Patent Abstract:
A method of performing a servicing operation within a pipeline comprises positioning a swellable component about at a desired location within a pipeline, exposing the swellable component to a swelling agent within the pipeline, expanding the swellable component into sealing engagement with the pipeline, thereby forming a seal across the pipeline, and opening a fluid pathway through the pipeline without removing the swellable component. Another method of performing a servicing operation within a pipeline comprises inserting into the pipeline a pipeline tool comprising an externally mounted swellable component, propelling the pipeline tool through the pipeline to about a desired location via a flow of fluid, expanding the swellable component into sealing engagement with the pipeline at about the desired location, and opening a flow path through the pipeline tool.

Full Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
       [0001]    None. 
       STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT 
       [0002]    Not applicable. 
       REFERENCE TO A MICROFICHE APPENDIX 
       [0003]    Not applicable. 
       FIELD OF THE INVENTION 
       [0004]    The present invention relates generally to apparatus and methods for sealing and isolating pipelines. More particularly, the present invention relates to various embodiments of a pipeline sealing and isolation tool that permits sealing of an annular area within a pipeline using a swellable component, and temporary sealing of a flowbore through the tool using a temporary internal seal. Still more particularly, the present invention relates to methods of sealing and isolating a pipeline to perform maintenance, seal leaks, or install permanent devices within the pipeline. 
       BACKGROUND 
       [0005]    Conventional pipeline maintenance and repair methods comprise first discontinuing normal pipeline operations, then isolating the section of pipeline to be repaired or maintained by closing a valve or providing some other type of seal in the pipeline, and then draining liquids or blowing down gases within the isolated section of pipeline. Once the product is removed from the isolated section of pipeline, repair and/or maintenance operations may then be performed. These operations may include cutting and replacing a leaking section of pipeline and/or installing permanent devices in the pipeline, such as a valve. When making such permanent installations in the pipeline, a structural integrity test, such as a hydrostatic test, may be performed thereafter, in which case the water used in the test must be drained, and in some cases, the pipeline is also dried depending upon the pipeline service. Finally, the pipeline can be re-commissioned with product and normal operations resumed. 
         [0006]    These conventional methods are both time-consuming and expensive due to the discontinued pipeline operations, the loss of product that may be incurred due to draining or blowing down, and the time and expense associated with cutting into the pipeline to make the actual repair and/or perform the maintenance operation, such as replacing a leaking section of pipeline or installing a permanent device. 
         [0007]    To address some of these inefficiencies, a pipeline isolation pig has been developed that may be used to isolate a section of pipeline so that maintenance and repair operations may then be performed. The pipeline isolation pig is a remote-controlled device that may be positioned at any desired location within the pipeline to isolate a section of pipeline so as to minimize the amount of product to drain or blow down before performing the work. It may be launched into a pipeline and pushed along by the product while being tracked to its intended destination. Then the pipeline isolation pig may be locked into position to completely seal across the pipeline. Drawbacks to the pipeline isolation pig is that it does not act as a permanent repair device, and it does not permit product flow therethrough. Instead it seals the pipeline in such a way that the seal is only removable by removing the pipeline isolation pig entirely from the pipeline. Hence, after the repair and/or maintenance operations are complete, the pipeline isolation pig must be removed from the pipeline to permit normal pipeline operations to resume. 
         [0008]    Therefore, a need exists for a more efficient, less costly, and optionally permanent repair apparatus, and methods of performing pipeline maintenance, leak repair, and installation of permanent devices. 
       SUMMARY OF THE INVENTION 
       [0009]    Disclosed herein is a method of performing a servicing operation within a pipeline comprising positioning a swellable component about at a desired location within a pipeline, exposing the swellable component to a swelling agent within the pipeline, expanding the swellable component into sealing engagement with the pipeline, thereby forming a seal across the pipeline, and opening a fluid pathway through the pipeline without removing the swellable component. In various embodiments, the servicing operation comprises repairing a leak in the pipeline wall, or positioning a permanent device within the pipeline. Opening the fluid pathway may comprise opening the permanent device and disengaging a temporary seal connected to the swellable component. The method may further comprise closing the pathway through the pipeline and performing another service operation and tracking the swellable component as it is propelled to the location. In an embodiment, the positioning comprises inserting he swellable component into the pipeline and propelling the swellable component to about the desired location via a flow of fluid. The fluid may be the swelling agent, and the swelling agent may comprise natural gas, a hydrocarbon fluid, water, brine, or another aqueous solution. 
