EP0178709B1 - Stabilizer - Google Patents

Stabilizer Download PDF

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Publication number
EP0178709B1
EP0178709B1 EP85201531A EP85201531A EP0178709B1 EP 0178709 B1 EP0178709 B1 EP 0178709B1 EP 85201531 A EP85201531 A EP 85201531A EP 85201531 A EP85201531 A EP 85201531A EP 0178709 B1 EP0178709 B1 EP 0178709B1
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EP
European Patent Office
Prior art keywords
drilling
rot
passageways
stabilizing device
ribs
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EP85201531A
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German (de)
French (fr)
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EP0178709A1 (en
Inventor
Honoré Joseph Lambot
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Diamant Boart NV SA
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Diamant Boart NV SA
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Priority claimed from BE0/213816A external-priority patent/BE900804A/en
Application filed by Diamant Boart NV SA filed Critical Diamant Boart NV SA
Priority to AT85201531T priority Critical patent/ATE39011T1/en
Publication of EP0178709A1 publication Critical patent/EP0178709A1/en
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    • E—FIXED CONSTRUCTIONS
    • E21—EARTH OR ROCK DRILLING; MINING
    • E21B—EARTH OR ROCK DRILLING; OBTAINING OIL, GAS, WATER, SOLUBLE OR MELTABLE MATERIALS OR A SLURRY OF MINERALS FROM WELLS
    • E21B17/00—Drilling rods or pipes; Flexible drill strings; Kellies; Drill collars; Sucker rods; Cables; Casings; Tubings
    • E21B17/10—Wear protectors; Centralising devices, e.g. stabilisers
    • E21B17/1092—Gauge section of drill bits
    • E—FIXED CONSTRUCTIONS
    • E21—EARTH OR ROCK DRILLING; MINING
    • E21B—EARTH OR ROCK DRILLING; OBTAINING OIL, GAS, WATER, SOLUBLE OR MELTABLE MATERIALS OR A SLURRY OF MINERALS FROM WELLS
    • E21B17/00—Drilling rods or pipes; Flexible drill strings; Kellies; Drill collars; Sucker rods; Cables; Casings; Tubings
    • E21B17/22—Rods or pipes with helical structure

Definitions

  • the present invention relates to a device for stabilizing a drill string, consisting of a steel cylinder having laterally helical projections provided with a coating offering good resistance to erosion and abrasion.
  • the stabilization devices are mainly intended to control the direction and quality of drilling in deep vertical or directional wells.
  • a stabilizing sleeve usually used for directional turbine or rotary drilling consists of a cylindrical steel casing fixed to the end of a drill string, in the vicinity of a diamond-tipped bit or a crown, in alignment with the latter, by means of a cylindrical end piece of determined length, provided with a standardized fixing thread.
  • Helical projections provided on the outer side wall of the aforementioned envelope determine a cylinder of diameter substantially equal to the diameter of the drilled hole.
  • the diameter of the envelope is generally a few tens of millimeters less than the diameter of the cylinder determined by the helical projections.
  • the helical projections are covered with a coating, having excellent resistance to erosion and abrasion.
  • the recesses formed between the projections allow the rock waste entrained by the drilling fluid to rise.
  • the stabilizing sleeve allows the forces of the diamond drilling tool to be distributed along a larger contact surface on the side wall of the drilled well, thus reducing the capacity of lateral destruction of the rock by the tool under the 'effect of its own weight and limiting the pendulum effect of the entire drilling rig as well as spiraling in drilling with a turbine.
  • Spiraling is a deformation of the corkscrew hole. It has the effect of increasing the risk of the drill string getting stuck in the hole.
  • the deviation intensity is defined as the increase in the deviation from an initial direction of drilling per unit of length drilled.
  • the stabilizer has large water passages arranged helically along the sleeve, in a symmetrical configuration which does not contribute to generating or increasing any tendency to deflect the cutting tool from a straight path.
  • the BURGE patent makes it possible to prevent but does not make it possible to correct a deviation from the trajectory.
  • the present invention provides the means to modify at will to the left or to the right, the deviations generated by a rapid rotation of the drill string in a directional deep drilling. It of course makes it possible to reduce the amplitude of the unwanted deviations.
  • the invention therefore relates to a method, according to which stabilizer sleeves are advantageously used which have modifications on the wings which provide them with a sufficient contact surface only to limit the lateral aggressiveness of the drilling tool and at the same time to control, that is to say modify at will, the angle of azimuthal deviation towards the left of the lining in drilling with the turbine.
  • It relates to a device for stabilizing a drill string, consisting of a cylindrical steel body having laterally helical projections separated by passages of drilling fluid provided with a coating offering good resistance to erosion and abrasion, essentially characterized in that it comprises at least one substantially circumferential groove formed in the aforesaid projections, so as to connect the recesses therebetween between them; according to a feature of the invention, the aforementioned grooves are formed over part of the height of the projections.
  • the grooves are advantageously provided, preferably by milling, at regular intervals along the helical projections.
  • a single groove has a helical shape with a short pitch.
  • a different embodiment includes at least two portions of sleeves of the same diameter arranged in the same alignment behind the drilling tool.
  • a drilling tool designated as a whole by the reference notation 1 usually used for deep directional drilling with a turbine or rotary, consists of a drilling head 2 proper, produced either made of composite material shaped by powder metallurgy techniques, either steel or cast metal.
  • the head 2 is a drill bit or a drilling crown provided over its entire surface in contact with the bottom of the well, with cutting elements 3 placed so as to make effective both the destruction of the rock and the evacuation of shavings.
  • This drilling head 2 is fixed to the end of a drill string, not shown, by means of a frustoconical end piece 4 of variable length between 15 and 100 cm and having a fixing thread 5 meeting the standards in force.
  • a stabilization device consisting of a cylindrical body 6 of steel, having laterally helical projections 7 provided with a coating 8 having sufficient resistance to erosion and abrasion and generally designated by the reference notation 9, is mounted in alignment with the drilling head 2, behind the latter, on the cylindrical end piece 4.
  • the coating 8 of the helical projections 7 may be made of a hard metal or a composite material, possibly diamond-coated.
  • an oil film 13 is constantly established between the two surfaces in relative movement, namely the shaft 11 and the bearing 12.
  • the oil film under pressure is generated by the very movement of the 'shaft 11 provided that the speed of rotation is sufficient.
  • the choice of operating mode namely hydrodynamic lubrication or direct contact depends on the speed of rotation of the bearing, the dynamic viscosity of the lubricating fluid, the length of the bearing, the diameter of the bearing, the load applied to the rotor and relative radial clearance, with respect to the radius, relative radial clearance between 0.8 - 1 (J3 and 4 - 10 -3 .
  • the setting angle is one of the parameters that characterize the average position of the rotor in the stator. It is indicated by the reference notation ⁇ in FIG. 4.
  • Sommerfeld's theory also demonstrates that the setting angle, the resisting torque, the dissipated power and the axial flow of lubricant depend only for a given length / diameter ratio, relative eccentricity s, equal to e / c, that is to say the ratio of absolute eccentricity, expressed in millimeters, on absolute radial clearance also expressed in millimeters.
  • Figure 6 shows, in fact, the relationship observed for a turbine drill tilted at about 45 ° C between the intensity of deviation to the left and the length of the stabilization device. We can assimilate this relation to a function of the first degree, when all the other parameters remain identical.
  • FIG. 7 shows how the static load Pst corresponding to an equivalent hydrodynamic behavior varies, as a function of the length of the stabilization device.
  • the invention consists in providing a known stabilizing device with an improvement with a view to controlling accidental deviations without, however, modifying the total length of the above-mentioned device 9, essential to avoid spiraling.
  • This improvement consists in providing, perpendicular to the longitudinal axis of the stabilizing device 9, at least one groove 15, substantially circumferential formed in the projections 8 above, so as to interconnect, the recesses 14 included therebetween.
  • the grooves 15 can be formed in the above projections, by milling, over a portion of their height. These grooves 15 have the effect of bringing into communication an area in which the lubricant is subjected to a high pressure, with an area in which the lubricant is at a lower pressure. Such a groove 15 reduces the bearing capacity of the bearing and therefore the deviation to the left due to the hydrodynamic operation.
  • Figure 3 shows a second possible embodiment in which the groove 15, of helical shape is formed in a direction different from that of the helical projections 8 above. A doubly spiraled sleeve is thus obtained.

