EP1514995A1 - Drilling rig with rotating head - Google Patents

Abstract

There are means (54) of displacing a pressing part (52) which is part of the side wall (42) of a stabilizer (40) between a rest position in the stabilizer side wall and an active position protruding from the side wall to press against the wall of the shaft. There are means of controlling this displacement and means (64,66) of giving the pressing part a predetermined angular orientation : A drill string (20) to cause the rotation and the lifting/lowering of the drill head (18); means (16) of controlling the rotation of the drill string, and a stabilizer (40) that rotates freely about the drill string near the drill head. The stabilizer is mounted to move freely along the drill string between two abutments (48, 50) connected to the drill string. The means of giving the pressing part the predetermined angular orientation are first means forming an abutment, fixed in rotation to the stabilizer, and second means forming an abutment fixed in rotation to the drill string and movable relative to the drill string to take a first active position in which the first and second means forming an abutment can act together to transmit the rotation of the drill string to the stabilizer. The second means forming an abutment is a jack (60) whose body is fixed to the drill string and the rod (64) moves parallel to the axis of the drill string : in the out position the end of the rod acts together in rotation with the first means forming an abutment. The jack is a hydraulic or pneumatic jack and the first means forming an abutment are on the stabilizer. The means of displacing the pressing part include at least one hydraulic jack whose body is fixed to the stabilizer and the end of the rod is fixed to the pressing part. The hydraulic jack is fed with liquid by a circuit formed from the rods of the drill string, a rotating joint with a first part fixed to the drill string and a second part fixed to the stabilizer and by a pipe connecting the second part of the rotating joint to the hydraulic jack.

Description

The present invention relates to a drilling installation rotary head comprising means for correcting the trajectory of the head and in particular verticality correction means when the realized drilling is vertical.

More specifically, the present invention relates to such drilling rig that can be controlled automatically, in that concerning the correction of the possible errors of trajectory of the drilling and in particular of verticality.

When making piles drilled with a head of rotary drilling driven by a train of rods, many parameters can influence the verticality of the drilling actually carried out. These parameters are notably the inhomogeneity of the terrain that meets with the same depth the drilling head or rigidity necessarily limited the drill string. When drilling needs to be realized at a great depth, for example of the order of 100 meters, it is understood that a deviation even of a reduced angle compared to the vertical can cause a positioning error in the bottom of the borehole important. In many cases, it is impossible to tolerate such differences, because of the tolerances imposed by the specifications of the work.

More generally, drilling may be required non-vertical, for example, boreholes with all their depth an inclination noted relative to the vertical or Drilling with several portions, each portion having a own inclination with respect to the vertical. In these situations, it is important that the borehole is tilted or tilted defined by the specifications of the book.

It is therefore very desirable to have an installation of rotary head type drilling to correct errors possible trajectory.

In the present text, by "mistake of trajectory", it is necessary hear the fact that drilling actually performed using the rotary tool makes an angle with the planned route for drilling. Most often, the route planned drilling is vertical and we will be led to detect errors of verticality.

It is also understandable that it is highly desirable that means used to correct this error of trajectory do not lead to periods of unavailability of the drill head significant.

In Figure 1 attached, there is shown a type of installation known drilling rotary cutting head. In this figure, we have represented the drilling 10 in progress with its casing 12. At the upper portion 14 of the casing 12 is mounted a head 16 for setting rotation and displacement in translation of the cutting head. The head of rotation and displacement 16 is connected to the cutting tool 18 by a train of rotating rods 20. At regular intervals, the drill string 20 is preferably equipped with stabilizing fins such as 22 which ensure a certain centering of the drill string 20 in the borehole. The lower end 20a of the drill string is connected to the cutting tool 18 via two stabilizing drums 24 and 26. Although heard, there could be only one stabilizing drum. In the following the description, the stabilizing drums 24 or 26 will be called "Stabilizers". Stabilizing drums 24 or 26 are parts constituted by an outer cylindrical skirt whose diameter is slightly lower than that of the cutting tool 18 but much greater than that of the drill string. As will be explained in more detail later, the stabilizer 24 or 26 is freely rotatably mounted around of the drill string 20 but immobilized in translation. The drum or drums the stabilizers 24 or 26 allow (s) to ensure a certain orientation or trajectory to the cutting tool 18. However, even with the presence of these stabilizers, the path of the cutting tool can not be the most often provided with the required tolerance.