         [0010]    Also disclosed herein is a method of performing a servicing operation within a pipeline comprising inserting into the pipeline a pipeline tool comprising an externally mounted swellable component, propelling the pipeline tool through the pipeline to about a desired location via a flow of fluid, expanding the swellable component into sealing engagement with the pipeline at about the desired location, and opening a flow path through the pipeline tool. In various embodiments, the method further comprises tracking the pipeline tool during the propelling, or running a pipeline pig through the pipeline tool. In an embodiment, inserting the pipeline tool comprises launching the pipeline tool from a pig launcher. Expanding the swellable component may comprise absorbing the fluid, and opening a flow path through the pipeline tool may comprise disengaging a temporary seal. Expanding the swellable component may comprise sealing a leak in a wall of the pipeline. In an embodiment, the method further comprises closing the flow path through the pipeline tool, and may also comprise depressurizing a section of the pipeline upstream or downstream of the pipeline tool, and performing the servicing operation on the depressurized pipeline section. The method may further comprise re-pressurizing the depressurized pipeline section, reopening the flow path through the pipeline tool, and resuming fluid flow through the flow path. In another embodiment, the method comprises disposing a permanent device within the pipeline tool, and opening the flow path may comprise actuating the permanent device. 
     
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0011]    For a more detailed description of the present invention, reference will now be made to the accompanying drawings, wherein: 
           [0012]      FIG. 1  is an enlarged cross-sectional side view of one representative pipeline sealing and isolation tool; 
           [0013]      FIG. 2  is an enlarged cross-sectional side view of one representative swellable component; 
           [0014]      FIGS. 3A to 3D  depict one embodiment of a pipeline leak repair operation wherein the embodiment of the tool depicted in  FIG. 1  may be utilized; 
           [0015]      FIGS. 4A to 4D  depict one embodiment of a pipeline maintenance operation wherein the embodiment of the tool depicted in  FIG. 1  may be utilized; and 
           [0016]      FIGS. 5A to 5C  depict one embodiment of a pipeline operation wherein a permanent device may be installed using the embodiment of the tool depicted in  FIG. 1 . 
           [0017]      FIGS. 6A to 6D  depict one embodiment of a pipeline operation wherein the embodiment of the tool depicted in  FIG. 1  may be utilized in such a way as to allow for passage of a pipeline pig. 
       
    
    
     NOTATION AND NOMENCLATURE 
       [0018]    Certain terms are used throughout the following description and claims to refer to particular assembly components. This document does not intend to distinguish between components that differ in name but not function. In the following discussion and in the claims, the terms “including” and “comprising” are used in an open-ended fashion, and thus should be interpreted to mean “including, but not limited to . . . ”. 
         [0019]    As used herein, the term “pipeline” includes any line or conduit in which fluid is moved, including but not limited to any onshore or offshore flow system, such as mainline systems, risers, flow lines used to transport untreated fluid between a wellhead and a processing facility, and flow lines used to transport treated fluids. 
         [0020]    In the drawings, the cross-sectional views of the pipeline sealing and isolation tool should be viewed from left to right, with the upstream end of the pipeline at the left end of the drawing and the downstream end of the pipeline at the right end of the drawing. Stated alternatively, the pipeline sealing and isolation tool is traveling from left to right in the drawings. However, this should in no way infer that the tool is unidirectional, and proper tool design will allow for bi-directional positioning of the tool within the pipeline. 
       DETAILED DESCRIPTION 
       [0021]    Various embodiments of a pipeline sealing and isolation tool operable to provide a seal within a pipeline for various purposes, including pipeline maintenance, leak repair, and installing permanent devices within the pipeline, will now be described with reference to the accompanying drawings, wherein like reference numerals are used for like features throughout the several views. There are shown in the drawings, and herein will be described in detail, specific embodiments of the pipeline tool with the understanding that this disclosure is representative only and is not intended to limit the invention to those embodiments illustrated and described herein. The embodiments of the pipeline tool and methods disclosed herein may be used in any type of application, operation, or process where it is desired to perform maintenance, repair, and/or installation of permanent devices in a pipeline. It is to be fully recognized that the different teachings of the embodiments disclosed herein may be employed separately or in any suitable combination to produce desired results. 
