EP0463939B1 - Method and apparatus for conducting logging or work-over operations in a borehole - Google Patents

Description

The present invention relates to an improved method and device for carrying out measurement operations or interventions in wells and in particular wells drilled through oil zones. These measurements can be carried out as part of seismic prospecting operations or to carry out localized studies of a well or surrounding formations. The method and the device are particularly suitable for carrying out measurement operations in deviated wells, by designating by this term wells at least part of which is more or less deviated with respect to the vertical, or more generally. in any well where progression of a gravity measurement tool is difficult.

From FR-A-2 609 105 or US-A-4 945 987, a method and a device are known for carrying out interventions such as measurements in wells which are particularly suitable when these interventions must take place in deviated wells.

The measurement or intervention tool is arranged at the base of a first section of tube constituting the terminal part of a rigid column. It is connected to a support element provided with removable retaining means by which it can be made integral with the terminal part of the column and with a multi-contact male plug. The retaining means are engaged to secure the support element to this section. By successive additions of sections, the measurement or intervention tool is lowered and pushed along the well until it reaches the upper limit of the area where the interventions are planned. By means of a side window fitting, a female plug surmounted by a load bar is introduced and propelled by a current of fluid to a male multi-contact plug or it is inserted. Additional tube sections are added so that the tool is pushed until the tool reaches the place intended to start the measurements. The tool is provided with anchoring arms which are opened to immobilize it in the well and one goes up several sections of the column so as to move the tool away from its base. The support element then comes to bear against a stop at the lower end of the column. The measurements can then be carried out either discontinuously by moving the tool from one location to the next after each measurement with the tool placed against the wall of the well by opening the anchoring arms, or continuously within limits. more or less narrow according to the importance of the recoil of the column.

The displacement of the tool being carried out in all cases by traction on the column, and the latter having to be shortened section after section as it is withdrawn, it is clear that the maximum length over which a continuous movement is possible, is limited to the length of the sections used.

The method according to the invention overcomes these limitations.

Like the method described in the above-mentioned patent, the improved method according to the invention comprises the use of a rigid column provided with a terminal end piece, comprising an insert, a side window connector, a measuring assembly consisting of at least one measurement probe, positioning or holding this measurement assembly in a first position at the end of a rigid column by a support element provided with removable locking means, the introduction into the well of the measuring system associated with the end of the column, the descent of the measuring system into the well by lengthening this column until reaching a first position in a well zone where logging measurements are planned , the delayed electrical connection of the measuring assembly to an electro-carrying cable unwound from a surface installation, which passes from the outside to the inside of the rigid column through the window of said side window fitting, this cable being terminated by delayed connection electrical connection means provided with locking elements making it possible to secure on command the electrically-carrying cable and the support element after its descent into the well, the displacement by pushing on the rigid column of the measuring assembly from the first position to a second position at the end of the measurement zone furthest from the surface, and the immobilization on command of the measurement assembly in the well by anchoring against the walls of the latter.

• le retrait de la colonne après ancrage de l'ensemble de mesure dans le puits sur une distance supérieure à la distance séparant les moyens de verrouillage en position de retrait maximale de l'extrémité de celle-ci et inférieure à la distance séparant le raccord à fenêtre latérale de la tête du puits, de façon à dégager l'ensemble de la sonde de mesure et son élément-support relié à l'installation de surface directement par l'intermédiaire dudit câble électro-porteur, l'embout terminal de la colonne rigide étant conformé pour permettre la sortie sans retenue dudit élément support; et
• le retrait de la sonde de mesure sur ladite distance ainsi définie par une traction exercée sur le câble par des moyens de manoeuvre en surface, jusqu'à la réintégration complète de l'élément-support dans la colonne rigide, son verrouillage et la remontée de l'ensemble de mesure dans la colonne jusqu'à la surface.

The method is characterized by:

• removal of the column after anchoring of the measuring assembly in the well over a distance greater than the distance separating the locking means in the position of maximum withdrawal from the end of the latter and less than the distance separating the fitting to side window of the well head, so as to clear the assembly of the measurement probe and its support element connected to the surface installation directly by means of said electro-carrying cable, the end piece of the column rigid being shaped to allow the unrestricted exit of said support element; and
• the withdrawal of the measurement probe over said distance thus defined by a traction exerted on the cable by surface operating means, until the complete reintegration of the support element in the rigid column, its locking and the raising of the measuring system in the column to the surface.

