EP0504008B1 - Method and device for the installation of a probe against the wall of a cased borehole - Google Patents

Description

The present invention relates to a method and a device for the temporary placement of one or more measurement probes against the interior wall of a cased well. The well probe according to the invention can be installed in a well, for example for various operations related to the production of hydrocarbons.

A well equipped for petroleum production, for example, includes a casing or casing tube installed during drilling operations. It is held in place by cement injected into the annular space between it and the borehole. In the cased well, a tubular column or tubing is put in place for the flow of fluids outside the production area.

The well probe according to the invention can be used in this flush, to contain seismic or acoustic sensors (accelerometers, geophones, piezoelectric sensors, etc.) that we want to couple with the casing for passive listening of the area put into production to determine its evolution over time for example.

The well probe according to the invention can also be used, for example, in the context of hydraulic fracturing operations in an oil zone where a fluid under pressure is injected into a portion of a well confined so as to create fractures therein, in order to promote its production. We know that in this type of operation, it is useful to place in the well a probe provided with directional sensors sensitive to the noise emitted by the rocks subjected to the fracturing fluid, so as to determine the directions of propagation of the fractures. In such a probe, it is also possible to include temperature and pressure sensors.

By US patents 4,690,214; 4,898,237; 4,898,240 and 2,898,241, various probes are known which can be used in the context of hydraulic fracturing operations. They are lowered into the intervention zone by a column constituted by interconnection of tubular sections and connected to a control and recording installation on the surface by electro-carrying cable which can possibly be connected once the probe has already descended into the well. . The use of such a column sometimes has drawbacks for certain applications. This is the case for fracturing operations where injecting agents must be injected through the column which, as we can see, tend to erode the electro-carrying cable and sometimes to obstruct the column, which sometimes prevents reassemble the probe after use.

By US patent 4,775,009, there is known a method and a device for installing a receiving assembly in a well, which essentially consists of placing the sensors outside the casing tube and drowning them in cement which is injected into the annular space between it and the well. This process provides a particularly good coupling of the sensors with the surrounding formations. It is suitable for fixed installation due to its irreversible nature.

The method according to the invention is suitable for the temporary establishment for intervention in a well provided with a casing tube, of at least one measurement probe connected by conductive means to a control and recording assembly, and its recovery after use, which avoids the drawbacks mentioned above.

• l'adjonction à chaque sonde, de moyens de couplage magnétiques capables de la maintenir plaquée contre la paroi intérieure du tube de cuvelage,
• le déplacement vers un lieu d'intervention dans le puits de chaque sonde maintenue plaquée à ladite paroi par couplage magnétique, au moyen d'un organe d'entraînement rigide relié à un ensemble de manoeuvre et, avant toute intervention de chaque sonde,
• son découplage mécanique par rapport audit organe d'entraînement rigide par déplacement longitudinal relatif de celui-ci par rapport à la sonde.

The method according to the preamble of claim 1 is known from US-A-4898240. It is characterized in that it comprises in combination

• the addition to each probe of magnetic coupling means capable of keeping it pressed against the inner wall of the casing tube,
• moving to an intervention site in the well of each probe kept pressed against said wall by magnetic coupling, by means of a rigid drive member connected to an operating assembly and, before any intervention by each probe,
• its mechanical decoupling relative to said rigid drive member by relative longitudinal displacement of the latter relative to the probe.

According to a first embodiment, the displacement of each probe is carried out by direct contact between it and the rigid drive member.

The displacement of each probe is carried out for example by means of thrust pieces forming stops, fixed to the rigid connecting member on either side of the probe and at a longitudinal distance from each other greater than the greater longitudinal dimension of the probe, and also of radial centering parts to limit the angular movement of said probe relative to the rigid connecting member.

According to a second embodiment, the displacement of each probe is carried out by traction on flexible cables connecting said probe to the rigid connecting member.