         [0022]      FIG. 1  depicts one representative pipeline sealing and isolation tool  100  being propelled through a pipeline  190  by a fluid  115 . The fluid  115  may be a gas or liquid, and may comprise natural gas, a hydrocarbon fluid, water, brine or other aqueous solution. As depicted, the tool  100  comprises a body  140  with an optional flared tail  150  and an internal flow cavity  160 , a plurality of front guide discs  170  and a plurality of rear guide discs  110  disposed about the body  140 , a temporary seal  130  positioned within the flow cavity  160 , a swellable component  120  surrounding the body  140  and disposed between the sets of guide discs  110 ,  170 , and a tracking device  125  secured to the exterior surface of the body  140 . 
         [0023]    The body  140  of the pipeline tool  100  is operable to transport the swellable component  120  and the temporary seal  130  to a desired position along the pipeline  190  to form a seal across the pipeline  190  when the swellable component  120  expands into engagement with the internal pipe wall  180 . The body  140  also functions as a secondary pressure barrier against the pressure of the fluid  115 , with the primary pressure barrier being the temporary seal  130 . In order for the body  140  to have sufficient structural strength to perform these functions, the body  140 , including the optional flared tail  150 , may be constructed of a metal alloy, such as a steel or ferrous alloy, for example. Moreover, although the body  140  depicted in  FIG. 1  has a solid, smooth-wall configuration, in another embodiment, the body  140  may be long, thin, flexible and/or corrugated to manipulate turns and corners along the pipeline  190 . The flared tail  150  of the body  140  is an optional feature of the pipeline tool  100 . When present, the flared tail  150  facilitates transit of a pipeline pig through the internal flow cavity  160  after the pipeline device  100  is positioned along the pipeline  190  and the swellable component  120  is set against the internal pipe wall  180  (as illustrated in  FIGS. 6A-6E ). The flared tail  150  also minimizes the accumulation of debris near the pipeline tool  100  and reduces the effects of flow restrictions that may result due to the reduction in the flowpath caused by the presence of the pipeline tool  100 . One of ordinary skill in the art will readily appreciate that the angle of the flared tail  150  may vary, even be optimized, to maximize its effectiveness in reducing debris accumulation and flow restrictions. 
         [0024]    The swellable component  120  may be a chemically activated material that expands over time into sealing engagement with the inner pipe wall  180  by absorbing the fluid  115  in the pipeline  190 . The expanded swellable component  120  thus seals across the annulus  135  formed between the pipeline tool  100  and the inner pipe wall  180  of the pipeline  190 . Referring now to  FIG. 2 , in one embodiment, the swellable component  120  comprises a core  230  surrounded by an external membrane  210  that is permeable to the fluid  115  and may include an inner reinforcement layer  220 . In another embodiment, the swellable component  120  only comprises the core  230 . The external membrane  210  shown in  FIG. 2  is designed to surround and protect the core  230 , but also allows migration of fluid  115  to the core  230 . The membrane  210  is also permeable to the fluid  115 , but the fluid  115  permeates the membrane  210  more slowly than the core  230 . Thus, the membrane  210  may control the rate of swelling of the core  230  such that the tool  100  may be positioned in the pipeline  190  and engaged with the inner pipe wall  180  in a controlled manner. Upon exposure to the fluid  115 , the core  230  swells at a known-rate due to absorption of the fluid  115  and the swellable component  120  expands into engagement with the inner pipe wall  180 , eventually forming a seal that prevents fluid  115  flow through the annulus  135  between the pipeline tool  100  and the pipeline  190 . 
         [0025]    The choice of material for the core  230  may depend upon the type of fluid  115 . The rate at which the core  230  swells upon exposure to the fluid  115  may depend primarily the material composition of the core and the viscosity of the fluid, but may also depend upon the construction of the core and/or process parameters such as fluid  115  temperature and pressure. For example, the core may have a layered construction, where different layers and/or materials are used in the core having different diffusion or swelling properties. In hydrocarbons, including natural gas and liquid hydrocarbons, the core  230  may be manufactured from an elastic polymer, such as a rubber or rubber-like material selected from the group comprising EPDM, styrene-butadiene rubber, natural rubber, ethylene-propylene monomer rubber, ethylene-vinyl acetate rubber, hydrogenated acrylonitrile-butadiene rubber, acrylonitrile-butadiene rubber, isoprene rubber, chloroprene rubber or polynorbomene. Other materials may be dissolved in mechanical mixture such as cellulose fibres. Other options for core  230  materials comprise rubber in mechanical mixture with polyvinyl chloride, methyl methacrylate, acrylonitrile, ethylacetate or other polymers. Where the fluid  115  is an aqueous fluid, such as water or brine, the core  230  may be formed using material manufactured from hydrogen dichromate dissolved in water and mixed into a compound of glycerol, diethylene glycol, and polycrylamide. 
