EP0294252B1 - Equipment for a drill string with a side entry sub and method for its use - Google Patents

Description

The present invention relates to a drill string equipment, such as a drill string, comprising a side window connection for the passage of a cable from the inside to the outside of the rods, with hydraulic sealing around the cable.

Side window fittings (often referred to as "Side entry subs" in the petroleum industry) are well known to specialists in petroleum drilling. Such a device is, for example, described in British patent 2,135,719.

We can also cite the equipment described in document US-A-4,607,693.

A side window fitting is, for example, used in the technique described in French patents 2,501,777 and its first two additions FR-A-2,522,059 and FR-A-2,564,893.

According to this technique, allowing logging or interventions in horizontal or strongly inclined wells, a logging probe (or an intervention tool) is initially fixed to the lower part of a drill string which is lowered into the well as it is formed.

An electrical cable with a weighted connector is lowered inside the rods (by gravity and by pumping) (the connector can be surmounted by a load bar) which is connected to a complementary connector fixed at the top probe (or tool). In the portion of the drill string corresponding to the vertical or slightly inclined part of the well, a side window fitting passes the cable from the interior to the exterior of the rods.

The measurement recording (or intervention in the well) is carried out by moving the entire drill string from the surface.

Current equipment with side window cannot be used when the dimensions of the well are too small. This occurs especially when a small diameter well has been cased.

By proposing compact equipment which solves this difficulty, the present invention provides a connection allowing the circulation of fluid in the lower part of the drill string, in particular for the movement of parts, tools, load bars, etc. connected by cable to surface installations.

This drill string equipment comprises a side window connector, the connector having an upper end and a lower end, and being adapted to be incorporated into a drill string and to be introduced into a well with said drill string, said window allowing the passage of a cable. The connection comprises means providing a seal around the cable with the window and is characterized in particular in that the connection with said sealing means is adapted to isolate an area inside the fitting, the inside area being less than said sealing means and opening at the lower end in a lower part of the drill string, and in that the zone has a lateral opening adapted to be connected to a pumping installation, when said connector is close to the surface.

The sealing means may include two complementary parts adapted to be sealed to the fluid passages from the interior to the exterior and vice versa and adapted to be placed around a cable, the two parts defining an interior shape, these means d '' sealing comprising internal means adapted to cooperate with the internal shape and the cable to achieve a sealing between the cable and the two complementary parts, said sealing means further comprising external means adapted to cooperate with the two parts and the connector to achieve a seal.

The connector may include a cable anchoring member to said connector.

The anchoring member may include means adapted to release the cable under the action of a remote control.

The release means may be implemented under the action of a traction exerted by the cable.

The anchoring member may be expandable to allow the cable to be released.

The section of the cable located to the right of the two complementary parts may be straight and have an axis substantially parallel to the axis of said fitting.

The section of the cable located to the right of the two complementary parts may have an axis substantially coincident with the axis of said connector.

The anchoring member and the sealing means can be integrated with one another.

The diameter of the upper elements may be substantially equal to or less than the diameter of the lower elements.

This connection can be adapted so that the lower and upper elements have a substantially common generator.

The diameter of the upper elements may be substantially equal to or less than the diameter of the lower elements.

In addition, the present invention relates to a method of using said equipment and is in particular characterized in that a circulation of fluid is produced in the lower part of the drill string by connecting, by the lateral opening, the lower part of the drill string. rods at the pumping installation, when said fitting is close to the surface.

We can move by the circulation of fluid, inside the lower part of the drill string, a load bar placed in the lower part and connected to the cable.

The present invention also provides a safety anchor for a cable. This member is particularly suitable for being placed inside a fitting with side window. This safety anchoring member comprises a body and a clamping element defining a passage for the cable, this passage having a variable section over at least part of the length of the passage, the anchoring member being retained at the interior of the support by releasable immobilization means, the body cooperating with the clamping element to reduce the cable cross-section, for clamping this cable. This anchoring member also comprises at least one stop, adapted to modify the section by displacement of the clamping element relative to the body by resting on the support and on a surface of the element, the surface having a shape adapted to increase the section of the passage and to anchor the cable when the immobilization means release the anchoring member and when a sufficient translation of the body is produced relative to the support.