The method may include transmitting the signals received by the sensors of the probe to the control and recording assembly via an intermediate box fixed to said rigid drive member. In this case, the transmission is carried out by flexible connection conductors or possibly by a non-material connection between the probe and the intermediate box, and by conductors between the latter and the control and recording assembly.

It is also possible to use detection means to verify the absence of contact between said probe on the one hand and the thrust parts and the centering parts on the other hand.

The method can also include the use of means for measuring the angular orientation of said probe and in this case also, optionally, the angular orientation of the rigid drive member allowing, by comparison, decoupling. mechanical of said probe relative to said drive member.

The method according to the invention offers a very safe and simple solution to implement for the installation of a probe and its recovery after intervention in a well. The probe being placed outside and decoupled from the column, it is possible to perform listening for long periods in wells used for injection. The tubular column is completely free for production or various interventions. In the context of fracturing operations in particular, the column can be used to inject support agents without any risk for the probe which is out of reach in the annular space.

The method can be used in the context of operations in production wells for example, in which case a tubular column is advantageously used externally provided with drive means as a rigid member for moving the probe pressed against the casing tube. The column remains entirely free for the circulation of fluids: production of petroleum effluents or active agents for interventions in the production area.

The device for implementing the method is characterized in that it comprises at least one probe for measuring instruments or sensors, provided with magnets capable of keeping it pressed against the inner wall of a casing tube in a well and a rigid member associated with drive means for translating said probe pressed against the interior wall along said tube.

The drive means comprise for example stops fixed to the rigid member which can be brought to bear against the plated probe by displacement of said column.

The drive means may also include flexible slings or cables fixed to the column and to the probe and which can be tensioned by displacement of said column.

The device may also include means for controlling the mechanical uncoupling of said probe relative to the drive means.

The device may also include an acquisition and transmission assembly connected to said probe by connection means and / or angular measurement means for knowing the position of said probe in the well.

The rigid member is for example a column provided towards its base with an expandable closure member, a packer for example. The well equipment can also comprise various auxiliary sensors (such as hydrophones, manometers, temperature probes, etc.) which are placed under the parking lot and which are associated with electrical conductors passing through the shutter member. which provides a more complete set of measures.

• la Fig.1 montre une sonde de puits d'un type connu qui est couplée magnétiquement avec la paroi d'un tube de cuvelage et des moyens d'entraînement permettant de la déplacer le long d'un puits;
• la Fig.2 montre une sonde de puits conformée pour obtenir un bon contact avec la paroi du puits, encadrée aussi par des moyens d'entraînement du même type;
• la Fig.3 montre une sonde de puits de forme annulaire constituée par exemple de deux demi-coquilles de part et d'autre de la colonne tubulaire reliées lâchement l'une à l'autre;
• la Fig.4 montre un deuxième mode de réalisation où les moyens d'entraînement comportent des câbles de liaison;
• la Fig.5 montre schématiquement la disposition des mêmes câbles lors d'un mouvement en sens inverse de l'organe de liaison rigide;
• la Fig.6 montre un mode de réalisation où la sonde contenant les capteurs, est reliée à un boîtier d'acquisition et de transmission fixé à l'organe de liaison rigide; et
• la Fig.7 montre un mode de réalisation d'un moyen tel qu'un pendule par exemple dans le cas d'un puits dévié, pour contrôler de l'orientation de chaque sonde dans un puits dévié;
• la Fig.8 montre un mode de mise en oeuvre de la méthode où les moyens employés sont répartis de part et d'autre d'un organe d'obturation du puits;
• la Fig. 9 montre une variante du mode de mise en oeuvre précédent où les moyens employés sont tous disposés au-dessus d'un organe d'obturation de puits; et
• la Fig. 10 montre un mode d'utilisation du dispositif avec mise en place d'un écran-acoustique.