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  • Engineering & Computer Science (AREA)
  • Geology (AREA)
  • Mining & Mineral Resources (AREA)
  • Life Sciences & Earth Sciences (AREA)
  • General Life Sciences & Earth Sciences (AREA)
  • Fluid Mechanics (AREA)
  • Mechanical Engineering (AREA)
  • Environmental & Geological Engineering (AREA)
  • Physics & Mathematics (AREA)
  • Geochemistry & Mineralogy (AREA)
  • Earth Drilling (AREA)
  • Sliding-Contact Bearings (AREA)
  • Sampling And Sample Adjustment (AREA)
  • Pharmaceuticals Containing Other Organic And Inorganic Compounds (AREA)
  • Drilling Tools (AREA)

Abstract

1. A method for modifying the trajectory of a cutting tool for a deep directional drilling well, driven either by a hanging motor or a hanging turbine with a rate of at least 700 rot/min or by a rotary table from the surface at a rate of at least 100 rot/min, by means of a stabilizing device having helicoïdal lateral ribs (8) separated by passageways (14) of drilling fluid and provided with a hardfacing material affording good erosion and abrasion resistance, characterized in that at least one substantially circumferential groove is defined in the ribs and located in a plane which is perpendicular to the axis of rotation, so as to interconnected the passageways (14) of drilling fluid.

Description

La présente invention est relative à un dispositif de stabilisation d'une garniture de forage, constitué d'un cylindre en acier présentant latéralement des saillies hélicoïdales munies d'un revêtement offrant une bonne résistance à l'érosion et à l'abrasion.The present invention relates to a device for stabilizing a drill string, consisting of a steel cylinder having laterally helical projections provided with a coating offering good resistance to erosion and abrasion.

Les dispositifs de stabilisation sont principalement destinés à contrôler la direction et la qualité du forage dans les puits profonds verticaux ou directionnels.The stabilization devices are mainly intended to control the direction and quality of drilling in deep vertical or directional wells.

Comme il est connu par le brevet américain N° 4 245 709 un manchon stabilisateur mis en oeuvre habituellement pour le forage directionnel à turbine ou rotary, est constitué d'une enveloppe cylindrique en acier fixée à l'extrémité d'un train de tiges, au voisinage d'un trépan à pointe diamantée ou d'une couronne, dans l'alignement de celui-ci, par l'intermédiaire d'un embout cylindrique de longueur déterminée, muni d'un filet de fixation normalisé.As is known from US Pat. No. 4,245,709, a stabilizing sleeve usually used for directional turbine or rotary drilling, consists of a cylindrical steel casing fixed to the end of a drill string, in the vicinity of a diamond-tipped bit or a crown, in alignment with the latter, by means of a cylindrical end piece of determined length, provided with a standardized fixing thread.

Des saillies hélicoïdales prévues sur la paroi latérale extérieure de l'enveloppe susdite déterminent un cylindre de diamètre sensiblement égal au diamètre du trou foré. Le diamètre de l'enveloppe est en général inférieur de quelques dizaines de millimètres, au diamètre du cylindre déterminé par les saillies hélicoïdales.Helical projections provided on the outer side wall of the aforementioned envelope determine a cylinder of diameter substantially equal to the diameter of the drilled hole. The diameter of the envelope is generally a few tens of millimeters less than the diameter of the cylinder determined by the helical projections.

Les saillies hélicoïdales sont recouvertes d'un revêtement, présentant une excellente résistance à l'érosion et à l'abrasion.The helical projections are covered with a coating, having excellent resistance to erosion and abrasion.

