the opening will be more fully described using figures 4A, 4B, 4C, 4D or 15A, 15B and 15C.

It should be noted in this FIG. 2A that the end 13 of the connection fitting 7 does not penetrate into the interior of the column 4 and is located substantially in the same plane as the opening. The details of the connection fitting are shown in FIGS. 6A, 6B, 6C, 6D and 6E.

The door 12 is held on the column 4 by a casing 16. A shear pin 17 fixes the door 12 in the high or open position, position in which the opening 21 has a dimension which allows the passage of the drilling tool and of the side column. In FIGS. 2B and 2A, the pin 17 is sheared and the door is in the closed position on the opening 21, around the connection fitting 7.

• une extrémité ou partie inférieure référencée 11, détaillée sur les figures 3A, 3B, 3C, 3D et 3E.
• une partie centrale comportant une rampe 15 dont la face est orientée en direction de l'ouverture 21. L'angle l que forme la rampe par rapport à l'axe longitudinal est préférentiellement égal ou compris entre 1° et 5°, bien que la valeur de l'angle de la rampe n'est pas limitatif de la portée de la présente invention. En particulier, la rampe peut avoir des angles progressifs entre 1 et 5 degrés,
• une extrémité ou partie supérieure 18 comportant un passage intérieur 22 de préférence cylindrique permettant le passage de l'outil de forage latéral ainsi que de la colonne 3 d'équipement du drain, des moyens d'accrochage 19 de l'outil de manoeuvre du dispositif de guidage, des moyens d'orientation 20 permettant à la fois de remonter le dispositif dans la direction de la surface sans être bloqué par la clavette 23 solidaire de la colonne 4 et d'orienter le raccord de liaison 7 par rapport à la rampe. Les figures 5A et 5B, décrites ci-après, précisent les différents constituants.

The guide means 10 comprise three main parts:

• an end or lower part referenced 11, detailed in FIGS. 3A, 3B, 3C, 3D and 3E.
• a central part comprising a ramp 15 whose face is oriented in the direction of the opening 21. The angle l formed by the ramp relative to the longitudinal axis is preferably equal to or between 1 ° and 5 °, although the value of the angle of the ramp is not limitative of the scope of the present invention. In particular, the ramp can have progressive angles between 1 and 5 degrees,
• an end or upper part 18 comprising an inner passage 22 preferably cylindrical allowing the passage of the lateral drilling tool as well as of the column 3 of equipment for the drain, hooking means 19 of the device operating tool guide, orientation means 20 allowing both to reassemble the device in the direction of the surface without being blocked by the key 23 secured to the column 4 and to orient the connection fitting 7 relative to the ramp. Figures 5A and 5B, described below, specify the different constituents.

A channel or a conduit 36 arranged in the guide means connects the interior space of the column 4 on either side of these guide means.

Centering pads 70 are arranged on the circumference of the means 10, substantially at the level of the two ends 11 and 18.

FIG. 4A shows a top view of a tubular element 24 intended to be assembled with other tubes to constitute the column 4. The assembly is done by means of threads 25 and 26. The opening 21 is in fact composed of two windows 27 and 28 cut respectively in the casing or cover 16 and the tubular body of the element 24. The function of the cover 16 is to hold and guide the sliding door 12 shown in top view in FIG. 4D.

The width of the opening 21 is adapted to let the lateral drilling tool pass, the length of the opening depends on the slope of the ramp. The flat surface 29 forming part of the circumference of the window 27 of the cover is the place where the connection fitting 7 abuts and possibly attaches.

A key 23 is welded to the body of the element 24, preferably in the longitudinal axis of the opening. The key protrudes from the inner wall of the tubular element so that the top of the flat of the key is at a distance D from the diametrically opposite point. This dimension D is functionally important for the positioning of the guide device, role that is played to the key 23 integral with the element 24. Furthermore, this dimension is sufficient not to hinder the passage of organ or d intervention equipment.

The door 12 is fixed in the open position by a shear pin 17. In this position, the opening 21 has maximum dimensions.

FIG. 4C is a section of the element 24 which shows the stacking of the door 12 on the body of the element 24 and the assembly of the cover 16 on the same body by welding two bars 30 and 31 over the entire length. Preferably, the largest diametrical dimension of the element 24 should not be greater than the outside diameter of the sleeves of the tube fittings making up the column 4. Thus, the element 24 can be lowered into a well drilled by a tool of conventional diameter without substantially providing friction greater than that provided by a tube connection.

FIG. 4D is a top view of the sheet metal constituting the door 12. The bore 32 receives the shear pin 17. The branches 33 and 34 separated by the distance referenced 35 will close off the clearance between the opening 21 and the connection connector 7. The shape of the U and its width referenced 35 is a function of the external shape of the connection fitting 7. It should be noted that the U of the door window, once it is closed, cooperates with the portion 29 of the circumference of the window 27 of the cover 16, to form a rectangle of dimensions substantially equal to the section of the end of the connection fitting 7. In fact, referring to FIGS. 6A, 6B, 6C, 6D and 6E representing schematically the connection fitting of square cross section, it is noted that the end section 13 of the connection fitting has a rectangular shape corresponding to the U-shaped opening of the door 12 and to the width of the portion of periphery 29. In l In the case of a section of different shape for the connection fitting 7, the door and the portion of the periphery 29 of the opening 21 will always be adapted so that, once the door is closed on the connection fitting, it does not there is only a reduced space or clearance, if not zero, between the connection fitting and the element 24. The objective of the cooperation of the door with the connection fitting is to obtain a sufficient seal for practically prevent the flow of fluid around the connection fitting or the ingress of sand. It is possible, within the framework of this invention, to add a resilient seal either to the connection fitting, or to the door and the line 29 or else both, in order to improve the sealing.

Holes 75 are machined in the door 12. Their shape is adapted to cooperation with a means for moving the door, which is part of the fitting tool. An illustration of this means is for example the finger 76 of the fitting tool illustrated by FIGS. 10A, 10B and 10C. Depending on the length of the travel path of the door 12 and the translational travel of the finger 76 (FIGS. 10), several openings 75 are necessary and spaced apart at most from the length of the travel of the said finger 76. The openings 75 must correspond with a slot 66 in the body of the tube 24 so as to be able to actuate the door 12 from the inside of the pipe 4 and through the wall of the tubular element 24.

