WO2012056011A1

WO2012056011A1 - Method for the underground placement of a pipeline

Info

Publication number: WO2012056011A1
Application number: PCT/EP2011/069017
Authority: WO
Inventors: Hans-Jürgen John
Original assignee: T.I.C. Technology Innovation Consulting Ag
Priority date: 2010-10-29
Filing date: 2011-10-28
Publication date: 2012-05-03
Also published as: CA2815739A1; AU2011322539A1; EP2447462A1

Abstract

In a method for the underground placement of a pipeline (20) of a specified diameter between a starting side (2) and a target side (4), a pilot drill hole (16) is first created from the starting side (2) to the target side (4), a drilling head being moved forward by means of drilling rods (12). Optionally, the pilot drill hole (16) can be enlarged to a diameter that is smaller than a specified end diameter in one or more steps using a reamer. A reamer (30) that is configured to the end diameter of the drill hole (50) is assembled on the target side (4) and coupled to the pipeline (20) that is provided on the target side (4) by means of a coupling device. The reamer (30) and the pipeline (20) are subsequently moved from the target side (4) to the starting side (2), wherein the reamer (30) enlarges the drill hole (50) to the end diameter and the pipeline (20) comes to rest in the drill hole (50).

Description

Method for underground insertion of a pipeline

The invention relates to a method for the underground introduction of a pipeline, which is particularly suitable for pipeline construction. In the previously known HDD method ("Horizontal Directional Drilling"), a pilot bore with a drill string is created from a start page to a target side. After reaching the destination side so ^¬ called scraper is mounted on the drill head and the drill bit. This reamer is now pulled to the starting side in a rotating manner, whereby a suitable drilling fluid (eg bentonite) escapes from the boom tip under pressure, which on the one hand releases the existing soil and on the other hand supports the resulting borehole against collapse. The clearances are repeated with larger and larger scrapers until the hole is made in the desired size. At ^¬ the created borehole diameter is considerably larger than the diameter of the product tubing to be introduced later. The considerable oversize is necessary to reduce the friction ^¬ forces during Einbringvorgang. The lubricating action of a bentonite suspension, on the one hand, and the floating of the product tubing with low skin friction on the borehole wall, on the other hand, require a spacious distance from the pipe wall to the borehole wall. The success of the HDD method depends on specific geological conditions ^¬ rule and the final hole size. For a 56 "(1.42 m) diameter product pipe, a 1.80 m diameter hole will be made, and in case of failure, the hole will need to be abandoned.

The method described in EP 1 802 844 B1 ("Easy-Long") is a microtunnelling method for pipeline construction, in which steel support tubes are propelled in a microtunnelling process from a starting side to a target side. To- When the support pipe string has reached the target side, the product pipe string (ie the pipeline) prepared in the area of the target side is connected to the support pipe string and pulled or pushed into the supported borehole. This method is safe in any geology because the borehole wall can not collapse because of the support tubes, but because of the microtunnelling propulsion, it is slower and more expensive than the HDD method. The created hole has a slightly larger diameter than the product tube to be installed. Less soil is mined and less bentonite is used than in the HDD process. The process "EasyLong" is thus more ecological than the HDD process.

It is an object of the invention to provide a method for underground insertion of a pipeline, which can be performed similarly fast as the HDD method, but is fundamentally safer and more ecological.

This object is achieved by a method for underground see introducing a pipeline with the features of claim 1. Advantageous embodiments of the invention will become apparent from the dependent claims.

In the method according to the invention, a pipeline with a predetermined diameter is introduced underground between a starting side and a target side. First, similar to the HDD method, a pilot hole is created, with a drill bit (preferably with a drill bit) being advanced from the start page to the landing page by means of a drill string. To drive the drill pipe a so-called HDD rig can be used, as it is known from HDD methods and which is built on the start page. With the HDD rig, the drill pipe can be rotated, in the direction of the target side vorbe ^¬ because and, if necessary, back towards the home page to move back.

The next steps are optional, if the pilot hole is not in a single step to the desired final diameter (which is at least as large as the diameter of the pipeline) to be expanded. These optional process steps, the pilot hole is increased in one or more steps by means of an under appropriation of the drill string from the target side to the Home be ^¬ wegten reamer to a diameter of the borehole which is smaller than the final diameter of the borehole, as explained in more detail below , After creating the pilot hole or after performing the optional method steps, the Bohrge ^¬ rod extends to the target side. A reamer designed for the final diameter of the borehole, eg at the drill head or at the end of the drill string, is then mounted on the target side. At the reamer or the end of the drill pipe or the drill head to be prepared before ^¬ or parallel to the previous process steps on the target side pipe is coupled. This is done ei ^¬ ne coupling device between the reamer and the end of the pipeline. The scraper and the pipeline are then moved from the landing page to the start page. The reamer enlarges the wellbore to the final diameter and the tubing comes to rest in the wellbore.