Les évidements ménagés entre les saillies permettent la remontée des déchets de roche entraînés par le fluide de forage.The recesses formed between the projections allow the rock waste entrained by the drilling fluid to rise.

Le manchon stabilisateur permet de répartir le long d'une plus grande surface de contact, les efforts de l'outil de forage diamanté sur la paroi latérale du puits foré, diminuant ainsi la capacité de destruction latérale de la roche par l'outil sous l'effet de son propre poids et limitant l'effet pendulaire de l'ensemble de la garniture du forage ainsi que le spiralage en forage à la turbine.The stabilizing sleeve allows the forces of the diamond drilling tool to be distributed along a larger contact surface on the side wall of the drilled well, thus reducing the capacity of lateral destruction of the rock by the tool under the 'effect of its own weight and limiting the pendulum effect of the entire drilling rig as well as spiraling in drilling with a turbine.

Le spiralage est une déformation du trou en tire-bouchon. Il a pour effet d'augmenter le risque de coinçage de la garniture de forage dans le trou.Spiraling is a deformation of the corkscrew hole. It has the effect of increasing the risk of the drill string getting stuck in the hole.

L'effet pendulaire quant à lui a pour effet de rapprocher de la verticale le profil du puits. Or, ce but n'est pas recherché en forage dévié. L'utilisation d'un manchon stabilisateur permet de réaliser une stabilisation adéquate de l'ensemble de la garniture de forage. On parvient ainsi à maintenir ou même à augmenter l'inclinaison des puits déviés.The pendulum effect meanwhile brings the profile of the well closer to the vertical. However, this goal is not sought in deviated drilling. The use of a stabilizing sleeve makes it possible to achieve adequate stabilization of the entire drill string. We thus manage to maintain or even increase the inclination of the deviated wells.

On a constaté que les manchons stabilisateurs mis en oeuvre dans les forages profonds déviés pour les raisons évoquées ci-dessus, exercent une influence importante sur la déviation azimutale de la garniture de forage.It has been found that the stabilizing sleeves used in deviated deep boreholes for the reasons mentioned above have an important influence on the azimuthal deviation of the drill string.

Des nombreuses données collectées sur divers chantiers, on peut caractériser de façon générale le comportement de la garniture de forage. On constate que :

  • - dans le cas du forage rotary, une déviation azimutale orientée vers la droite, lorsqu'on prend la direction instantanée de forage comme référence,
  • - dans le cas du forage à la turbine, une déviation azimutale vers la gauche, lorsqu'on prend la direction instantanée de forage comme référence.
From the numerous data collected on various sites, we can generally characterize the behavior of the drill string. We observe that :
  • - in the case of rotary drilling, an azimuth deviation oriented to the right, when the instantaneous direction of drilling is taken as a reference,
  • - in the case of turbine drilling, an azimuth deviation to the left, when the instantaneous direction of drilling is taken as a reference.

De nombreux tests ont démontré que l'intensité de déviation azimutale à gauche en forage à turbine est fortement influencée par la longueur du manchon stabilisateur. L'intensité de déviation est définie comme étant l'accroissement de la déviation par rapport à une direction initiale de forage par unité de longueur forée.Numerous tests have shown that the intensity of azimuthal deflection to the left in turbine drilling is strongly influenced by the length of the stabilizing sleeve. The deviation intensity is defined as the increase in the deviation from an initial direction of drilling per unit of length drilled.

On observe en moyenne dans des puits inclinés à 45° environ, une intensité de déviation de 0,5 à 1,80 degrés par cent pieds pour des longueurs de dispositifs de stabilisation comprises entre 9 et 18 pouces (22.86 à 45.72 cm).On average observed in wells inclined at about 45 °, a deviation intensity of 0.5 to 1.80 degrees per hundred feet for lengths of stabilization devices between 9 and 18 inches (22.86 to 45.72 cm).

On a pu également observer que ces déviations ne se rencontrent systématiquement que dans les forages à turbine ou les forages ROTARY mettant en oeuvre des vitesses de rotation du train de tiges d'au moins 700 t/min. en turbo-forage et respectivement 100 t/min. en forage rotary.It has also been observed that these deviations are systematically encountered only in turbine boreholes or ROTARY boreholes employing rotation speeds of the drill string of at least 700 rpm. in turbo-drilling and respectively 100 rpm. in rotary drilling.

Ces phénomènes ne se rencontrent pas dans les forages à rotation lente, comme par exemple ceux effectués à l'aide d'un trépan à molettes.These phenomena are not encountered in slow-rotating boreholes, such as those carried out using a rotary drill bit.

Par le document US-A-4 467 879, on connaît des stabilisateurs et alésoirs montés le long d'un train de tiges entraînant un trépan à molettes. Le train de tiges est soumis à une rotation lente de quelques tours seulement par minute.Document US-A-4 467 879 discloses stabilizers and reamers mounted along a string of rods driving a rotary drill bit. The drill string is subjected to a slow rotation of only a few revolutions per minute.

Le stabilisateur présente de larges passages d'eau ménagé hélicoïdalement le long du manchon, selon une configuration symétrique qui ne contribue pas à engendrer ni à accroître une quelconque tendance à dévier l'outil de coupe d'une trajectoire rectiligne. Le brevet BURGE permet de prévenir mais ne permet pas de corriger une déviation de trajectoire.The stabilizer has large water passages arranged helically along the sleeve, in a symmetrical configuration which does not contribute to generating or increasing any tendency to deflect the cutting tool from a straight path. The BURGE patent makes it possible to prevent but does not make it possible to correct a deviation from the trajectory.

La présente invention propose le moyen de modifier à volonté à gauche ou à droite, les déviations engendrées par une rotation rapide du train de tiges dans un forage profond directionnel. Elle permet bien sûr de réduire l'amplitude des déviations non souhaitées.The present invention provides the means to modify at will to the left or to the right, the deviations generated by a rapid rotation of the drill string in a directional deep drilling. It of course makes it possible to reduce the amplitude of the unwanted deviations.

