Apparatus and method for placing pipe in a borehole

Abstract

The lining pipe (103) is mechanically pulled through the HDD borehole from one end. As the HDD borehole lengthens, the total friction experienced by the pipe increases, and therefore greater forces / stresses are exerted on the pipe (103). For a given pipe (103) material and diameter, the only way to address these stresses traditionally is to increase the pipe (103) wall thickness. The present invention provides at least one gripping device (201) on the line (107) that is movable through the inside of the pipe (103) and is configured to grip the inside of the pipe (103). In this manner, the gripping device (201) can be used to grip the pipe (103) at a point away from the end of the pipe (103), thereby reducing the pulling forces on the pipe.

Description

[Technical Field]

[0001] The present invention relates generally to apparatus and methods for placing pipe in a borehole and finds particular, but not exclusive, utility in completing holes formed using horizontal directional drilling techniques. [Background technology]

[0002] Boreholes are mechanically lined with pipe to enhance their structural integrity and protect any items placed downhole (i.e., within the borehole). Such items may include permanent or temporary downhole equipment or machinery / rigging. It is recognized that such pipe must withstand external loads, including hydraulic pressures, the weight of the surrounding soil, etc. However, pipe configured as a component in a horizontal directional drilling (HDD) application must be designed with additional considerations in mind.

[0003]

[0003] Specifically, when an HDD borehole is lined with pipe, the lining pipe is pulled from one end through the HDD borehole. Therefore, the pipe must be able to withstand pullback loads, which include tensile forces and tensile bending stresses. As HDD boreholes extend longer and longer lengths of pipe are pulled through longer boreholes, the total friction experienced by the pipe increases, and therefore greater forces / stresses are exerted on the pipe. For a given pipe material and diameter, there is traditionally only one way to address these stresses: by increasing the wall thickness of the pipe. Summary of the Invention [Problem to be solved by the invention]

[0004] One particular challenge that arises in lining long HDD boreholes is the need to join two or more sections of pipe together to form a pipe long enough to line the entire borehole. Traditionally, the joints between each pipe section must also withstand these increased forces / stresses.

[0005] The pipes themselves can be made from any suitable material, typically PVC, polyethylene, polypropylene, ductile iron, and steel, provided that the pipe properties (wall thickness and material strength) are below allowable stress limits so that they are effective both during installation and (if applicable) during operation. [Means for solving the problem]

[0006] According to a first aspect of the present invention, there is provided a pipe installation apparatus comprising a line suitable for passing through the inside of a pipe to be installed and at least one gripping device disposed on the line, the gripping device having a first operational state suitable for the gripping device to pass through the inside of the pipe to be installed, and a second operational state in which the gripping device is configured to grip the inside of the pipe to be installed.

[0007] In this manner, the gripping device can be used to reduce tension on a pipe by gripping the pipe at a point away from the end of the pipe. Specifically, this apparatus can be used in conjunction with a conventional pipe pulling device attached to the end of the pipe. In this manner, the load due to the pipe can be divided between the apparatus and the device, reducing tension on the pipe. Avoiding an increase in pipe wall thickness avoids unnecessary costs, particularly with regard to raw materials (e.g., plastics from which the pipe is made), pipe pulling equipment required to pull heavier pipes, and transportation and storage costs.

[0008] The lines may be comprised of cables, chains, and / or other suitable lines, e.g., the lines may be strong under tension and / or flexible but not substantially elongated. Alternatively, the lines may be comprised of shafts, rods, and / or other suitable lines, e.g., the lines may be strong under compression and / or substantially incompressible and / or the lines may be substantially rigid.

[0009] The cord may have an outer diameter less than the inner diameter of the pipe, which may be at least 10 cm, in particular at least 15 cm, or even at least 20 cm.

[0010] The gripping device may be permanently or removably secured to a particular point on the line. For example, the gripping device may be secured to the end of the line or secured at a point spaced from both ends of the line. In some embodiments, the line may be formed from a first line section on the uphole side of the gripping device and a second line section on the downhole side of the device. The first and second line sections are connected to each other via (but not directly with) the gripping device.

[0011] In alternative embodiments, the gripping device may be configured to move along the line, so that its position on the line can be changed as required. In particular, while the gripping device may be manually lockable and detachable at any particular point on the line, in some embodiments the gripping device may be configured to move along the line remotely, so that after inserting the gripping device into the pipe, the holding device can be commanded to move to different points along the line.

