EP0196339A1 - Centralizer for casings and drill pipes - Google Patents

Centralizer for casings and drill pipes Download PDF

Info

Publication number
EP0196339A1
EP0196339A1 EP85103343A EP85103343A EP0196339A1 EP 0196339 A1 EP0196339 A1 EP 0196339A1 EP 85103343 A EP85103343 A EP 85103343A EP 85103343 A EP85103343 A EP 85103343A EP 0196339 A1 EP0196339 A1 EP 0196339A1
Authority
EP
European Patent Office
Prior art keywords
spring clips
centering
resistance
forces
pull
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Withdrawn
Application number
EP85103343A
Other languages
German (de)
French (fr)
Inventor
Rainer Burghardt
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Weatherford Oil Tool GmbH
Original Assignee
Weatherford Oil Tool GmbH
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Weatherford Oil Tool GmbH filed Critical Weatherford Oil Tool GmbH
Publication of EP0196339A1 publication Critical patent/EP0196339A1/en
Withdrawn legal-status Critical Current

Links

Images

Classifications

    • 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
    • E21B17/1014—Flexible or expansible centering means, e.g. with pistons pressing against the wall of the well
    • E21B17/1021—Flexible or expansible centering means, e.g. with pistons pressing against the wall of the well with articulated arms or arcuate springs
    • E21B17/1028—Flexible or expansible centering means, e.g. with pistons pressing against the wall of the well with articulated arms or arcuate springs with arcuate springs only, e.g. baskets with outwardly bowed strips for cementing operations

Definitions

  • the invention relates to a centering basket for drilling and casing pipes, consisting of spaced from each other, the pipes to be centered, ien support rings with radially outwardly bent spring clips, the ends of which are attached to the support rings.
  • the pull-in forces should not exceed certain limit values, while the centering forces should reach high values. These requirements are difficult to achieve, since high spring forces in the radial direction require spring clips with a strongly pronounced arc, so that the form resistances to be overcome when pulling in are large. Low pull-in forces naturally presuppose low form resistance or lower radial forces due to flatter bends. The centering baskets can be compressed more easily to a smaller diameter. Changes in the shape of the spring clip and the spring forces due to appropriate dimensions can only ever move within the narrow framework of specified test conditions. Therefore, it was practically not possible to reduce the pull-in forces to any appreciable extent in the case of centering baskets with high centering forces.
  • the invention is based on the object of designing a centering basket in such a way that the resistance to pulling into pipes or borehole walls is reduced while maintaining the required centering forces. do not exceed a limit.
  • the solution according to the invention is characterized in that the arches of some adjacent spring clips are offset in the axial direction. It is thereby achieved that when pulling into a tube or into a borehole wall not every spring clip comes to rest and carry against the outer wall and that the pull-in forces are thereby reduced.
  • the displacement of the bends in the axial direction can preferably be achieved in that the spring clips are alternately attached to the support rings, alternately offset in the axial direction.
  • the spring clip with an asymmetrical bend and attaching it to the support rings in such a way that, with a corresponding arrangement of the centering basket on the tube to be centered, the flatter pitch angles of the asymmetrical bends point in the feed direction. In this case, when pulling into the borehole wall or into an outer tube, not only some but all of the brackets rest on the outer wall. Due to the flatter pitch angle, however, the form resistance is significantly reduced.
  • the design according to the invention is not limited to certain centering baskets or spring clips, but can be used both for welded and unwelded designs. There is also the possibility of not alternately moving every second spring clip, but possibly only every third and the like, so that the pull-in forces can be varied accordingly.
  • the centering basket 1 consists of two spaced apart support rings 2 and 3 and a number of spring clips 4a, 4b, the ends of which are firmly connected to the support rings. These have hinges 5 in order to be able to divide the centering baskets for transport purposes. All that is required is to pull out the hinge nails 6. The centering baskets can then be stacked to save space.
  • the spring clips are offset in an alternating sequence in the longitudinal axis direction of the centering cage, as a result of which the curve maxima, which are determined by the tangents running parallel to the longitudinal basket direction, are not located on a common circumferential line, but are shifted relative to one another in the longitudinal axis direction.
  • the first stage of the drawing-in process is ended as soon as the spring clips 4b reach the pipe edge and are also compressed in the further course of the drawing-in process.
  • the entire pull-in resistance is thus divided into two stages, which results in a significant reduction in the maximum value of the pull-in resistance.
  • the starting angles of adjacent spring bars remain unchanged.
  • a further possibility of reducing the pull-in forces is achieved by asymmetrical arches of the spring clips 10a, 10b.
  • the spring clips are identical in their design, but are mounted alternately in opposite directions, so that different starting angles ⁇ a, ⁇ b can again be used to achieve a gradual division of the pull-in resistances.
  • the spring clip 10a comes into contact with the end edge of the casing tube 8.
  • the spring clip 10b Only after covering a considerable feed path does the spring clip 10b also come into contact with the pipe edge of the casing pipe, with which the second stage of the drawing-in process begins.
  • the spring clips 10a have not yet been completely drawn into the casing 8a, but this already applies to their curve maxima.
  • the forces of the further retraction process are therefore determined only by sliding friction of the spring clips 10a and additionally by the gradually increasing form resistance of the spring clips 10b.
  • the spring clips 10a and 10b are alternately arranged in opposite directions.
  • such a design requires the correct position of the centering cage to be observed on the pipe 7 to be drawn in and centered.

