DE19808478C2 - Process for trenchless laying of pipes - Google Patents

Description

The present invention relates to a method for trenchless laying of pipes.

With the advancing mechanization of human life, more and more Measures required to connect this to the infrastructure network. Includes the infrastructure network has a multitude of elements, starting almost from today understandable things like electricity, water and gas up to information-carrying cables for telecommunications, television and the like.

Especially the supply lines mentioned above in the broadest sense are constantly dig improved and expanded. It is particularly necessary in conurbations that these measures do not interfere with the usual processes  

Trenchless laying of pipes such as piping is particularly suitable for this. and product pipes that allow pipes to be closed in the broadest sense without disturbing the environment embarrassed. They can be used to run cables under the runway of an airport, a street, a track body or a house can be relocated without their normal use also would be limited in the least. At the same time, the trenchless laying he allowed limit required earth movements to a minimum, which is also an advantage.

In the prior art there are in particular two methods for the trenchless laying of Product lines of greater length and / or large diameter are known. On the one hand, this is the so-called micro-tunneling and on the other hand the controlled horizontal drilling technology.

In micro-tunneling, a starting shaft is typically created around a drill head including the pre-press unit to the depth at which the product pipe is to run. Except From the bottom of the starting shaft, the drill head is then regularly used Prepress unit driven. The thrust elements used for propulsion are Rohrele elements that should ultimately form the actual conduit.

Disadvantages of micro-tunneling can be seen in the fact that on the one hand the geometric sizes zen with regard to length and radius of curvature as well as the coupling of the pipe construction to the Drilling process exists or exists. This leads to difficulties in quality assurance, especially in the pressure test, and to disturbances and interruptions of the actual Drilling process. In addition, complex construction pits (depth, Wi derlager) is necessary, for which in areas with high groundwater levels sometimes from ecological undesirable groundwater holdings are necessary. The pipe covering is exposed to large mechanical loads during the pulling process, which in particular in unfavorable soil conditions, damage to the casing and in the case of high loads demands - e.g. B. you gas pipelines - sometimes for non-acceptance of the installed lines through the client

With the controlled horizontal drilling technology, the alignment of the drill head is made accordingly the desired drill route by suitable controls ge during the drilling process changes.  

The horizontal drilling technique is in a special way on suitable ground such as sand and Sound instructed. In addition, there are those related to micro-tunneling mentioned problems regarding the load on the pipe casing here as well. Still is due to the open irrigation circuit in horizontal drilling technology and the large one to be supported A large drilling fluid volume is required. This must be after the move be disposed of in an environmentally friendly manner. There are also ecological problems me due to drilling fluid eruptions along the drilling route. Another disadvantage of this construction process is the possibility of day breaks in large borehole diameters in little cohesive soils or above the groundwater horizon.

The laying of a pipe string along a given, also curved Laying route belongs to the state of the art in the application of the two trenchless laying process controlled horizontal drilling technology and microtunnelling.

A method is also known (EP 89 20 2233), in which, upon withdrawal of the the known way introduced pipe (drill string) through the borehole a scraper mounted centrally at the end of the strand is expanded and the product pipe that is firmly connected to the scraper is drawn in. The Räumer is a well-known tool in the field of Horizontal drilling technology and is achieved by rotating the drill string with the help of Drilling rig driven.

The problem with this method is the encounter of gravel / stones from one certain size or compact soil formations, as with the help of the used Räumers a full-surface mechanical soil degradation only limited and one Crushing stones are not possible at all.

That which is new in relation to this prior art relates to the present invention essentially expanding the borehole with the help of a drill own drive, the eccentric connection of this machine with the pull used drill string and the possibility for putting a protective tube in a defined section of the route.

A conventional microtunnelling machine is used as a drilling machine Area of controlled pipe jacking used with either a Scraper, a cutting wheel or a drill head is equipped, larger Can crush stones with the help of an integrated crusher and at their Outside not rotated.

The drill string used for pulling rotates in contrast to all known ones Neither do procedures during the laying process.

The object of the present invention is to provide a method for laying product lines to provide gene, which the aforementioned disadvantages of the known Avoids proceedings.

According to the invention, the object is achieved by a method for trenchless laying of pipes, which has the following steps:

• a) performing a pilot bore ( 1 ) along a laying route ( 3 ) starting at an entry point (E) and ending at an exit point (A);
• b) expanding the pilot bore ( 1 ) by a drilling machine ( 10 ) by guiding it from the exit point (A) of the pilot bore to the entry point (E) of the pilot bore; and a tube ( 7 ) is drawn in at the same time.