L'invention concerne donc une méthode, selon laquelle on utilise à bon escient des manchons stabilisateurs présentant sur les ailes, des modifications qui assurent à celles-ci une surface de contact suffisante que pour limiter l'agressivité latérale de l'outil de forage et à la fois de maîtriser, c'est-à-dire modifier à volonté, l'angle de déviation azimutale vers la gauche de la garniture en forage à la turbine.The invention therefore relates to a method, according to which stabilizer sleeves are advantageously used which have modifications on the wings which provide them with a sufficient contact surface only to limit the lateral aggressiveness of the drilling tool and at the same time to control, that is to say modify at will, the angle of azimuthal deviation towards the left of the lining in drilling with the turbine.

Elle est relative à un dispositif de stabilisation d'une garniture de forage, constitué d'un corps cylindrique en acier présentant latéralement des saillies hélicoïdales séparées par des passages de fluide de forage munies d'un revêtement offrant une bonne résistance à l'érosion et à l'abrasion, essentiellement caractérisé en ce qu'il comprend au moins une gorge sensiblement circonférentielle ménagée dans les saillies susdites, de manière à relier entre eux les évidements compris entre celles-ci ; suivant une particularité de l'invention, les gorges susdites sont ménagées sur une partie de la hauteur des saillies.It relates to a device for stabilizing a drill string, consisting of a cylindrical steel body having laterally helical projections separated by passages of drilling fluid provided with a coating offering good resistance to erosion and abrasion, essentially characterized in that it comprises at least one substantially circumferential groove formed in the aforesaid projections, so as to connect the recesses therebetween between them; according to a feature of the invention, the aforementioned grooves are formed over part of the height of the projections.

Les gorges sont avantageusement ménagées, de préférence par fraisage, à intervalles réguliers le long des saillies hélicoïdales.The grooves are advantageously provided, preferably by milling, at regular intervals along the helical projections.

Dans une forme de réalisation particulière, une seule gorge présente une allure hélicoïdale à pas court.In a particular embodiment, a single groove has a helical shape with a short pitch.

Une forme de réalisation différente comprend au moins deux portions de manchons de même diamètre disposées dans le même alignement derrière l'outil de forage.A different embodiment includes at least two portions of sleeves of the same diameter arranged in the same alignment behind the drilling tool.

D'autres particularités et détails de l'invention apparaîtront au cours de la description détaillée suivante d'une forme de réalisation particulière de l'invention donnée à titre d'exemple non limitatif en faisant référence aux dessins ci-annexés. Dans ces dessins :

  • - la figure 1 est une vue en élévation latérale d'un trépan de forage à pointes diamantées muni d'une première forme de réalisation d'un dispositif de stabilisation suivant l'invention ;
  • - la figure 2 est une vue en perspective de la jupe de stabilisation illustrée à la figure 1 ;
  • - la figure 3, est une vue semblable à la figure 1, d'une deuxième forme de réalisation d'un dispositif de stabilisation;
  • - la figure 4 montre une coupe transversale perpendiculaire à l'axe de forage d'un palier radial en fonctionnement hydrodynamique ;
  • - la figure 5 montre une coupe transversale, perpendiculaire à l'axe de forage, d'un palier radial en fonctionnement par contact direct ;
  • - la figure 6 est un diagramme illustrant une première relation existant entre l'intensité de la déviation à gauche d'un puits de forage à la turbine en fonction de la longueur du dispositif de stabilisation ;
  • - la figure 7 est un diagramme illustrant une seconde relation existant entre la charge statique correspondant à un comportement hydrodynamique équivalent, en fonction de la longueur du dispositif de stabilisation ; et
  • - la figure 8 montre la corrélation existant entre l'intensité de la déviation à gauche d'un puits de forage à la turbine et la charge statique correspondant à un comportement hydrodynamique équivalent.
Other features and details of the invention will become apparent during the following detailed description of a particular embodiment of the invention given by way of non-limiting example with reference to the attached drawings. In these drawings:
  • - Figure 1 is a side elevational view of a drill bit with diamond points provided with a first embodiment of a stabilization device according to the invention;
  • - Figure 2 is a perspective view of the stabilization skirt illustrated in Figure 1;
  • - Figure 3, is a view similar to Figure 1, of a second embodiment of a stabilization device;
  • - Figure 4 shows a cross section perpendicular to the drilling axis of a radial bearing in hydrodynamic operation;
  • - Figure 5 shows a cross section, perpendicular to the drilling axis, of a radial bearing in operation by direct contact;
  • - Figure 6 is a diagram illustrating a first relationship between the intensity of the deviation to the left of a wellbore to the turbine as a function of the length of the stabilization device;
  • - Figure 7 is a diagram illustrating a second relationship between the static load corresponding to an equivalent hydrodynamic behavior, as a function of the length of the stabilization device; and
  • - Figure 8 shows the correlation between the intensity of the deviation to the left of a wellbore to the turbine and the static load corresponding to an equivalent hydrodynamic behavior.

Dans les dessins susdits, les mêmes notations de référence désignent des éléments identiques ou analogues.In the above drawings, the same reference notations designate identical or analogous elements.

Comme illustré à la figure 1, un outil de forage désigné dans son ensemble par la notation de référence 1, mis habituellement en oeuvre pour le forage directionnel profond à turbine ou rotary, est constitué d'une tête de forage 2 proprement dite réalisée, soit en matériau composite mis en forme par des techniques de métallurgie des poudres, soit en acier ou métal moulé. La tête 2 est un trépan ou une couronne de sondage munie sur toute sa surface en contact avec le fond du puits, d'éléments de coupe 3 placés de manière à rendre efficaces, à la fois la destruction de la roche et l'évacuation des copeaux.As illustrated in FIG. 1, a drilling tool designated as a whole by the reference notation 1, usually used for deep directional drilling with a turbine or rotary, consists of a drilling head 2 proper, produced either made of composite material shaped by powder metallurgy techniques, either steel or cast metal. The head 2 is a drill bit or a drilling crown provided over its entire surface in contact with the bottom of the well, with cutting elements 3 placed so as to make effective both the destruction of the rock and the evacuation of shavings.