Landscapes

  • Engineering & Computer Science (AREA)
  • Life Sciences & Earth Sciences (AREA)
  • Geology (AREA)
  • Mining & Mineral Resources (AREA)
  • Mechanical Engineering (AREA)
  • Physics & Mathematics (AREA)
  • Environmental & Geological Engineering (AREA)
  • Fluid Mechanics (AREA)
  • General Life Sciences & Earth Sciences (AREA)
  • Geochemistry & Mineralogy (AREA)
  • Earth Drilling (AREA)
  • Clamps And Clips (AREA)

Abstract

Centralizers for casings and drill pipes in earth-boring technology put up considerable resistance to insertion in earth bores or drill pipes. This resistance is not to exceed certain limits. In order to reduce the insertion resistance, the curves of some adjacent spring clips (10A, 10B) are offset in the axial direction. This prevents all spring clips of a centralizer from coming to bear at the same time against the end of a surrounding drill pipe or the like. <IMAGE>

Description

Die Erfindung betrifft einen Zentrierkorb für Bohr- und Futterrohre, bestehend aus mit Abstand zueinander angeordneten, die zu zentrierenden Rohre umfa, ien Tragringen mit radial nach außen gebogenen Federbügeln, deren Enden an den Tragringen befestigt sind.The invention relates to a centering basket for drilling and casing pipes, consisting of spaced from each other, the pipes to be centered, ien support rings with radially outwardly bent spring clips, the ends of which are attached to the support rings.

In der Tiefbohrtechnik sind zur zentralen Führung von Rohren Zentrierkörper in Gebrauch, die aus einer Anzahl auswärts gebogener und mit einem oberen und unteren Tragring verbundenen Federbügeln bestehen. Die auf die zu zentrierenden Rohre aufgeschobenen Zentrierkörbe setzen dem Einziehen in ein Bohrloch oder in ein umhüllendes Futterrohr durch die auswärts gerichteten Bogen der Federbügel bzw. Federstäbe erhebliche Widerstände entgegen, die nur durch hohe Einzugskräfte überwunden werden können. Sobald ein Zentrierkorb mit seinem größten Umfang in ein Bohrloch bzw. in ein Futterrohr eingezogen ist, nimmt der Gesamtwiderstand erheblich ab, da der Formwiderstand entfällt und nur noch der Widerstand infolge Gleitreibung überwunden werden muß. Innerhalb eines umgebenden Rohres oder eines Bohrlochs sollen die Federbügel hohe Zentrierkräfte aufbringen, um das vom Zentrierkorb umfaßte Rohr möglichst genau zentrieren zu können.In deep drilling are to central guiding pipes centering in use consist of a number Eder iron the outwardly bent and connected to an upper and lower support ring F. The centering baskets pushed onto the pipes to be centered provide considerable resistance to pulling them into a borehole or into an enveloping casing due to the outward-pointing arches of the spring clips or spring bars, which can only be overcome by high pull-in forces. As soon as a centering basket with its largest circumference has been drawn into a borehole or a casing, the total resistance decreases considerably, since the form resistance is eliminated and only the resistance due to sliding friction must be wounded. The spring clips should exert high centering forces within a surrounding tube or a borehole in order to be able to center the tube enclosed by the centering basket as precisely as possible.