In one embodiment it is provided that the pilot bore ( 1 ) is carried out by means of a controlled horizontal borehole.

In a further preferred embodiment it is provided that the pilot bore ( 1 ) created by step (a) is widened by withdrawing the pilot drill string by means of a reamer ( 16 ).

It can be provided that at least one drill string ( 9 a, 9 b) is drawn in with the expansion of the pilot bore ( 1 ) by withdrawing the pilot drill string.

In a preferred embodiment it is provided that the pilot hole ( 1 ) created by step a) is expanded by withdrawing the pilot drill string and at least one new drill string ( 9 a, 9 b) is drawn into this larger drill hole.

In the method according to the invention, it is particularly preferred that two drill strings ( 9 a, 9 b) are drawn in.

In a further embodiment of the method according to the invention it is provided that the drilling machine ( 10 ) is pulled from the drilling system ( 2 ) via the pilot drill string.

In one embodiment, it can in particular be provided that the drilling machine ( 10 ) is pulled from the drilling rig 2 by the high-strength drilling string / by the high-strength drilling strands ( 9 a, 9 b).

In the method according to the invention it can be provided that in addition to the tube ( 7 ) at least one cable protection tube ( 8 a, 8 b) is drawn in.

In a very particularly preferred embodiment it can be provided that the cable protection tube ( 8 a, 8 b) is attached to the drill string and is pulled in together with tube ( 7 ).

It can be provided that the pipe ( 7 ) to be laid is drawn in as the drill ( 10 ) proceeds as part of step (b).

In a further embodiment it is provided that at least one protective tube ( 5 , 6 ) is further drawn in.

In a preferred embodiment it can be provided that the protective tube ( 5 , 6 ) is connected to the drilling machine ( 10 ).

In the method according to the invention it can further be provided that the protective tube ( 5 , 6 ) is retracted in that the drilling machine ( 10 ) is withdrawn.

It is particularly preferred if the drilling machine ( 10 ) is withdrawn from the drilling rig ( 2 ) via the drill string ( 9 a, 9 b).

In a preferred embodiment it can be provided that a protective tube ( 5 , 6 ) is placed and this protective tube ( 5 , 6 ) is placed at the entry point (E), at the exit point (A) or between the entry point (E) and the exit point (A).

In a further, alternative embodiment of the method according to the invention it can be provided that several protective tubes ( 5 , 6 ) are placed one after the other.

It can be provided that unsecured borehole areas remain between the protective tubes ( 5 , 6 ).

The invention is based on the surprising finding that the inventive Process for laying pipes the disadvantages of the Ver known in the prior art driving can be avoided while realizing the inherent advantages.

In particular, the method according to the invention relates, inter alia, to the following, aspects of general importance for the laying of pipes basic, quality assurance, environment and safety, efficiency and pipe construction.

Regarding the ground, the method according to the invention has advantages in that Clay, sand and gravel, especially coarse gravel, does not cause any impairment in the Contrary to the pure horizontal drilling technique, which in the end is satisfactory only with clay and sand can be used.

The method according to the invention has advantages from the aspect of quality assurance both with regard to the extent of the stress on the pipe casing, which is in the present case is particularly low compared to a high load in the case of the micro- Tunnelings or moderate loads in the case of horizontal drilling technology. Still possible the method according to the invention is the only one of the three methods discussed herein provide additional protection of the product pipe for trenchless laying of pipes Sections.

In the area of environment and safety, the low risk of day breaks is particularly high risk of flushing outbreaks, the small volume of the total flush volume and the  to mention small amount of flushing to be deposited, each in particular compared to the Horizontal drilling technology are advantageous. In addition, the Ver drive only very small construction pits and no water drainage required in contrast to Micro tunneling.

This is particularly important with regard to the performance of the method according to the invention with long installation lengths, e.g. B. at lengths that are more than five hundred times the through knife, and in the case of relatively tight curve radii, where it is particularly against over micor tunneling is an advantage.

Finally, the method according to the invention is also actually the case with regard to pipe construction Senses, d. H. Particularly advantageous compared to micro-tunneling, since the related ones Work is not linked to the drilling process, in contrast to the conditions when Micro tunneling. In addition, the pipe construction is in turn opposite Micro-tunneling easier because all pipe construction work on surface and above ground can be processed one after the other.

The term "pipe" is intended to be understood in a non-limiting manner; it embraces also the terms "line", "pipeline" and "product line". The invention The process is therefore not limited to the laying of certain pipes, ins special not on the object contained in the tubes, contained in these, is promoted, transported or managed.