Figures 15A, 15B and 15C show another embodiment of a tubular element 24 and another drawing of the door 12. Compared to Figures 4A and 4B, Figures 15A and 15B differ mainly in the shape of the openings 27 and 28 respectively in the cover 16 and the tubular body 24, the coincidence of these openings 27 and 28 constituting the opening or passage 21. The wide part 136 of the opening 27 narrows in the form of a funnel 137 to finally have at 138 substantially the width of the connection fitting 7. Thus, the wings 139 of the connection fitting 7 (FIGS. 6C and 6D) are blocked by the cover 16 substantially in the zones referenced 140, below which the tube 24 is opened by the opening 28. The part 135, welded to the body 24, has a tooth-shaped section whose slope allows the displacement of the connection fitting in the direction of its introduction into the lateral well but blocks the movement of the connection fitting once the part 141 of said fitting has reached its final position. In FIG. 6C, one can see the cooperation of the part 135 with the part 141 linked to the connection fitting, after the connection fitting 7 has been put in place with respect to the opening.

One or more shear pins 134 are fixed in the cover 16 between the branches 33 and 34 of the door, the latter being positioned open. A series of pins 134 can be arranged along the axis of the U of the door 12. The role of these pins is as follows: when the means for closing the door break the pin 17, the latter is driven in translation until the bottom of the U of the door comes to lock on the pins 134. The closing means then signal to the surface that there is locking in translation by a rise in hydraulic pressure, if the means are activated hydraulically, or an increase in mechanical force (for example a torque), if they are activated mechanically. The operator thus knows that the door has moved from the distance between the original position of the door and the pins 134. By placing a series of series of pins 134, the operator can deduce from the surface the position reached by the door.

Of course, to follow the movement of the door from the surface, it will also be possible to connect the door to sensors whose information can be transmitted to the surface by one of the means known in the profession.

FIG. 15C shows a top view of a door 12 comprising branches 33 and 34 separated by a distance 35. The branches 33 and 34 have their ends 143 cut into a point in order to facilitate guiding with respect to the connection fitting 7. The door is cut to form slots 142 promoting sliding in translation of the door. On one of the slots 142, teeth have been machined for locking the door in the closed position around the connection fitting. The details of this lock are illustrated in Figure 12.

Figure 12 shows the principle of locking the door 12 in the closed position. A flexible blade 144 is fixed to at least one of the bars 30 and 31 which serve as lateral guide to the door and means for fixing the cover 16 to the tubular body 24. The end 145 of the blade 144 is adapted to cooperate with the teeth 143 when the door has been made to move completely. The asymmetrical shape of the teeth irreversibly locks the door once the end 145 of the blade is engaged in one of the teeth 143.

In FIG. 15C, the holes 75, the function of which is identical to those of FIG. 4D, have an oblong shape and a relatively large surface area in order to allow a certain tolerance of positioning of the door relative to the finger 76 of the means of movement of the door, as well as a mechanical reinforcement of this finger.

Figures 3A, 3B and 3C detail the end 11 of the guide means 10. Figure 3B is a section of the means when they are positioned and anchored in the pipe 4 by the cooperation of the key 23 and a groove 37. The groove 37 comprises a pawl 38 carried by a flexible blade 45 secured to a drawer 40 which can slide in the parallel housing 41 and disposed under the groove 37. A return spring 42 of the drawer 40 is held in the housing 41 by a plug 43. The pawl 38 has a slope 44 on the side opposite the bottom 39 of the groove 37, relative to the edge 47 defined below. The flexibility of the blade 45 keeps the pawl 38 prominent relative to the bottom of the groove, through an opening 46 between the housing 41 and the groove 37. Thus mounted, an edge or a bearing surface 47 of the pawl locks the key 23 in the housing defined by the bottom 39 of the groove 37 and the edge 47. When the operator applies a sufficient tensile force to the means 10 to compress the spring 42, the edge 47 abuts on the key 23, a edge 48 of the opening 46 cooperates with the slope 44 of the pawl to retract the pawl 38 and release the means 10 of the key.

The groove 37 has an open end. The latter opposite the bottom 39 of the groove 37 opens onto a flat surface 49 forming one face of the tip of the end 11. Another flat surface 50 forms the other side of the tip. These two flat surfaces 49 and 50 belong to a dihedral. The point formed by the surfaces 49 and 50 constitutes the means for orienting the guide means relative to the key which must, as the case may be, penetrate into the groove 37 or into a groove 51 diametrically opposite with respect to the groove 37. The groove 51 is formed over the entire length of the means 10 so that when the key is guided in the groove 51, the means do not anchor and can be moved either towards the bottom of the well or towards the surface passing from one side of the key 23 to the other.

The double bevel shape of the end 11 of the guide means 10, obtained by the surfaces 49 and 50 is a preferred embodiment since it is easily produced. However, only the periphery of the surfaces 49 and 50 is functional since the end 11 cooperates with the key 23 for guiding and orienting. We will remain within the scope of the invention if the guide rails of the key in the groove 37 or in the groove 51 are produced differently, for an equivalent result.

FIGS. 3D and 3E illustrate another embodiment of the means for anchoring the guide means 10 in the pipe 4. The means for orienting the guide means relative to the key 23 remain identical, as does the arrangement of the grooves 37 and 51. The reversible locking means of the key 23 in the bottom of the groove 37 is constituted by a button 77 placed in a housing such as a bore 78 machined radially relative to the guide means, perpendicular to the axis of the groove 37 The button 77 is held by a nut 79 and is pushed in the direction of the groove 37 by a stack of spring washers 80 of the Belleville type. The force required to compress the button can be adjusted by the number and type of spring washer 80. The upper shape 81 of the button obstructs the groove preventing the end 11 from moving relative to the key 23 as long as the tensile force on the guide means is not sufficient to compress the washers 80. The shape 81 is advantageously on a slope inclined towards the bottom of the groove and towards the opening of the groove 37.

We will not depart from the present invention if other mechanisms are designed to achieve the reversible anchoring of the guide means in the main column.

In this embodiment, the conduit 36, having the same axis as the part 11, is interrupted before the housing 78. The conduit 36 is extended to the end of the guide means by conduits 82 and 83 parallel to the axis guide means and arranged on either side of the housing 78 so as not to interfere with the latter.

In FIGS. 3E and 3D, the double-pointed end is not substantially solid, but pierced with a cylindrical hole with a diameter referenced 133 and the bottom of which is referenced 132. In this variant, the conduits 82 and 83 open out into the bottom 132.