Nach vorgegebenen Prüfkriterien sollen die Einzugskräfte bestimmte Grenzwerte nicht überschreiten, die Zentrierkräfte sollen dagegen hohe Werte erreichen. Diese Forderungen sind schwer zu realisieren, da hohe Federkräfte in radialer Richtung Federbügel mit einem stark ausgeprägten Bogen erfordern, so daß gleichzeitig die beim Einziehen zu überwindenden Formwiderstände groß sind. Geringe Einzugskräfte setzen naturgemäß einen geringen Formwiderstand bzw. geringere radiale Kräfte durch flachere Bogen voraus. Die Zentrierkörbe können leichter auf einen geringeren Durchmesser zusammengedrückt werden. Änderungen der Form der Federbügel und der Federkräfte durch entsprechende Dimensionierungen können sich jedoch immer nur im engen Rahmen vorgegebener Prüfbedingungen bewegen. Deshalb war es praktisch nicht möglich, bei Zentrierkörben mit hohen Zentrierkräften die Einzugskräfte in nennenswertem Umfang zu senken.According to specified test criteria, the pull-in forces should not exceed certain limit values, while the centering forces should reach high values. These requirements are difficult to achieve, since high spring forces in the radial direction require spring clips with a strongly pronounced arc, so that the form resistances to be overcome when pulling in are large. Low pull-in forces naturally presuppose low form resistance or lower radial forces due to flatter bends. The centering baskets can be compressed more easily to a smaller diameter. Changes in the shape of the spring clip and the spring forces due to appropriate dimensions can only ever move within the narrow framework of specified test conditions. Therefore, it was practically not possible to reduce the pull-in forces to any appreciable extent in the case of centering baskets with high centering forces.

Der Erfindung liegt die Aufgabe zu Grunde, einen Zentrierkorb so auszubilden, daß unter Einhaltung geforderter Zentrierkräfte die dem Einziehen in Rohre oder Bohrlochwandungen entgegengesetzen Widerstände verringert werden.bzw. einen Grenzwert nicht überschreiten. Die erfindungsgemäße Lösung zeichnet sich dadurch aus, daß die Bogen einiger benachbarter Federbügel in Axialrichtung versetzt sind. Dadurch wird erreicht, daß beim Einziehen in ein Rohr bzw. in eine Bohrlochwandung zunächst nicht jeder Federbügel an der äußeren Wandung zum Anliegen und Tragen kommt und daß dadurch die Einzugskräfte verringert werden.The invention is based on the object of designing a centering basket in such a way that the resistance to pulling into pipes or borehole walls is reduced while maintaining the required centering forces. do not exceed a limit. The solution according to the invention is characterized in that the arches of some adjacent spring clips are offset in the axial direction. It is thereby achieved that when pulling into a tube or into a borehole wall not every spring clip comes to rest and carry against the outer wall and that the pull-in forces are thereby reduced.

Die Versetzung der Bogen in Axialrichtung kann vorzugsweise dadurch erreicht werden, daß die Federbügel insgesamt wechselweise in Achsrichtung versetzt an den Tragringen ansetzen. Außerdem besteht die Möglichkeit, die Federbügel mit einer asymmetrischen Biegung zu versehen und so an den Tragringen zu befestigen, daß bei entsprechender Anordnung des Zentrierkorbes auf dem zu zentrierenden Rohr die flacheren Steigungswinkel der asymmetrischen Bogen in Einzugsrichtung weisen. In diesem Fall liegen beim Einziehen in die Bohrlochwandung oder in ein äußeres Rohr nicht nur einige, sondern alle Bügel an der äußeren Wandung an. Durch die flacheren Steigungswinkel wird jedoch der Formwiderstand erheblich herabgesetzt. Bei einer wechselweise gegenläufigen Anordnung der asymmetrisch gebogenen Federbügel an den Tragringen ergibt sich hierbei der Vorteil, daß unabhängig von der Lage des Zentrierkorbes auf dem einzuziehenden Rohr der Einzugswiderstand herabgesetzt werden kann und bei den Arbeiten am Bohrturm auf die richtige Lage nicht geachtet werden muß.The displacement of the bends in the axial direction can preferably be achieved in that the spring clips are alternately attached to the support rings, alternately offset in the axial direction. In addition, there is the possibility of providing the spring clip with an asymmetrical bend and attaching it to the support rings in such a way that, with a corresponding arrangement of the centering basket on the tube to be centered, the flatter pitch angles of the asymmetrical bends point in the feed direction. In this case, when pulling into the borehole wall or into an outer tube, not only some but all of the brackets rest on the outer wall. Due to the flatter pitch angle, however, the form resistance is significantly reduced. With an alternating arrangement of the asymmetrically curved spring clips on the support rings, there is the advantage that regardless of the position of the centering basket on the pipe to be pulled in, the pull-in resistance can be reduced and the correct position does not have to be taken into account when working on the drilling rig.