The device according to the invention allows both the implementation of the method. It comprises a rigid column provided with a side window connection, an intervention unit comprising for example one or more measuring tools or instruments and anchoring means making it possible to immobilize it in the well, a support element assembled to said intervention assembly by means of connection and movable inside the column between a first position where the intervention assembly is in the vicinity of a first end of the column, and a second position, the support element being provided with fixing means making it possible to lock the support element to the column in its first position, these fixing means being remotely controllable from a surface installation, by means of a multi-conductor electrically-carrying cable connected to a control and acquisition assembly on the surface and passing from the outside to the inside of the column through the fitting with side window, and a system for deferred connection of said cable to the intervention assembly after its descent into the well.

• la colonne est pourvue, à sa première extrémité, d'un embout de section suffisante pour laisser sortir l'élément-support sur une distance supérieure à la distance séparant les moyens de verrouillage en position de retrait maximale, de l'extrémité de celle-ci, et inférieure à la distance séparant le raccord à fenêtre latérale de la tête du puits hors de la colonne en position de verrouillage desdits moyens de fixation; et en ce qu'il comporte
• des moyens pour limiter l'accès aux moyens de fixation et aux moyens de verrouillage, de débris solides susceptibles d'empêcher leur fonctionnement.

The device is characterized in that

• the column is provided, at its first end, with a nozzle of sufficient section to allow the support element to exit over a distance greater than the distance separating the locking means in the position of maximum withdrawal, from the end of the latter ci, and less than the distance separating the fitting with side window from the well head out of the column in the locking position of said fixing means; and what it entails
• means for limiting access to the fixing means and to the locking means, of solid debris capable of preventing their operation.

The structure of the device makes it possible to extend the continuous intervention zone as much as desired without being limited, as in the previous method, by the length of the sections of the thrust column, and therefore possibly to carry out interventions in a manner regular without being hampered by periodic shortening maneuvers of the rigid column for example.

• la Fig.1 montre schématiquement un mode de réalisation du dispositif où l'outil est relié à son élément support par une liaison rigide;
• la fig.2 montre une étape à l'issue de laquelle l'outil d'intervention est conduit jusqu'à sa position de descente maximale; et
• la Fig.3 montre une autre étape où, après recul de la colonne, l'outil d'intervention est prêt à être déplacer tout au long de la zone d'intervention par traction sur le câble.

Other characteristics and advantages of the method and of the device according to the invention will appear more clearly on reading the description below of embodiments described by way of nonlimiting examples, with reference to the appended drawings in which:

• Fig.1 schematically shows an embodiment of the device where the tool is connected to its support element by a rigid connection;
• Fig.2 shows a step at the end of which the intervention tool is led to its maximum descent position; and
• Fig.3 shows another step where, after the column has retreated, the intervention tool is ready to be moved throughout the intervention zone by pulling on the cable.

To carry out interventions in a well 1, a tubular or tubing column 2 is lowered there. At the lower end of the column 2, an intervention assembly 3 is adapted, which may for example be a logging tool.

The intervention tool 3 is fixed (Fig. 1) to a first end of a connecting rod 4. The opposite end of this rod 4 is connected, inside the column 2, to a support element 5 of section smaller than that of the column. Anchoring fingers 6 are pivotally mounted relative to the support element 5. Under the action of a motor not shown, they can be moved apart to an open position (Fig. 1) where they come block in a groove 7 made in the inner wall of the column 2. The support element 5 comprises, on the side opposite to the rod 4, a tubular extension 8. In the center of the tubular extension 8 and along its axis, a plug is arranged multi-contact male 9. The column 2 is provided with an internal annular bulge 10 which is used for guiding towards the male plug 9 of a suitable female socket 11. This is connected to the various conductors of a control cable 12 connected to a surface installation 13 (Fig. 2) comprising maneuvering means 14 and a control and recording assembly 15 adapted to record data captured by measurement means in the intervention tool 3. The outlet female 11 is topped with a ba re of tubular ballasting 16 of substantially equal section. The socket 11 also includes anchoring fingers 17 of a known type which can be moved apart by the action of electromagnetic means or an electric motor. Notches 18 for the fingers 17 are formed in the inner wall of the tubular extension 8. The fingers can engage there when the male plug 9 is in the correct insertion position. The unlocking of the fingers 17 allows the translation of the support element 5 by traction on the cable 12 exerted by the lifting means 14 on the surface. Inside the support element 5, and the rod 4 of the conductors (not shown) ensure the electrical interconnection of the cable 12 and the various electrical conductors of the intervention tool.