The body can be adapted to move the clamping element during the translation of the body.

The means for immobilizing the anchoring member and the cable can be released by remote control.

The release of the immobilization means can be obtained under the action of a traction exerted by the cable from the surface.

The immobilization means may include a shearable pin beyond a certain stress threshold.

The surface of the anchoring element may comprise at least one part inclined at a certain angle relative to the oriented axis of translation of the anchoring element relative to the support, the inclined part being oriented in the direction s deviating from the passage and the angle of inclination, between the oriented axes of the translation and of the inclined part, will be an acute angle.

The surface of the anchoring element can be crenellated and include at least one notch and the stop can be adapted to penetrate into the notch when the translation is carried out.

The anchoring member can be adapted to a lateral introduction of the cable into the passage.

The anchoring member may include means providing a seal around the cable with the inside of the support.

• les figures 1A et 1B représentent des coupes sensiblement adjacentes d'un raccord selon l'invention, avec en détail les moyens d'étanchéité et l'organe d'ancrage,
• la figure 2 est une section de détail de l'organe d'ancrage, et
• la figure 3 est une section d'un deuxième mode de réalisation de l'organe d'ancrage.

The invention will be able to be well understood and all of its advantages will appear clearly on reading the description which follows, an exemplary embodiment of which is illustrated by the appended figures among which:

• FIGS. 1A and 1B show substantially adjacent sections of a connector according to the invention, with details of the sealing means and the anchoring member,
• FIG. 2 is a detailed section of the anchoring member, and
• Figure 3 is a section of a second embodiment of the anchor member.

The reference 1 represents the connection with side window screwed by its upper 1a and lower 1b ends respectively to an upper element 2 and a lower element 3 of the drill string.

This connector has a side window 5 allowing the passage of an electric cable 4 from the outside to the inside of the rods, by relying on two guide rollers 6a and 6b. This cable is, for example, of a type used for logs or interventions carried out according to the technique described in patent FR-A-2,501,777 and its aforementioned additions.

The upper end 1a may include a plug allowing the upper element 2 to be closed.

The member 8 seals around the cable 4 between a zone 9 inside the fitting 1 and the outside of the fitting.

The inner zone 9 opens into the lower part of the drill string, through the lower element 3. This inner zone 9 is in communication with a lateral opening 10 located in the connector and which can be connected to an installation of pumping adapted to produce in particular a circulation of fluid for the displacement of tools and of measuring or intervention instruments connected or not to the cable 4. One of these instruments can be a load bar comprising an electrical connector adapted to cooperate with another complementary electrical connector.

The member 8 also ensures the anchoring of the cable 4 to said connector 1.

The means of the connector 1 specifically intended for sealing and carried by the member 8 comprise two complementary parts (8a, 8b) assembled by screws 7 and adapted to be placed around the cable (4) and to be watertight at the passage of fluid from the inside to the outside and vice versa. The interior of these two parts is bored so as to be able to place deformable rings 16 and a compression ring 17 therein and to keep these rings locked in a direction. All these rings, or some of them only, are split so that they can be put in place once the cable passes through the fitting 1.

A nut 18, comprising a lateral opening for its introduction around the cable 4 and on the member 8, makes it possible to compress the deformable washers 16 so as to produce a seal. The assembly suitable for producing the internal sealing means and comprising the two complementary parts 8a, 8b, the deformable washers 16, the compression washer 17 with half-moon and, the nut 18 corresponds to the cable gland generally retained for this usage.

The external sealing means comprise the two complementary parts or body 8a, 8b cooperating with one or more external seals 14, such as an O-ring, and the internal wall of fitting 1.