Die erfindungsgemäße Gestaltung beschränkt sich nicht auf bestimmte Zentrierkörbe oder Federbügel, sondern kann sowohl für geschweißte als auch ungeschweißte Ausführungen zur Anwendung gelangen. Es ist ferner die Möglichkeit gegeben, nicht wechselweise jeden zweiten Federbügel zu versetzen, sondern gegebenenfalls erst jeden dritten und dergl.,so daß die Einzugskräfte entsprechend variiert werden können.The design according to the invention is not limited to certain centering baskets or spring clips, but can be used both for welded and unwelded designs. There is also the possibility of not alternately moving every second spring clip, but possibly only every third and the like, so that the pull-in forces can be varied accordingly.

In der Zeichnung sind zwei Ausführungsbeispiele der Erfindung schematisch dargestellt und nachstehend erläutert.In the drawing, two embodiments of the invention are shown schematically and explained below.

Es zeigen:

  • Fig. 1a die schaubildliche Darstellung eines Zentrierkorbes in geschweißter Ausführung,
  • Fig. ab die schaubildliche Darstellung eines Zentrierkorbes mit einer formschlüssigen Verbindung von Federbügeln und Tragringen,
  • Fig. 2 einen Einziehvorgang mit einem Zentrierkorb gemäß Fig. 2 und
  • Fig. 3 einen Zentrierkorb mit asymmetrisch gebogenen Federbügeln beim Einzugsvorgang.
Show it:
  • 1a shows the diagrammatic representation of a centering basket in a welded design,
  • From the diagrammatic representation of a centering basket with a positive connection of spring clips and support rings,
  • Fi g. 2 a pull-in process with a centering basket according to FIG. 2 and
  • Fig. 3 shows a centering basket with asymmetrically curved spring clips during the retraction process.

Der Zentrierkorb 1 besteht aus zwei mit Abstand zueinander angeordneten Tragringen 2 und 3 und einer Anzahl von Federbügeln 4a, 4b, deren Enden fest mit den Tragringen verbunden sind. Diese weisen Scharniere 5 auf, um zu Transportzwecken die Zentrierkörbe teilen zu können. Hierfür sind lediglich die Scharniernägel 6 herauszuziehen. Die Zentrierkörbe können dann raumsparender gestapelt werden.The centering basket 1 consists of two spaced apart support rings 2 and 3 and a number of spring clips 4a, 4b, the ends of which are firmly connected to the support rings. These have hinges 5 in order to be able to divide the centering baskets for transport purposes. All that is required is to pull out the hinge nails 6. The centering baskets can then be stacked to save space.