Cette tête de forage 2 est fixée à l'extrémité d'un train de tiges, non montré, par l'intermédiaire d'un embout tronconique 4 de longueur variable compris entre 15 et 100 cm et présentant un filet de fixation 5 répondant aux normes en vigueur.This drilling head 2 is fixed to the end of a drill string, not shown, by means of a frustoconical end piece 4 of variable length between 15 and 100 cm and having a fixing thread 5 meeting the standards in force.

Un dispositif de stabilisation, constitué d'un corps cylindrique 6 en acier, présentant latéralement des saillies hélicoïdales 7 munies d'un revêtement 8 présentant une résistance suffisante à l'érosion et à l'abrasion et désigné dans son ensemble par la notation de référence 9, est monté en alignement avec la tête de forage 2, derrière celle-ci, sur l'embout cylindrique 4.A stabilization device, consisting of a cylindrical body 6 of steel, having laterally helical projections 7 provided with a coating 8 having sufficient resistance to erosion and abrasion and generally designated by the reference notation 9, is mounted in alignment with the drilling head 2, behind the latter, on the cylindrical end piece 4.

Le revêtement 8 des saillies hélicoïdales 7 peut être constitué d'un métal dur ou d'un matériau composite, éventuellement diamanté.The coating 8 of the helical projections 7 may be made of a hard metal or a composite material, possibly diamond-coated.

Ces outils connus présentent, comme expliqué ci-dessus, une tendance à dévier vers la gauche ou vers la droite suivant qu'il s'agit d'un forage à turbine ou d'un forage rotary.These known tools have, as explained above, a tendency to deviate to the left or to the right depending on whether it is a turbine drilling or a rotary drilling.

Les phénomènes de déviation des outils de forage dans des puits déviés profonds trouvent une explication lorsqu'on leur applique la théorie de Sommerfeld des paliers à fonctionnement hydrodynamique.The phenomena of deviation of drilling tools in deep deviated wells are explained when we apply the Sommerfeld theory of bearings with hydrodynamic functioning.

Il est en effet permis d'assimiler un dispositif de stabilisation 9 mis en rotation dans un puits profond dévié à un palier lisse conventionnel 10 constitué d'un arbre 11 tournant à l'intérieur d'un coussinet 12 (figures 4 et 5).It is indeed permissible to assimilate a stabilization device 9 rotated in a deep well deviated to a conventional smooth bearing 10 consisting of a shaft 11 rotating inside a bearing 12 (Figures 4 and 5).

Suivant la théorie de Sommerfeld, les paliers lisses 10 peuvent fonctionner de deux manières distinctes, sous les conditions suivantes :

  • 1. Lubrification hydrodynamique, ou
  • 2. contact direct.
According to Sommerfeld's theory, the plain bearings 10 can operate in two distinct ways, under the following conditions:
  • 1. Hydrodynamic lubrication, or
  • 2. direct contact.

En lubrification hydrodynamique, il s'établit en permanence un film d'huile 13 entre les deux surfaces en mouvement relatif, à savoir l'arbre 11 et le coussinet 12. Le film d'huile sous pression est généré par le mouvement même de l'arbre 11 à condition que la vitesse de rotation soit suffisante.In hydrodynamic lubrication, an oil film 13 is constantly established between the two surfaces in relative movement, namely the shaft 11 and the bearing 12. The oil film under pressure is generated by the very movement of the 'shaft 11 provided that the speed of rotation is sufficient.

Dans le deuxième cas, les surfaces 10 et 11 en mouvement relatif sont en contact direct. Ce cas se rencontre en mécanique au démarrage des paliers hydrodynamiques et dans certains engins de génie civil, où les vitesses relatives sont faibles.In the second case, the surfaces 10 and 11 in relative movement are in direct contact. This case is encountered in mechanics at the start of hydrodynamic bearings and in some civil engineering machines, where the relative speeds are low.

La théorie de Sommerfeld qui permet de prévoir le comportement de paliers lisses soumis à une lubrification hydrodynamique est décrit dans la revue intitulée « Technique de l'ingénieur », volume B, dans le chapitre 671 consacré aux Paliers Hydrodynamiques.Sommerfeld's theory which makes it possible to predict the behavior of plain bearings subjected to hydrodynamic lubrication is described in the review entitled “Engineering technique”, volume B, in chapter 671 devoted to Hydrodynamic bearings.

De la théorie de Sommerfeld, on peut déduire qu'un palier lisse est caractérisé géométriquement par :

  • - son diamètre ;
  • - le rapport sans dimension de la longueur du palier sur son diamètre.
From Sommerfeld's theory, we can deduce that a smooth bearing is characterized geometrically by:
  • - its diameter;
  • - the dimensionless ratio of the length of the bearing on its diameter.

Le choix du mode de fonctionnement, à savoir la lubrification hydrodynamique ou le contact direct dépend de la vitesse de rotation du palier, de la viscosité dynamique du fluide lubrifiant, de la longueur du palier, du diamètre du palier, de la charge appliquée sur le rotor et du jeu radial relatif, par rapport au rayon, jeu radial relatif compris entre 0,8 - 1(J3 et 4 - 10-3.The choice of operating mode, namely hydrodynamic lubrication or direct contact depends on the speed of rotation of the bearing, the dynamic viscosity of the lubricating fluid, the length of the bearing, the diameter of the bearing, the load applied to the rotor and relative radial clearance, with respect to the radius, relative radial clearance between 0.8 - 1 (J3 and 4 - 10 -3 .

