Drill pipe for producing a drill string

Abstract

The invention relates to a drill pipe (1) for producing a cased string bore and is characterized in that it consists of at least two longitudinal elements (2, 3) which can be connected to one another to form the drill pipe (1), wherein the at least two longitudinal elements (2, 3) have different fixing means (4, 5, 6) in order to fix the at least two longitudinal elements (2, 3) against one another with the aid of a securing element (7) and to connect them to one another to form the drill pipe (1).

Description

[0001] The invention relates to a drill pipe for the production of a cased string bore. Such string bores, in the broadest sense, form a protective pipe system in which the drill string, as the inner pipe for driving a machine, a drill head, a tool, or the like, must be protected. Since such an inner pipe is sometimes many times longer than the length of the individual drill pipe, considerable coupling and threading work is required during the production of the drill string to form the protective pipe system.

[0002] DE 10 2007 002 399 A1, for example, discloses a method and a device for producing such a cased string bore. This document describes, in particular, the production of a horizontal filter well. To produce a cased string bore extending horizontally from a well shaft for the installation of a filter string, a starter drill pipe is driven horizontally through an opening in the wall of the well shaft by a press arranged in the well shaft into the rock surrounding the well shaft.Once the drilling has progressed so far that the starter drill pipe has completely emerged from the well shaft, another drill pipe must be placed on top of the starter drill pipe to form the string bore, so that this too can be pressed out of the well shaft and into the rock using the press, whereby the starter drill pipe is also driven further into the rock.

[0003] Once the drilling process has progressed to the point where the starter casing has completely emerged from the casing shaft, the drilling process must be interrupted so that a new casing can be attached to the starter casing. To do this, the supply and disposal lines of the drill head, i.e. the entire inner string to the drill head, must be disconnected from the drill head in order to attach a new casing or thread it over the inner string. Only after the previously severed line connections have been restored can the drilling process continue and the newly inserted casing, together with the starter casing, can be pressed further into the rock. This process is repeated until the string bore has reached the desired length for the horizontal screen well.

[0004] A disadvantage of this method for creating a string bore, however, is that in order to attach or set up a new drill pipe, the pipe connections or the inner string to the drill head must be repeatedly interrupted in order to arrange or thread new drill pipes over the pipe connections. This is associated with a significant expenditure of time and energy, making continuous drilling impossible without interrupting the pipe connections to the drill head.

[0005] It is therefore an object of the invention to provide a drill pipe with which a bore for producing a drill string requires less time and less energy than the drill pipes known from the prior art.

[0006] This object is achieved by a drill pipe for the production of a cased string bore with all the features of patent claim 1. Advantageous embodiments of the invention can be found in the subclaims.

[0007] The drill pipe according to the invention for producing a cased string bore is characterized in that it consists of at least two longitudinal elements which are connected to one another to form the drill pipe, wherein the at least two longitudinal elements have different fixing means in order to fix the at least two longitudinal elements against one another by means of securing elements and to connect them to one another to form the drill pipe.

[0008] The inventive design of the drill pipe for creating a cased string bore eliminates considerable coupling and overthreading work, which leads to enormous time and energy savings. The entire drill string forms a protective pipe system in which an inner pipe (e.g. rods, coil tubing, internal power supply and the like) must be protected, e.g. for driving a machine, a tool, a drill head or the like. These elements to be protected are also referred to as the inner string. Since this inner string is often many times longer than the length of the individual drill pipe for the planned length of the bore, the drill pipe according to the invention eliminates the coupling and overthreading work known from the prior art when creating a cased string bore or such a protective pipe system, which is both time-consuming and energy-intensive.

[0009] In addition to the time and energy savings, the use of drill pipes according to the invention in the production of a cased string bore also results in a considerable economic advantage, since the time and energy savings naturally also result in significantly lower costs for the production of such a string bore.