Erfindungsgemäß sind bei dem gezeigten Beispiel die Federbügel in wechselnder Reihenfolge in Achslängsrichtung des Zentrierkorbes versetzt angeordnet, wodurch sich die Kurvenmaxima, die durch die parallel zur Korblängsrichtung verlaufenden Tangenten bestimmt werden, nicht auf einer gemeinsamen Umfangslinie befinden, sondern in Achslängsrichtung gegeneinander verschoben sind. Beim Einziehen in ein Bohrloch bzw. in ein Futterrohr in Richtung der Einzugskraft PE ist zunächst nur der Formwiderstand der Federbügel 4a zu überwinden. Die Widerstandskräfte der Federbügel 4b kommen bis zum vollen Eintreten der Federbügel 4a mit ihrem Kurvenmaximum in die äußere Umhüllung nur z. T. zur Wirkung. Insgesamt wird dadurch der Widerstand des Zentrierkorbes beim Einziehen herabgesetzt, so daß die Einzugskräfte verringert werden können. Nach dem vollständigen Eintreten der Federbügel 4a ist nur noch deren Gleitreibung zu überwinden, die wesentlich geringer ist als der Formwiderstand während der ersten Hälfte des Einzugsweges. In Figur 2 ist deutlich der in zwei Stufen erfolgende Einzugsvorgang erkennbar dargestellt. Der Zentrierkorb ist auf einem zu zentrierenden Rohr 7 aufgeschoben. Sein Sitz wird durch einen Stoppring 9 fixiert. Das Rohr 7 soll innerhalb des äußeren Futterrohres 8 zentriert werden. Zunächst laufen beim Einzugsvorgang die Federbügel 4a mit ihren vorderen Bereichen an der Endkante des Futterrohres 8 auf und werden im Verlaufe des Einzugsvorganges etwas zusammengedrückt, was durch die unterbrochene Strichführung 4'a gekennzeichnet ist. Die erste Stufe des Einzugsvorganges wird beendet, sobald die Federbügel 4b die Rohrkante erreichen und im weiteren Verlauf des Einzugsvorgangs ebenfalls zusammengedrückt werden. Der gesamte Einzugswiderstand wird also in zwei Stufen aufgeteilt, wodurch sich eine erhebliche Verringerung des Maximalwertes des Einzugswiderstandes ergibt. Die Anfangswinkel benachbarter Federstäbe bleiben hierbei unverändert. Nach dem vollständigen Einziehen eines Zentrierkorbs in eine Bohrlochwandung oder in ein umgebendes Futterrohr kommt die radial wirkende Zentrierkraft P in z voller Höhe nach den Bestimmungen des API zur Wirkung. Die Zentrierkräfte werden also von der Herabsetzung der Einzugskräfte bzw. Einzugswiderstände nicht berührt.According to the invention, in the example shown, the spring clips are offset in an alternating sequence in the longitudinal axis direction of the centering cage, as a result of which the curve maxima, which are determined by the tangents running parallel to the longitudinal basket direction, are not located on a common circumferential line, but are shifted relative to one another in the longitudinal axis direction. When pulling into a borehole or a casing in the direction of the pull-in force P E , only the form resistance of the spring clip 4a has to be overcome. The resistance forces of the spring clips 4b come up to the full entry of the spring clips 4a with their curve maximum into the outer casing only z. T. to the effect. Overall, this reduces the resistance of the centering basket when it is pulled in, so that the pull-in forces can be reduced. After the spring clips 4a have fully entered, only their sliding friction has to be overcome, which is considerably less than the form resistance during the first half of the feed path. The drawing-in process taking place in two stages is clearly shown in FIG. The centering basket is pushed onto a tube 7 to be centered. Its seat is fixed by a stop ring 9. The tube 7 is to be centered within the outer casing 8. First, the spring clips 4a run with their during the pulling-in process front areas on the end edge of the casing 8 and are somewhat compressed in the course of the drawing-in process, which is characterized by the broken line 4'a. The first stage of the drawing-in process is ended as soon as the spring clips 4b reach the pipe edge and are also compressed in the further course of the drawing-in process. The entire pull-in resistance is thus divided into two stages, which results in a significant reduction in the maximum value of the pull-in resistance. The starting angles of adjacent spring bars remain unchanged. After a centering cage has been completely drawn into a borehole wall or into a surrounding casing, the radially acting centering force P comes into effect in full in accordance with the provisions of the API. The centering forces are therefore not affected by the reduction in the pull-in forces or pull-in resistances.