L'angle de calage est un des paramètres qui caractérisent la position moyenne du rotor dans le stator. Il est indiqué par la notation de référence Ø à la figure 4. La théorie de Sommerfeld démontre également que l'angle de calage, le couple résistant, la puissance dissipée et le débit axial de lubrifiant dépendent uniquement pour un rapport longueur/diamètre donné, de l'excentricité relative s, égale à e/c, c'est-à-dire au rapport de l'excentricité absolue, exprimée en millimètres, sur jeu radial absolu exprimé également en millimètres.The setting angle is one of the parameters that characterize the average position of the rotor in the stator. It is indicated by the reference notation Ø in FIG. 4. Sommerfeld's theory also demonstrates that the setting angle, the resisting torque, the dissipated power and the axial flow of lubricant depend only for a given length / diameter ratio, relative eccentricity s, equal to e / c, that is to say the ratio of absolute eccentricity, expressed in millimeters, on absolute radial clearance also expressed in millimeters.

Dans le cas simple où le palier 10 est complètement lisse et la charge appliquée rigoureusement constante, la limite du fonctionnement hydrodynamique est atteinte lorsque la différence entre le jeu radial absolu c et l'excentricité absolue e est égale à la somme des rugosités des surfaces usinées, il s'ensuit alors un contact direct et une modification radicale du comportement du palier.In the simple case where the bearing 10 is completely smooth and the applied load strictly constant, the limit of the hydrodynamic operation is reached when the difference between the absolute radial clearance c and the absolute eccentricity e is equal to the sum of the roughnesses of the machined surfaces , it then follows a direct contact and a radical modification of the behavior of the bearing.

Dans le cas d'un dispositif de stabilisation 9 entraîné en rotation dans un puits en cours de forage, le problème est évidemment plus complexe :

  • - la paroi rocheuse est géométriquement irrégulière ;
  • - le fluide « lubrifiant est en réalité de la boue de forage chargée des débris de roche ;
  • - l'arbre 11 constitué par le dispositif stabilisateur 9 n'est pas lisse mais comprend des saillies 8 délimitant des évidements 14 pour le passage du fluide de forage et des déblais.
In the case of a stabilization device 9 rotated in a well during drilling, the problem is obviously more complex:
  • - the rock wall is geometrically irregular;
  • - the “lubricating fluid is actually drilling mud loaded with rock debris;
  • - The shaft 11 formed by the stabilizing device 9 is not smooth but includes projections 8 delimiting recesses 14 for the passage of drilling fluid and cuttings.

Malgré ces imperfections, on peut imaginer d'extrapoler la théorie de Sommerfeld au dispositif de stabilisation 9 en rotation dans un puits dévié.Despite these imperfections, one can imagine extrapolating Sommerfeld's theory to the stabilization device 9 in rotation in a deviated well.

Vu l'imperfection des conditions au fond de trou vis-à-vis du cas idéal du palier lisse, on doit s'attendre à ce que pour un nombre de Sommerfeld S défini conventionnellement, l'excentricité relative sera plus proche de 1 que pour un palier lisse de même longueur, même diamètre et même vitesse de rotation.Given the imperfection of the conditions at the bottom of the hole vis-à-vis the ideal case of the plain bearing, it must be expected that for a number of Sommerfeld S defined conventionally, the relative eccentricity will be closer to 1 than for a plain bearing of the same length, same diameter and same speed of rotation.

Il existe donc des conditions de forage pour lesquelles on observe une transition entre un comportement hydrodynamique et un comportement en contact direct.There are therefore drilling conditions for which a transition is observed between a hydrodynamic behavior and a behavior in direct contact.

Lorsqu'on met en oeuvre des outils équipés de manchons stabilisateurs entraînés en rotation par une turbine atteignant des vitesses de rotation importantes de l'ordre de 700 tours par minute environ, on peut supposer que le nombre de Sommerfeld minimum est atteint. En raison des conditions particulières déjà évoquées plus haut, le fonctionnement en lubrification hydrodynamique n'est cependant jamais entièrement établi. On s'en rapproche de plus en plus au fur et à mesure que le nombre de Sommerfeld augmente, c'est-à-dire, toutes autres conditions restant identiques, au fur et à mesure que la longueur du manchon stabilisateur 9 augmente.When using tools equipped with stabilizing sleeves driven in rotation by a turbine reaching high speeds of the order of about 700 revolutions per minute, it can be assumed that the minimum Sommerfeld number is reached. Due to the special conditions already mentioned above, the operation in hydrodynamic lubrication is however never fully established. It is getting closer and closer as the Sommerfeld number increases, that is to say, all other conditions remaining identical, as the length of the stabilizing sleeve 9 increases.

La figure 6 montre en effet, la relation observée pour un forage à la turbine incliné à environ 45 °C entre l'intensité de déviation à gauche et la longueur du dispositif de stabilisation. On peut assimiler cette relation à une fonction du premier degré, lorsque tous les autres paramètres restent identiques.Figure 6 shows, in fact, the relationship observed for a turbine drill tilted at about 45 ° C between the intensity of deviation to the left and the length of the stabilization device. We can assimilate this relation to a function of the first degree, when all the other parameters remain identical.

La figure 7 montre comment varie la charge statique Pst correspondant à un comportement hydrodynamique équivalent, en fonction de la longueur du dispositif de stabilisation.FIG. 7 shows how the static load Pst corresponding to an equivalent hydrodynamic behavior varies, as a function of the length of the stabilization device.

Lorsqu'on porte les points de mesure de l'intensité de déviation à gauche et de la charge statique susdite correspondant à un comportement hydrodynamique équivalent sur un diagramme montré à la figure 8, on s'aperçoit que lesdits points montrent une tendance à l'alignement.When the measurement points of the deviation intensity on the left and of the aforementioned static load corresponding to an equivalent hydrodynamic behavior are plotted on a diagram shown in FIG. 8, it can be seen that said points show a tendency towards alignment.

On observe donc une corrélation indéniable entre les variables susdits lorsqu'on met en oeuvre des vitesses de rotation importantes.There is therefore an undeniable correlation between the above variables when implementing high rotational speeds.