[0012] The placement may include pulling and / or pushing the pipe.

[0013] Uphole may be defined as the direction in which the line (and therefore the pipe) is pulled / pushed through the borehole. Similarly, downhole may be defined as the direction in which the pipe is deployed before being pulled / pushed through the borehole.

[0014] The first operating state may include the gripping device having a lateral extent less than the inner diameter of the pipe. In this context, the lateral direction may be interpreted as being perpendicular to the axial direction, which in turn is parallel to the longitudinal extension of the line and / or pipe. The lateral direction may be interpreted as being radial within the pipe. The second operating state may include the gripping device having a lateral extent substantially equal to, or in some cases greater than, the inner diameter of the pipe.

[0015] For example, the gripping device may include at least one inflatable bag that is in a first operational state when the bag is uninflated and in a second operational state when the bag is inflated. The inflatable bag may be elastic so that it expands under pressure. The inflatable bag may return to its previous size once the pressure is released. Alternatively, the inflatable bag may only expand under pressure and collapse once the pressure is released.

[0016] The gripping device may include a pump for inflating the bag. Alternatively, the gripping device may include a supply line from a pump located anywhere (uphole / downhole, etc.).

[0017] Alternatively or additionally, the gripping device may include at least one arm movable between a first operational state in which the arm is in a first position and a second operational state in which the arm is in a second position, the arm in the second position extending farther from the axis of the gripping device than the arm in the first position.

[0018] The arms are configured such that in a first direction (e.g., uphole / downhole), tension and / or compression in the line causes the arms to move radially outward from the line, and in a second direction (e.g., downhole / uphole), tension and / or compression in the line causes the arms to move radially inward toward the line. In this manner, the gripping device can be moved into position by pulling / pushing the line in the second direction. Then, when the pipe needs to be pulled / pushed uphole, the line can be pulled / pushed in the first direction. The arms can be biased either inward or outward so that their default position is in either the first or second operating state.

[0019] As another optional addition / alternative, the gripping device may include at least one wedge configured such that tension and / or compression on the line in a first direction (e.g., uphole / downhole) moves the wedge radially outward from the line, and such that tension and / or compression on the line in a second direction (e.g., downhole / uphole) moves the wedge radially inward toward the line. In this manner, the gripping device may be moved into position by pulling / pushing the line in the second direction. Then, when the pipe needs to be pulled / pushed uphole, the line may be pulled / pushed in the first direction. The wedge may be biased either inward or outward so that its default position is in either the first or second operating state.

[0020] Alternatively, the first operating state may include the gripping device making low-resistance contact with the inside of the pipe, for example, by engaging a pipe on skids, a rotatable wheel, a track, or the like, and / or any other form of low-resistance contact. The second operating state may include the gripping device making high-resistance contact with the inside of the pipe, for example, by engaging a high-resistance pad, a wheel locked against rotation, a track locked against movement, a pipe engaged with pins / teeth, a heating element to soften the pipe wall (e.g., a heated pad where heating increases friction), and / or any other form of high-resistance contact. In particular, any wheel and / or track may only allow one rotational direction (e.g., to allow only downhole movement) and prohibit movement in the other rotational direction (e.g., to prevent uphole movement). Such wheel / track locking may be controllable (e.g., remotely). In some arrangements, the wheel / track may be driven to transport the gripping device in a desired direction. Such actuation may be controllable (eg, remotely).

[0021] In the context of this application, the terms "low resistance" and "high resistance" should be construed as being relative to one another, with a low resistance component being deemed to have a lower resistance than a corresponding high resistance component, and vice versa.

[0022] Specifically, the first contact portion and the second contact portion may be a single contact portion. For example, the wheel may be free to rotate (constituting the first contact portion) and, in at least one direction of rotation, the wheel may be locked against rotation (constituting the second contact portion). The first operating state may further include movement of the gripping device in a first axial direction, and the second operating state may further include movement of the gripping device in a second axial direction.

[0023] The single contact may comprise a contact wheel configured to rotate only in a first rotational direction. The wheel may form part of a continuous track propulsion system. The contact wheel may comprise a plurality of contact wheels.