FIGS. 5A and 5B relate to the upper end 18 of the guide means. This part is preferably tubular, with an outside diameter compatible with the inside diameter of the main column and with the dimension D mentioned above, and has an inside passage 22 of diameter compatible with the diameter of lateral drilling tool. The conduit 22 opens at the entrance to the ramp 15.

The end of the part 18 is cut in the form of a bevel 20 constituting a means for guiding and orienting the means 10 relative to the key 23. The groove 51 opens into the lowest part of the bevel as indicated by the Figure 5B. Indeed, in the case where the operator ascends to the surface said means 10, when the key 23 is an obstacle against the bevel 20, all of the guide means will be rotated along the slope of the bevel 20 until that the key 23 enters the groove 51 previously described. As the groove 51 opens at the other end of the means 10, these can be raised to the surface without being stopped by the key (s) 23.

A slot 53, of determined length, is machined in the thickness of the wall of the part 18, from its internal bore, in the direction of a generator substantially at 90 ° from the main axis of the groove 51. Thus , the slot 53 does not interrupt the continuity of the bevel guide ramp 20, since the slot 53 has a depth less than the thickness of the wall of the end 18.

Internal grooves 19 machined in the wall of the passage 22 allow the attachment of the operating rods of the guide means by means of an installation tool fixed to the end of these rods. The slot 53 can cooperate with a finger secured to the setting tool so that a rotation of the operating rods, from the surface, drives the guide means in the same rotation. There may be another means for rotationally fixing the means 10 relative to the setting tool, in particular by an adapted shape of the grooves 19. To maneuver and set up the guide means 10, a conventional tool is preferably used. or "releasing spear" which is anchored in the bore 22 by a system of wedges.

FIGS. 6A and 6B, already cited above, relate to the end of the lateral column 3 comprising the connection fitting 7 and an intermediate seal 8 between the tubes of the column 3 and the connection fitting 7. The seal 8 allows orientation of the connection fitting around the longitudinal axis of column 3 relative to the lateral opening, without requiring rotation of the whole of column 3. Indeed, the length and / or the inclined arrangement of this column can create significant friction that should be overcome by the orientation means cooperating with the upper part 18 of the guide means. The joint 8 thus makes it possible to decouple in rotation the connector 7 of the column 3 and to facilitate its orientation. In addition, the flexibility of the seal 8 allows the correct inclination of the connecting fitting 7 relative to the lateral opening and the closing means. Such a seal 8, illustrated in Figure 13 is described below.

The cross section of the connector 7 preferably has a square outside shape and of dimension such that it is substantially inscribed in a circle of diameter equal to the inside diameter of the duct 22. In fact, the whole of the lateral column 3 must pass through the duct 22 of the upper part 18 of the guide device 10. The inside diameter of the duct 22 therefore limits the outside diameter of the components of the column 3.

The square tube is cut along a plane, orthogonal to two parallel faces and making an angle i with the longitudinal axis of the fitting 7. The angle i is substantially equal to the angle l of the ramp or to the angle of the tangent to the end of the ramp relative to the longitudinal axis of the main column. Thus, Figure 6B shows a bottom view of the rectangular section ABCD of the end 13 of the connecting fitting. As described above, the perimeter consisting of the AB-BC-CD sides comes into close proximity or in contact with the sliding door when the latter is closed. The side DA comes into contact with the periphery portion 29 of the window of the cover 16 (FIG. 4A). The peripheral contacts thus limit the clearance between the connection fitting and the lateral opening. Of course, this form is in no way limitative of the system, but was preferably chosen for the ease of design and manufacture of the opening, the door and the fitting.

A shoe is welded to the connector in order to constitute a stop 14 and a locking of the connector in the opening. The finger 54 of the shoe 14 comes, at the end of translation of the fitting on the slide, penetrate into the housing 55 existing between the cover 16 and the body of the tubular element 24 (FIG. 4B). A mechanical coupling, for example an elastic hook can be integrated between the two cooperating parts: the finger 54 and the housing 55. The finger can have a dovetail section. The housing 55 will then have the corresponding female shape in order to improve the guiding and the maintenance of the connection fitting. In addition, to complete the fixing in position of the connection fitting in the opening, the door may include locking means cooperating at the end of closing with complementary means carried by the fitting 7 in the vicinity of the periphery BC. These means, not shown, are within the reach of ordinary skill in the art.

Figures 6C and 6D show another embodiment of the connection fitting 7 comprising slides having portions substantially parallel to section 13. The slides consist of two rails 84 and 85 welded substantially along each side BA and CD. The space between the rails corresponds to the thickness of the branches 33 and 34 of the door 12. The lower rails 84 are shorter than the upper rails 85. The end of the rails 85, on the BC side, has a part 146 of a centering device cooperating with another part 147 linked to the holding part 86 (FIG. 9A). In FIG. 6F, the connection fitting 7 is shown in perspective and assembled with the holding piece 86. The centering device is substantially in the shape of a V-shaped truncated sphere on the side of the tip of the fitting 7. This shape in V serves as a guide for the branches 33 and 34 of the door 12. The part 147 is adapted to place the junction plane 130 substantially at the level of the opening 21 when the lateral column is read in place. Once the door is closed, the slides hold the connection fitting 7 in place.

In FIG. 6C, another variant of a locking device between the connector 7 and the body of the tube 24 is illustrated. It comprises a shoe 141 whose profile is in the form of an inverted tooth relative to the shoe 135 of the tubular body 24 ( Figure 15B). The profile of the part 135 is shown here for the easy understanding of the cooperation of the shoes 135 and 141 which provides a blocking of the connection fitting in the direction of the ascent to the surface. Verification of the correct position of the connection fitting can be done by trying to pull on the fitting via the operating rods, if there is resistance, the operator can deduce that shoe 141 is correctly placed relative to the opening 21, and therefore that the relative positions of the different elements are good.

FIG. 6E is a section of the connection fitting in the vicinity of the wings 139. These wings 139 position the connection fitting 7 relative to the tubular body 24 by their placement under the cover 16 at the level of the zones 140 (FIG. 15A).

The advantages and functions of the various elements of the system according to the invention will be better understood on reading the following description of operational sequences given as a non-limiting example.