Other characteristics and advantages of the method and the device according to the invention will appear better on reading the following description of embodiments described by way of nonlimiting examples, with reference to the appended drawings where:

• Fig.1 shows a well type probe known which is magnetically coupled with the wall of a casing tube and drive means for moving it along a well;
• Fig.2 shows a well probe shaped to obtain good contact with the wall of the well, also framed by drive means of the same type;
• Fig.3 shows an annular well probe consisting for example of two half-shells on either side of the tubular column loosely connected to each other;
• Fig.4 shows a second embodiment where the drive means comprise connecting cables;
• Fig.5 shows schematically the arrangement of the same cables during a movement in the opposite direction of the rigid connecting member;
• Fig.6 shows an embodiment where the probe containing the sensors is connected to an acquisition and transmission unit fixed to the rigid connecting member; and
• Fig.7 shows an embodiment of a means such as a pendulum for example in the case of a deviated well, for controlling the orientation of each probe in a deviated well;
• Fig.8 shows an embodiment of the method where the means used are distributed on either side of a shutter member of the well;
• Fig. 9 shows a variant of the previous embodiment where the means used are all disposed above a well shutter member; and
• Fig. 10 shows a mode of use of the device with the installation of an acoustic screen.

The method according to the invention can be applied, for example, to the installation of a measurement probe in a well equipped for petroleum production. This well has a casing tube 2 which is held in place by injecting cement into the annular space between it and the well. A production tube 3 provided with an expandable obturation member 4, is lowered into the well as far as the zone which is put into production possibly as a result of hydraulic fracturing operations. A probe connected to a control and recording assembly on the surface by a CL multi-conductor cable, must be lowered to the vicinity of the production area to make various measurements making it possible to monitor the development of the basin.

The method according to the invention consists first of all in placing sufficient magnets 5 in the probe to be lowered to keep it pressed against the metal casing 2. For example, magnets made of a samarium-cobalt alloy are used, the power to volume ratio is very favorable. Is interposed on the production column 3, a tubular section 6 provided with drive means. These means consist of two shoulders or stops 6 made of metal or elastomer, the longitudinal spacing of which is greater than the length of the probe to be driven. The drive means may also include two radial extensions 7 when it is desired to angularly position the probe relative to the rigid column. The angular spacing of these two extensions is greater than the angular sector occupied by the probe so that in an intermediate position, it does not touch either of the two. Of magnets 8 are preferably included in the radial extensions 7. Electromagnetic sensors 9 are also included in the probe to detect any contact between it and the extensions 7.

The probe is then introduced into the well by pressing it against the metal casing 3 so that it is between the two shoulders 6 and the two radial extensions 7 of the column section 3. The column is lowered into the well by connections successive sections and, progressively, the CL multi-conductor cable is unwound. In its translation, the column drives the probe pressed against the casing towards the intervention area.

When the probe has reached the chosen location, the operating means are actuated so as to make the column move back over a distance approximately equal to half the longitudinal spacing of the stops 6. In this way, it is possible to deviate from the probes the upper longitudinal drive stop 6 which was used to push it down. The operator can also control the rotation of the column on itself in case contact between the probe and one of the radial extensions is detected by one of the sensors 9. After the planned intervention, the probe can be moved to another intervention point or brought back to the surface by displacement of the column, the lower stop then pressing against the probe to drive it upwards.

When the probe is used in the context of production operations, it generally includes acoustic or seismic sensors 10 (accelerometers, geophones, velocimeters, piezoelectric sensors, etc.) making it possible to listen to noises emanating from the tank being production. They may for example be tri-axial geophones making it possible to detect the direction of propagation of the acoustic waves received.

The probe being pressed against the casing, a good acoustic coupling of the sensors with the formation is obtained in the contact zone. To increase this area, a probe 11 is preferably chosen with an outer wall with a radius of curvature substantially identical to that of the casing (Fig. 2). This rounded wall probe, may be in the form of a greater or lesser angular sector depending on the case. When we want to have sensors on the entire periphery of the well, we use a ring-shaped probe (Fig. 3), split into several parts. The probe consists for example of two half-shells 11A and 11B joined to each other so that they each retain sufficient mobility to remain in any circumstance pressed against the tube, and each provided with holding magnets against the casing tube. The ring constituting the probe can also of course be subdivided into several angular sectors distributed similarly around the column. Sufficient space is left between the parts to allow the possible passage of fluids.