Examples of electrical connectors using this type of multi-contact male plug and suitable female socket are described for example in European patent EP 122,839 or American patent US 4,690,214.

A profiled end piece 18 is attached to the lower end of the tubular column. Its internal section is slightly greater than that of the support element. The rod 4 connecting the support element to the intervention tool 3, is provided with a peripheral shoulder 19 of section substantially equal to the internal section of the column, in the vicinity of the lower end of the latter. In the locking position of the support element 5, the shoulder 19 and the profiled end piece 18 cooperate to prevent the penetration of solid debris inside the tubular column, capable of blocking the opening of the retaining fingers 6 of the support element.

The intervention tool 3 is provided with an arm or several anchoring arms 20 pivotally mounted relative to the body of the tool 3 and capable, in the spacing position, of immobilizing it in the well. Each arm 20 is actuated by motor means (not shown) which can be controlled from the surface control assembly 15.

• L'outil 3 prolongé de la tige 4 est introduit dans la section terminale de la colonne 2 et raccordé mécaniquement et électriquement à la base de l'élément support 5. Celui-ci est positionné dans la colonne de manière à pouvoir enclencher les doigts 6 dans la rainure 7 et à placer l'épaulement 19 au voisinage de l'ouverture de la colonne 2. La vanne 25 est fermée.
• L'outil d'intervention 3 avec son élément de support 5 verrouillé dans la colonne 2 , est descendu dans le puits et des sections de colonne sont progressivement rajoutés pour l'amener jusqu'à la partie supérieure de la zone de puits où des opérations doivent avoir lieu.
• Dans cette position, à l'extrémité supérieure du tubage, on introduit la prise multi-contacts 11 reliée au câble de transmission 12 et surmontée par sa barre de charge 16, et on met en place un raccord spécial à fenêtre latérale 21 du type "Side Entry Sub" à travers l'ouverture duquel passe le câble 12.
• La prise 11 surmontée de sa barre de charge 16, est ensuite descendue dans le puits 1 au bout du câble de commande 12 soit par gravité si c'est possible, soit propulsée par pompage jusqu'à ce qu'elle s'enfiche sur la fiche multi-contacts 9, comme décrit dans le brevet européen précité EP 122 839. On commande alors le verrouillage des doigts 17 dans leurs encoches 18.

The operations of setting up the intervention tool described above and the conduct of operations using the tool take place as follows:

• The tool 3 extended from the rod 4 is introduced into the end section of the column 2 and mechanically and electrically connected to the base of the support element 5. The latter is positioned in the column so as to be able to engage the fingers 6 in the groove 7 and to place the shoulder 19 near the opening of the column 2. The valve 25 is closed.
• The intervention tool 3 with its support element 5 locked in column 2, is lowered into the well and sections of column are gradually added to bring it to the upper part of the well area where operations must take place.
• In this position, at the upper end of the casing, we introduce the multi-contact socket 11 connected to the transmission cable 12 and surmounted by its load bar 16, and a special fitting with side window 21 of the type "is put in place. Side Entry Sub "through the opening through which the cable passes 12.
• The outlet 11 surmounted by its load bar 16, is then lowered into the well 1 at the end of the control cable 12 either by gravity if possible, or propelled by pumping until it plugs into the multi-contact plug 9, as described in the aforementioned European patent EP 122 839. The locking of the fingers 17 in their notches 18 is then controlled.

Rigid pipe sections are assembled at the upper end of the column 2, so as to ensure the progression of the lower end where the tool 3 is located, until the latter has substantially reached the location of its first measurement and / or intervention.

• On télécommande l'ouverture des bras d'ancrage 20 de l'outil de mesure de manière à l'immobiliser dans le puits.
• On remonte ensuite progressivement la colonne de manière que sa base atteigne la partie supérieure de la portion de puits où les mesures sont effectuées (Fig. 3).

The intervention tool 3, which has reached the position intended for the start of operations, is moved away from the end of the column by remote control from the surface, the closing of the anchoring fingers 6 and possibly by establishing a flow of fluid in the column so as to move the tool from its first position. This is made possible by running cable lengths through the window fitting where it passes freely.

• The opening of the anchoring arms 20 of the measuring tool is remote controlled so as to immobilize it in the well.
• The column is then gradually raised so that its base reaches the upper part of the portion of the well where the measurements are taken (Fig. 3).

The measurement tool is then connected to it via a cable length 12 which can reach several hundred meters.