[0010] In addition, the multi-part drill pipe according to the invention enables the quick and secure encasing of the inner string and the low-interruption to uninterrupted operation or installation of the inner string without the need to overthread it. The use of drill pipes according to the invention to produce such a protective pipe system also makes it possible to provide a flexible inner string on a reel that can be continuously fed without interruption. Such drill pipes can be used for both horizontal and vertical drilling. Areas of application and use include all activities in which working and protective strings are required or offer these advantages.

[0011] As already mentioned, the drill pipe according to the invention consists of at least two longitudinal elements. In principle, it is advantageous if it consists of exactly two longitudinal elements. This embodiment of the invention has the advantage that the drill pipe according to the invention consists of only two individual longitudinal elements, which can be fixed to one another via the fixing means and the securing elements and connected to one another to form the drill pipe. In this embodiment, it is advantageously possible to only have to fix two longitudinal elements to one another and then connect them to one another. In principle, however, it is possible for the drill pipe according to the invention to consist of more than two longitudinal elements, which are fixed to one another via fixing means and securing elements and connected to one another to form the drill pipe.However, with more than two longitudinal elements, the effort required to manufacture the drill pipe is significantly greater than with a drill pipe consisting of only two longitudinal elements.

[0012] According to a first advantageous embodiment of the invention, the at least two longitudinal elements have different positioning means in order to position the at least two longitudinal elements axially relative to one another before being connected to the drill pipe. In this case, the positioning means of one longitudinal element is advantageously designed to engage with a positioning means of the other longitudinal element, wherein the positioning elements are designed such that the longitudinal elements can no longer be displaced relative to one another in the longitudinal direction of the drill pipe. Advantageously, the engagement of the positioning means of one longitudinal element takes place in a form-fitting manner and, in the longitudinal direction of the drill pipe, advantageously also in a force-fitting manner in order to prevent the longitudinal elements from displacing relative to one another.

[0013] Furthermore, it is advantageous if these positioning means, together with the fixing means and the securing elements, form a smooth surface when the at least two longitudinal elements are connected to one another to form the drill pipe. Such a configuration of the invention is advantageous because it creates a substantially circular outer surface over the entire longitudinal extent of the drill pipe, from which no part of the drill string protrudes in the radial direction. This is particularly advantageous when driving the drill string through rock, since such radial protrusions create additional resistance in the rock and thus require increased energy expenditure to drive the drill string through the rock.

[0014] According to a further advantageous embodiment of the invention, each of the at least two longitudinal elements has connecting elements at opposite axial ends for connecting different drill pipes to form a drill string. These connecting elements are also advantageously designed such that two interconnected drill pipes form a flat cylindrical surface that has no radial projections but rather a constant cylinder radius. This also prevents radial projections from occurring in the drill string during advancement of the drill string in the rock, which would result in increased resistance during advancement of the drill string.This is also particularly advantageous compared to the state of the art, in which rods and pipe connectors often have a conical thread, thus creating a thickening which protrudes radially beyond the cylindrical surface of the drill string and thus causes increased resistance when driving through the rock, which significantly increases the energy required to drive the drill string.

[0015] In order to be able to connect drill pipes according to the invention to one another in a rotationally secure manner, a further advantageous concept of the invention provides that a securing means is detachably arranged on the drill pipe, which is in particular fixed by the securing element. The securing means advantageously ensures that interconnected drill pipes cannot rotate against one another or become detached from one another. Since this securing means is detachably arranged on the drill pipe when two drill pipes are unconnected, it is advantageously fixed by the securing element when two drill pipes are connected. As a result, the securing means is captively fixed to the drill pipe or the drill string.

[0016] According to a further advantageous embodiment of the invention, the securing means is designed to engage positively in a receptacle of another drill pipe or a securing element of another drill pipe. This positive engagement ensures that interconnected drill pipes are connected to one another in a rotationally secure manner. It is advantageous if the engagement of the securing means in a receptacle of another drill pipe or a securing element of another drill pipe not only engages positively but also non-positively in the radial direction. This non-positive radial connection ensures particularly good anti-rotation and loosening protection between interconnected pipes.

