Wellbore lining apparatus and method of lining a wellbore |
|||||||
申请号 | EP05004441.1 | 申请日 | 2000-09-06 | 公开(公告)号 | EP1555386B1 | 公开(公告)日 | 2008-04-16 |
申请人 | e2Tech Limited; | 发明人 | Oosterling, Peter; | ||||
摘要 | |||||||
权利要求 | |||||||
说明书全文 | The present invention relates to an apparatus for and a method of anchoring a first conduit to a second conduit, the apparatus and method particularly, but not exclusively, using an inflatable device to provide a temporary anchor. A borehole is conventionally drilled during the recovery of hydrocarbons from a well, the borehole typically being lined with a casing. Casings are installed to prevent the formation around the borehole from collapsing. In addition, casings prevent unwanted fluids from the surrounding formation from flowing into the borehole, and similarly, prevents fluids from within the borehole escaping into the surrounding formation. Boreholes are conventionally drilled and cased in a cascaded manner; that is, casing of the borehole begins at the top of the well with a relatively large outer diameter casing. Subsequent casing of a smaller diameter is passed through the inner diameter of the casing above, and thus the outer diameter of the subsequent casing is limited by the inner diameter of the preceding casing. Thus, the casings are cascaded with the diameters of the casing lengths reducing as the depth of the well increases. This gradual reduction in diameter results in a relatively small inside diameter casing near the bottom of the well that could limit the amount of hydrocarbons that can be recovered. In addition, the relatively large diameter borehole at the top of the well involves increased costs due to the large drill bits required, heavy equipment for handling the larger casing, and increased volumes of drill fluid that are required. Each casing is typically cemented into place by filling cement into an annulus created between the casing and the surrounding formation. A thin slurry cement is pumped down into the casing followed by a rubber plug on top of the cement. Thereafter, drilling fluid is pumped down the casing above the cement that is pushed out of the bottom of the casing and into the annulus. Pumping of drilling fluid is stopped when the plug reaches the bottom of the casing and the wellbore must be left, typically for several hours, whilst the cement dries. This operation requires an increase in rig time due to the cement pumping and hardening process, that can substantially increase production costs. It is known to use a pliable casing that can be radially expanded so that an outer surface of the casing contacts the formation around the borehole. The pliable casing undergoes plastic deformation when expanded, typically by passing an expander device, such as a ceramic or steel cone or the like, through the casing. The expander device is propelled along the casing in a similar manner to a pipeline pig and may be pushed (using fluid pressure for example) or pulled (using drill pipe, rods, coiled tubing, a wireline or the like). Examples of such expander devices are shown in Lengths of expandable casing are coupled together (typically by threaded couplings) to produce a casing string. The casing string is inserted into the borehole in an unexpanded state and is subsequently expanded using the expander device, typically using a substantial force to facilitate the expansion process. Alternatively, a portion of the expandable casing can be pre-expanded to allow the expansion tool to be run into the wellbore with the casing string, such as that shown in Slips are conventionally used to temporarily anchor the unexpanded casing to the borehole during the expansion process. Slips are generally wedge-shaped, steel, hinged portion that provide a temporary anchor when used. Slips are actuated whereby the wedge-shaped portions engage with the surrounding borehole formation or a casing or liner. However, the mechanical configuration of slips often causes damage to the casing or liner. In some cases, the damage causes the slip to fail due to a loss of mechanical grip. Slip-type devices in open-hole engaging formation are often prone to slippage also. According to a first aspect of the present invention, there is provided a wellbore lining apparatus according to claim 1. Further apparatus features can be defined according to any of the dependent claims 2 to 12. According to a second aspect of the present invention, there is provided a method of lining a wellbore according to claim 13. Further method steps can include any of those defined in dependent claims 14 to 26. The first conduit is typically an expandable conduit. The first or expandable conduit may comprise any type of expandable conduit that is capable of sustaining plastic and/or elastic deformation. The first conduit typically comprises an expandable liner, casing or the like. The first conduit can be expanded into contact with a second conduit that may comprise any type of conduit. The second conduit typically comprises a liner, casing, borehole or the like. The inflatable device typically comprises an inflatable balloon-type portion coupled to a ring. This allows a string or the like to be passed through the inflatable device in use. Optionally, the inflatable device includes an expander device. The expander device is optionally telescopically coupled to the inflatable device, so that