Par contre, pour un forage rotary sans dispositif stabilisateur ou avec manchon relativement court, à une vitesse de rotation comprise entre 100 et 200 tours par minute seulement, le nombre de Sommerfeld et donc la charge admissible à excentricité relative donnée est beaucoup plus faible ; on peut dès lors admettre que les conditions de fonctionnement hydrodynamique ne sont jamais remplies et la garde d'outil 1 seule ou la garde d'outil 1 prolongée par un dispositif stabilisateur 9 court fonctionne en contact direct.On the other hand, for rotary drilling without a stabilizing device or with a relatively short sleeve, at a rotation speed of between 100 and 200 revolutions per minute only, the Sommerfeld number and therefore the admissible load at given relative eccentricity is much lower; it can therefore be assumed that the hydrodynamic operating conditions are never fulfilled and the tool guard 1 alone or the tool guard 1 extended by a short stabilizing device 9 operates in direct contact.

Des arguments développés ci-dessus, on déduit que la variation de l'intensité de déviation à gauche en forage à la turbine est liée à un comportement plus ou moins hydrodynamique du système. Cette explication est confirmée par l'observation d'une déviation à gauche à la turbine et à droite au rotary.From the arguments developed above, it is deduced that the variation in the intensity of deviation to the left when drilling with a turbine is linked to a more or less hydrodynamic behavior of the system. This explanation is confirmed by the observation of a deviation to the left at the turbine and to the right at the rotary.

En effet, en examinant les figures 4 et 5, on remarque que la différence fondamentale existant entre le fonctionnement hydrodynamique et celui à contact direct se trouve dans la position moyenne du palier rotorique dans le logement statorique.Indeed, by examining FIGS. 4 and 5, it is noted that the fundamental difference existing between the hydrodynamic operation and that with direct contact is in the average position of the rotor bearing in the stator housing.

Supposons, comme indiqué aux figures 4 et 5 :

  • - une charge verticale agissant de haut en bas sur le palier rotorique,
  • - une rotation w du palier rotorique dans le sens horlogique semblable à celle de l'outil de forage vu de l'arrière.
Suppose, as shown in Figures 4 and 5:
  • - a vertical load acting from top to bottom on the rotor bearing,
  • - a rotation w of the rotor bearing in a clockwise direction similar to that of the drilling tool seen from the rear.

On remarque que le point de contact ou le point d'éloignement minimum du palier rotorique par rapport au palier statorique est situé :

  • - à gauche de la verticale passant par le centre du palier rotorique dans le cas du fonctionnement hydrodynamique ;
  • - à droite de la verticale passant par le centre du palier rotorique dans le cas du fonctionnement en contact direct.
Note that the contact point or the minimum point of separation of the rotor bearing from the stator bearing is located:
  • - to the left of the vertical passing through the center of the rotor bearing in the case of hydrodynamic operation;
  • - to the right of the vertical passing through the center of the rotor bearing in the case of direct contact operation.

Or, le trou foré à la turbine, pour lequel on a supposé un fonctionnement plus ou moins hydrodynamique de la jupe, dévie précisément vers la gauche et le trou foré en rotary, pour lequel on a montré que la jupe ou la garde de l'outil seule devait avoir un comportement en contact direct, dévie précisément vers la droite.Now, the hole drilled in the turbine, for which we have assumed a more or less hydrodynamic functioning of the skirt, deviates precisely to the left and the hole drilled in rotary, for which it has been shown that the skirt or the guard of the tool alone must have a behavior in direct contact, deviates precisely towards the right.

L'invention consiste à apporter à un dispositif stabilisateur connu, un perfectionnement en vue de maîtriser les déviations accidentelles sans toutefois modifier la longueur totale du dispositif susdit 9, indispensable pour éviter le spiraling.The invention consists in providing a known stabilizing device with an improvement with a view to controlling accidental deviations without, however, modifying the total length of the above-mentioned device 9, essential to avoid spiraling.

Ce perfectionnement consiste à ménager, perpendiculairement à l'axe longitudinal du dispositif stabilisateur 9, au moins une gorge 15, sensiblement circonférencielle ménagée dans les saillies 8 susdites, de manière à relier entre eux, les évidements 14 compris entre celles-ci.This improvement consists in providing, perpendicular to the longitudinal axis of the stabilizing device 9, at least one groove 15, substantially circumferential formed in the projections 8 above, so as to interconnect, the recesses 14 included therebetween.

Comme illustré aux figures 1 et 2, les gorges 15 peuvent être ménagées dans les saillies susdites, par fraisage, sur une partie de leur hauteur. Ces gorges 15 ont pour effet de mettre en communication une zone dans laquelle le lubrifiant est soumis à une pression élevée, avec une zone dans laquelle le lubrifiant se trouve à une pression moins élevée. Une telle gorge 15 réduit la capacité portante du palier et donc la déviation vers la gauche due au fonctionnement hydrodynamique.As illustrated in Figures 1 and 2, the grooves 15 can be formed in the above projections, by milling, over a portion of their height. These grooves 15 have the effect of bringing into communication an area in which the lubricant is subjected to a high pressure, with an area in which the lubricant is at a lower pressure. Such a groove 15 reduces the bearing capacity of the bearing and therefore the deviation to the left due to the hydrodynamic operation.

La figure 3 montre une deuxième forme de réalisation possible dans laquelle la gorge 15, de forme hélicoïdale est ménagée dans une direction différente de celle des saillies hélicoïdales 8 susdites. On obtient ainsi un manchon doublement spiralé.Figure 3 shows a second possible embodiment in which the groove 15, of helical shape is formed in a direction different from that of the helical projections 8 above. A doubly spiraled sleeve is thus obtained.

Exemple 1Example 1

Pour donner un ordre de grandeur de l'influence de ces modifications, prenons un exemple numérique : soit une jupe stabilisatrice dont on suppose que le comportement est semblable à celui d'un palier lisse de même diamètre et même longueur. On considère une jupe de référence dont le rapport L/D = 1, et dont la capacité portante est posée égale à 1.To give an order of magnitude of the influence of these modifications, let us take a numerical example: either a stabilizing skirt whose behavior is assumed to be similar to that of a plain bearing of the same diameter and same length. We consider a reference skirt whose ratio L / D = 1, and whose bearing capacity is set equal to 1.