[0017] In order to ensure that the securing elements of the at least two longitudinal elements are permanently connected to one another, a further advantageous embodiment of the invention provides for an anti-displacement element for the securing element to be arranged on at least one of the longitudinal elements. This anti-displacement element serves in particular to ensure that, when the at least two longitudinal elements of the drill pipe according to the invention are connected, the securing element cannot be displaced in the longitudinal direction of the drill pipe and then detaches from the drill pipe. In a particular embodiment of the invention, the anti-displacement element is part of the anti-twist element. This has the particular advantage that only one additional element is required to prevent the drill pipe from twisting and the securing element from shifting, which assumes this dual function.

[0018] In a particularly advantageous embodiment of the invention, the fixing means of the at least two longitudinal elements form pairs that are trapezoidal in shape and have undercuts toward the outer surface of the respective longitudinal element. Such longitudinal edges, in conjunction with the trapezoidal shape, are particularly well suited for captively fixing the securing elements to the drill pipe.

[0019] In order to achieve such a captive fixation of the securing elements to the drill pipe, it is provided that the securing element is designed as a closure plate and has trapezoidal openings whose longitudinal edges are bevelled, wherein the securing element is displaceable from an opening position into a shooting position and wherein, in a closing position, the undercuts of the longitudinal edges of the pairs of fixing means of the longitudinal elements engage behind.

[0020] This embodiment of the invention allows the securing elements designed as closure plates to be applied particularly well and easily to the drill pipe according to the invention. The trapezoidal shape and the undercut create a clamping effect that positions the at least two longitudinal elements against each other, fixes them, and connects them to form the drill pipe. The anti-twist and anti-displacement feature also prevents the securing elements designed as closure plates from being accidentally released when the drill pipes according to the invention are connected.

[0021] It has proven advantageous that, in the closed position, the beveled longitudinal edges of the openings of the securing elements at least partially engage behind the undercuts of the longitudinal edges of the pairs of fixing means. This embodiment of the invention enables a particularly effective fixation of the securing elements to the drill pipe according to the invention.

[0022] According to a further concept of the invention, the longitudinal elements have milled recesses on their connecting sides in the region of the fixing means, into which the securing element engages such that the drill pipe has essentially the same radius over its entire longitudinal extent, with, in particular, no radial projections occurring in the region of the securing elements. This embodiment of the invention also serves to prevent any radial projections from occurring in the drill string, which would require greater energy expenditure to drive the drill string further into the rock.

[0023] According to a further concept of the invention, two longitudinal elements to be connected can be connected to one another along their longitudinal extent in their connecting area via a tongue-and-groove connection. One longitudinal element has a groove into which a tongue of the other connecting element engages. The tongue and groove can be designed such that at least the groove or the tongue is provided with a sealing element, so that the connection between the two longitudinal elements is fluid-tight along their entire longitudinal extent.

[0024] Further objects, advantages, features, and possible applications of the present invention will become apparent from the following description of exemplary embodiments with reference to the drawings. All described and / or illustrated features, individually or in any meaningful combination, constitute the subject matter of the present invention, regardless of their summary in the claims or their reference back to them.

[0025] They show: Figure 1: an embodiment of a drill pipe according to the invention, which is already connected to a starter drill pipe to form a drill string, Figures 2 to 10: chronological sequence for extending the drill string of the Figure 1 with a further drill pipe according to the invention according to Figure 1 , Figure 11: a cross-sectional view of a drill pipe according to the invention of the Figures 1 to 10in the area of ​​the fixing means and Figure 12: a cross-sectional view of an embodiment of a drill pipe according to the invention in the connection area of ​​two longitudinal elements.