[0024] The apparatus may further include a line tensioner / compressor configured to ensure that a first tension / compression in a first section of the line on the first side of the gripping device is equal to a second tension / compression in a second section of the line on the second side of the gripping device. The line tensioner / compressor may be a passive mechanical link; however, in alternative embodiments, the line tensioner / compressor may comprise an active and / or motorized system configured to monitor the tension / compression of the line and / or pipe and adjust the corresponding tension / compression accordingly.

[0025] The at least one gripping device may comprise a plurality of gripping devices. Thus, in applications where two or more sections of pipe are to be joined together to form a pipe of sufficient length to line the entire borehole, each pipe section may be individually gripped, thereby requiring each pipe section to overcome its own resistance by pulling / pushing its own weight. In this manner, the joints between adjacent pipe sections only need to be robust enough to prevent damage from relatively low tension / compression forces (compared to those that may be experienced when pulling / pushing multiple pipe sections from one end of a finished pipe, for example). This additional economy would reduce the time it takes to join pipe sections on-site. In effect, this could make the production of longer boreholes practical.

[0026] When multiple gripping devices are used, the line may be pre-tensioned between each gripping device. In this way, each gripping device may use equal force to pull the pipe into place. Without this feature, when the line is stretched under tension, different forces may be transmitted to each gripping device, thereby applying different forces to different portions of the pipe being pulled, potentially to different pipe sections, which could cause undesirable distortion at the joints of the pipe sections.

[0027] Multiple gripping devices may be individually actuable or may be part of a system in which all such gripping devices are actuable in unison. The or each gripping device may be remotely / manually actuable (e.g., via wireless and / or wired communication techniques) and / or may be automatic. The or each gripping device may be remotely monitored.

[0028] The apparatus may comprise a line pulling / pushing device for pulling / pushing the line and therefore the pipe through the borehole.

[0029] According to a second aspect of the present invention there is provided a system for placing pipe in a borehole, the system comprising: a pipe placement apparatus of the first aspect; and a pipe into which the pipe placement apparatus is to be installed.

[0030] The system may further comprise a line pulling / pushing device for pulling / pushing respectively the line and therefore the pipe through the borehole.

[0031] In some arrangements, the line pulling / pushing device may comprise a line pushing and pulling device. In this way, the oscillation of the line between pushing and pulling may be used to vibrate the pipe. This may free stuck pipe from obstructions in the borehole, particularly where the borehole is not level or there are imperfections in the borehole, particularly at the junction of one or more pipe sections.

[0032] The pipe may comprise a plurality of pipe sections, each of which may be provided with a respective gripping device therein for pulling and / or pushing the respective pipe section.

[0033] According to a third aspect of the present invention, a method of installing pipe in a borehole comprises: providing a borehole; providing a pipe for installation in the borehole; providing a pipe installation apparatus of the first aspect; installing the pipe installation apparatus within the pipe using a gripping device in a first operating state; transitioning the pipe installation apparatus to a second operating state; and pulling and / or pushing a line to respectively pull / push the pipe through the borehole.

[0034] These and other characteristics, features and advantages of the present invention will become apparent from the following detailed description, taken in conjunction with the accompanying drawings, which illustrate, by way of example, the principles of the invention. This description is given by way of example only and is not intended to limit the scope of the invention. The reference figures referred to below refer to the attached drawings. [Brief explanation of the drawings]

[0035] [Figure 1] FIG. 1 shows a first gripping device deployed within a pipe. [Figure 2] FIG. 10 is a cross-sectional view of a first gripping device within a pipe. [Figure 3] FIG. 10 shows a second gripping device deployed within a pipe. [Figure 4] FIG. 10 is a plan view of a second gripping device. [Figure 5] FIG. 10 is a partial plan view of a third gripping device. [Figure 6] FIG. [Figure 7] FIG. 10 is a cross-sectional view of a fourth gripping device positioned within a pipe and in a first operating state. [Figure 8] 10 is a perspective view of a fourth gripping device transitioning between first and second operating states; FIG. [Figure 9] FIG. 10 is a cross-sectional view of a fourth gripping device positioned within a pipe and in a second operating state. [Figure 10] FIG. 10 is a partial cutaway view of a fifth gripping device deployed within the end of a pipe. [Figure 11] 11 is a partial cutaway and cross-sectional view of the fifth gripping device in FIG. 10. FIG. [Figure 12] 11 is a partial cutaway view of the fifth grasping device of FIG. 10 connected to a reamer by a tether. [Figure 13] 13 is a partial cutaway view of a fifth series of gripping devices deployed within a pipe section coupled to the reamer of FIG. 12. FIG. [Figure 14] FIG. 10 is a partial cutaway view of a fifth gripping device stacked on a line within a pipe. [Figure 15] A cutaway view of a borehole drilled through the mountainside. [Figure 16] FIG. 1 is a cutaway view of the pipe being pulled back through the borehole. [Figure 17] FIG. 1 is a cutaway view of the pipe being pulled forward through the borehole. [Figure 18] FIG. 1 is a cutaway view of the pipe being pushed forward through the borehole. DETAILED DESCRIPTION OF THE INVENTION