In the case of the realization of drilled piles, case of the invention, the stems have a diameter of 200 to 400 millimeters and the diameter of the drilling is at least 1000 millimeters and most often at least 1500 millimeters. The diameter of the stabilizing drums is also from minus 1,000 to 1,500 millimeters and therefore at least three times greater than that of the stems.

An object of the present invention is to provide an installation rotary cutting head of the type described in particular with reference in FIG. 1 but which comprises path correction means tool to respect the desired theoretical trajectory.

• une tête rotative de forage ;
• un train de tiges pour provoquer la rotation et la montée/descente de ladite tête de forage ;
• des moyens de commande de la rotation du train de tiges ; et
• un stabilisateur monté libre en rotation autour du train de tiges à proximité de ladite tige de forage,

   ladite installation se caractérisant en ce qu'un patin de la paroi latérale du stabilisateur constitue une partie d'appui mobile par rapport au reste du stabilisateur selon une direction radiale par rapport au train de tiges, et en ce qu'elle comprend en outre :

• des moyens pour déplacer ledit patin entre une position de repos dans laquelle il est sensiblement disposé dans la paroi latérale du stabilisateur et une position active dans laquelle il fait saillie hors de ladite paroi latérale pour venir en appui sur la paroi du forage ;
• des moyens de commande des moyens de déplacement du patin ; et
• des moyens pour donner temporairement au patin une orientation angulaire prédéterminée.

To achieve this object, according to the invention, the drilling installation equipped with trajectory correction means comprises:

• a rotary drilling head;
• a drill string for causing rotation and raising / lowering of said drill head;
• means for controlling the rotation of the drill string; and
• a stabilizer mounted free to rotate about the drill string near said drill pipe,

said installation being characterized in that a pad of the stabilizer sidewall constitutes a movable bearing portion relative to the remainder of the stabilizer in a radial direction relative to the drill string, and further comprising:

• means for moving said pad between a rest position in which it is substantially disposed in the side wall of the stabilizer and an active position in which it projects out of said side wall to bear on the wall of the borehole;
• means for controlling the means for moving the pad; and
• means for temporarily giving the pad a predetermined angular orientation.

It is understood that when the trajectory error is detected by example using sensors mounted on the cutting tool, the drill string stopped. Then, we control the rotation of the drill string to bring the bearing pad in the angular orientation corresponding to the correction of trajectory to bring. This orientation having been realized, we order the displacement means for applying the bearing pad against the wall drilling.

Rotation and movement of the drill string and therefore the tool cutting are then ordered again, the action of the support pad to correct the path of the rotary cutting tool.

It must also be emphasized that the skate is a part of the lateral wall of the stabilizer, it can fully fulfill its role guidance outside the error correction phases of trajectory.

According to a first mode of implementation, preferably, the means of angular orientation of the pad comprise first stop means, integral in rotation, of said stabilizer and second means forming a stop integral in rotation with the drill string and mobile in relation to the drill string to take a first active position in which the first and second means forming stop can cooperate to transmit the rotation of the drill string stabilizer audit.

More preferably, said second means forming an abutment include an orientation cylinder whose body is attached to the train of rods and whose rod is movable parallel to the axis of the drill string. In position, the end of the rod of said cylinder is able to cooperate in rotation with the first means forming a stop.