FIG. 7A represents a main well 1 into which a column 4 has been lowered, at least a portion of which has a lateral opening 21. The equipment phase of well 1 is generally similar to the conventional operation of casing a well. Column 4 is preferably made up of elements of "casing" or "tubing" according to the standard name of "the American Petroleum Institute". These tubes are assembled to each other by threads. The column portion comprising the opening 21 is preferably made from a length of tube to obtain the element 24 as illustrated by FIGS. 4A, 4B and 4C or 15A and 15B.

As the column 4 descends, the operators integrate the element (s) 24 into the column so that, at the end of the descent, these are located at the start of the planned lateral drilling.

In the most common case, where several lateral drilling is prepared from the main well 1, it is necessary to orient the elements 24 between them so that the direction of the openings is according to the forecasts of the drainage scheme desired by the operators. The lower connection means 25 (FIGS. 4B, 15B) of the element 24 may comprise means for specific fixing of the orientation of said element 24 relative to the lower tubular column. All the means known in general mechanics can be used, for example the principle of screw-nut with locking lock nut. This principle can be transposed in the present case as follows: the connection 25 consists of a cylindrical male thread; the tube on which the connection 25 is screwed has a corresponding female thread; a ring acting as a lock nut is mounted on the male thread.

The element 24 is screwed on the surface on the end of the already assembled column and introduced into the well. We adjust the direction of opening of the element in assembly, knowing the orientation of the opening of the previous element already assembled in the main column by the installation in the column of a measurement tool at this first opening. The measurement tool, for example of the gyroscope type "steering tool" or "MWD", is indexed with respect to the opening for example using the key 23. The position of the element is blocked by screwing, at a tightening torque determined by the size of the thread, the ring against the end shoulder of the female thread. Other fixing systems are within the reach of the mechanic knowing the characteristics of the connections of the tubes "casing" or "tubing".

FIG. 14 illustrates a simple means of connection between a tubular element 24 and a tube of the column 4, connection allowing adjustment and fixing in orientation of the element 24. A casing sleeve 150 comprises two different types of female threads, 151 and 153. The thread 151 corresponds to the male thread type of the tubes constituting the column 4. The connection by the threads 151 comprises a shoulder 152 on which the male end of the tube 4 is blocked under the action of a tightening torque. This connection conventionally called "premium connection" has, among other things, the particularity of not allowing relative rotation of the tubes with respect to each other in the event of the application of a torque to the entire column. On the contrary, the connection comprising the thread 153 is not shouldered, for example of the LTC (Long Thread Collar) type according to the 5CT standards of the American Petroleum Institute. Thus, the rotation of the element 24 can be adjusted relative to the sleeve 150 as a function of the locking torque applied. The orientation being carried out, lateral needle screws 154 are blocked on the outside of the male thread 25 of the element 24.

When the entire column 4 has been lowered into the main well, the column is rotated about its axis to orient all the openings relative to the producing formation. The rotational movement is done from the surface either directly on the top of the column if it rises to the surface, or on the operating rods if the column is of the "liner" type, ie 'it is interrupted at the hoof of the previous cemented column.

The main column and its openings are correctly positioned by controlling the orientation using a conventional measuring device, adapted to the type of main well concerned.

A lateral drilling phase will be undertaken after installation of the guide means 10 illustrated in FIG. 7A.

The means are assembled on the surface on a setting tool 56, for example using hooking means 19 comprising grooves (FIG. 5A) and slot 53 or using a "releasing spear" comprising an orientation fitting 161, hooking means 160 and a guide 162. It is not going beyond the scope of this invention if the fixing is done by another equivalent means. The means are lowered into column 4 by means of operating rods 57. The depth reached by these means is checked by adding the lengths of rods 57. When the tip 58 with double slope (49, 50) abuts on the key 23, the tip 58 guides the device 10, either in the anchoring position when the key enters the groove 37 (FIG. 3B), or in the displacement position when the key enters the groove 51 (FIG. 3C).

As has already been explained, when the tip 58 is guided towards an unwanted position, the operator raises the means 10 above the key 13, as shown in FIG. 7A, then rotates by half turn the rods 57 and in the same movement the means 10 now have the other guide plane (49 or 50 of FIG. 3A) on the key 23. The operator can thus choose to anchor or not to anchor the means 10 on the key 23 located at the dimension concerned.

In the case where the anchoring is made at the opening provided for lateral drilling, the setting tool 56 is disconnected by a controlled action from the surface. Systems are known which can be disconnected, for example by rotation, mechanical threshing or by hydraulic control. The drilling operation can then be carried out according to the diagram of FIG. 7B.

In the other case, it is necessary to add rods 57 to reach another opening located deeper, towards the bottom of the main well.

It is also possible to descend together into the well the guide means and the lateral drilling string. This is then fixed to the guide means by a reversible lock, for example of the shear pin type. In this case, once the means 10 put in place relative to the key 23, the release of the drill string from the guide means by shearing said pin, makes it possible to perform lateral drilling without additional maneuver.

FIG. 7B shows a drilling tool 59 during drilling of the lateral well 2, the deflection angle I1 between the main well and the start of the lateral drilling is substantially equal to the angle I2 formed by the tangent to the surface of the ramp 15 at its lower end. The surface of the ramp may be flat, as shown in FIG. 2A, but will preferably be curved so as to be able to reduce the length of the opening. The curvature of the ramp can also be at a variable angle and increasing in the direction of the window 21. Of course, the admissible curvature of the ramp is limited by the rigidity of the drill string and that of the lateral column.

FIG. 7C relates to the introduction of the lateral column 3 into the lateral well 2. FIG. 7C shows the equipment being lowered, before the final fitting of the connection fitting 7 at the level of the window 21. The column of liner type ends with a connection fitting 7. The connection fitting is connected to the tubes of column 3 by means of a seal 8. Column 3 is shown being introduced into the lateral well 2, but the seal 8 and the connection fitting 7 are still located in the interior of the main column (FIG. 7C). The entire column is lowered by the means of operating rods 60 rising to the surface. An installation tool 61 is screwed substantially to the lower end of the rods 60. The column 3 is suspended from the installation tool 61 by hooking means 62.

• tenir la charge représentée par le poids de la colonne 3,
• supporter une poussée vers le bas sur la colonne, poussée exercée généralement par des masses-tiges ou des tiges lourdes vissées au-dessus de l'outil 61,
• contrôler son ancrage sur la colonne latérale à partir de la surface,
• orienter le raccord de liaison dans le voisinage de la glissière pour permettre son positionnement par rapport à l'ouverture, les moyens d'orientation coopérant avec la partie supérieure 20 des moyens de guidage 10,
• déplacer en translation le raccord de liaison 7 sur la glissière en maintenant l'orientation désirée,
• manoeuvrer la porte 12 dans le sens de la fermeture autour du raccord 7 une fois celui-ci lié à la colonne principale.

