EP2820228B1 - Drill pipe - Google Patents

Description

The invention relates to a drill pipe having the features of the preamble of claim 1.

Such a drill pipe is from EP 0 257 744 A known.

A key element in modern oil, gas and

Geothermal drilling is the acquisition of data during the drilling process ("Measurement While Drilling" (MWD), "Logging While Drilling" (LWD)). However, the same also applies to the construction of the borehole ("well site construction") and the subsequent oil, gas and hot water production. A well can only be operated safely, efficiently and economically by recording the relevant measured variables. A problem arises both in the real-time data transmission ("online data transmission") of measurement data to the surface and in the power supply ("power supply") of the underground measurement units from the surface. The data should be transmitted at a high data rate (e.g. 200kbaud) from a depth of several kilometers, and the underground measuring units should be supplied with energy (e.g. 200W) from above ground.

One of the biggest problems is the risk of explosion. In particular, the occurrence of gas accumulations, which can only be predicted to a limited extent, must be considered. Special safety precautions must therefore be taken for the wiring of drill rods, which prevent the occurrence of possible ignition sparks or only allow them to occur in explosion-protected areas.

Approaches to a solution in which the individual elements of the drill string are only inductively coupled to one another, i.e. there are no exposed electrical conductors or contacts, circumvent this problem, but neither the desired data rates can be achieved nor underground consumers can be supplied with electricity. A solution is therefore required that makes it possible to galvanically connect drill string elements or drill pipes to one another. This requires suitable solutions for the coupling of the individual drill string elements or drill pipes as well as for the wiring of the drill pipes themselves. the former will by the device for connecting electrical conductors according to the AT 508 272 B1 solved.

The invention is therefore based on the object of creating a solution for the cabling within a drill pipe or drill string.

This problem is solved by a drill pipe with the features of claim 1.

This arrangement protects the wiring in two ways. On the one hand, the environment is protected against the electrical conductor, since this is separated from the environment. On the other hand, there are conditions both inside and outside of a drill string that place special demands on the materials used and lead to rapid wear, against which the conductor is also protected.

Due to the regional spacing of the drill pipe from the inner pipe, a cavity is created between the two. According to a preferred embodiment of the invention, this can contain a filling material. However, the cavity can also be empty. This counteracts possible deformations of the inner tube, which can be caused by the rinsing liquid being conducted through the inner tube at very high pressure. In addition, if necessary, suitable filling material can be used to dampen vibrations or oscillations that occur during operation, or the flushing liquid can be thermally insulated from the surroundings of the drill pipe.

Alternatively, according to a preferred embodiment, the filling material can be used for sensory purposes, since various measurable properties of the filling material change due to the conditions prevailing in and around the tube. Both properties that correlate directly with the environment, such as pressure and temperature, and those that only indirectly correlate with the environment, such as the electrical conductivity of the filling material, can be measured.

According to a preferred embodiment, the electrical conductor is arranged on the outside of the inner tube. The fastening must be done in such a way that the conductor and the inner tube are electrically isolated from one another, since this is usually made of a conductive material, such as steel.

By attaching the conductor directly to the inner tube, changes in the inner tube, in particular changes in length, for example as a result of thermal expansion or its own weight, can be transmitted directly to the conductor. As a result, the head itself sensory purposes, for example, to measure the length of the drill string as in the AT 504 294 A described, fulfill.

According to a particularly preferred embodiment, the electrical conductor on the outside of the inner tube is preferably connected to the inner tube over the entire length of the conductor, for example glued on. Ideally, the conductor itself takes the form of a section of pipe. Furthermore, as a result, the conductor stands out little or not at all from the shape of a tube or a section thereof. In this way, the largest possible conductor cross section can be achieved for the given space, as a result of which the electrical resistance of the conductor is kept as low as possible. If several conductors are desired, electrically insulating webs can be provided, for example, through which the conductor is divided lengthwise into partial conductors, e.g. halved or quartered. The number of leaders can be adjusted to the needs and/or different leaders can each be assigned a different task. For example, six conductors can be provided, two of which are used to supply energy to loads and four as data conductors. Two conductors are preferably used, one as a forward conductor and one as a return conductor, which are used both as power and data conductors.

According to a further preferred embodiment of the invention, at least one electrical and/or electronic device is arranged in the cavity independently of or in addition to the aforementioned embodiments. This can fulfill different functions. On the one hand, according to a preferred embodiment of the invention, it can fulfill sensory tasks, including measuring the various properties of the filling material or the conductor itself, as described above, or, for example, detecting the position or orientation of the drill string with a position sensor. On the other hand, it can be used, for example, as a signal amplifier, for example for data signals coming from adjacent drill string elements or instruments in the drill head.