[0036] The present invention will be described with reference to certain drawings, but the invention is not limited thereto but only by the claims. The drawings shown are schematic and non-limiting. Each drawing may not include all features of the invention and therefore need not necessarily be considered an embodiment of the invention. In the drawings, the size of some elements may be exaggerated and not drawn to scale for illustrative purposes. The dimensions and relative dimensions do not correspond to actual reduction to practice of the invention.

[0037] Furthermore, terms such as first, second, third, etc. in the specification and claims are used to distinguish between similar elements and do not necessarily represent an order, either temporally or spatially, in ranking or in any other way. It is to be understood that terms so used are interchangeable under appropriate circumstances, and that operations may be performed in orders other than those described or illustrated herein. Similarly, method steps described or claimed in a particular order may be understood to be performed in a different order.

[0038] Furthermore, terms such as top, bottom, upper, lower, and the like are used in this specification and claims for descriptive purposes and not necessarily to denote relative positions, with the understanding that the terms so used are interchangeable under appropriate circumstances and that directions of operation other than those described or illustrated herein are possible.

[0039] It should be noted that the term "comprising" used in the claims should not be interpreted as being limited to the means listed thereafter, nor as excluding other elements or steps. Thus, when referred to, it should be interpreted as specifying the presence of the stated features, integers, steps, or components, but not as excluding the presence or addition of one or more other features, integers, steps, or components, or groups thereof. Thus, the scope of the expression "a device comprises means A and B" should not be limited to devices consisting of only components A and B. In the context of the present invention, it simply means that the relevant components of the device are A and B.

[0040] Similarly, it should be noted that the term "connected" as used herein should not be construed as being limited solely to direct connections. Thus, the scope of the phrase "device A connected to device B" should not be limited to devices or systems in which the output of device A is directly connected to the input of device B. It means that a path exists between the output of A and the input of B, which may be a path that includes other devices or means. "Connected" can mean that two or more elements are in either direct physical or electrical contact, or that two or more elements are not in direct contact with each other but still cooperate or interact with each other. For example, wireless connections are contemplated.

[0041] References throughout this specification to an "embodiment" or "aspect" mean that a particular feature, structure, or characteristic described in connection with the embodiment or aspect is included in at least one embodiment or aspect of the invention. Thus, the phrases "in one embodiment," "in an embodiment," or "in an aspect" appearing in various places throughout this specification do not necessarily refer all to the same embodiment or aspect, but may refer to various embodiments or aspects. Furthermore, particular features, structures, or characteristics in any one embodiment or aspect of the invention may be combined in any suitable manner with any other particular features, structures, or characteristics of other embodiments or aspects of the invention, in one or more embodiments or aspects, as will be apparent to those skilled in the art from this disclosure.

[0042] Similarly, it should be understood that in the description, various features of the invention are sometimes grouped together in a single embodiment, drawing, or description for the purpose of streamlining the disclosure and aiding in understanding one or more of the various inventive aspects. This method of disclosure, however, should not be interpreted as reflecting an intention that the claimed invention requires more features than are expressly recited in each claim. Moreover, the description of any individual drawing or aspect is not necessarily considered an embodiment of the present invention. Rather, as the following claims reflect, inventive aspects lie in less than all features of a single above-disclosed embodiment. Thus, the claims following the Detailed Description are hereby expressly incorporated into this Detailed Description, with each claim standing on its own as a separate embodiment of the present invention.

[0043] Furthermore, while some embodiments described herein include some features included in other embodiments, combinations of features in different embodiments are meant to be within the scope of the present invention and will form yet other embodiments, as will be understood by those skilled in the art. For example, in the following claims, any of the claimed embodiments can be used in any combination.