This fitting tool 61 is preferably adapted to perform at least the following functions:

• hold the load represented by the weight of column 3,
• withstand a downward thrust on the column, thrust generally exerted by drill collars or heavy rods screwed above the tool 61,
• check its anchoring on the lateral column from the surface,
• orient the connection fitting in the vicinity of the slide to allow its positioning relative to the opening, the orientation means cooperating with the upper part 20 of the guide means 10,
• move the connection fitting 7 in translation on the slide while maintaining the desired orientation,
• maneuver the door 12 in the closing direction around the fitting 7 once the latter is connected to the main column.

The installation tool may include anchoring means 62 from the inside of the tubes of the column 3, an orientation and displacement assembly 63, an assembly 64 for operating the door 12 comprising a finger 65 adapted to cooperate with the slot 66 of the body of the tube 24 (FIG. 4B) to be placed above the door. The finger 65 is adapted to be moved in translation to slide the door in its housing and close the space between the opening and the connection fitting. The finger can be activated diametrically and longitudinally via a means comprising a screw driven in rotation by the surface rotation of the rods 60, or by the displacement of a hydraulic cylinder subjected to a pressurized fluid injected from the surface .

We will remain within the framework of this invention, using a fitting tool designed from other mechanical systems, insofar as the main functions, described above, are in particular for the implementation of the system or the present method.

FIG. 9A represents a tool for lowering and placing 61 of the lateral column 3, anchored in the connection fitting 7, which is integral with the column 3 by means of a seal 8. The tool comprises an assembly 64 for operating the door 12, not shown in FIG. 9A but detailed by FIGS. 10A, 10B and 10C, an assembly 63 for orientation and positioning of the connection fitting 7 in the opening 21, an anchoring assembly 62 of the fitting tool 61 in the connector 7. The anchoring assembly comprises a means of locking 87 secured to the end of an operating tube 88 and a piece 86 for holding the connection 7. The holding piece 86 has a face 130 complementary to the section 13 of the connection fitting 7. The joining of the piece 86 on the tube 88 fixes the connector 7 in rotation relative to the tube 88 when the section 13 of the connector 7 is in contact with the face 130 of the holding part. To increase the resistance to torsional torque, the part of the tube 88 located inside the connection fitting 7 may include longitudinal grooves in which are trapped transverse pins secured to the wall of the fitting 7.

The centering device constituted by the parts 146 and 147 of FIG. 6F, is not shown in this figure for reasons of clarity.

FIG. 9B illustrates an anchoring system 87. The connector 7 has a circular groove 89 in its interior passage. A cylindrical piece 90 is secured to the end of the tube 88 by a thread 92. The piece 90 has several slots 93 distributed over the periphery allowing a radial expansion of the end 91 of the split piece 90. This end is machined according to a male shape, complementary to the groove 89. A plug 94 widens the end 91 of the slotted piece 90, locking the tube 88 in the connector 7. The plug 94 is integral with a piston 95 located in the bore of the tube 88 Sealing means 96 isolate the interior space of the tube 88 from the annular space. A shear pin 97 secures the piston 95 in the tube 88. Thus mounted, the column 3 is lowered into the well by rods integral with the tube 88. The longitudinal forces are supported by the cooperation of the groove 89 and the shape 91 Unlocking will be carried out by increasing the pressure inside the tube 88, via the internal space of the operating rods and a pumping installation on the surface. When the pressure provides a thrust on the piston 95 greater than the shear resistance of the pin 97, this breaking breaks free the piston which moves under the effect of the pressure down the figure of a stroke C determined. This translational movement of the piston causes the plug 94 to be disengaged from the end of the part 90. Given the elasticity of the form 91, the latter retracts by itself or under the action of a longitudinal force applied to tube 88, thereby releasing tube 88 from fitting 7.

In FIG. 9A, the orientation assembly 63 comprises a jacket 98 secured to the tube 88 by a shear pin 99. The jacket has a shape 100 complementary to the shape of the orientation means 20 of the upper end of the means guide 10 (Figure 2B). To facilitate understanding, the silhouette of the upper part 18 of the guide means is shown in dotted lines in FIG. 9A. A key 101, integral with the tube 88 is located in a slot 102 cut in the jacket 98. At the end of the positioning of the column 3 in the lateral drilling, the shape 100 of the jacket of the fitting tool cooperates with the orientation means 20 of the guide means. The cooperation directs the fitting tool and the connecting fitting 7 in a determined direction, direction given by the orientation of the guide means in the pipe 4. At the end of orientation, the downward movement of the pose and column 3, is blocked by the part 18. The slot 102 is located opposite the slot 53 of the upper part 18 of the guide means. The operator applies a shearing force to the pin 99 by the action of rods or drill collars. The rupture of the pin releases the tube 88 from the jacket 98, and in the same movement moves downward in a translational movement. In this movement, the key 101 enters the slot 53. When the translational movement has made a stroke of predetermined length, at most equal to the length of the slot 53, the connector 7 is correctly positioned in the opening 21. From even, at the end of this last movement, the door operating assembly is in the operating position.

Figures 10A and 10B show an embodiment of an operating assembly 64 of the door 12. Figure 10C shows said assembly in action. The two ends 103 and 104 of the assembly 64 are respectively connected to the orientation assembly 63 and to the operating lining, which may include drill collars, heavy rods or rods. The outer body 105 of the assembly 64 comprises a window 106 of elongated shape along a generatrix of the body 105, an upper guide bearing 107 and a lower guide bearing 108. A longitudinally movable assembly 109, coaxial with said outer body 105, comprises an upper piston 110, a lower piston 111, integral with a support 112 of a finger 76 for operating the door 12. Sealing means 113 and 114 are placed respectively in the guide bearings 107 and 108 of the assembly 109 in the outer body 105. The shoulders 117 and 116 of the body 105 limit the movement in translation of the assembly 109 by their respective cooperation with the shoulders 118 and 115 secured to the support 112. A return spring 119 holds the assembly 109 in the high position relative to the body 105 or the rest position. In this rest position the shoulders 118 and 117 are in contact, as shown in FIGS. 10A and 10B. The outside diameter of the upper piston 110, or the inside diameter of the seals 113, is substantially greater than the outside diameter of the lower piston 111, or the inside diameter of the seals 114. The assembly 109 thus constitutes a differential piston, the pressure in the interior of the tubes applies to different sections, the largest section being on the upper piston side 110. The finger 76 is articulated around the axis 120. A leaf spring 131 (FIG. 10C) is held on the body 112 by a piece 122 carrying the axis 120. The spring disposed under the finger 76 tends to pivot it towards the outside of the support 112. In the so-called rest position, shown in the figures 10A and 10B, the finger 76 is kept retracted, parallel to the axis of the tool 64, by the part 121 of the external body 105. A tubular rod 123 is located inside the lower piston 111 The rod 123 has at its lower end a shoulder 132 adapted to cooperate with a stop (not shown) placed at a determined distance in the end tube 103, and at its upper end a sealing sleeve 124. A return spring 126 keeps the rod 123 in abutment e on the shoulder 127 of the lower piston 111. The sealing sleeve 124 comprises sealing means 128 and 129 on either side of at least one orifice 125 drilled in the support 112.