Eine weitere Möglichkeit, die Einzugskräfte herabzusetzen, wird durch asymmetrische Bogen der Federbügel 10a, 10b erreicht. Bei dem gezeigten Beispiel sind die Federbügel in ihrer Ausbildung zwar identisch, jedoch wechselweise gegenläufig montiert, so daß sich durch unterschiedliche Anfangswinkel α a, α b wieder eine stufenweise Unterteilung der Einzugswiderstände erreichen läßt. Zunächst gelangt durch den größeren Anfangswinkelo( a der Federbügel 10a zur Anlage an die Endkante des Futterrohres 8. Erst nach Zurücklegen eines erheblichen Einzugsweges gelangt der Federbügel 10b ebenfalls zur Anlage an die Rohrkante des Futterrohres, womit die zweite Stufe des Einzugsvorganges beginnt. In diesem Moment sind zwar die Federbügel 10a noch nicht vollständig in das Futterrohr 8a hineingezogen, jedoch trifft das bereits für ihre Kurvenmaxima zu. Die Kräfte des weiteren Einzugsvorganges werden deshalb lediglich durch Gleitreibungen der Federbügel 10a und zusätzlich durch die allmählich ansteigenden Formwiderstände der Federbügel 10b bestimmt.A further possibility of reducing the pull-in forces is achieved by asymmetrical arches of the spring clips 10a, 10b. In the example shown, the spring clips are identical in their design, but are mounted alternately in opposite directions, so that different starting angles α a, α b can again be used to achieve a gradual division of the pull-in resistances. First, through the larger starting angle o (a, the spring clip 10a comes into contact with the end edge of the casing tube 8. Only after covering a considerable feed path does the spring clip 10b also come into contact with the pipe edge of the casing pipe, with which the second stage of the drawing-in process begins. At this moment the spring clips 10a have not yet been completely drawn into the casing 8a, but this already applies to their curve maxima. The forces of the further retraction process are therefore determined only by sliding friction of the spring clips 10a and additionally by the gradually increasing form resistance of the spring clips 10b.

Bei dem gezeigten Beispiel gemäß Figur 3 sind die Federbügel 10a und 10b wechselweise gegenläufig angeordnet. Es besteht jedoch auch die Möglichkeit, alle Federbügel einheitlich anzuordnen, so daß sie alle die Lage der Federbügel 10b einnehmen und der Formwiderstand durch den kleineren Winkel α b verringert werden kann. Eine solche Ausbildung erfordert jedoch im Gegensatz zur Ausführung gemäß Figur 3 die Beachtung der richtigen Lage des Zentrierkorbs auf dem einzuziehenden und zu zentrierenden Rohr 7.In the example shown in Figure 3, the spring clips 10a and 10b are alternately arranged in opposite directions. However, there is also the possibility of arranging all the spring clips uniformly, so that they all assume the position of the spring clips 10b and the shape resistance can be reduced by the smaller angle α b. However, in contrast to the embodiment according to FIG. 3, such a design requires the correct position of the centering cage to be observed on the pipe 7 to be drawn in and centered.

Claims (4)

1. Zentrierkorb für Bohr- und Futterrohre, bestehend aus mit Abstand zueinander angeordneten, die zu zentrierenden Rohre umschließenden Tragringen mit radial nach außen gebogenen Federbügeln, deren Enden an den Tragringen befestigt sind, dadurch gekennzeichnet, daß die Bogen einiger benachbarter Federbügel (4a, 4b; 10a, 10b) in Achsrichtung versetzt sind.1. Centering basket for drilling and casing pipes, consisting of spaced-apart, surrounding the pipes to be centered supporting rings with radially outwardly bent spring clips, the ends of which are attached to the supporting rings, characterized in that the bows of some adjacent spring clips (4a, 4b ; 10a, 10b) are offset in the axial direction. 2. Zentrierkorb nach Anspruch 1, dadurch gekennzeichnet, daß die Federbügel (4a, 4b) wechselweise in Achsrichtung versetzt an den Tragringen (2, 3) ansetzen.2. centering cage according to claim 1, characterized in that the spring clips (4a, 4b) alternately in the axial direction to the support rings (2, 3). 3. Zentrierkorb nach Anspruch 1, dadurch gekennzeichnet, daß die Federbügel (10a, 10b) asymmetrisch gebogen und mit ihren flacheren Steigungswinkeln (α b) in Einzugsrichtung weisend an den Tragringen (2) befestigt sind.3. Centering cage according to claim 1, characterized in that the spring clips (10a, 10b) are bent asymmetrically and are attached to the support rings (2) with their flatter pitch angles (α b) pointing in the feed direction. 4. Zentrierkorb nach Anspruch 3, dadurch gekennzeichnet, daß die asymmetrisch gebogenen Federbügel (10a, 10b) wechselweise gegenläufig an den Tragringen (2, 3) ansetzen.4. centering cage according to claim 3, characterized in that the asymmetrically curved spring clip (10a, 10b) alternately in opposite directions to the support rings (2, 3).
EP85103343A 1985-03-07 1985-03-22 Centralizer for casings and drill pipes Withdrawn EP0196339A1 (en)