[0044] In the description provided herein, numerous specific details are set forth. However, it should be understood that embodiments of the present invention may be practiced without these specific details. In other instances, well-known methods, structures, and techniques have not been shown in detail in order not to obscure an understanding of this description.

[0045] In the description of the present invention, unless stated to the contrary, the disclosure of alternative values ​​at the upper or lower limits of an acceptable range of a parameter is to be construed as an implicit expression that one of those values ​​is preferred over the other, and that each intermediate value of said parameter between said more preferred and less preferred alternatives is itself preferred over said less preferred value, and also over each value between said less preferred value and said intermediate value.

[0046] Use of the term "at least one" may mean only one in certain contexts. The term "any" may mean "all" and / or "each" in certain contexts.

[0047] The principles of the present invention will now be explained by a detailed description of at least one drawing of exemplary features. It is clear that other arrangements can be constructed according to the understanding of those skilled in the art without departing from the underlying concept or technical teachings. The present invention is limited only by the terms of the appended claims.

[0048] Figure 1 shows a first gripping device 101 deployed within a pipe 103. The pipe 103 is made up of multiple pipe sections, as indicated by the joints 105 between adjacent sections.

[0049] The first gripping device 101 is represented as consisting of an inflatable bag 111 connected to a tether 107 by a collar 109 and shown in an inflated state.

[0050] 2 shows a cross section of the first gripping device 101 within the pipe 103, but with the inflation bag 111 shown in a deflated state. The dashed line represents the same inflation bag 111 in an inflated state, with the arrow indicating the direction of inflation.

[0051] Between the collars 109 of the first gripping device 101 is shown the body 113 of the gripping device 101 enclosing the tether 107. The body 113 may optionally include a source of compressed air and / or an air pump to enable inflation and deflation of the inflation bag 111, and may optionally include communication and control equipment for actuating the inflation and / or deflation.

[0052] FIG. 3 shows a second gripping device 201 on a line 107 deployed in a pipe 103 with a joint 105 .

[0053] 4 shows a plan view of the second gripping device 201 connected to the tether 107 by a connecting piece 203. The tether 107 passes inside the main body 205 of the second gripping device 201 and helps to maintain the orientation of the second gripping device 201 inside the pipe, but in a preferred embodiment, the tether 107 is not rigidly attached to the main body 205. Rather, the main body 205 is connected to the connecting piece 203 by a coil spring 207, which provides a smooth connection between the tether 107 and the pipe 103. Three pairs of pivot arms 209 are connected to the main body 205, radially spaced approximately 120° apart. Each arm can pivot from a position substantially parallel to the tether 107 (not shown) to a position protruding outward from the main body 205. A wheel 211 mounted on each arm thereby engages the inside of the pipe 103. Additionally, the arms 209 are biased outward, which causes the arms 209 to tend to urge outward and engage the inside of the pipe 103. Each pair of arms is connected by a connecting member 213, which causes each pair of arms 209 to pivot together.

[0054] Wheels 211 are provided at the end of each arm and are configured as unidirectional wheels, allowing rotation in one direction (allowing pipe forward movement in one direction) but preventing rotation in the opposite direction (prohibiting pipe forward movement in the opposite direction). These wheels have a large gripping effect, whereby when force is applied, the gripping device is forced to advance the pipe in the opposite direction. Their "unidirectional" mechanism locks the wheels. In this way, friction between the wheels and the pipe enables a force parallel to the line to be applied to the pipe to pull / push the pipe.

[0055] The effect of this arrangement of arm 209 and wheel 211 is that pulling and / or pulling line 107 to the left in Figure 3 locks wheel 211 and more tightly engages arm 209 with pipe 103, while pulling and / or pushing line 107 to the right in Figure 3 rotates wheel 211 and loosely engages arm 209 with pipe 103.

[0056] Figure 5 shows a partial plan view of a third gripping device 301, which differs from the second gripping device 201 in Figure 4 in that it replaces the wheel 211 with a high-friction pad 303 extending between a pair of arms 209 and additionally has an actuation piston 305 for pushing the high-friction pad 303 outwards towards the pipe 103 or for retracting the high-friction pad 303 again.