[0026] In the Figure 1 1 shows a drill string 100, which consists of a starter drill pipe 101 and a drill pipe 1 according to the invention connected thereto. The drill pipe 1 according to the invention essentially consists of two interconnected longitudinal elements 2 and 3. The longitudinal elements 2 and 3 have different fixing means 4, 5, 6, with the aid of which the two longitudinal elements are fixed against each other before they are connected and are positioned exactly relative to each other by positioning means 8 and 9 and are then connected to a securing element 7 designed as a closure plate 17.

[0027] On the in the Figure 1On the opposite side of the drill pipe 1, which cannot be seen, the two longitudinal elements 2 and 3 are connected to each other accordingly.

[0028] At its ends 10 and 11, the drill pipe 1 is designed with connecting elements 12 and 13 for connecting another drill pipe according to the invention or for connecting it to the starter drill pipe 101 to form the drill string. A securing element 14 is provided, which prevents the connection between the drill pipe 1 and the starter drill pipe 101 from becoming loose. The securing element 14 engages positively and non-positively in a receptacle of the starter drill pipe 101 and is secured against loosening by the securing element 7, which is designed as a closure plate. As a result, the securing element 14 is captively secured between the drill pipe 1 and the starter drill pipe 101. The securing element 14 not only prevents the drill pipe 1 from becoming loose from the starter drill pipe 101, but also prevents them from twisting relative to one another.

[0029] The Figures 2 to 10now show the chronological sequence for extending the drill string 100, wherein a further drill pipe 1 according to the invention is connected to the drill string 100 of the Figure 1 is connected.

[0030] As it is in Figure 3 As shown, a lower longitudinal element 2 is connected to an upper longitudinal element 3 before it is connected in a further step to the already existing drill string 100, consisting of the starter drill pipe 101 and a drill pipe 1 according to the invention.

[0031] In the presentation of the Figure 3 The fixing means 4 and 6 of the upper longitudinal element 3 and the fixing means 5 and 6 of the lower longitudinal element 2 are clearly visible. The fixing means 4 of the upper longitudinal element 3 have positioning means 8, which can engage with corresponding positioning means 9 of the fixing means 5 of the lower longitudinal element 2.

[0032] Further in the Figure 3On the further drill pipes 1 to be connected to the already existing drill string 100, the connecting means 12 and 13 can be seen, with the aid of which the drill pipes 1 can be connected to one another in a form-fitting manner and secured against axial displacement in a process step to be described.

[0033] Furthermore, the upper longitudinal element 3 has a displacement protection element 15 for the securing element 7, designed as a closure plate 17, of the drill pipe 1 already connected to the starter drill pipe 101. In the connected state of the two drill pipes 1, this prevents the securing element 7, designed as a securing plate 17, of the drill pipe 1 already connected to the starter drill pipe 101 from becoming detached. Furthermore, in the illustration of the Figure 3 The receptacles 18 at both ends 10 and 11 of the lower longitudinal element 2 can already be seen, into which a securing means for protecting the two drill pipes 1 from twisting and loosening can be inserted.

[0034] In the presentation of the Figure 4 The two longitudinal elements 2 and 3 of the drill pipe 1 to be connected to the drill string 100 are now already brought together by their longitudinal edges, with the positioning means 8 of the fixing means 4 of the upper longitudinal element 3 engaging the positioning means 9 of the fixing means 5 of the lower longitudinal element. The fixing means 4, 5 and 6 as well as the positioning means 8 and 9 now secure the two longitudinal elements 2 and 3 against axial displacement of the two longitudinal elements 2 and 3 relative to one another.