Scavengers are also used in HDD processes. A scraper can be used to clear a not too hard floor. Preferably, the scraper is rotated when moving from the target side to the home using the drill string. Furthermore, the process flow is usually greatly facilitated if, when moving the reamer from the target side to the home, a drilling fluid is introduced into the wellbore, e.g. via arranged on the reamer nozzles. The drilling fluid preferably has a bentonite suspension.

If the pilot hole is increased in the optional process steps to a hole diameter that is still below the final diameter, the intermediate steps already indicated can be performed. For this, a scraper is gezo- with ^¬ means of the drill string from the target to home page with the reamer enlarging the pilot hole. This reamer provides a hole diameter that is smaller than the final diameter. When the hole must be gradually increased, for example because of the size of the final diameter, or the ground, the drill string wherein said enlarged reamer is advanced again to the target page, and then an enlarged reamer is ge ^¬ tightened by means of the drill string from the target side to the home page, previously created Boh ^¬ tion further increased. If appropriate, this step is repeated once or several times with increasingly enlarged scrapers. Finally, the drill string is advanced again to Zielsei ^¬ te to assume the starting position, the hole for the already explained steps to create the final diameter of the borehole, and for introducing the tubing into the bore is required.

To enlarge the reamer, a larger reamer is preferably mounted each time. In principle, it is also conceivable to use an adjustable reamer, which can possibly even be adjusted so far that it is designed for the final diameter. If a reamer is designed for a specific diameter, it does not necessarily mean that he himself must have that diameter. The reamer may also be smaller because of the effect of the drilling fluid.

Typically, the borehole will have a smaller diameter than the tubing prior to use of the final diameter scraper. In principle, however, applications are also conceivable in which the borehole is widened so far that its diameter is already greater.

In preferred embodiments of the method according to the invention, the pipeline is advanced from the target side to the starting side using a sliding device arranged on the target side. For such a purpose suitable sliding devices (eg "Pipethruster") are known and can basically exert high shear forces, for example, when a hydraulic device by means of a coat-like sleeve te on the outer wall of the prepared pipeline attacks. However, if the pipeline is tension resistant and relatively easy to move through the well, it is also conceivable to pull the pipeline from the target side to the home using the drill string.

When a pushing device is used, preferably the movement of the system adapted to the final diameter of the reamer to start using the drill string and the ic ^¬ ACTION the shifter to be synchronized with each other so that the movements carried out with the same possible Grundgeschwindig ^¬ speeds and not of the pipeline and forces transmitted by the drill string must be aligned.

The coupling device preferably has a rotary coupling and also means for engaging the end of the pipeline. The pipeline should not rotate when placed in the ground around its longitudinal axis while the remover ro ^¬ advantage. To compensate, the rotary joint is used.

Since the distance between the reamer and the end of the pipeline is low when introducing the pipeline, the borehole usually does not fall. However, depending on the upcoming geology, when moving the reamer and tubing from the target side to the home, a support shell may be carried in the space between the reamer and the end of the tubing to prevent a drilled hole. The diameter of the support jacket is adapted to the diameter of the pipeline, e.g. the same size or slightly larger.

As already mentioned, the pipeline is prepared at the target side before moving into the wellbore. For this purpose it can be be ^¬ already fully Prepared, eg welded together from individual pipes and provided if necessary with a corrosion protection, and are also tested. The pipeline can be stored on the destination side eg on a roller conveyor. The pipe can be used for the transport of media, but also designed as a conduit, eg for later retraction of cables.

The method according to the invention, which can be called HDJ ("Horizontal Directional Jacking") method, combines the advantages of the HDD method and the "EasyLong" method. The diameter of the borehole needs only to be slightly larger than the diameter of the pipeline to be introduced, since a lubricating film (for example of bentonite suspension) is generally sufficient to reduce skin friction. The HDJ process is more economical than the "EasyLong" process and safer and more ecological than the HDD process.

In the following, the invention will be explained with reference to Ausführungsbeispie ^¬ len. The drawings show in

1 shows a schematic longitudinal section through a construction site, in which the method according to the invention is used, in a first phase,

FIG. 2 shows a schematic longitudinal section through the construction site according to FIG. 1 in a second phase,

3 shows a schematic longitudinal section through the construction site according to FIG. 1 in a third phase and a schematic longitudinal section through an embodiment of a reamer attached to a drill pipe, to which the end of a pipeline is coupled by means of a coupling device, during the construction phase according to FIG.