The operation of the operating assembly 64 of the door 12 is described below. When the column 3 and its connection fitting 7 are correctly positioned and oriented by the fitting tool 61, the key 101 is in abutment in the bottom of the slot 53 of the upper part of the guide means. The window 106 is located opposite the window 66 of the body of the tube 24 (FIGS. 4A and 4B). The pressure is increased in the interior space of the rods and of the tube 88 by pumping means located on the surface. The interior space is blocked by the piston 95 of the anchoring means 87. Taking into account the differential sections of the assembly 109, the latter receives a downward thrust, proportional to the pressure and to the differential section. For example, for outer diameters of the upper and lower pistons, respectively 3.870 '' (9.8298 cm) and 3.495 '' (8.8773 cm) and a pressure of 2000 psi (13789 kpa), the pushing force is about 4300 Ibs, or 19126 Newton. The force compresses the spring 119 by lowering the assembly 109. When the axis 120 is substantially released from the casing 121, the finger 76 is radially expanded by its spring 131 (FIG. 10C). The finger 76 thus passes through the window 106, the window 66 and the end of the finger cooperates with one of the openings 75 in the door 12. The pushing force moves the door thus driven by the assembly 109 until that the stop 115 arrives near the stop 116. At the same time, the stop 132 of the rod 123 cooperates with a stop (not shown), moving, at the end of the race of the assembly 109, the sealing sleeve 124. In this movement, the orifice 125 is released, putting the interior space of the rods 88 into communication with the annular space of the well and thus causing a pressure drop inside these tubes 88. The end of a stroke is thus signaled to the operator who can cause the internal pressure to drop so that the assembly 109 returns to its rest position under the action of the return spring 119. In the direction of the ascent, the shape of the finger 76 and the opening 75 are such that this finger 76 is automatically released from this opening 75. The operator repeats the operation to advance the door by successive strokes, until total closure. A certain number of openings 75 are necessary for this displacement by successive strokes. When, following a rise in pressure in the tubes, the operator does not observe any pressure drop caused by the end-of-stroke signal constituted by the sleeve 124 and the tube 123, he can deduce therefrom that the door is fully closed. This can be confirmed by the number of closing cycles that have already been carried out.

To release the installation tool 61 from column 3, now assembled by connection 7 to the main column, it suffices to mount to an internal pressure sufficient to break the shear pin 97, the piston 95 releases the plug 94 from the 'end 91, releasing it from the groove 89 (Figure 9B). For operational safety, a specific emergency connection can be inserted between the anchoring system 87 and the tube 88. This emergency connection is suitable for releasing the tube 88 from the anchoring system 87 which could be trapped, by a mechanical action such as a torque, a weight or a traction, or by explosion according to the back-off type unscrewing operations.

FIG. 13 is a particularly advantageous variant of the joint 8 intermediate between the tubes 3 of the lateral column and the connection fitting 7. It comprises two tubular parts 171 and 172 connected together by a connection 170 of the spherical type. Part 171 has a certain length (about 1 meter) and a cross section such that it has relative flexibility. Part 171 may advantageously be in the form of a bellows or of a tube with a corrugated wall which thus has great lateral flexibility even for a short length. One end 173 has a substantially spherical shape, the other end 174 is integral with the connection fitting 7. The end 173 is held in a tubular part 175, integral with one end of the part 172 and whose internal shape cooperates with the spherical shape 173 to constitute a spherical connection 170. The other end of the part 172 is connected to the tubes of the lateral column 3. Thus a flexible rotary joint is formed allowing the axial rotation and the longitudinal misalignment of the connection fitting relative to the side column 3. In addition, part 173 comprises in its inner wall the shape 89 (FIG. 9B) adapted to cooperate with the hooking device 87 fixed to the end of the tube 88 located in the interior space of the different tubular parts.

FIGS. 11A, 11B and 11C detail an example of plugging the opening 21 of the element 24 during the casing of the main well and before drilling the side wells from the window 21. Strips 180 are wound around the element 24 over the entire length of the cover 16, taking care that the covering of the ends of the cover is as shown in detail in FIG. 11C. In addition to increase the strength of the bandage, the spaces 181 (FIG. 11A) are filled with a filling material before the winding. In another variant, a plate 182 made of reforable material can seal the opening 27 (FIG. 15B) before being covered with bandages. The bandages can be made of fiber-reinforced composite material.

FIGS. 16A and 16B illustrate a variant of the means for closing the space between the connection fitting 7 and the periphery of the opening 21. The principle here is to equip the element 24 with closing means in several parts 191 and 190. A part 190 slides parallel to the longitudinal axis of the element 24, and two parts 191 have a rotational movement around this same axis. FIGS. 16A and 16B only show the operating principle because the production of these means is within the reach of those skilled in the art, taking into account the present invention.

The reference 193 represents the opening 27 of the cover 16 in top view according to FIGS. 15A or 4A. The reference 192 represents the cross section of the connection fitting 7 substantially in the plane of the opening 27. In FIG. 16B, the opening is maximum. Side doors 191 are spaced from each other by a distance corresponding to the width of the opening 21. A door 190 with longitudinal displacement has a V-shaped end 194 whose slope corresponds to the shape 195 of the side doors. The doors 190 and 191 are held in a casing constituted by the body of the tubular element 24 and a cover 16. Once the lateral column and its connection fitting 7 put in place in the lateral drilling, a translation is made of door 190 to the right of Figure 16B. The wedge system between the shapes 194 and 195 then causes the side doors 191 to tighten around the connection fitting in a rotational movement around the axis of the element 24. FIG. 16A shows the doors 190 and 191 which close off the space between the fitting and the opening, after they have moved. Of course, other equivalent mechanical systems can be used to move closing elements in a given direction from a first translational movement.