Une jupe de longueur double, présentant donc un rapport L/D = 2 aura une capacité portante de 3,35 alors que si on pratique deux gorges perpendiculaires à l'axe de l'outil découpant la surface portante en trois parties égales, la même jupe de longueur double n'aura qu'une capacité portante de 1,05, c'est-à-dire presque identique à celle de la jupe de référence.A skirt of double length, therefore having a ratio L / D = 2 will have a bearing capacity of 3.35 whereas if we practice two grooves perpendicular to the axis of the tool cutting the bearing surface into three equal parts, the same double length skirt will have a bearing capacity of 1.05, that is to say almost identical to that of the reference skirt.

Il est évident que l'invention n'est pas limitée aux formes de réalisation décrites ci-dessus et que de nombreuses modifications peuvent être apportées auxdites formes sans pour autant soustraire celles-ci de la portée des revendications suivantes.It is obvious that the invention is not limited to the embodiments described above and that numerous modifications can be made to said forms without thereby withdrawing them from the scope of the following claims.

Claims (7)

1. A method for modifying the trajectory of a cutting tool for a deep directional drilling well, driven either by a hanging motor or a hanging turbine with a rate of at least 700 rot/min or by a rotary table from the surface at a rate of at least 100 rot/min, by means of a stabilizing device having helicoïdal lateral ribs (8) separated by passageways (14) of drilling fluid and provided with a hardfacing material affording good erosion and abrasion resistance, characterized in that at least one substantially circumferential groove is defined in the ribs and located in a plane which is perpendicular to the axis of rotation, so as to interconnect the passageways (14) of drilling fluid.
2. A method according to claim 1, characterized in that the depth of the groove (15) is varied.
3. A method according to claim 1 or 2, characterized in that the number and the arrangement of the grooves (15) are varied.
4. A stabilizing device of a line of rods equipped with a cutting tool, for a deep directional drilling well, driven either by a hanging motor or a hanging turbine, with a rate of at least 700 rot/min or by a rotary table from the surface at a rate of at least 100 rot/min, formed of a cylindrical steel body having helicoidal lateral ribs (8) separated by passageways (14) of drilling fluid and provided with a hardfacing material affording good erosion and abrasion resistance, characterized in that said ribs have at least one substantially circumferential groove (15), located in a plane, which is perpendicular to the axis of rotation, so as to interconnect the passageways (14) of drilling fluid.
5. A stabilizing device according to claim 4, characterized in that the grooves (15) are formed over a portion of the height of the ribs (8).
6. A stabilizing device according to anyone of the claims 4 and 5, characterized in that the circumferential grooves (15) are formed at intervals which are regular along the helicoidal projections.
7. A stabilizing device, according to anyone of the claims 4 to 6, characterized in that it is constitued by at least two sections of sleeves of equal diameter arranged in the same alignment behind the drilling tool (1).
EP85201531A 1984-10-11 1985-09-24 Stabilizer Expired EP0178709B1 (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
AT85201531T ATE39011T1 (en) 1984-10-11 1985-09-24 STABILIZER.

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
BE213816 1984-10-11
BE0/213816A BE900804A (en) 1984-10-11 1984-10-11 Stabiliser for rock face - has cylindrical body with helical ribs on circumference having cross grooves

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Publication Number Publication Date
EP0178709A1 EP0178709A1 (en) 1986-04-23
EP0178709B1 true EP0178709B1 (en) 1988-11-30

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EP (1) EP0178709B1 (en)
AT (1) ATE39011T1 (en)
DE (1) DE3566566D1 (en)
DK (1) DK162459C (en)
NO (1) NO854028L (en)

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CN104179464A (en) * 2014-08-08 2014-12-03 陆威延 Downhole tool used for righting and centralizing geological resource exploration drilling tool and capable of preventing drilling tool and sleeve from abrasion

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DE3822249A1 (en) * 1988-07-01 1990-01-04 Hilti Ag HOLLOW DRILLING TOOL
GB9202163D0 (en) * 1992-01-31 1992-03-18 Neyrfor Weir Ltd Stabilisation devices for drill motors
FR2789438B1 (en) * 1999-02-05 2001-05-04 Smf Internat PROFILE ELEMENT FOR ROTARY DRILLING EQUIPMENT AND DRILLING ROD WITH AT LEAST ONE PROFILED SECTION
EP2118429B1 (en) * 2007-02-02 2016-04-13 Halliburton Energy Services, Inc. Rotary drill bit steerable system and method
CA2687544C (en) * 2007-05-30 2016-11-08 Halliburton Energy Services, Inc. Rotary drill bit with gage pads having improved steerability and reduced wear
GB201519636D0 (en) 2015-11-06 2015-12-23 Smart Stabilizer Systems Ltd Stabilizer for a steerable drilling system
CN108442889A (en) * 2017-12-19 2018-08-24 中国石油天然气股份有限公司 Rotating wear-resistant resistance absorber

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GB879156A (en) * 1958-09-05 1961-10-04 Hughes Tool Co Tool joint for drill pipe sections
US3554307A (en) * 1969-07-03 1971-01-12 W E Eeds Turbulent flow drill collar
CA948181A (en) * 1971-02-12 1974-05-28 Lionel Lavallee Diamond drills
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US4245709A (en) * 1979-04-27 1981-01-20 Christensen, Inc. Removable drill string stabilizers
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Publication number Priority date Publication date Assignee Title
CN104179464A (en) * 2014-08-08 2014-12-03 陆威延 Downhole tool used for righting and centralizing geological resource exploration drilling tool and capable of preventing drilling tool and sleeve from abrasion

Also Published As

Publication number Publication date
EP0178709A1 (en) 1986-04-23
DE3566566D1 (en) 1989-01-05
DK464085D0 (en) 1985-10-10
DK464085A (en) 1986-04-12
DK162459C (en) 1992-04-21
NO854028L (en) 1986-04-14
ATE39011T1 (en) 1988-12-15
DK162459B (en) 1991-10-28

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