According to this preferred mode of implementation, it is understood that when the orientation cylinder is not activated, there is no connection in rotation between the drill string and the stabilizer. On the other hand, when cylinder is activated, the end of its rod comes to cooperate with the stop stabilizer, which gives the stabilizer and thus the support pad the desired orientation. When this orientation is obtained, the orientation cylinder is deactivated and the mechanical connection rotation between the drill string and the stabilizer is removed.

• la figure 1 déjà décrite montre une installation de forage à tête rotative de coupe de type connu ;
• la figure 2A montre en coupe verticale un premier mode de réalisation du système de correction d'erreur de trajectoire ;
• la figure 2B est une vue en coupe horizontale selon la ligne B-B de la figure 2A ; et
• la figure 3 illustre une variante de réalisation du système de correction d'erreur de trajectoire.

Other features and advantages of the invention will appear better on reading the following description of several embodiments of the invention given by way of non-limiting example. The description refers to the appended figures in which:

• Figure 1 already described shows a drilling rig rotary head cutting known type;
• FIG. 2A shows in vertical section a first embodiment of the trajectory error correction system;
• Figure 2B is a horizontal sectional view along line BB of Figure 2A; and
• FIG. 3 illustrates an alternative embodiment of the trajectory error correction system.

Referring now to Figures 2A and 2B, we will describe a first embodiment of the error correction system of path. This system as already explained is made from the stabilizer 40 which is mounted on the drill string 20 near the tool cutting not shown in these figures.

The stabilizer 40 consists essentially of a wall external cylindrical 42 of axis X, X '. The side wall 42 is completed by two annular end portions 44 and 45. The stabilizer 40 also comprises in simplified manner an axial sleeve 46 which is engaged around the rods 20 of the drill string. This sleeve is connected mechanically to the side wall 42 for example by radial arms not shown in the figures. As shown in FIG. 2A, the rod 20 on which is mounted the stabilizer 40 has two rings ring rings 48 and 50 which act as a stop to limit the possibilities of translational movement of the stabilizer 40 along the 20. On the other hand, as already explained, the stabilizer 40 is free in rotation around the rod 20.

According to the invention, part of the side wall 42 of the stabilizer 40 constitutes a separate part 52 which is therefore in the form of a portion of cylindrical surface. This separate portion 52 which forms a bearing pad on the borehole wall is mounted movable relative to the rest of the stabilizer by means of displacement cylinders by example the four cylinders referenced 54 in the figures. These cylinders, preferably hydraulic, have a body 55 which is secured by any means of the main part of the stabilizer 40 and whose ends 56a of the rods 56 are integral with the shoe 52 also by any suitable way. The rods 56 of the jacks 54 can move in planes orthogonal to the axis X, X 'and in parallel directions y, y' at the median plane P, P 'of the stabilizer. Thus, the pad 52 can be moved to using the cylinders 54 between a retracted position shown in Figure 2B in which the shoe 52 constitutes a continuity of the lateral wall 42 of the stabilizer itself and an output position represented in dotted lines in Figure 2B. In this extended position, the pad 52 is applied with pressure against the wall of the borehole or against the casing when provided. It is understood that this action of the pad 52 against the wall of the borehole transmits a force to the drill string 20 and thus to the axis of rotation of the cutting tool 18 to change the path of the cutting tool and correct the axis of the drilling.

To obtain the correction of the desired trajectory, it is well necessary, before causing the release of the support pad 52, give it the angular orientation corresponding to the correction of trajectory to bring. This orientation of the shoe 52, that is to say the stabilizer 40 is obtained by making a temporary mechanical connection in rotation between the drill string and the stabilizer 40. When this temporary link is made, by controlling the rotation of the train of stems from a predetermined angle, the same rotation is stabilizer 40 and thus the support pad 52. Once this orientation is achieved, the mechanical connection between the drill string and the stabilizer is interrupted. The rotary cutting tool is then restarted. The action of the pad 52 on the tool makes it possible to correct the error of trajectory. Yes the length of relative movement of the pad with respect to the drill string, defined by the annular rings 48 and 50 and which is for example of the order of one meter is insufficient to obtain the desired correction, it Do the following: disable skid 52 for allow the descent of the stabilizer 40 down the rod 20 until that it comes to bear on the lower annular ring; proceed to new orientation of the pad 52; and restoring the pad on the wall drilling after the pad has been reoriented.