[0035] The Figure 5 now shows the drill pipe 1 to be connected to the drill string 100 of the Figure 4as it engages with its connecting elements 12 and 13 at its end 11 into the corresponding connecting elements 13 and 12 of the drill pipe 1 already connected to the starter drill pipe 101. Although the upper longitudinal element 3 and the lower longitudinal element 2 are already positioned relative to the drill pipe 1, they are not yet fixed to one another. Also clearly visible in this illustration is the anti-displacement element 15 of the drill pipe 1 to be connected to the drill string 100, which prevents displacement and thus detachment of the securing element 7, designed as a closure plate 17, of the drill pipe 1 already connected to the starter drill pipe 101.

[0036] In a further step, which Figure 5As shown, a securing means 14 is now inserted into the receptacle 18 in the connecting area of ​​the two drill pipes 1. In doing so, the securing means 14 engages with a part of the securing element 7, designed as a closure plate 17, of the drill pipe 1 already connected to the starter drill pipe 101. Clearly visible in the illustration of the Figure 5 also the anti-displacement element 15, which prevents displacement and thus loosening of the securing element 7, designed as a closure plate 17, of the drill pipe 1 already connected to the starter drill pipe 101.

[0037] In the Figures 6 and 7 It is now shown how the securing means 14 is fully inserted into the receptacle 18 and is thereby in the final or closed position according to Figure 7 which engages under the securing element 7, designed as a closure plate 17, of the drill pipe 1 connected to the starter drill pipe 101.

[0038] The securing means 14 is designed such that, in its final position according to Figure 7, it forms a flat surface with the outer surface of the two pipes, so that no radial projections occur in the area of ​​the securing means 14. Such radial projections would make it more difficult to drive the drill string 100 through the rock and would require increased energy expenditure.

[0039] Figure 8 now shows the securing elements 7, designed as closure plates 17, with which the two longitudinal elements 2 and 3 are permanently connected to one another at their longitudinal edges. Clearly visible here are trapezoidal openings 16 of the securing elements 7, designed as closure plates 17, into which the pairs of fixing means 4, 5, and 6 of the longitudinal elements 2 and 3 subsequently engage, whereby the securing element 7 can be displaced from an open position to a closed position.

[0040] The Figure 9then shows the securing element 7 designed as a closure plate 17 arranged in an open position. As can be seen therefrom, the pairs of fixing means are also trapezoidal, these trapezoids being smaller than the trapezoidal openings 16 of the securing element 7 designed as a closure plate 17.

[0041] The pairs of fixing means 4, 5 and 6 also have longitudinal edges 19 which have a bevel not visible here towards the jacket surface of the respective longitudinal element 2, 3, which will be described in more detail later.

[0042] In the Figure 10 The locking element designed as a closure plate 17 is now separated from the opening position of the Figure 9into the closed position. In this closed position, the securing element 7 now also engages over the securing means 14, so that the latter is fixed captively between the two connected drill pipes 1. In the closed position according to Figure 10 The trapezoidal pairs of fixing means 4, 5 and 6 not only form a positive connection with the trapezoidal openings 16 of the closure element 7 designed as a closure plate 17, but also, through an undercut 21 of the longitudinal edges 19, which, through bevelled longitudinal edges 20 of the openings 16, form a frictional connection in the radial direction of the drill pipe 1 now arranged on the drill string 100.

[0043] This undercut 21 is shown again in the illustration of the Figure 11explicitly visible, which shows a cross-sectional view in the area of ​​the securing element 7 designed as a closure plate 17 and the fixing means 6 of the longitudinal elements 2 and 3 in a closed position of the securing element 7. This explicitly illustrates the radial form and force connection, so that the drill pipe 1, which is now connected to the drill string 100, is captively connected to the drill pipe already connected to the starter drill pipe 101.

[0044] The two longitudinal elements 2 and 3 are secured against each other by the fixing means 6, and the beveled longitudinal edges 20 of the opening 16 of the securing element 7 engage behind the undercuts 21 of the longitudinal edges 19 of the fixing means 6. Because the securing element 7 is secured against displacement, as described above, the two longitudinal elements 2 and 3 of the drill pipe 1 are securely fixed against each other. A similar securing also exists in the areas of the fixing means 4 and 5, which are not shown in cross-section here.

