EP3259434B1 - "twin-tube drill rod section, twin-tube drill rod length and method for forming an electrically conductive connection in a twin-tube drill rod section" - Google Patents

Description

The invention relates to a double pipe rod section, a double pipe rod section and a method for forming an electrically conductive connection in a double pipe rod section.

In the case of rod-based drilling in the ground, in particular for the production of so-called horizontal bores, a drill head is driven by means of a drill rod from a drive device arranged on the surface of the earth or in a construction pit. The drill rods used here consist of individual, interconnected rod sections, which - according to the drilling path - are gradually attached to the rear end of the already drilled drill rod and connected to it.

For rock drilling, ie drilling in rock or stony earth formations, a double pipe rod or double rod is used. In these drilling devices, the drill head is additionally driven in rotation via an inner rod of the double pipe rod from the drive device arranged on the surface or in the excavation, which also provides for the propulsion of the drill head. For this purpose, the inner linkage is rotatably mounted within an outer linkage of the double pipe linkage. With the double pipe rods, the individual rod sections of both the outer rod and the inner rod are either screwed to one another or plugged into one another.

To supply electrical consumers in the double pipe system and / or to transmit signals, there is a need to provide electrical connections in the double pipe system. For this purpose it is known to use a conductor or a cable which is guided inside the inner pipe rod.

A disadvantage of the previous provision of electrical connections is that the electrical connection for conducting electrical energy - for an electrical voltage or power supply and / or transmission of data - can only be made in the inner pipe rods, since it was previously assumed that the conductor or the cable must be protected in the inner pipe rod.

U.S. 5,468,153 A discloses a cordless vortex and method of using it. A rotatable mandrel is described which is disposed in a housing body. A ladder rod is arranged in the mandrel, which ends in an enlarged head with respect to the diameter. The head represents an electrical contact with a cup-shaped counterpart.

EP 2 957 710 A1 is postpublished and discloses a drill head and apparatus for making a bore in the earth. The drill head has a sliding contact arrangement for establishing an electrical connection between a first unit and a second unit. The first unit can be coupled with an inner linkage of a double pipe linkage. The second unit can be coupled to an outer linkage of the double pipe linkage. Drilling fluid is passed through the units.

Proceeding from this prior art, the invention was based on the object of creating an improved double pipe rod section, an improved double pipe rod section and an improved method for forming an electrically conductive connection in a double pipe rod section, in which an electrical connection in the annulus between the inner pipe rod and outer pipe rod is also possible is.

The object is achieved by the subjects of the independent patent claims. Advantageous further developments of the subjects of the independent claims are the subject of the respective dependent claims and result from the following description.

The core idea of the invention is to lead the at least one conductor provided in the inner rod section out of the inner rod section in such a way that a pick-up present in the annular space between the inner rod section and the outer rod section is in contact with an external contact formed on the inner rod section. An outer contact is formed on the inner linkage section, which is formed essentially in a ring shape around the circumference of the inner linkage section. The external contact can be electrically connected to the at least one conductor of the inner rod section and the electrical signal or the current or the voltage can be tapped by means of the collector present in the annular space between the inner rod section and the outer rod section, since the collector is in contact with the annular external contact of the inner rod . The double pipe rod section has a sealing means for sealing against drilling fluid.

The outer contact is formed essentially annularly around the circumference of the inner linkage section, which includes that the outer contact is designed to be closed around the circumference of the inner linkage along the circumference. The extension of the external contact in the longitudinal direction of the inner linkage or inner linkage section can have any shape. For example, the external contact can be designed as a band placed around the internal linkage section. The band can have the same width along the circumference. The extension of the pickup in the direction of the longitudinal axis of the inner linkage is preferably equal to or less than the extension of the external contact in the longitudinal direction of the inner linkage.

According to the invention, the double pipe rod section can be a double pipe rod section of an earth drilling device. The term “section” includes a region of the double pipe rod in the longitudinal direction. The term “rod section” can be understood to mean a “rod section”. An "earth boring device" is understood to mean, in particular, any device which moves a double pipe rod into an existing or to be created channel in the ground in order to create or widen a bore, in particular a horizontal bore, or to pull lines or other long bodies into the earth. The earth drilling device can in particular be an HD device (horizontal drilling).

The term "conductor" within the meaning of the invention includes an electrically conductive conductor, which is used in particular as a cable, i.e. can be designed with an at least partially existing insulation that envelops the conductor.

By means of the double pipe rod section according to the invention, drilling fluid can be conveyed at least in sections through the interior of the inner rod and the annular space between the inner rod and the outer rod. This creates more difficult conditions for the transmission of electrical signals.