FIGS. 8A and 8B give examples of applications of the method and of the system according to the invention.

In Figure 8A, a main well is drilled from the surface to a geological area 71, preferably an oil deposit. The well 69 extends in the producing formation 71 by a substantially horizontal part 74. The main well is made according to known techniques. Part 74, at least, is cased according to the method according to the invention. Said casing, perforated or not, comprises at least one portion comprising at least one lateral opening from which side drains 72 are drilled. The side drains can be substantially horizontal in the producing layer 71, ascending or descending. The arrangement of the drainage wells 72 depends on the producing layer. The relative orientation of the openings, according to the present invention, allows the execution of the drains in the desired directions.

In FIG. 8B, the main well 69 is substantially vertical up to the producing zone 71. The lateral drilling 72 is carried out inclined, preferably substantially horizontal in the producing layer. The tubular portion 73 of the casing of the main well 69 has at least one opening from which the drain 72 is drilled. To obtain a substantially radiant drainage of the deposit, several openings located in the vicinity of the portion 73 allow the drilling of several drains 72 Preferably, the openings will be located at different levels, for example for reasons of mechanical strength of the main casing or for a simplification of the implementation of the different means used according to the system and the method of the present invention. The portion 73 may not be located in the producing formation. In addition, the main well 69 may include several portions 73 allowing the drainage of the deposit to levels of different depths.

The invention can also be applied to the drainage of several producing layers separated and crossed by the main well 69. The casing of the main well comprising several portions 73 and drains 72, for example one assembly per layer.

In FIG. 8B, the main well 69 is shown crossing entirely the producing layer 71. This arrangement is in no way limitative of the scope of the invention.

Claims (58)