when the expander device is moved a certain distance, the inflatable device is deflated and subsequently moves with the expander device. Alternatively, the expandable device may be releasably attached to the inflatable device, typically using a latch mechanism. The inflatable device may be located within the expandable conduit. Alternatively, the inflatable device may be coupled at or near an upper end of the expandable conduit, or at or near a lower end of the expandable conduit. The inflatable device may be coupled to the expandable conduit using any suitable connection. The inflatable device is typically inflated to expand the expandable conduit whereby the expandable conduit contacts the second conduit, thereby providing an anchor. In this embodiment, the expandable conduit is optionally provided with a slotted portion to facilitate expansion. This is advantageous as the contact between the expandable conduit and the second conduit provides the anchor, and forces applied to the expandable conduit are mainly channelled into the second conduit via the expandable conduit and not the inflatable device. Alternatively, the inflatable device is inflated whereby a portion thereof directly contacts the second conduit to provide an anchor. The expander device is typically manufactured from steel. Alternatively, the expander device may be manufactured from ceramic, or a combination of steel and ceramic. The expander device is optionally flexible. The expander device is optionally provided with at least one seal. The seal typically comprises at least one O-ring. The method optionally comprises one, some or all of the additional steps of inserting an expander device into the expandable conduit, operating the expander device to expand the expandable conduit, deflating the inflatable device, and removing the expander device and/or the inflatable device from the expandable conduit and/or the second conduit. The method optionally comprises one, some or all of the additional steps of attaching an expander device to the inflatable device, operating the expander device to expand the expandable conduit, re-attaching the expander device to the inflatable device, deflating the inflatable device, and removing the expander device and/or the inflatable device from the expandable conduit and/or second conduit. The expander device is typically operated by propelling it through the expandable conduit using fluid pressure. Alternatively, the expander device may be operated by pigging it along the expandable conduit using a conventional pig or tractor. The expander device may also be operated by propelling it using a weight (from the string for example), or may by pulling it through the expandable conduit (e.g. using drill pipe, rods, coiled tubing, a wireline or the like). Optionally, the inflatable device may act as a seal whereby fluid pressure can be applied below the seal. Embodiments of the present invention shall now be described, by way of example only, with reference to the accompanying drawings, in which:-
Referring to The borehole is conventionally lined with casing 12 to prevent the formation around the borehole from collapsing and also to prevent unwanted fluids from the surrounding formation from flowing into the borehole, and similarly, prevents fluids from within the borehole escaping into the surrounding formation. It should be noted that the casing 12 may comprise any type of conduit, such as a pipeline, a liner, a casing, a borehole or the like. An inflatable device 14, that in this embodiment has an expander device 16 telescopically attached thereto, is positioned within the expandable conduit 10 before the conduit 10 is inserted into the casing 12. Referring to The inflatable device 14 may be of any suitable configuration, but is typically a device that has an inflatable annular balloon-type portion 14b that is mounted on an annular ring 14r. The annular ring 14r allows a string, wireline or the like to be passed through the inflatable device 14 as required. This is particularly advantageous where the inflatable device 14 is positioned at the upper end of the conduit 10. Thus, substantially full-bore access is still possible. Referring to Referring to The first and second bands 102, 104 are preferably annular bands that extend circumferentially around the anchor point 10a of the conduit 10, although this configuration is not essential. The first and second bands 102, 104 typically comprise 1 inch wide (approximately 25.4mm) bands of a first type of rubber. The friction and/or sealing material 100 need not extend around the full circumference of the conduit 10. Located between the first and second bands 102, 104 is a third band 106 of a second type of rubber. The third band 106 preferably extends between the first and second bands 102, 104 and is thus typically 3 inches (approximately 76mm) wide. The first and second bands 102, 104 are typically of a first depth. The third band 106 is typically of a second depth. The first depth is optionally larger than the second depth, although they are typically the same, as shown in The first type of rubber (i.e. first and second bands 102, 104) is preferably of a harder consistency than the second type of rubber (i.e. third band 106). The first type of rubber is typically 90 durometer rubber, whereas the second type of rubber is typically 60 durometer rubber. Durometer is