un vérin d'orientation 60 est rendu solidaire de la tige 20 sur laquelle est monté le stabilisateur. Ce vérin d'orientation comporte un corps 62 qui est donc solidaire de la tige 20 et dont l'axe est parallèle à l'axe de la tige 20. La tige 64 du vérin d'orientation 60 peut donc se déplacer entre une position rentrée représentée sur la figure 2A en traits pleins et une position sortie représentée en pointillé sur la figure 2A, position dans laquelle l'extrémité 64a de la tige 64 du vérin, peut venir par rotation en butée sur une butée mécanique fixe 66 montée sur la partie 44 du stabilisateur 40. Ainsi, lorsque la tige 64 du vérin 60 est sortie, on réalise une liaison mécanique temporaire en rotation du stabilisateur et donc du patin 52 avec la tige 20. On réalise ainsi l'orientation angulaire du patin. Lorsque le patin 52 est amené en position d'appui contre la paroi du forage à l'aide des vérins 54, la tige 64 du vérin d'orientation 60 peut être rentrée de telle manière que le stabilisateur 40 soit à nouveau libre en rotation autour de la tige 20.

In the embodiment shown in FIGS. 2A and 2B, the temporary mechanical connection is obtained as follows:

an orientation cylinder 60 is made integral with the rod 20 on which is mounted the stabilizer. This steering cylinder comprises a body 62 which is thus secured to the rod 20 and whose axis is parallel to the axis of the rod 20. The rod 64 of the steering cylinder 60 can therefore move between a retracted position 2A in solid lines and an output position shown in dashed lines in FIG. 2A, in which position the end 64a of the rod 64 of the jack can come to rotate in abutment with a fixed mechanical stop 66 mounted on the part 44 of the stabilizer 40. Thus, when the rod 64 of the cylinder 60 is output, a temporary mechanical connection is made in rotation of the stabilizer and thus the pad 52 with the rod 20. The angular orientation of the pad is thus carried out. When the shoe 52 is brought into a bearing position against the wall of the bore using the jacks 54, the rod 64 of the steering cylinder 60 can be retracted in such a way that the stabilizer 40 is free to rotate again around of the stem 20.

Preferably, the orientation cylinder 60 is a hydraulic cylinder double effect. We can thus use the same liquid supply under pressure for the cylinders 54 which will be described later a mode preferred embodiment of their diet.

In FIGS. 2A and 2B, there is also shown schematically the control of the jacks 54 for moving the 52. In the embodiment shown, the supply of liquid under pressure is achieved through a pipe related to 20. The rod 20 on which the stabilizer 40 is mounted is equipped of a rotary joint 70. This rotary joint comprises a first part 72 secured to the rod 20 and connected to the liquid supply line under pressure and a mobile part 74. This mobile part 74 is equipped with a pipe 76 which enters the stabilizer 40. The pipe 76 is divided in four feed lines such as 78 to feed each jacks 54.

In FIGS. 2A and 2B, the initial orientation of the support pad 52 is performed by the temporary mechanical connection in rotation resulting from the action of the rod 64 of the steering cylinder 60 on the mechanical stop 66 secured to the stabilizer 40.