1) Method of drilling and lateral well equipment from a main well (1) cased by a tubular column (4) comprising at least one lateral opening (6, 21), characterized in that it comprises the following steps : - guide means (10) are positioned in said tubular column substantially at the level of said opening, - lateral drilling means are introduced to drill a lateral well from said opening, - a lateral well (2) is fitted with a tubular lateral column (3), - A junction of the lateral column is made substantially on the periphery of the tubular column. 2) Method according to claim 1, characterized in that one descends from the lateral drilling means (59) in the main well and in that they are guided in said opening by said guide means. 3) Method according to one of claims 1 or 2, characterized in that the introduction of said lateral column into the lateral well is guided by said guide means. 4) Method according to one of claims 1 to 3, characterized in that one directs the joining means (7) relative to said opening by the guide means. 5) Method according to one of claims 1 to 4, characterized in that one substantially plugs the space between said opening and the lateral column substantially at the junction means. 6) Method according to claim 5, characterized in that one activates closing means (12) linked to said tubular column substantially at the level of the lateral opening, for blocking said space. 7) Method according to one of claims 1 to 6, characterized in that one moves said guide means after performing the junction of the lateral column on the tubular column of the main well. 8) Method according to one of claims 1 to 7, characterized in that said lateral column is introduced into the lateral well by means of operating rods (57, 60) assembled from the surface, said rods being connected to said column lateral by means of a fitting tool (64, 63,62). 9) Method according to claim 8, characterized in that said closure means are activated by varying the pressure in the interior of the setting tool. 10) Method according to claim 8, characterized in that the setting tool is released from said lateral column by varying the pressure in the setting tool. 11) Method according to claim 1, in which the main column comprises several portions of tube comprising an opening, characterized in that: - the openings are oriented relative to each other by rotation of said portions around the axis of the column, - And we control said orientations using a measurement tool lowered into the interior of said column. 12) System for drilling and equipping at least one lateral well to a main well cased by a tubular column comprising at least one lateral opening (6, 21), said opening being suitable for the passage of a drilling tool ( 59), said system comprising a lateral tubular column housed in said lateral well and guide means (10) positioned relative to said opening, characterized in that said system comprises joining means (7) of the lateral column situated substantially on the periphery of the tubular column. 13) System according to claim 12, characterized in that it comprises means for closing (12) the space between said lateral column and said opening, said closing means being located substantially at the junction means. 14) System according to one of claims 12 or 13, characterized in that said guide means are adapted to guide said drilling means and said side column. 15) System according to one of claims 12 to 14, characterized in that the guide means comprise displacement means allowing the displacement of said guide means in the tubular column after the junction of the lateral column. 16) System according to claim 15, characterized in that it comprises a key integral with the main column in the vicinity of said opening, in that said displacement means consist of a continuous groove along the guide means, and in that said anchoring means consist of another groove and a reversible lock blocking the key in said other groove. 17) System according to claim 12, characterized in that it comprises a tool for installing said lateral column, said tool being linked to the lateral column by a reversible anchoring, said tool comprising means for orienting the joining means by cooperation with the guide means and means for activating the closure means, and in that said tool is lowered into the well by operating rods. 18) System according to claim 17, characterized in that said activation means comprise a differential piston and a drive finger in translation said closure means. 19) Connecting device between two tubular elements, characterized in that a first tubular element comprises a lateral opening of dimension adapted to allow the passage of the second element, and in that it comprises means for joining the second element on the first located on the periphery of the first element. 20) Device according to claim 19, characterized in that it comprises means for closing the space between the second tubular element and the opening. 21) Device according to claim 19, characterized in that said joining means comprise a connection fitting secured to the second tubular element by means of a flexible and rotary joint. 22) Device according to one of claims 20 or 21, characterized in that the end of the connection fitting has a section along a plane inclined relative to the main axis of the fitting, in that a portion of the periphery of said section is in contact with a corresponding portion of the periphery of the opening, and in that the closing means comprise at least one sliding plate adapted to substantially close off the space between the other peripheral portions of said section and of the opening. 23) Device according to claim 22, characterized in that said section is rectangle. 24) Device according to claim 23, characterized in that the end of said connecting connector comprises on the sides substantially parallel to the axis of the first element, connecting means cooperating with the sliding plate when the latter is moved. 25) Device according to one of claims 22 to 24, characterized in that the closure means comprise three sliding plates, two of which are adapted to be moved by a translation of the third. 26) System for drilling and equipping at least one lateral well to a main well cased by a tubular column, characterized in that said column comprises at least one tubular portion equipped with a lateral opening (6, 21) and means for at least partially closing said opening. 27) System according to claim 26, characterized in that it comprises guide means adapted to be placed in said column and to guide a tool or equipment from the interior of said column towards said opening. 28) System according to claim 27, characterized in that it comprises means for positioning said guide means relative to said opening, said positioning means being controlled from the surface. 29) System according to claim 28, characterized in that said guide means are moved inside said column by means of operating rods, in that said guide means comprise a ramp inclined relative to the axis longitudinal of said tubular portion and in that said positioning means comprise reversible anchoring means of said guide means in said column. 30) System according to one of claims 27 or 28, characterized in that it comprises reversible anchoring means of said guide means in said column, said anchoring means being adapted to anchor said guide means when these- ci, moved from the surface to the bottom of the well, are oriented in a first position relative to the longitudinal axis of the column, and not to anchor said guide means when they are oriented in a second position. 31) System according to one of claims 27 to 30, characterized in that said positioning means comprise a key integral with at least one tubular portion, in that said guide means comprise two grooves adapted to cooperate with said key, a first groove has a pawl to lock the guide means on the key, and a second groove extending over the total length of the guide means. 32) System according to claim 31, characterized in that the guide means comprise means for engaging said key in one or the other of the two grooves, said engagement means being controlled from the surface. 33) System according to claim 32, characterized in that the engagement means comprise a substantially cylindrical part with an outside diameter less than the inside diameter of said tubular portion, one end of said cylindrical point part formed by two planes symmetrical with respect to a plane passing through the longitudinal axis and intersecting on a line orthogonal to said longitudinal axis, and each of the grooves emerging on one of the faces of said point, symmetrically with respect to said axis. 34) System according to one of claims 27 to 33, characterized in that said guide means comprise means of connection with the operating rods, said connection means being adapted to release the rods when the guide means are positioned in the tubular part. 35) System according to claim 26, characterized in that said closing means are adapted to be operated from the surface by means of the operating rods. 36) System according to one of claims 26 to 35, characterized in that it comprises an element placed in the opening and in that the closure means comprises closure means adapted to substantially isolate the interior of the column of the annular space between the column and the main well. 37) System according to claim 36, characterized in that said sealing means comprises complementary shapes between said closing means, the end of said element and the opening, said complementary shapes cooperating with each other. 38) System according to claim 37, characterized in that said element comprises a lateral tubular column adapted to be placed in the lateral well and a connection fitting between the lateral column and the tubular portion. 39) System according to claim 38, characterized in that the connection fitting comprises anchoring means adapted to be engaged by a translation of the fitting on the ramp of the guide means, in that a portion of the periphery of the opening is in contact with a portion of the periphery of one end of the connector, thus limiting the space between the corresponding portions and in that the closing means comprise a door adapted to substantially close the space between the opening and the connection fitting. 40) System according to claim 39, characterized in that said periphery of one end of the connection fitting is rectangle. 41) System according to claim 38, characterized in that said connecting connector is connected to the lateral column by a flexible and rotary joint and in that said system comprises a fitting tool adapted to place said lateral column in the well lateral, said fitting tool cooperating with means for orienting the connection fitting relative to the opening, said orienting means cooperating with said guide means. 42) System according to claim 41, characterized in that said setting tool is fixed to the lower end of operating rods, said tool comprising means for moving a door adapted to close the space between the opening and the connecting fitting. 43) System according to one of claims 41 or 42, characterized in that said fitting tool comprising means for moving the door is adapted to be actuated by a hydraulic pressure generated from the surface. 44) System according to claim 26, characterized in that said opening is closed by closing means adapted to be punctured by a lateral drilling tool, said means comprising strips of composite material wound circumferentially around the tubular column of the main well . 45) Method of drilling and lateral well equipment from a main well (1) cased by a tubular column (4), characterized in that it comprises the following stages: - the main well is cased by a tubular column, at least a portion of which has at least one lateral opening, - The orientation of the direction of said lateral opening is effected by a rotation of the column from the surface, - The direction of said opening is controlled by measuring means. 46) Method according to claim 45, characterized in that: - guide means are positioned in the main column substantially at the level of said lateral opening, - a drill string is assembled and lowered into the main tubular column, - A lateral well is drilled from said opening, a drilling tool being guided by said guide means. 47) Method according to claim 46, characterized in that said tubular column comprises at least two tubular portions comprising at least one lateral opening, in that the openings are oriented relative to each other by rotation about the axis of said portions tubular, and in that the orientation is controlled by means of a measuring tool lowered into said column. 48) Method according to one of claims 46 or 47, characterized in that said guide means are moved and their anchoring controlled in the main column using a packing of operating rods extending to the area. 49) Method according to claim 48, characterized in that in the case where there is no anchoring of the guide means during their movement on either side of an opening, said means are raised to the surface of a determined height, then a rotation of substantially 180 ° is carried out and the means are moved down to be anchored. 50) Method according to claim 48, characterized in that in the case where the guide means are anchored following their movement in the column, a tensile force is applied to the operating lining to unlock the anchoring and position said means above the opening, in that a rotation of substantially 180 ° is applied to said means in order to move said means in said column. 51) Method according to claim 48, characterized in that the lining of operating rods is taken out of the main column once the anchoring of the guide means has been carried out. 52) Method according to one of claims 46 to 51, characterized in that the lateral well is equipped with a lateral tubular column comprising at its upper end a connection fitting with the main tubular column. 53) Method according to claim 52, characterized in that said lateral tubular column is guided in the lateral well by said guide means and in that the lateral tubular column is lowered into the well by means of a lining of rods maneuver and a setting tool attached to the lower end of said packing. 54) Method according to one of claims 52 or 53, characterized in that the connecting connector is oriented relative to the lateral opening and fixed in the vicinity of the opening after being guided by said guide means, and in that the space between the connection fitting and the lateral opening is substantially closed. 55) Method according to claim 54, characterized in that a door is moved to close off said space. 56) Method according to claim 55, characterized in that said door is moved by the injection of a pressurized fluid at said laying tool. 57) Device according to claim 21, characterized in that said flexible and rotary joint comprises a tubular part with corrugated wall. 58) System according to claim 41, characterized in that said flexible and rotary joint comprises a tubular part with a corrugated wall.

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