[0045] Figure 12shows a cross-sectional view of an embodiment of a drill pipe according to the invention in the connection area of ​​two longitudinal elements 2, 3 in the area of ​​fixing elements 6. Two longitudinal elements 2, 3 to be connected are connected to one another over their entire longitudinal extent in their connection area via a tongue and groove connection. One longitudinal element 3 has a groove 23 into which a tongue 22 of the other connecting element 2 engages. The groove 23 and tongue 22 can be designed such that at least the groove 23 or the tongue 22 is provided with a sealing element, so that the connection between the two longitudinal elements 2, 3 is liquid-tight over their entire longitudinal extent. Also visible in this illustration are the securing elements 7 for the longitudinal elements 2, 3, designed as closure plates 17. List of reference symbols

[0046] 1Drill pipe 2Longitudinal element 3Longitudinal element 4Fixing element 5Fixing element 6Fixing element 7Securing element 8Positioning element 9Positioning element 10End 11End 12Connecting element 13Connecting element 14Securing element 15Anti-displacement element 16Opening 17Closing plate 18Receptacle 19Longitudinal edge 20Longitudinal edge 21Undercut 22Keyway 23Groove 100Drill string 101Starter drill pipe

Claims

1. Drill pipe (1) for the production of a cased string bore, characterized in that it consists of at least two longitudinal elements (2, 3) which are connected to one another to form the drill pipe (1), wherein the at least two longitudinal elements (2, 3) have different fixing means (4, 5, 6) in order to fix the at least two longitudinal elements (2, 3) against one another by means of securing elements (7) and to connect them to one another to form the drill pipe (1).

2. Drill pipe (1) according to claim 1, characterized in that the at least two longitudinal elements (2, 3) have different positioning means (8, 9) in order to position the at least two longitudinal elements (2, 3) axially relative to one another before connecting them to the drill pipe (1).

3. Drill pipe (1) according to claim 1 or 2, characterized in that each of the at least two longitudinal elements (2, 3) has connecting elements (12, 13) at opposite axial ends (10, 11) in order to connect different drill pipes (1) to form a drill string (100).

4. Drill pipe (1) according to one of the preceding claims, characterized in that a securing means (14) is detachably arranged on the drill pipe (1), which is advantageously fixed by the securing element (7).

5. Drill pipe (1) according to claim 4, characterized in that the anti-twist element (14) is designed to engage positively in a receptacle of a further drill pipe and / or a securing element (7) of a further drill pipe (1).

6. Drill pipe (1) according to one of the preceding claims, characterized in that a displacement protection element (15) for the securing element (7) is arranged on at least one of the longitudinal elements (2, 3).

7. Drill pipe (1) according to one of the preceding claims, characterized in that the fixing means (4, 5, 6) form pairs which are trapezoidal in shape and have longitudinal edges (19) which are formed with an undercut (21) towards the jacket surface of the respective longitudinal element (2, 3).

8. Drill pipe (1) according to one of the preceding claims, characterized in that the securing element (7) is designed as a closure plate (17) and has trapezoidal openings (16) into which the pairs of fixing means (4, 5, 6) of the longitudinal elements (2, 3) engage, wherein the securing element (7) is displaceable from an open position into a closed position.

9. Drill pipe (1) according to claim 8, characterized in that in the closed position, the longitudinal edges (19) of the pairs of fixing means (4, 5, 6) provided with an undercut (21) are at least partially engaged behind by bevelled longitudinal edges (20) of the securing element (7).

10. Drill pipe (1) according to one of the preceding claims, characterized in thatthe longitudinal elements (2, 3) have milled recesses on their connecting sides in the region of the fixing means (4, 5, 6), into which the securing element (7) engages in such a way that the drill pipe (1) has the same radius over its entire longitudinal extent.

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