[0057] 6 shows a perspective view of a line tensioner on a line 107. The tensioner is configured to be movable along the line 107 by an internal motor with a housing 53. The internal motor can actuate three sets of radially spaced tracks 51. The tensioner tensions the line by wrapping slack around it, allowing it to control its front and rear tension. The tracks 51 are configured to be expandable to allow the tensioner to brace itself within the pipe 103.

[0058] In principle, the mechanical components of the tensioner, such as the expandable track 51, can be utilized in the alternative gripping device 301.

[0059] 7 shows a cross-sectional view of the fourth gripping device 401 positioned within the pipe 103 and deployed on the line 107 in a first operating state. The fourth gripping device 401 comprises a central guide portion 403 through which the line 107 passes and a cone section 405 deployed thereon. Surrounding the central guide portion 403 and the cone section 405 is a wedge portion 407, which is configured to be biased outwardly towards the pipe 103.

[0060] FIG. 8 shows a perspective view of the fourth gripping device 401 transitioning between a first operating state (with the wedge portion 407 shown in solid lines) and a second operating state (with the wedge portion 407 shown in dashed lines).

[0061] 9 shows a cross-sectional view of the fourth gripping device 401 deployed on the line 107 positioned within the pipe 103 and in a second operating state. As can be seen, when the line 107 is pulled / pushed to the left in the figure, the cone section 405 slides through the wedges 407, forcing them outward with increasing force, thereby providing a stronger grip on the pipe 103. Conversely, when the line 107 is pulled and / or pushed to the right in the figure, the cone section 405 slides out between the wedges 407, reducing the force pressing the wedges against the inside of the pipe 103 and allowing the wedges 407 to slide to the right along with the cone section 405.

[0062] 10 shows a partial cutaway view of a fifth gripping device deployed within the end of a pipe 1001 and slidably received over a line 1003. The fifth gripping device comprises a body 1005 that surrounds the line 1003 and four arms 1007, each configured to pivot about a respective intermediate point (not shown) connected to the body 1005. The inner end 1009 of each arm 1007 is provided with an inner high-friction surface (e.g., teeth) for gripping the line 1003 around which the body 1005 is deployed. The outer end 1011 of each arm 1007 is provided with an outer high-friction surface (e.g., teeth) for gripping the inside of the pipe 1001.

[0063] Moving the line 1003 to the right in the figure in the direction of arrow 1013 causes the inner end 1009 of each arm to move right with the line, thereby pivoting the outer ends 1011 outward to more firmly grip the pipe. Thus, moving the line 1003 to the right automatically causes the fifth gripping device to grip the pipe and pull the pipe to the right, also in the direction of arrow 1015.

[0064] Moving the line 1003 to the left in the figure in the direction of arrow 1017 causes the inner end 1009 of each arm to move left with the line, thereby pivoting the outer ends 1011 inward and releasing their grip on the pipe. Thus, automatically moving the line 1003 to the left causes the fifth gripping device to release its grip on the pipe.

[0065] Figure 11 shows a partial cutaway and cross-sectional view of the fifth gripping device in Figure 10, illustrating the structure of one arm 1007. The arm 1007 includes a slot 1101 therein through which a peg 1103 on the body 1005 passes and about which the arm 1007 is free to rotate.

[0066] A biasing member, in this example a coil spring 1105, urges the arm inward from the peg 1103 towards the line 1003 so that there is always minimal friction between the line 1003 and the arm 1007. Similarly, a stop block 1107 aligns the fifth gripping device within the pipe and prevents the outer end 1011 of the arm 1007 from moving too far from the inner surface of the pipe 1001.

[0067] Figure 12 is a partial cutaway view of the fifth gripping device of Figure 10 connected to a generic reamer 1201 by tether 1003. It is recognized that any design of reamer may be suitable.

[0068] Figure 13 is a partial cutaway view of a series of fifth gripping devices 1301 deployed within a pipe section 1303, coupled to the reamer 1201 of Figure 12. Once the borehole has been reamed and the pipe placed, the reamer 1201 can be detached from the line 1003, which can be moved to the left as depicted in Figure 10. A line restraint (not shown) at the free end of the line 1003 (formerly occupied by the reamer) can pull the first of the fifth gripping devices 1301a with the line. The cable 1003 passes through the center of the remaining fifth gripping devices 1301b-1301d until the first fifth gripping device 1301b abuts the second fifth gripping device 1301b, and this is repeated, pulling each of the fifth gripping devices 1301a-1301d using the cable 1003, resulting in the arrangement of Figure 14.