In the figures 1 to 3 different phases in the implementation of an embodiment of a method for underground insertion of a pipeline in a schematic longitudinal section are shown. The arrangement of the construction site can be seen in FIG. Between a Home page 2 and a target 4, a tube ^¬ pipe is to be laid under a body of water 6 forth. On the home page 2, a HDD rig 10 is constructed and anchored. HDD rigs are used in HDD processes and are known to the person skilled in the art. With the help of a HDD rig you can turn a drill pipe and move it forward and pull it down. In the exemplary embodiment, a pilot bore 16 is created with the help of the HDD rig 10, a drill pipe 12 driven therefrom and a drill head 14 mounted at the end of the drill string 12, which leads to the target side 4 and determines the later Ver ^¬ run of the pipe to be introduced. The drill head 14 is controllable so that the pilot bore 16 can be guided along a curved and predetermined path. In the view shown in Figure 1, the drill head 14 just arrived below the water body 6.

While the pilot hole 16 is created, the einzubrin ^¬ ing pipe, which is designated 20, is prepared at the landing page 4. In the exemplary embodiment, the pipe 20 is welded together from steel pipe sections, the area of the welds is provided with a corrosion protection, and a leak test is performed. By Rohrlei ^¬ device 20 can later be transported a liquid or gaseous medium. Other designs, for example as a conduit or other material, are also conceivable.

As can be seen in FIG. 1, the pipeline 20 is mounted on a roller conveyor 22. Furthermore, a so-called Pipethruster is already brought into position. The Pipethruster has a pipe clamp 24 which acts on the outside of the pipe 20 via a kind of sleeve and can exert large forces. The pipe clamping device 24 is connected via feed cylinder 26 with an anchor 28 shown schematically in Figure 1. By actuating the feed cylinder 26, the pipeline 20 can later be advanced in the direction of the starting side 2. In Figure 2 is shown a state in which the Pilotboh ^¬ tion is completed after 16 and the drill head 14 has arrived at the target side. 4 The drill head 14 is then removed from the drill string 12, and instead a reamer 30 is mounted at the forward end of the drill string 12. The reamer 30 is then connected by means of a coupling device to the end of the pipeline 20. The reamer 30 and the coupling device are shown in an enlarged view in FIG. 4 (the coupling device being configured slightly differently than in FIGS. 1 to 3).

Scavengers such as the scraper 30 are known in the art of HDD method ago. The reamer 30 has a larger diameter than the drill head 14. In the embodiment of the reamer 30 is mounted instead of the drill head 14 at the end of the drill string 12. But it is also conceivable that the drill head 14 left on the drill pipe 12 and the reamer 30 is attached to the drill head 14. With the help of an embodiment conically shaped attack side 32 of the reamer 30 can widen the borehole when it is rotated by means of the drill string 12 and pulled to the home page 2. Here, a drilling fluid exits the Angriffssei ^¬ te 32 nitsuspension a bentonite in the exemplary embodiment which facilitates the expansion of the hole, the solidified wall of the borehole and simultaneously serves as a lubricating film.

The reamer 30 is connected to the pipeline 20 via the coupling device. As the figure 4 shows, these couplers ^¬ averaging means to a joint part 34, a rotary coupling 36, a further joint part 38 and a tensile performance 40th The train ^¬ receptacle 40 is mounted at the end of the pipe 20 and is removed later, when the pipe 20 is laid completely.

Thus, FIG. 2 shows the state of the construction site immediately after the assembly of the reamer 30 and the coupling device 34, 36, 38, 40. The reamer 30 is now pulled over the drill pipe 12 with the aid of the HDD rig 10 in the direction of the starting side 2 Pipethruster is set in action and at the same time tig by means of the feed cylinder 26, the pipeline 20 advances. In the exemplary embodiment, the movements of the drilling ^¬ rod 12 and the feed cylinder 26 are synchronized to avoid unnecessary tensile or compressive forces in the drill pipe 12 and the pipe 20. FIG. 3 shows a state in which the reamer 30 has arrived under the body of water 6. The range of the reamer 30 to the end of the pipe 20 is, as already explained, in figure 4 in an enlarged view is provided ^¬.

While the reamer 30 is rotated by the drill string 12 and the drilling fluid at the attack side 32 of the reamer 30 from ^¬ occurs, the reamer 30 widens the generally designated 50 well 50 on. As a result, the pilot bore 16, whose wall 52 has a first diameter, is enlarged in the exemplary embodiment to a borehole with a wall 54 which already has the desired final diameter. The reamer acts in particular at a transition zone 56. The rotary coupling 36 ensures that the reamer 30 can rotate easily, while the pipe 20 performs no rotational movement. The drilling fluid also passes into a gap 58 between the conduit 20 and the wall 54 of the borehole 50 and forms there a kind of lubricating film, which significantly reduces the frictional forces between the pipeline 20 and the wall 54 of the borehole 50.