We can then proceed with the planned interventions. With this arrangement, it is possible, if the intervention in progress requires it, to move the tool throughout the useful area, by pulling on the cable by means of a lifting device on the surface. It is possible for example to make continuous logs over a significant length of the well.

In the embodiment described, the intervention tool 3 is connected to its support element 5 by a rigid rod 4 and it remains outside the tubular column 2.

It would not be departing from the scope of the invention, however, to replace the rigid rod 4 with an element of the multi-line cable with a pre-established connection or provided with a plug-in connector differed in a humid environment such as the connector (9, 11). It would also not depart from the scope of the invention to extend the tubular column 2 at its base by a casing which can contain at least part of the intervention tool 3. The presence of a protective casing is sometimes useful when the well is congested or traversed by cavities where the intervention tool can engage and lock up. With a more resistant protective casing, it is possible without fear of damaging the tool to carry out disengagement maneuvers to bring it back into the axis of the well.

By this use of such a cable element strong enough to withstand the tensile forces of the tool but nevertheless flexible enough to avoid the transmission to the body of the tool of vibrations which can be propagated along the rigid column, can improve the signal-to-noise ratio of seismic sensors.

Claims (5)

1. Improved method of conducting logging operations in wells (1) that are sharply deflected or horizontal, consisting in using a rigid string provided with a terminal end-piece having a side entry sub incorporated therein, a measuring unit consisting of at least one measuring sonde (3), this measuring assembly being positioned or retained in a first position at the end of a rigid string (2) by a support element (5) provided with movable locking means (6, 7), introducing the measuring assembly linked to the end of the string (2) into the well, lowering the measuring assembly into the well by extending this string until it reaches a first position in a zone of the well in which logging measurements are to be carried out, establishing a delayed-action electrical connection between the measuring assembly and an electric cable (12) unwound from a surface installation and passing from the outside of the rigid string to the inside through the window of the said side entry sub, this cable having at its end electrical means (16) for delayed-action connection, provided with locking elements (9, 11) enabling the electric cable (12) to be joined, on the issue of a command, to the support element (5) after it has been lowered into the well, moving the measuring assembly, by pushing on the rigid string, from the first position to a second position at the end of the measuring zone farthest away from the surface and immobilising the measuring assembly in the well, on the issue of a command, by anchoring against the walls thereof, the method being characterised by

   - withdrawal of the string (2), once the measuring assembly (3) has been anchored in the well, by a distance that is greater than the distance separating the locking means (6, 7) in the position of maximum withdrawal and the end thereof and smaller than the distance separating the side entry sub from the well head, so as to disengage the unit with the measuring sonde (3) and its support element, directly linked to the surface installation by means of the said electric cable (2), the terminal end-piece (18) of the rigid string being shaped so as to allow the said support element to be removed unhampered; and

   - withdrawal of the measuring sonde (3) over the said distance as defined by exerting a traction on the cable using operating means at the surface until the support element (5) has been fully re-integrated inside the rigid string, locking it and raising the measuring assembly through the string to the surface.
2. Device for conducting workover or measuring operations in wells using the method defined by claim 1, comprising a rigid string (2) provided with a side entry sub, an operating assembly (3) having, for example, one or several tools or measuring instruments and anchoring means enabling it to be immobilised in the well, a support element (5) joined to the said operating assembly by linking means (4) and displaceable inside the string between a first position in which the measuring assembly is close to a first end of the string and a second position, the support element (5) being provided with fixing means so that the support element can be locked to the string in its first position, these fixing means (6, 7) being remotely controllable from a surface installation by means of a multi-core electric cable (12) linked to a control and acquisition unit (15) at the surface and passing from the outside of the string to the inside through the side entry sub and a system for providing a delayed-action connection between the said cable and the operating assembly after it has been lowered into the well, the device being characterised in that

   - at its first end, the string is provided with an end-piece (18) of a section big enough to allow the support element (5) to be removed over a distance greater than the distance separating the locking means (6, 7) in the position of maximum withdrawal and the end thereof and smaller than the distance separating the side entry sub and the well head outside the string in the position in which the said fixing means are locked; and in that it has

   - means (19) for restricting ingress to the fixing means and locking means by solid debris that might prevent operation thereof.
3. Device as claimed in claim 2, characterised in that the operating assembly is linked to the support element (5) by a rigid rod (4).
4. Device as claimed in claim 2, characterised in that the operating assembly is linked to the support element (5) by a flexible link.
5. Device as claimed in one of claims 2 to 4, characterised in that the rigid string (2) is extended by a casing designed to contain at least a part of the operating assembly.

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