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
DE3508086 1985-03-07
DE19853508086 DE3508086C1 (en) 1985-03-07 1985-03-07 Centering basket for drilling and casing pipes

Publications (1)

Publication Number Publication Date
EP0196339A1 true EP0196339A1 (en) 1986-10-08

Family

ID=6264463

Family Applications (1)

Application Number Title Priority Date Filing Date
EP85103343A Withdrawn EP0196339A1 (en) 1985-03-07 1985-03-22 Centralizer for casings and drill pipes

Country Status (2)

Country Link
EP (1) EP0196339A1 (en)
DE (1) DE3508086C1 (en)

Cited By (8)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
EP2464811B1 (en) * 2009-08-10 2014-02-26 Domain Licenses Limited Downhole device
US20150354291A1 (en) * 2014-06-10 2015-12-10 Top-Co Inc. Easy-start centralizer with asymetrical bow springs
CN107747476A (en) * 2017-11-22 2018-03-02 江阴德玛斯特钻具有限公司 Anti-shake drilling rod with antifriction band
CN107939303A (en) * 2017-11-22 2018-04-20 江阴德玛斯特钻具有限公司 High strength safe type drilling rod
CN108019156A (en) * 2017-11-22 2018-05-11 江阴德玛斯特钻具有限公司 The high-strength drill pipe of laced belt muff
CN108035683A (en) * 2017-11-22 2018-05-15 江阴德玛斯特钻具有限公司 Sulfur resistive heavy weight drill pipe
CN108049823A (en) * 2017-11-22 2018-05-18 江阴德玛斯特钻具有限公司 High antitorque, anti-rock drilling rod
US10156103B2 (en) 2014-03-20 2018-12-18 Downhole Products Limited Centraliser

Families Citing this family (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4787458A (en) * 1987-05-29 1988-11-29 Weatherford U. S., Inc. Spring bow, centralizer, and related methods
US4794986A (en) * 1987-11-27 1989-01-03 Weatherford U.S., Inc. Reticulated centralizing apparatus
US5458196A (en) * 1994-08-31 1995-10-17 Halliburton Company Through tubing gun hanger
WO2016030689A1 (en) * 2014-08-27 2016-03-03 Reece Innovation Centre Limited Improvements in or relating to centralisers

Citations (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2594550A (en) * 1950-03-15 1952-04-29 Gist Fred Morgan Multisection pipe protector
US2998074A (en) * 1959-08-11 1961-08-29 Camo Tool Company Inc Oil and gas well cleaning apparatus
US3556042A (en) * 1966-08-16 1971-01-19 Mark Tool Co Inc Centering device
US3575239A (en) * 1969-04-18 1971-04-20 B & W Inc Progressive centralizer
US4159742A (en) * 1977-12-27 1979-07-03 Chromalloy American Corporation Well bore cleaning tool

Family Cites Families (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3289768A (en) * 1962-06-19 1966-12-06 B & W Inc Turbulence generating centralizer
GB1014736A (en) * 1962-10-26 1965-12-31 Albert Edward Atkinson Improvements in and relating to devices for centralizing casing in boreholes
US3566965A (en) * 1968-07-22 1971-03-02 B & W Inc Variable size,multi-hinge centralizer
US4520869A (en) * 1983-09-29 1985-06-04 Svenson Bert N Centralizer for well casings

Patent Citations (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2594550A (en) * 1950-03-15 1952-04-29 Gist Fred Morgan Multisection pipe protector
US2998074A (en) * 1959-08-11 1961-08-29 Camo Tool Company Inc Oil and gas well cleaning apparatus
US3556042A (en) * 1966-08-16 1971-01-19 Mark Tool Co Inc Centering device
US3575239A (en) * 1969-04-18 1971-04-20 B & W Inc Progressive centralizer
US4159742A (en) * 1977-12-27 1979-07-03 Chromalloy American Corporation Well bore cleaning tool