The reamer 30 is retracted to the home page 2 while the tubing 20 is advanced so that the tubing 20 comes to lie in the final path in the desired path.

In the exemplary embodiment, it is assumed that the base, in particular ^¬ sondere, is so firm after exposure to the drilling fluid, that the wellbore does not collapse in the area between the reamer 30 and the cable holder 40 of the conduit 20 50th If the soil is problematic, a support shell can be arranged in this zone, whose outer diameter corresponds to the final diameter of the borehole 50 or has a slightly smaller diameter. The support jacket prevents the borehole 50 occurs in this critical area, and is moved with the pipe 20 to the home 2.

In the exemplary embodiment, the pilot bore 16 is widened by means of the reamer 30 in one step to the required for the pipeline 20 end diameter (wall 54). Depending on the nature of the soil and the diameter of the pipe to be introduced, however, intermediate steps can also be carried out. For this purpose, first a reamer with a diameter smaller than that of the reamer 30 is mounted after the pilot bore 16 has been created and pulled to the start side 2 without the pipeline 20, the bore hole 50 being widened. Subsequently, the drill pipe 12 is moved by means of the HDD rig 10 back to the landing page 4. There, if necessary, a larger reamer can be set, which is still smaller than the reamer 30, to perform a further intermediate step for widening the wellbore 50. If necessary, this process is repeated once or more, until finally the reamer 30, which produces the desired final diameter of the wellbore 50, can be mounted.

Claims

claims

Method for underground introduction of a pipe of predetermined diameter between a home page and a landing page, comprising the steps of:

- creating a pilot hole (16) from the starting side (2) to the target side (4), wherein a drill head (14) is advanced by means of a drill rod (12),

optionally enlarging the pilot bore (16) in one or more steps by means of a scraper moved using the drill string (12) from the target side (4) to the starting side (2) to a diameter of the wellbore (50) smaller than a final diameter wherein the final diameter is at least as large as the diameter of the pipeline (20),

- mounting a final diameter scraper (30) on the target side (4) and coupling the pipeline (20) prepared at the target side (4) by means of coupling means (34, 36, 38, 40) between the scraper (30) and the end the pipeline (20),

Moving the reamer (30) and the pipeline (20) from the target side (4) to the starting side (2), the reamer (30) increasing the borehole (50) to the final diameter (54) and the pipeline (20) in the borehole (50) comes to lie

- wherein the pipeline (20) is moved from the target side (4) to the starting side (2) by using a sliding device (24, 26, 28) arranged on the target side (4).

A method as claimed in claim 1, characterized in that the movement of the raker (30) to the starting side (2) of the final diameter (54) is synchronized with each other using the drill string (12) and the action of the pusher (24, 26, 28) ,

Method according to claim 1 or 2, characterized in that the optional enlargement of the pilot bore (16) is carried out and comprises the following steps: - pulling a reamer of the target page (4) for Startsei ^¬ te (2) by means of the drill string (12), the reamer enlarges the pilot hole (16),

optionally renewed advancement of the drill string (12) to the target side (4) and pulling an enlarged scraper from the target side (4) to the start (2) by means of the drill string (12), wherein the enlarged scraper further increases the hole made up to ^now , and optionally repeating this step once or several times with ever-larger scrapers,

- again advancing the drill string (12) to the target side (4).

Method according to one of claims 1 to 3, characterized in that the scraper (30) is rotated when moving from the target side (4) to the starting side (2) using the drill string (12).

Method according to one of claims 1 to 4, characterized in that when moving the reamer (30) from the target side (4) to the start (2) a drilling fluid is introduced into the wellbore (50).

A method according to claim 5, characterized in that the drilling fluid is introduced into the borehole (50) via nozzles arranged on the reamer (30).

A method according to claim 5 or 6, characterized in that the drilling fluid comprises bentonite.

Method according to one of claims 1 to 7, characterized in that the coupling device (34, 36, 38, 40) has a rotary coupling (36).

Method according to one of claims 1 to 8, characterized in that when moving the reamer (30) and the pipe (20) from the target side (4) to the starting side (2) a support jacket in the space between the reamer (30) and the end of the pipeline (20) is arranged, wherein the diameter of the support jacket is adapted to the diameter of the pipe (20).

Method according to one of claims 1 to 9, characterized in that the pipeline (20) before moving into the borehole (50) on the target side (4) completely pre ^¬ directed and checked.

Method according to one of claims 1 to 10, characterized in that the borehole (50) has a smaller diameter than the pipeline (20) before the use of the raker (30) designed on the final diameter (54).