According to a second embodiment, the drive means of the probe are constituted by flexible cables or slings 12 made of steel or nylon. The cables are fixed to the probe on the one hand and to points in column 3. The longitudinal spacing of these cable anchoring points is greater than the length of the probe. The length of the cables is chosen so that they are all relaxed in an intermediate position of the probe and cannot transmit parasitic vibrations to it. The displacement of the probe towards the place of intervention is obtained by traction on the probe by means of the lower cables. The probe is raised (Fig. 5) by traction using the upper cables 12.

Whatever the embodiment, the probe can be made up of two parts. A first part 13 containing sensors and provided with magnets, is pressed against the casing or casing tube. A second part is contained in a housing 14 which is for example fixed to the rigid column, is connected to the first by flexible electrical conductors 15. This second part is adapted to acquire the signals received by the sensors of the probe 13 and to transmit them on the CL connection cable connected on the surface with the control and recording unit.

According to a variant of the previous embodiment, the connection can be replaced by flexible electrical conductors 15 between the probe and the acquisition unit 14 by electromagnetic transmission means, when the flow of the signals to be transmitted is not too great.

Means can be used to obtain precise angular positioning of the probe containing the sensors. In the case where the probe is placed in a deviated part of a well (Fig. 7), the angular measurement elements used are for example of the pendulum type with an electric potentiometer to measure the position of the vertical plane where it is placed.

According to one embodiment, two angular measuring elements 16, 17 of this type are used. One, 16, is associated with the probe pressed against the casing and the other, 17, with the electronic unit fixed to the column. By a rotation of the column on itself, the probe is brought into a determined plane and by equalizing the indications provided by the two elements 16, 17, they are placed substantially in the same radial plane.

The embodiments described make it possible to obtain a very good coupling between acoustic or seismic sensors and the wall of the well. To increase their effectiveness in detecting the noises emanating from the surrounding formations, they can be protected against the so-called tube waves, propagating along the well, by isolating them by one or more acoustic screens 18 fixed to the column, which seal the ring between it and the casing tube.

According to the embodiment of FIG. 10, the probe is arranged above and in the vicinity of a parking space 19 confining for example a production area, and it is surmounted by an acoustic screen 18 capable of significantly attenuating the tube waves.

The probe section can sometimes be too large for the annular space available. In this case, it is possible to use eccentrics to offset the column laterally at least in the installation area of the probe.

The mode of implementation of the method shown diagrammatically in FIGS. 8, 9 provides a more complete set of data. he suitable for certain applications in particular in oil production wells from which one descends, a production column 3 provided towards its base with an expandable obturation member 19 of the parker type for example to confine the underground zone where one intervenes either for its production or for fracturing operations with injection of fracturing agents for example. In these cases, the electronic unit 15 is connected on the one hand to the probe 1 magnetically coupled to the wall of the casing tube 2 and on the other hand to auxiliary sensors adapted to measure certain parameters in the confined area.

The auxiliary sensors may include hydrophones 20 and an element 21 for measuring the pressure prevailing in the confined area. They are connected to the electronic unit 15 by conductors 22 passing through the shutter member 19. These sensors may or may not be coupled with the casing tube.

By the method according to the invention, it is possible to set up more or less complex measuring devices. According to the mode of implementation in FIG. 8, the parker 19 is arranged towards the production area. Above it, one or as the case may be, several sensor housings 13 are pressed against the wall of the casing tube each associated with their thrust stops 6 and their centering extensions 7. The housings for sensors 13 are connected for example to a common acquisition and transmission box 14. On the opposite side of the parking lot, one can have a series of auxiliary sensors 20 so as to make measurements at several different depths which, in the case of hydrophones, allows focusing effects. One or more boxes for sensors 13 can optionally be added thereto. The auxiliary sensors 20 and these possible boxes are all connected through the parker 19, by conductors 22, to the common electronic box 14.