The anchoring member specifically intended for immobilizing the cable 4 relative to the connector 1 and carried by the member 8 comprises the two complementary parts or body 8a, 8b, and a clamping element 8c actuated by clamping screws 12.

One 8b of the complementary parts or body 8a, 8b has a flared recess opening onto the cable 4 and in which the clamping element 8c is positioned which, under the action of the stud screws 12, prevents the cable 4 from move.

These screws 12 include sealing means preventing any passage of fluid between their body and the holes in which they are housed.

The pins of these screws 12 act on the tightening element 8c by means of clearance surfaces 13.

The sealing and anchoring member 8 further comprises a lug 19 cooperating with a groove 20 located in the connector 1, both adapted to allow relative movement when the cable is detached.

The member 8 is immobilized relative to the connector 1 by a shearable pin 11 which allows, by its shearing, to release the member 8 in translation when a traction is exerted on the cable 4.

The equipment is implemented as follows, while the side entry fitting is accessible, for example when it is close to the surface.

• on introduit par la fenêtre 5 une extrémité du câble,
• on place ensuite l'organe 8 autour du câble 4, puis
• on positionne l'organe 8 dans le raccord 1 avant de mettre dans la rainure 20 l'ergot 19 qu'il comporte et avant d'immobiliser l'organe 8 par la goupille cisaillable 11.
• on s'assure que l'étanchéité 12a des vis à tétons 12 est active.
• on relie la zone intérieure 9 du raccord à l'installation de pompage grâce à l'ouverture latérale 10 et l'on effectue la circulation de fluide.

After removing the member 8 and the guide roller,

• one end of the cable is introduced through window 5,
• the member 8 is then placed around the cable 4, then
• the member 8 is positioned in the connector 1 before putting the lug 19 that it comprises in the groove 20 and before immobilizing the member 8 by the shearable pin 11.
• it is ensured that the sealing 12a of the nipple screws 12 is active.
• the inner zone 9 of the connector is connected to the pumping installation by means of the lateral opening 10 and the circulation of fluid is carried out.

When it is desired to anchor the cable 4 to the connector, the screws 12 are tightened so that the clamping element 8c cooperating with the two complementary parts 8a, 8b cooperating with this element, secures the cable 4.

The clamping screws act as adjustable stops, but fixed stops could also be used. Thus, when the clearance surfaces are inclined, the cable can be clamped by wedging the anchoring member, or more precisely the clamping member, inside the connector, by axial pressure on said member. , or by self-pinching the cable once the jamming has started.

To remove the cable 4 from the drill string 3, it suffices to carry out the preceding operations in reverse.

However, if for another reason we could not or if we did not want to remove the cable by this procedure, as may be the case when blocking the column in the well, it is possible to exercise a sufficient traction on the cable so as to shear the pin 11 and thus move the member 8 relative to the connector 1 over a sufficient distance so that the pins of the screws 12 no longer act on the release surfaces 13.

When the screws 12 release the clamping element 8c, the cable runs freely inside the member 8 and the connector 1, until the cable can be completely removed and thus be able to perform operations, such as unlocking the column, which the presence of the cable would prevent.

The clearance surfaces 13 shown in FIGS. 1A and 1B have a slope whose inclination is adapted to increase the clearance between the anchoring element 8c and the pins of the screws 12 when the member 8 follows the movement of the cable printed by a pull on it. Thus, if the inclined part of the clearance surface 13 is oriented in the direction OS deviating from the passage, the angle alpha between the oriented axes of the translation 0T and of the inclined part is an acute angle. Thus, the apex of this acute angle is oriented towards the bottom of the well, that is to say in the opposite direction to that in which the traction intended to release the cable will be exerted.

FIG. 3 represents a second embodiment of the clamping element, in which the release surfaces comprise a part without inclination 13a on which the stud of one of the screws 12 rests, followed by a part 13b , such that the clearance between the stud and the anchoring element 8c increases suddenly. The surface therefore assumes a crenellated shape 13a, 13b, where the vertices 13a correspond to the clamping positions of the clamping element 8c, and where the notches 13b correspond to the cable release positions.