In the method according to the invention, a drilling route can be defined before the pilot bore is carried out after step a), which is the basis for the pilot bore as well as for the subsequent drawing in of the pipe ( 7 ) to be laid, and consequently the route for the pipe to be laid .

It is also within the scope of the present invention that the pilot bore through the back pulling the pilot drill string is expanded, the drilling rig then advantageously as Double-head drilling system is designed. This process is then followed by expansion using the drilling machine according to step b) of the method.  

In step b) of the method according to the invention, the pilot bore is optionally widened in that a drilling machine ( 10 ) is used. The drilling machine advances or advances by withdrawing the pilot drill string ( 1 ). At the same time, however, it is also possible and within the scope of the present invention, that the drill is additionally or exclusively driven by the drill string (s) ( 9 a, 9 b).

With regard to the retraction of protective tubes, there are basically different alternatives to be regarded as equal. For example, it is possible that no protective tube is used becomes. This is especially appropriate when the pipe is in geologically stable soil strata is carried out or the surface events are such that none for the pipe after partial effects are to be feared or the pipe itself absorb the forces that occur can.

Accordingly, it is possible that only near the entry point and / or the exit point of the original hole, d. H. the pilot hole requires protective tubes, again as a result of the considerations made by the expert. It can the protective tube is placed at the beginning of the pulling-in process or between on and off step point. It is also possible that a protective tube between the entry and the exit step is set.

In addition, it is also within the scope of the invention that several protective tubes are placed which, in one embodiment, can be put together. In one of these alternative embodiment, it is also possible that between the individual Protection tubes also exist in unsecured borehole areas. This is allowed one more Reduction in the cost of the procedure, and is particularly indicated when the geological conditions, it is possible to dispense with one protective tube or several protective tubes let appear.

Further features of the invention result from the following example, which is based on the following figures is illustrated, the different stages of the inventive method rens when laying a line below a foot run. (To get a detailed one To enable representation, the overall representation was made up of several partial figures divided that in an arrangement according to the ascending numerical values from the left  to the right give the overall figure.) The numerical values for Diameters, tensile and compressive forces and torques are only examples, and are not to be understood in any way as limiting. Such information depends exclusively of the specifications made and the respective - especially geological - conditions breaks and can be determined or set by the specialist within the scope of his knowledge be.

example Step 1

In a first step, shown in FIGS . 1-1 to 1-6, a controlled horizontal bore ( 1 ) is carried out from an above-ground drilling device ( 2 ) along an intended laying route ( 3 ) with an entry point E and an exit point A. In the present example, the diameter of the horizontal bore is 250 mm.

The top bend ( 4 ) is set up parallel to the creation of the pilot bore and the necessary pipe construction work for the PE protective pipe SR-1 ( 5 ) and SR-2 ( 6 ), the product pipe PR ( 7 ) and the two cable protection pipes KSR- 1 ( 8 a) and KSR-2 ( 8 b).

Furthermore, a corresponding di dimensioned abutment ( 14 ) for z. B. 7,500 kN horizontal forces are introduced into the subsoil and the drilling rig ( 2 ) is thus connected positively or positively.

step 2

In a second step, shown in FIGS. 2-1 to 2-6, the pilot bore ( 1 ) is expanded to a diameter of, for example, approximately 400 mm and at the same time two high-strength drill strands ( 9 a, 9 b) are drawn in.

The drilling rig used ( 2 ) should, for example, be designed for maximum tensile forces of approx. 6,000 kN and maximum torques of approx. 5 kNm. For the simultaneous handling of the two drill strings ( 9 a, 9 b) used from this second step onwards, the design as a double-head drilling system is required.

step 3

In a third step, shown in FIGS . 3-1 to 3-6, the drilling machine B ( 10 ) with the high-strength drill strings ( 9 a, 9 b), the cable protection tubes ( 8 a, 8 b) and the product tube ( 7 ) connected. This is followed by the start of the pulling-in process by pulling back the drill strings ( 9 a, 9 b). The rotating drill head of the drilling machine ( 10 ) widens the already widened pilot hole ( 1 ) to a diameter that is slightly larger than that of the protective tube.

After the drilling machine ( 10 ) has reached the first target point ( 11 ), the protective tube SR-1 ( 5 ) is uncoupled and remains in this position in the underground.