The at least one conductor is sealed in the area of the annular outer contact in the inner rod section. The term “sealed” in the context of the invention includes, in particular, a sealing of an area with respect to the drilling fluid present at least in sections in the double pipe string. To form the seal, a sealing means is present in the inner rod section, which prevents the passage of drilling fluid into the area of the inner rod section in which the at least one conductor is connected to the external contact. Additionally and / or alternatively it can be provided that before the sealing of the area in which the at least one electrical conductor is connected to the external contact, pressure relief is carried out by having at least one through-hole in the inner rod in front of this area or in front of the sealant that creates a fluidic connection between the interior of the inner linkage and the annular space between the inner linkage and the outer linkage.

The outer area of the inner rod section in the area of the outer contact is sealed by means of sealing elements spaced apart in the longitudinal direction of the double pipe rod section. This can prevent electrical currents from occurring via the drilling fluid that is present at least in sections in the double pipe string.

The consumer is sealed off from the annular space between the inner rod section and the outer rod section, so that undesired electrical (creeping) currents can be reduced.

The external contact is preferably electrically isolated from the internal linkage section. For electrical insulation of the external contact with respect to the internal linkage, an insulating layer, which can be designed as an insulating sleeve, can be present between the external contact and the internal linkage. The external contact can be connected non-rotatably to the internal linkage via the insulating layer.

In a particularly preferred embodiment, a double pipe rod section is created which comprises an aforementioned double pipe rod section which has a probe present in the annular space between the inner rod and the outer rod. The probe can be connected to the outer rod and connected to the consumer by means of at least one conductor.

A method is also provided for forming an electrically conductive connection in a double pipe rod section, the electrically conductive connection being formed between an interior of an inner rod section and the annular space between the inner rod section and the outer rod section. It will a substantially annular outer contact is provided on the inner rod section and a conductor, which is provided in the interior of the inner rod section, is connected to the annular outer contact, a consumer in contact with the outer contact, which is arranged in the annular space, being guided in conductive contact via the outer contact .

The above statements, like the following description of an exemplary embodiment, do not represent a waiver of specific embodiments or features.

The invention is explained in more detail below using an exemplary embodiment shown in the drawings.

Fig. 1

einen erfindungsgemäßen Doppelrohrgestängeabschnitt von der Seite;

Fig. 2

eine teilweise Schnittdarstellung der Fig. 1;

Fig. 3

eine Schnittdarstellung eines vergrößerten Bereichs der Fig. 2; und

Fig. 4

eine weitere Vergrößerung der Fig. 3 in einer Teildarstellung.

In the drawings shows:

Fig. 1

a double pipe rod section according to the invention from the side;

Fig. 2

a partial sectional view of the Fig. 1 ;

Fig. 3

a sectional view of an enlarged area of FIG Fig. 2 ; and

Fig. 4

another enlargement of the Fig. 3 in a partial representation.

Figures 1 and 2 show a double pipe linkage in a front area. The Figures 1 and 2 show a double pipe rod section 6 with an outer rod section 1 and an inner rod section 2, an electrical connection being established from the inside of the inner rod section 2 to the annular space 4 between the inner rod section 2 and the outer rod section 1. By means of the electrical connection in the double pipe rod section 6, a probe 3 which is off-center in the double pipe rod can be supplied with energy and / or data. A transmission of energy and / or data in the direction of the probe 3 and / or bidirectional to the probe 3 and from the probe 3 is possible. The double pipe rod section 6 can enable the function of a transmission of energy and / or data between the interior of the inner rod and the annular space 4 between the inner rod and the outer rod.

The probe 3 is located in a probe housing which is connected to the outer rod. The inner rod can rotate within the outer rod independently of the rotational movements of the outer rod and drive a drill head. A desired drilling direction can be set by rotating the outer rod. The probe 3 moving along with the outer rod can detect certain values, such as the roll angle or the inclination of the double rod rod, and transmit them to a further unit known from the prior art. The transmission can take place wirelessly and / or wired.

A conductor 8 or a cable is routed inside 5 of the hollow inner rod (cf. Fig. 3 ), which can be used to transmit data and / or energy. In the double pipe rod section 6, the conductor 8 or the cable is guided to the outside via a bore and electrically connected to an annular external contact 10, which is designed as a slip ring. The annular outer contact 10 has an electrically insulating sleeve 16 which is firmly seated on the inner rod section. As a result, the annular outer contact is electrically isolated from the inner rod section. The conductor carried out from the inner rod section is clamped to the annular outer contact, for which purpose in the illustrated embodiment Figures 3 and 4th a screw 11 is used.