a conventional hardness scale for rubber. The particular properties of the rubber may be of any suitable type and the hardnessess quoted are exemplary only. It should also be noted that the relative dimensions and spacings of the first, second and third bands 102, 104, 106 are exemplary only and may be of any suitable dimensions and spacing. As can be seen from The two outer bands 102, 104 being of a harder rubber provide a relatively high temperature seal and a back-up seal to the relatively softer rubber of the third band 106. The third band 106 typically provides a lower temperature seal. Referring to The expandable conduit 120 is provided with a pre-expanded portion 120e in which an expander device (e.g. expander device 16) and/or an inflatable device (e.g. device 14) may be located whilst the conduit 120 is run into a borehole or the like. It should be noted that the expander device need not be located in the conduit 120 whilst it is being run into the borehole, and can be located in the conduit 120 once it is in place. As shown in The friction and/or sealing material 122 is best shown in To provide a zigzag pattern and hence increase the strength of the grip and/or seal that the formation 150 provides in use, a number of slots 124a, 124b (e.g. 20) are milled into the band of rubber. The slots 124a, 124b are typically in the order of 0.2 inches (approximately 5mm) wide by around 2 inches (approximately 50mm) long. To create the zigzag pattern, the slots 124a are milled at around 20 circumferentially spaced-apart locations, with around 18º between each along one edge 122a of the band. The process is then repeated by milling another 20 slots 124b on the other side 122b of the band, the slots 124b on side 122b being circumferentially offset by 9° from the slots 124a on the other side 122a. In use, the friction and/or sealing material 122 is applied to the outer surface 120s of the (unexpanded) expandable conduit 120. It should be noted that the configuration, number and spacing of the friction and/or sealing material 122 can be chosen to suit the particular application. It should be noted that forces applied to the conduit 10, 120 e.g. by subsequent movement of the conduit 10, 120 that is by pushing or pulling on the conduit 10, 120 for example, will be mainly transferred to the casing 12 via the anchor point and not through the inflatable device 14. This is advantageous as it reduces the risk of damage to the inflatable device 14. Additionally, this also reduces the risk of damage to the casing 12 that may have occurred where a conventional slip is used. Also, conventional slips may lose their grip on the casing 12 where damage ensues or the casing 12 is weak. Transferring substantially all of the forces directly to the casing 12 via the anchor point obviates these disadvantages. The expander device 16 can then be pulled through the expandable conduit 10, 120 to radially expand the conduit 10, 120 as shown in In the embodiment shown in It should be noted that the inflatable device 14 is no longer required to anchor the conduit 10, 120 to the casing 12 as the expanded conduit 10 ( The expander device 16 is continually pulled upwards towards the surface until the expandable conduit 10, 120 is fully expanded to contact the casing 12. Thereafter, the inflatable device 14 and the expander device 16 may be removed from the expandable conduit 10, 120 and/or the casing 12 at the surface. Anchoring and expanding the expandable conduit 10, 120 in this way has several advantages. With the embodiment shown in It should be noted that the method described with reference to Referring to In the embodiment shown in Additionally, the conduit 30 may be provided with friction and/or sealing material (e.g. material 100, 122) at a lower end 301 of the conduit 30 to enhance the anchoring effect at this portion of the conduit. Additionally, the friction and/or sealing material can be provided at various spaced-apart locations along the length of the conduit 30 to enhance the coupling between the conduit 30 and the borehole 34 or casing 36. Referring to The inflatable device 40 may be of any suitable configuration, but is typically a device that has an inflatable annular balloon-type portion 40b that is mounted on an annular ring 40r. The annular ring 40r allows a string, wireline or the like to be passed through the inflatable device 40 as required. This is particularly advantageous where the inflatable device 40 is positioned at the upper end of the conduit 30. Referring to As with the previous embodiment, the expander device 42 is then pulled through the expandable conduit 30 to radially expand the conduit 30, as shown in As the expander device 42 is pulled upwards, the upward movement thereof is stopped after a predetermined time or distance, at which point the expander device 42 is lowered until a coupling between the expander device 42 and the inflatable device 40 latches. As with the previous embodiments, the inflatable annular balloon-type portion 40b is automatically deflated and further upward movement of the expander device 42 causes the inflatable device 40 also to move upward, as shown in It should also be noted that the portion 44 is no longer required to anchor the conduit 30 to the borehole 34 as the expanded conduit 30 ( The expander device 42 is continually pulled upwards until the conduit 30 is fully expanded, as