According to a further alternative or additional preferred embodiment, an electronically readable information carrier, in particular a chip, is arranged in the cavity and the electronically readable information carrier is connected to the electrical conductor via a switch. On the one hand, individual drill pipes can be identified at any time, but on the other hand, information such as the time the drill pipe was last serviced can be stored directly in the drill pipe. In this case, for example, a warning can be given if a drill pipe was serviced too long ago.

Further preferred embodiments of the invention are the subject matter of the remaining dependent claims.

Fig. 1

einen schematisierten Querschnitt durch eine Ausführungsform eines erfindungsgemäßen Gestängerohrs mit vier Leitern,

Fig. 2

einen Längsschnitt durch ein Ende einer weiteren Ausführungsform des erfindungsgemäßen Gestängerohres mit einem Leiter und

Fig. 3

einen Längsschnitt durch das andere Ende der Aufführungsform des erfindungsgemäßen Gestängerohres von Fig. 2.

The invention will be explained further below with reference to the drawings. It shows:

1

a schematic cross section through an embodiment of a drill pipe according to the invention with four conductors,

2

a longitudinal section through one end of a further embodiment of the drill pipe according to the invention with a conductor and

3

a longitudinal section through the other end of the performance form of the drill pipe according to the invention 2 .

A drill pipe 1 according to the invention has an inner pipe 2 , a cavity 3 between drill pipe 1 and inner pipe 2 and at least one conductor 4 , 7 , 8 , 9 . In this embodiment, the drill pipe 1 consists of steel.

The 1 shows the structure of a drill pipe 1 according to the invention in a highly schematic form in section. The inner pipe 2 is electrically insulated from the outside by an insulation 5 . This is necessary above all if an electrically conductive or electrostatically chargeable material is used for the inner tube 2 . Since materials must be selected for the inner tube 2 that can withstand the special conditions encountered during drilling, steel is usually used for this purpose, ie an electrically conductive material. Without insulation 5, an interior 6 of the inner tube 2 would be exposed to an increased risk of explosion or the risk of a short circuit. If an electrically non-conductive material, for example a carbon fiber reinforced plastic, is used for the inner tube 2, the insulation 5 between the conductors 4, 7, 8, 9 and the inner tube 2 could also be dispensed with. In the illustrated embodiment, four conductors 4 , 7 , 8 , 9 are located on the insulation 5 and are insulated from one another by insulating webs 10 , 11 , 12 , 13 . In this example, the conductors 4, 7, 8, 9 are each in the form of quarter tube segments. Embodiments in which only one tubular conductor 4 is provided are just as conceivable as those in which other numbers, for example two, three, five or more, of conductors 4, 7, 8, 9 are provided. It is also possible to simply arrange round or flat conductors on the inner tube.

In the exemplary embodiment, the cavity 3 is located between the inner pipe 2 with the conductors 4, 7, 8, 9 and the drill pipe 1, which cavity extends essentially over the entire length of the drill pipe and is preferably filled with a filling material. The cavity is sealed at both ends by a seal 26, 27 ( 3 ) sealed. The filling material is preferably free-flowing or free-flowing. The filling material can consist of, for example, resin, silicone oil, sand, glass or ceramics or contain these materials. Should be a filler be chosen, which is electrically conductive, it is necessary to also attach insulation to the side of the conductors 4, 7, 8, 9 facing the drill pipe. Such an insulation makes sense in any case, also to avoid damage to the conductors 4, 7, 8, 9 during installation. In this sense, embodiments are also conceivable in which the conductors 4, 7, 8, 9 are partially or completely accommodated in the material of the inner tube 2.

In the illustrated embodiment, an electrical device 14 and an electronically readable information carrier 15 are in the cavity 3, surrounded by filling material. Both are connected, optionally via switches, to at least one conductor 4, 7, 8, 9 (not shown).