FIG. 3 is a simplified representation of a variant embodiment in which the temporary joining in rotation always includes the orientation cylinder 60 but it can cooperate in output position with a mechanical stop 80 integral in rotation with the mobile part 74 of the rotary joint 70. In this case, it must of course that it there is a sufficient mechanical connection between the stabilizer 40 and the mobile 74 of the rotary joint. This mechanical connection can be of any suitable nature and for example by metal rods such as connecting the movable portion 74 of the rotary joint to the wall to the portion upper 44 of the wall of the stabilizer 40. Of course, between the part rotary joint 70 and the stabilizer 40, it remains the driving link 76 for feeding cylinders 54 in liquid under pressure. In however, the fixed mechanical stop 66 is removed.

In the preceding description, the orientation jack 60 is a hydraulic cylinder. We would not go out of the invention if this cylinder was pneumatic. In this case, the rods 20 must be equipped with pressurized air supply lines 67 and 68 connected to the anterior chambers 60a and posterior 60b of the cylinder.

It is also understood that, preferably, the organs of control of the correction system are cylinders. They can therefore be controlled automatically and remotely.

As has already been explained, in the context of the invention, the stabilizer has a diameter that is at least three times greater than that of rods. In addition, the external diameter of the stabilizer is close to that of the rotary cutting tool and therefore that of the drilling.

In addition, at rest, the trajectory correction pad is a part of the side wall of the stabilizer.

As a result, the race of the correction skate to pass from its rest position to the active position is therefore very small. He goes from even that of the cylinders that control the pad. The efforts mechanical forces to which these cylinders are subjected are reduced.

Claims (9)

Drilling installation equipped with trajectory correction means comprising: a rotary drilling head (18); a drill string (20) for causing rotation and raising / lowering of said drill head; means (16) for controlling the rotation of the drill string; and a stabilizer (40) rotatably mounted about the drill string proximate said drill head, said installation being characterized in that a portion of the side wall (42) of the stabilizer (40) constitutes a bearing portion (52) movable relative to the remainder of the stabilizer in a radial direction relative to the drill string, and in that it further comprises: means (54) for moving said support portion (52) between a rest position in which it is substantially disposed in the stabilizer side wall (42) and an active position in which it projects out of said side wall for come to bear on the wall of the borehole; means for controlling the displacement means of the support part; and means (64, 66, 80) for temporarily providing the bearing portion with a predetermined angular orientation. Drilling installation according to claim 1, characterized in that said stabilizer (40) is mounted free in translation relative to the drill string (20) between two stops (48, 50) connected to the drill string. Drilling installation according to any one of claims 1 and 2, characterized in that the angular orientation means comprise first abutment means (66, 80) integral in rotation with said stabilizer (40); and second abutment means (60, 64) integral in rotation with the drill string (20) and movable relative to the drill string to assume a first operative position in which the first and second abutment means can cooperate to transmit the rotation of the drill string to said stabilizer. Drilling installation according to claim 3, characterized in that said second abutment means comprise a jack (60) whose body (62) is integral with the drill string (20) and whose rod (64) is movable parallel to the axis of the drill string, in the extended position, the end of the rod (64a) of said jack being adapted to cooperate in rotation with the first abutment means (66, 80). Installation according to claim 4, characterized in that said cylinder (60) is a hydraulic cylinder. Installation according to claim 4, characterized in that said cylinder (60) is a pneumatic cylinder with double effect. Drilling installation according to any one of claims 3 and 6, characterized in that said first means (66) forming a stop are mounted on said stabilizer. Drilling installation according to any one of claims 3 to 6, characterized in that said means for moving the bearing portion comprise at least one hydraulic cylinder (54) whose body is integral with the stabilizer (40) and whose end of the rod (56) is integral with the support portion (52). Drilling installation according to claim 8, characterized in that the hydraulic cylinder (54) is supplied with liquid by a circuit comprising the rods (20) of said drill string, a rotary joint (70) comprising a first portion (72) integral with the drill string, and a second portion (74) movable relative to the first portion and rotatably integral with said stabilizer and a pipe (76) connecting said second portion of the rotary joint to said hydraulic cylinder.

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