shown in With the embodiment shown in It should also be noted that successive lengths of expandable conduit may be coupled to casings or liners thereabove using the same method. Thus, the method(s) described herein may be used to line or case a borehole without the use of cement. Referring to An inflatable device 84 is releasably attached to a lower end 801 of the expandable conduit 80 before the conduit 80 is inserted into the casing 82. The expander device 86 is located within the lower end 801 of the conduit 80, the lower end 801 being expanded to accommodate the expander device 86. Similar to the previous embodiment, the inflatable device 84 has the expander device 86 releasably coupled thereto via a coupling 88. Otherwise, the inflatable device 84 and the expander device 86 are substantially the same as the previous embodiments. Referring to The inflatable device 84 may be of any suitable configuration, but is typically a device that has an inflatable annular balloon-type portion 84b that is mounted on an annular ring 84r. The annular ring 84r allows a string, wireline or the like to be passed through the inflatable device 84 as required. This is particularly advantageous where the inflatable device 84 and/or the expander device 86 are positioned at the upper end of the conduit 80. Referring to It should be noted that in this embodiment, the forces applied to the conduit 80 by subsequent movement of the conduit 80, that is by pushing or pulling on the conduit 80 for example, will be transferred to the casing 82 via the inflatable device 84. However, unlike conventional slips, the inflated balloon-type portion 84b is less likely to damage the casing. Additionally, the size of the balloon-type portion 84b can be chosen whereby it is sufficiently large so as not to lose its grip on the casing 82, even when the inflatable device 84 is moved upwardly or downwardly. The expander device 86 is pulled through the expandable conduit 80 to radially expand the conduit 80, as shown in Also, and as with the previous embodiments, an outer surface 80s of the conduit 80 can be provided with a friction and/or sealing material. The friction and/or sealing material may comprise, for example, any suitable type of rubber or other resilient materials. For example, the friction and/or sealing material can be configured in a similar way to the friction and/or sealing material 100, 122 described above with reference to Additionally, the conduit 80 may be provided with friction and/or sealing material (e.g. material 100, 122) at a lower end 801 of the conduit 80 to enhance the anchoring effect at this portion of the conduit 80. Additionally, the friction and/or sealing material can be provided at various spaced-apart locations along the length of the conduit 80 to enhance the coupling between the conduit 80 and the casing 82. As the expander device 86 is pulled upwards, the upward movement thereof is stopped after a predetermined time or distance, at which point the expander device 84 is lowered until the coupling 88 between the expander device 86 and the inflatable device 86 latches. As with the previous embodiments, the inflatable balloon-type portion 84b is automatically deflated and further upward movement of the expander device 86 causes the inflatable device 84 also to move upward, as shown in The expander device 86 is continually pulled upwards towards the surface until the conduit 80 is fully expanded to contact the casing 82. Thereafter, the inflatable device 84 and the expander device 86 may be removed from the borehole at the surface. Anchoring and expanding the conduit 80 in this way has the same advantages as in the previous embodiment, but the The method and apparatus described herein may be used for a plurality of different downhole functions relating to the use of expandable conduit. For example, they may be used where the original liner or casing requires to be repaired due to damage or the like by overlaying the damaged portion with a portion of expandable conduit. They may also be used to tie back to the liner or casing, as described herein. Thus, there is provided in certain embodiments an apparatus and method of anchoring an expandable conduit to a second conduit. The apparatus and method of certain embodiments provide numerous advantages over conventional mechanical anchoring devices, such as slips, particularly by reducing the potential damage to conduits that mechanical slips may cause. Certain embodiments of apparatus and methods involve the use of an inflatable device that can either be a) attached directly at or near the top or bottom of the expandable conduit, or b) placed within the top or bottom of the expandable conduit. In a), anchoring forces are generated as a result of friction between the inflatable device and the second conduit, the forces being passed into the conduit via the inflatable device. In b), anchoring forces are generated by friction between an outer surface of the expandable conduit and the second conduit, the forces being substantially passed into the second conduit directly via the expandable conduit. The outer surface of the expandable conduit may be suitably prepared (ie provided with a friction enhancing material) to increase the strength of the anchor. Modifications and improvements may be made to the foregoing without departing from the scope of the present invention. |