The drilling fluid required for the drilling process is pumped via one of the high-strength drill strings ( 9 a) (specification, e.g. according to API) from the drilling device ( 2 ) to the drilling machine ( 10 ). From there, the drilling fluid loaded with cuttings returns to the surface via the second pump line ( 9 b), is cleaned there and pumped back to the drilling machine ( 10 ).

The (electrical) energy required for the operation of the drilling machine ( 10 ) is supplied via one of the cable protection tubes ( 8 a) by means of a cable. The necessary control cable for the control of the drilling machine ( 10 ) is protected in the second cable protection tube ( 8 b).

The energy required to operate the drilling machine ( 10 ) and the corresponding control devices are installed on a mobile device carrier ( 12 ). At the end of the product tube ( 7 ), this travels at the realized pull-in speed. About z. B. wireless se connection to the drilling rig ( 2 ), the functions of the drilling machine ( 10 ) can be remotely controlled from a central control station. At the same time, the mobile device carrier ( 12 ) can be used to prevent torsion in the product tube ( 7 ) via a holding device and thus serve as a counter bearing for the torques occurring at the drill head of the drilling machine.

Step 4

In the fourth step, shown in Fig. 4-1 to Fig. 4-6, the drill ( 10 ) is pulled from the drilling rig ( 2 ) over the high-strength drill strings ( 9 a, 9 b) along the drilled route. After reaching the second target point ( 13 ), the protective tube SR-1 ( 6 ) is set.

Step 5

In a fifth step, shown in FIGS. 5-1 to 5-6, the drilling machine ( 10 ) is pulled further by the drilling device ( 2 ) through the ground and appears on the drilling device, ie at the original entry point of the pilot hole. There the drilling machine ( 2 ) is dismantled and the product pipe ( 7 ) has reached its final position.

The cables for power supply and control of the drilling machine ( 2 ) are removed from the cable protection tubes ( 8 a, 8 b).

The in the foregoing description including the drawings and the claims Disclosed features of the invention can be used both individually and in any combination nation for the implementation of the invention in its various embodiments we be substantial.  

Reference list

1

Pilot drilling

2nd

Drilling rig

3rd

Intended laying route

4th

Upper bow

5

PE protective tube SR-

2nd

6

PE protective tube SR-

1

7

Product raw PR

8th

a KSR cable protection tube

1

8th

b KSR cable protection tube

2nd

9

a drill string BS-

1

9

b drill string BS-

2nd

10th

drilling machine

11

Target point

1

12th

Mobile device carrier

13

Target point

2nd

14

Abutment, sheet pile

15

Core bit

16

Clearers
A exit point
E entry point

Claims (9)

1. A method for trenchless laying of pipes in the ground along a predetermined route ( 3 ), characterized in that

• a) a drill string ( 9 a) is laid along the planned laying route ( 3 ) in the first step between the start and end point of the laying line by means of controllable horizontal drilling technology and
• b) in a second step, a microtunnel machine ( 10 ) is pulled along the predetermined route ( 3 ) with the aid of the drill string ( 9 a) fastened to the outside of this microtunnel machine ( 10 ), thereby through the microtunnel machine ( 10 ) the soil is excavated and in the subterranean cavity (drilling channel) created in the same operation, a product tube ( 7 ) following the microtunnel machine ( 10 ) and connected to it with a tensile strength, and an outer one also tensile connected to the microtunnel machine ( 10 ) Protective tube ( 6 ) can be introduced.

2. The method according to claim 1, characterized in that the protective tube ( 6 ) is only laid on a section of the laying route ( 3 ). 3. The method according to claim 1, characterized in that the setting of the protective tube ( 6 ) at the intended position by remote-controlled loosening (uncoupling) of the connection with the microtunnel machine ( 10 ). 4. The method according to claim 1, characterized in that the retraction of the microtunnel machine ( 10 ) with the aid of the drill string ( 9 a) is carried out by a horizontal drilling device ( 2 ). 5. The method according to claim 1, characterized in that no protective tube ( 6 ) is set. 6. The method according to claim 1, characterized in that the annular space between the tube introduced in step b) and the wall of the underground cavity created by the microtunnel machine ( 10 ) (drilling channel) is completely filled with a liquid medium, which is a hydraulic Supporting the underground cavity (drilling channel). 7. The method according to claim 6, characterized in that the liquid Medium is a bentonite suspension. 8. The method according to claim 1, characterized in that the removal of the soil material degraded by the microtunnel machine ( 10 ) is carried out hydraulically. 9. The method according to claim 1, characterized in that the tensile connection of the drill string introduced in step a) ( 9 a) with the microtunnel machine ( 10 ) takes place centrally.