[0069] Figure 15 shows a cutaway view of a borehole 1501 being drilled through a mountainside 1503 using a tool 1505 on a drill string 1507 and driven by a drill driver 1509. As can be seen, a portion of the mountainside has been excavated at each end 1511, 1513 to provide access to each end of the borehole.

[0070] Figure 16 shows a cut away view of pipe being pulled back through the borehole 1501 of Figure 15. The drill string 1507 is pulled back through the borehole 1501 by a pulling device 1603 which replaces the drill driver 1509. Attached to the free end of the drill string 1507 is a reamer 1601 which replaces the tool 1505. Behind the reamer 1601 is provided a section of pipe 1605. Access to both ends of the borehole 1501 is required in this arrangement and requires drilling 1511, 1513.

[0071] Figure 17, as an alternative to Figure 16, shows a cut away view of pipe being pulled forward through the borehole 1501 of Figure 15. The tool 1505 has been removed from the free end of the drill string 1507 and replaced with a pulling device 1603. A reamer 1601 replaces the drill driver 1509. Behind the reamer 1601 is provided a section of pipe 1605. Access to both ends of the borehole 1501 is required in this arrangement and requires drilling 1511, 1513.

[0072] Figure 18 is a cut away view of the pipe being forced forward through the borehole. In this arrangement, no drilling 1511, 1513 is required as the pushing device 1801 can replace the drill driver 1509 and will force the reamer 1601 and pipe section 1605 without requiring significant access at the distal end of the borehole.

Claims

1. A pipe installation device, a line suitable for passing through the interior of the pipe to be installed; at least one gripping device disposed on the cord line, a first operating state in which the gripping device is suitable for passing through the inside of the pipe to be placed; and a second operating state, in which the gripping device is configured to grip the inside of the pipe to be placed; a gripping device having A pipe arrangement device comprising:

2. The pipe laying apparatus of claim 1 , wherein the gripping device is configured to move along the line.

3. 3. The apparatus of claim 1 or 2, wherein the gripping device comprises at least one inflatable bag, the inflatable bag being in a first operative state when uninflated and in a second operative state when inflated.

4. 4. The apparatus of claim 1, wherein the gripping device comprises at least one arm movable between a first operational state in which the arm is in a first position and a second operational state in which the arm is in a second position, the arm in the second position extending further from an axis of the gripping device than the arm in the first position.

5. 5. The apparatus of claim 1, wherein the gripping device comprises at least one wedge configured such that tension and / or compression on the cord line in a first direction moves the wedge radially outward from the cord line into the second operating state, and such that tension and / or compression on the cord line in a second direction moves the wedge radially inward towards the cord line into the first operating state.

6. 6. The apparatus of claim 1, wherein the first operating state comprises the gripping device making a first contact with the inside of the pipe at a first resistance, and the second operating state comprises the gripping device making a second contact with the inside of the pipe at a second resistance, the first resistance being less than the second resistance.

7. 7. The apparatus of claim 6, wherein the first contact portion and the second contact portion are a single contact portion, the first operating state further comprising a first axial movement of the gripping device, and the second operating state further comprising a second axial movement of the gripping device.

8. The apparatus of claim 7 , wherein the single contact portion comprises a wheel, the wheel configured to rotate in only a first rotational direction.

9. 9. The apparatus of claim 1, further comprising a line tensioner / compressor configured to ensure that a first tension / compression of a first section of line on a first side of the gripping device is equal to a second tension / compression of a second section of line on a second side of the gripping device.

10. An apparatus according to any preceding claim, wherein the at least one gripping device comprises a plurality of gripping devices.

11. 1. A system for placing pipe in a borehole, comprising: A pipe installation device according to any one of claims 1 to 10, and a pipe in which the pipe arrangement device is installed; A system comprising:

12. 1. A method of placing pipe in a borehole, comprising: providing a borehole; providing a pipe to be installed in said borehole; Providing a pipe installation device according to any one of claims 1 to 10, placing the pipe installation apparatus inside the pipe with the gripping device in a first operational state; transitioning the pipe installation device to the second operating state; and pulling / pushing the line to pull / push the pipe into the borehole; A method comprising:

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