According to the mode of implementation of FIG. 9, the shutter member 19 can also be arranged towards the head of the well. In which case, the entire measuring device with its boxes for sensors 13, its electronic box 14 and all of the auxiliary sensors, is arranged under the shutter member.

Claims (17)

1. A method for carrying out operations in a well provided with a casing (2) by the temporary installation at specific operating locations along the well of a measuring apparatus having at least one measuring sonde (1) connected by transmission means (CL) to a control and recording unit, characterised in that it involves

   - the addition to each sonde (1) of magnetic coupling means (5) that are able to hold the sonde pressed against the inner wall of the casing,

   - moving each sonde held pressed against the wall by the magnetic coupling along the well by means of a rigid driving element (3) connected to an operating device and, before each sonde starts operation

   - mechanically uncoupling each sonde from the rigid driving element (3) by moving the latter longitudinally in relation to the sonde.
2. A method in accordance with claim 1, characterised in that the movement of each sonde is carried out by a direct contact between it and the rigid driving element (3).
3. A method in accordance with claim 2, characterised in that each sonde is moved by means of pushing parts (6) forming thrusts, fastened to the rigid driving element (3) on either side of the sonde and at a longitudinal distance from each other that is greater than the largest longitudinal dimension of the sonde and by means of radial centring parts (7) to limit the angular clearance of the sonde in relation to the rigid driving element (3).
4. A method in accordance with claim 1, characterised in that the movement of each sonde is made by exerting traction on flexible cables (12) linking the sonde to the rigid driving element (3).
5. A method in accordance with one of the previous claims, characterised in that it involves the transmission of signals received by the sonde's sensors (13) to the control and recording unit by means of an intermediate box (14) fastened to the rigid driving element.
6. A method in accordance with claim 5, characterised in that transmission is carried out by means of flexible connecting conductors (15).
7. A method in accordance with claim 5, characterised in that transmission is carried out by an immaterial link between the sonde (13) and the intermediate box (14) and by conductors (CL) between the latter and the control and recording unit.
8. A method in accordance with claim 1, characterised in that it also involves the use of means (17) for measuring the angular orientation of the rigid driving element (3) enabling by comparison the mechanical uncoupling of the sonde (13) from the rigid driving element (3).
9. A method in accordance with claim 1, characterised in that a tubing fitted on the exterior with driving means, such as a rigid element, is used to move the sonde pressed against the casing.
10. A device for implementing the method in accordance with claim 1, characterised in that it comprises a measuring apparatus having at least one sonde (1, 13) for measuring instruments or sensors, provided with magnets (5) capable of holding the sonde pressed against the inner wall of a casing (2) in a well and a rigid element (3) associated with driving means (6, 7) to translate the sonde pressed against the inner wall along the tubing.
11. A device in accordance with claim 10, characterised in that the driving means comprise thrusts (6) fixed to the rigid element that may be brought to bear against the sonde when pressed in position against the casing by moving the tubular column.
12. A device in accordance with claim 10, characterised in that the driving means comprise slings or flexible cables (12) fixed to the rigid element and to the sonde that may be tightened by moving the element.
13. A device in accordance with one of claims 10 to 12, characterised in that it comprises means (8, 9) for controlling the mechanical uncoupling of the sonde from the driving means (7).
14. A device in accordance with one of claims 10 to 13, characterised in that it comprises a collection and transmission assembly (14) connected to the sonde (13) by connecting means.
15. A device in accordance with one of claims 10 to 14, characterised in that it has means for taking angular measurements (16) in order to ascertain the position of the sonde (13) in the well.
16. A device in accordance with claim 10 or 14, characterised in that the rigid element (3) is a tubing provided with an expansible sealing element (19) towards its base, wherein the apparatus also has auxiliary sensors (20, 21) associated by connecting conductors (22) crossing the sealing element (19).
17. A device in accordance with claim 16, characterised in that it has a plurality of sondes associated with the column at different locations along the length of the column on one side at least of the sealing element and a plurality of auxiliary sensors located on a same side of the sealing element.

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