The 2 shows a longitudinal section through one end of a further embodiment of a drill pipe according to the invention. The drill pipe 1 has a thread 16 in the end 19 designated as a box, with which it is connected to the end 23 designated as a pin ( 3 ) of another drill pipe can be connected. Furthermore, it has a first part of a clutch mechanism. The clutch mechanism consists of two assemblies 17a, 17b and can, for example, as in the AT 508 272 B1 explained to be constructed. The clutch mechanism makes a galvanic connection only via the pin 18 which slides from the first assembly 17a of the clutch mechanism towards a second assembly 17b of the clutch mechanism. All other parts of the clutch mechanism are isolated from the environment. At its end remote from the thread 16, the first subassembly 17a of the clutch mechanism is galvanically connected to the conductor 4. In order to further reduce the risk of explosion and damage, the end of the conductor 4, the first assembly 17a of the coupling mechanism and their connection are insulated from the interior of the inner tube 2 by additional insulation 20. In the further course, the conductor 4 is then similar to in 1 shown on an insulation 5 on the inner tube 2.

So that the cavity 3 between the inner pipe 2 and the drill pipe 1 is also accessible after the drill pipe 1 has been completed, at least one opening 21 is provided in the drill pipe 1 which can be closed with a closure element 22 . The cavity 3 can be filled with different filling materials, or these can be exchanged according to the situation and/or the desired function. For example, in applications where it is to be expected that the inner pipe 2 will vibrate more strongly, the cavity can be filled with sand in order to dampen these vibrations. Alternatively, ceramic balls could also be used, for example. In other possible applications, it may be desirable for the drill pipe 1 to have buoyancy in the mud, which has a relatively high specific weight, which can be advantageous in horizontal drilling, for example, in order to reduce friction on the borehole wall. In this case, e.g. air or light oils would be a more suitable filling material.

Furthermore, electrical devices 14 or electronically readable data carriers 15 can be made accessible via the opening 21 and/or exchanged or repaired if necessary.

The 3 shows a longitudinal section through the other end of drill pipe 1, designated as pin 23 2 . The second subassembly 17b of the coupling mechanism creates a galvanic connection to the conductors of a following drill pipe. On its side facing away from the connection runs a conductor 24, for example a cable, to the conductor 4 located on the inner tube 2. In order to allow easy access to this connection, for example for maintenance, there is also an opening 21 here, which can be closed with a closure element 22 .

Claims (14)

1. Drill pipe (1) for a drill string, with at least one electrical conductor (4, 7, 8, 9) and an inner pipe (2), which is arranged inside the drill pipe (1), wherein the drill pipe (1) and the inner pipe (2) are at a distance from one another in places, by which the drill pipe (1) and the inner pipe (2) bound a hollow (3), and wherein the electrical conductor (4, 7, 8, 9) is arranged at an outer side of the inner pipe, characterized in that the hollow (3) is completely sealed relative to the environment.
2. Drill pipe (1) according to Claim 1, characterized in that the electrical conductor (4, 7, 8, 9) is arranged on the outer side of the inner pipe (2).
3. Drill pipe (1) according to Claim 1 or 2, characterized in that the electrical conductor (4, 7, 8, 9) is fastened on the outer side of the inner pipe (2).
4. Drill pipe (1) according to one of Claims 1 to 3, characterized in that the electrical conductor (4, 7, 8, 9) is connected to the inner pipe (2) on the outer side of the inner pipe (2) preferably over the entire length of the conductor (4, 7, 8, 9).
5. Drill pipe (1) according to one of Claims 1 to 4, characterized in that at least one electrical device (14) is arranged in the hollow (3).
6. Drill pipe (1) according to Claim 5, characterized in that the electrical device (14) is a sensor.
7. Drill pipe (1) according to Claim 6, characterized in that the sensor is a temperature sensor, a pressure gauge, a terrestrial magnetic field sensor or a strain sensor.
8. Drill pipe (1) according to one of Claims 1 to 7, characterized in that a filler is located in the hollow.
9. Drill pipe (1) according to Claim 8, characterized in that the filler is resin, silicone oil, sand, glass or ceramic.
10. Drill pipe (1) according to Claim 8, characterized in that the filler has a lower specific weight than a drilling fluid that flows through the drill pipe.
11. Drill pipe (1) according to one of Claims 1 to 10, characterized in that an electronically readable data carrier(15), in particular a chip, is arranged in the hollow (3), and in that the electronically readable data carrier (15) is connected via a switch to the electrical conductor (4, 7, 8, 9).
12. Drill pipe (1) according to one of Claims 1 to 11, characterized in that multiple conductors (4, 7, 8, 9) are separated from one another by optionally insulating webs (10, 11, 12, 13).
13. Drill pipe (1) according to one of Claims 1 to 12, characterized in that at least one conductor (4, 7, 8, 9) is a data conductor.
14. Drill pipe (1) according to one of Claims 1 to 13, characterized in that at least one conductor (4, 7, 8, 9) serves to supply consumers with power.

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