An electrically conductive pickup 13 is in contact with the external contact. In addition to the embodiment shown, several pickups 13 can also be used. The customer or customers 13 are arranged in an insulating sleeve 17 made of non-conductive material. A further conductor 14, to which the probe 3 can be connected, is connected to the receiver or consumers 13. The energy or data pending on the conductor 8 can be transmitted to the further conductor 14.

In the drilling operation, drilling fluid is initially conveyed during the drilling progress to avoid pressure losses through the increasingly longer double pipe rod via the annular space 4 between the inner rod and the outer rod and through the interior of the inner rod. Drilling fluid is discharged in the direction of the drill head, in front of the double pipe rod section in which the electrical connection between the at least one conductor 8 and the external contact is made, through outwardly leading holes 7 in the inner rod, which means that the drilling fluid from the inner rod on the last section up to the drill head is also passed through the annular space 4. In the direction of flow of the drilling fluid, behind the bores 7 of the double pipe rod section, the conductor 8 located in the inner rod and rotating with it is sealed against the prevailing drilling fluid pressure by means of a sealant 9.

The section of the double pipe rod in the area of the annular external contact is sealed by means of two sealing elements 12 which are spaced apart in the longitudinal direction of the double pipe rod section and which are designed as sealing rings. A further sealing means 15, which is designed as a sealing ring, is also present, which surrounds the further conductor 14. In the exemplary embodiment shown in the figures, the collector (s) 13 is / are connected in a rotationally fixed manner to the outer rod section, whereby a rotary movement relative to the outer rod is prevented. There is a torque support 18 which prevents a rotary movement of the pickup (s) 13. The collector or the collectors 13 are guided via the annular external contact, following the rotary movement of the external linkage.

Claims (6)

1. Double drill rod section (6) with an outer drill rod section (1) and an inner drill rod section (2), wherein the inner drill rod section (2) has at least one conductor (8) and drilling fluid can be conveyed through the interior of the inner drill string and the annulus (4) between the inner drill string and the outer drill string at least in some sections, wherein the inner drill rod section (2) has a substantially annular external contact (10) in the annulus (4), electrically connected with the externally routed conductor (8), for forming an electric connection of the conductor (8) with a further electric conductor (14), and a pick-up (13) is in contact with the annular external contact (10) of the inner drill rod section (2) in the annulus (4) between the outer drill rod section (1) and the inner drill rod section (2) connected with the outer drill rod section (1) in a torque-proof way, wherein the pick-up (13) is connected with the further conductor (14) and the outer region of the inner drill rod section (2) is sealed in the region of the external contact (10) by means of sealing elements (12) distanced from each other in longitudinal direction of the double drill rod section and the pick-up (13) is sealed off from the annulus (4) between the inner drill rod section (2) and the outer drill rod section (1), wherein the double drill rod section (6) has a sealing means (9) in the inner drill rod section (2), which prevents an ingress of drilling fluid into the region of the inner drill rod section (2) in which the conductor (8) is connected with the external contact (10).
2. Double drill rod section (6) according to claim 1, characterised in that the annular external contact (10) has an electrically insulating sleeve (16) that sits firmly on the inner drill rod section (2).
3. Double drill rod section (6) according to claim 1 or 2, characterised in that the external contact (10) is designed as a slip ring.
4. Double drill rod section (6) according to one of the claims 1 to 3, characterised in that the conductor (8) is clamped to the external contact (10) by means of a screw (11).
5. Double drill rod, having a double drill rod section (6) according to one of the claims 1 to 4, characterised in that a probe (3) is provided in the annulus (4) between the inner drill rod string and the outer drill string.
6. Method for forming an electrically conductive connection in a double drill rod section (6), wherein the electrically conductive connection between a conductor (8) in the interior (5) of an inner drill rod section (2) and a further conductor (14) formed in the annulus (4) between the inner drill rod section (2) and the out drill rod section (1), and drilling fluid can be conveyed through the interior of the inner drill string and the annulus (4) between the inner drill string and the outer drill string at least in sections, wherein the method includes the following steps: provision of a substantially annular external contact (10) on the inner drill rod section and the electrical connection of the externally routed conductor (8) with the annular external contact (10), wherein a pick-up (13) in contact with the external contact, which is arranged in the annulus (4) and connected with the outer drill rod section (1) in a torque-proof way, is routed via the external contact (10) and the inner drill rod section (2) is sealed by means of a sealing agent (9) located in the inner drill rod section, which prevents an ingress of drilling fluid into the region of the inner drill rod section (2) in which the conductor (8) is connected with the external contact (10), and the pick-up (13) is connected with the further conductor (14), and the external region of the inner drill rod section (2) is sealed in the region of the external contact (10), and the pick-up (13) is sealed off from the annulus (4) between the inner drill rod section (2) and the outer drill rod section (1).

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