However, the inclined release surfaces allow both the release of the cable after a slight displacement of the member 8 and greater precision in the tensile threshold to be exerted to shear the pin 11.

Preferably according to the present invention, the axes of the screws 12 may be substantially perpendicular to the relief surfaces 13. Thus, the surface area of the studs in contact with the inclined parts of the relief surface 13, or in contact with the parts 13a according to the second embodiment, will be as large as possible.

With the connector according to the invention, it is for example possible to be connected with lower elements of drill string of 2 inches 7/8 VAM and upper elements of 2 inches 3/8 VAM, which respectively correspond to outside diameters of 85 mm and 73 mm.

This reduction in diameter allows a cable to run along the upper elements of the drill string to the upper end of the well, especially when the lower and upper elements of the drill string are offset. An advantageous offset can be obtained when the lower and upper elements have a substantially common generator.

Hoods can be used to apply the cable to these upper parts of the drill string.

Claims (12)

1. Equipment for drill pipe strings comprising a side-entry (5) sub (1), the sub having an upper end (1a) and a lower end (1b) and being adapted for incorporation with a drill pipe string and placing in a well with the drill pipe string, this entry allowing a cable to be passed through it, the sub (1) having means (14, 16) for providing a seal around the cable with the entry, characterised in that the sub and the sealing means are adapted to isolate an inner area (9) from the sub, the inner area being located below the means and opening at the level of the lower end (1b) in a lower section of the drill pipe string, and in that the inner area has a side opening (10) adapted for connection to a pumping installation when the sub is close to the surface.

2. Equipment in accordance with claim 1, characterised in that the sealing means have two complementary parts (8a, 8b) adapted so as to provide a tight seal against the seepage of fluid from the inside to the outside and vice versa and adapted so as to be placed around a cable (4), the two parts delineating an internal form, the means comprising internal means adapted to co-operate with the internal form and the cable to achieve a tight seal between the cable and the complementary parts, the sealing means further comprising external means adapted to co-operate with the two parts and the sub so as to provide a tight seal.

3. Equipment in accordance with claims 1 or 2, characterised in that the sub comprises a member (8) for anchoring the cable (4) to the sub (1).

4. Equipment in accordance with claim 3, characterised in that the anchorage member (8) comprises means for releasing the cable (4) under the effect of a tractive force exerted by the cable.

5. Equipment in accordance with one of claims 3 and 4, characterised in that the anchorage member may be retracted in order to permit release of the cable.

6. Equipment in accordance with one of claims 1 to 5, characterised in that the cable section situated in line with the two complementary parts (8a, 8b) is rectilinear and has an axis substantially parallel to the axis of the sub (1).

7. Equipment in accordance with one of claims 1 to 6 comprising an anchorage member (8), characterised in that the anchorage member (8a, 8b, 8c) and the sealing means (8a, 8b) are integrated with each other.

8. Equipment in accordance with one of claims 1 to 7, comprising upper elements (2) co-operating with the upper end (1a) and comprising lower elements (3) co-operating with the lower end (1b), the equipment being characterised in that the external diameter of the upper elements (2) of the drill pipe string is less than the external diameter of the lower elements (3) of the drill pipe string.

9. Equipment in accordance with claim 8, characterised in that the sub is adapted so that the lower (3) and upper (2) elements have a substantially common generatrix.

10. Equipment in accordance with one of claims 1 to 8, characterised in that the diameter of the upper elements is substantially equal to or less than the diameter of the lower elements.

11. A method of using the equipment in accordance with one of claims 1 to 10, characterised in that fluid is caused to flow in the lower part of the drill pipe string by connecting the side opening of the lower part of the drill pipe string to a pumping installation, when the sub is close to the surface.

12. A method of using the equipment in accordance with claim 11, characterised in that a load bar placed in the lower part of the drill pipe string and connected to the cable is moved inside the lower part of the drill pipe string by means of the fluid flow.

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