Cited By (11)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
EP2464811B1 (en) * 2009-08-10 2014-02-26 Domain Licenses Limited Downhole device
US10156103B2 (en) 2014-03-20 2018-12-18 Downhole Products Limited Centraliser
US20150354291A1 (en) * 2014-06-10 2015-12-10 Top-Co Inc. Easy-start centralizer with asymetrical bow springs
US10012035B2 (en) * 2014-06-10 2018-07-03 Top-Co Inc. Easy-start centralizer with asymetrical bow springs
US20180347290A1 (en) * 2014-06-10 2018-12-06 Top-Co Inc. Easy-start centralizer with asymmetrical bow springs
US10443323B2 (en) 2014-06-10 2019-10-15 Top-Co Inc. Easy-start centralizer with asymmetrical bow springs
CN107747476A (en) * 2017-11-22 2018-03-02 江阴德玛斯特钻具有限公司 Anti-shake drilling rod with antifriction band
CN107939303A (en) * 2017-11-22 2018-04-20 江阴德玛斯特钻具有限公司 High strength safe type drilling rod
CN108019156A (en) * 2017-11-22 2018-05-11 江阴德玛斯特钻具有限公司 The high-strength drill pipe of laced belt muff
CN108035683A (en) * 2017-11-22 2018-05-15 江阴德玛斯特钻具有限公司 Sulfur resistive heavy weight drill pipe
CN108049823A (en) * 2017-11-22 2018-05-18 江阴德玛斯特钻具有限公司 High antitorque, anti-rock drilling rod

Also Published As

Publication number Publication date
DE3508086C1 (en) 1986-08-14

Similar Documents

Publication Publication Date Title
EP0512154B1 (en) Centralizer for casings and drill pipes
DE2759392C2 (en) Quick coupling for synthetic resin pipes
DE69230338T2 (en) PIPE COUPLING
EP0196339A1 (en) Centralizer for casings and drill pipes
DE7802307U1 (en) CENTERING BASKET, MOUNTED ON A PIPE, FOR PIPING DRILLING HOLES
EP1655811A1 (en) Connector and mating connector
WO2003040012A1 (en) Device and method for winding protective films provided in the form of a coreless reel
DE2620142A1 (en) ROUND WIRE CIRCLIP
DE69400606T2 (en) Door reinforcement for motor vehicles
EP0769329B1 (en) Cushioned basket roller
EP1883078A1 (en) Device for handling small components
DE2832763C3 (en) Inner helix for a hose and hose arrangement with helical support
DE3347503A1 (en) SELF-LOCKING BOLT
DE2205042A1 (en) Impact body for a drilling tool
DE102010053357A1 (en) Pipe clip for supporting pipe, has clamp brackets with hinge plates hooked with one another to interconnect clamp brackets in closed region, where contact surface of hinge plates includes angle passing through closed region
DE3405094A1 (en) Elastic retaining bracket for round rods having variable diameters
DE2734188A1 (en) FLEXIBLE PIPE, IN PARTICULAR DRILL PIPE, AND THE METHOD FOR ITS MANUFACTURING
EP0639244B1 (en) Roller bearing
DE2828121A1 (en) WRAPPING CARRIER WITH PARALLEL SUPPORTING ELEMENTS WITH ITS AXIS
DE3303178A1 (en) Plug socket for electrical lead cores
EP3517688B1 (en) Ground anchor element
DE9410500U1 (en) Fluidically operable. strip-like clamping tool
DE29513721U1 (en) Fastener
DE2028859B2 (en) Device for bringing a pipeline laid on the bottom of a body of water to a working platform near the coast
DE7304620U (en) CONNECTING PIPE FOR THE PRODUCTION OF PIPE CONNECTIONS, IN PARTICULAR FOR VENTILATION SYSTEMS

Legal Events

Date Code Title Description
PUAI Public reference made under article 153(3) epc to a published international application that has entered the european phase

Free format text: ORIGINAL CODE: 0009012

AK Designated contracting states

Kind code of ref document: A1

Designated state(s): AT FR GB IT NL SE

17P Request for examination filed

Effective date: 19861125

17Q First examination report despatched

Effective date: 19880126

STAA Information on the status of an ep patent application or granted ep patent

Free format text: STATUS: THE APPLICATION HAS BEEN WITHDRAWN

18W Application withdrawn

Withdrawal date: 19881125

RIN1 Information on inventor provided before grant (corrected)

Inventor name: BURGHARDT, RAINER