         [0026]    Depending upon the fluid  115 , the core  230  must be chosen such that the swellable component  120  will expand sufficiently when exposed to the fluid  115  to form a seal across the annulus  135  between the pipeline tool  100  and the inner pipe wall  180  of the pipeline  190 . The degree of swelling required depends upon a number of factors, including the width of the annulus  135 . Material selection and thickness of the membrane  210 , on the other hand, depends upon the distance the swellable component  120  must travel to its intended destination while being exposed to the fluid  115 . If the pipeline tool  100  must travel a significant distance, the membrane  210  material and thickness may be chosen such that the swellable component  120  will not complete its expansion process until after the pipeline tool  100  reaches its final destination. In that scenario, the membrane  210  material selected may have a low rate of fluid  115  permeability and the membrane  210  thickness may be significant, thereby slowing exposure of the core  230  to the fluid  115  and increasing the amount of time for the core  230  to fully expand so that the pipeline tool  100  will reach its final destination before the core  230  has expanded fully. In hydrocarbons, the membrane  210  may comprise a rubber, for example acrylonitrile, hydrogenated nitrile, chloroprene, ethylene vinylacetate rubber, silicone, ethylene propylene diene monomer, butyl, chlorosulphonated polyethylene, polyurethane, ACM, BIMS or other types of rubber having less expansion or slower diffusion than the core  230 . Typically, the swellable component  120  may require one to four days to filly expand. The presence of a thick membrane  210  with a low rate of permeability to the fluid  115  may, when needed, slow the core  230  expansion such that the swellable component  120  may require a longer time to fully expand. Such a slow expansion rate may be required when the pipeline tool  100  has a significant distance to travel before reaching its intended destination. 
         [0027]    The front guide discs  170  and the rear guide discs  110  permit the pipeline tool  100  to be pushed along the pipeline  190  by the fluid  115 . These discs  110 ,  170  form a sufficient seal with the inner pipe wall  180  of the pipeline  190  to prevent the fluid  115  from bypassing the pipeline tool  100 . Instead, the fluid  115  contacts the guide discs  110 ,  170  and the temporary seal  130  and pushes the pipeline tool  100  along the pipeline  190 . 
         [0028]    The temporary seal  130  performs multiple functions. In its closed position, fluid  115  contacts the temporary seal  130 , as well as the guide discs  110 ,  170 , and pushes the pipeline tool  100  along the pipeline  190 , as described above. Once the pipeline tool  100  is positioned at its intended location and the swellable component  120  has expanded against the inner pipe wall  180  to anchor the pipeline tool  100  in place, the temporary seal  130  permits isolation of a section of pipeline  190 , upstream or downstream of the temporary seal  130  from the remainder of the pipeline  190 . The isolated section of pipeline  190  may then be depressurized allowing for maintenance, leak repair, or installation of permanent devices such as a valve. Once such operations are complete, the temporary seal  130  may be selectively opened to permit the fluid  115  flow to resume through the pipeline  190 . 
         [0029]    One of ordinary skill in the art will readily appreciate that the temporary seal  130  may be any device that when closed allows the pipeline tool  100  to be pushed along the pipeline  190  by the fluid  115 , and when open permits fluid  115  to flow through the internal flow cavity  160  of the pipeline tool  100 . The temporary seal  130  is capable of selective actuation such that it will open when desired to permit fluid  115  flow through the internal cavity  160  of the pipeline tool  100 . 
         [0030]    In one embodiment, the temporary seal  130  is only actuatable to open once and can not be closed. In such an embodiment, the temporary seal  130  may comprise a rupture disc, which is a pressure-containing disc formed of a frangible material designed to burst open and relieve an overpressure at a predetermined differential pressure. In various embodiments, the disc may be formed of a metal or other materials, such as impervious graphite, which is a high-purity form of carbon impregnated with phenolic resin, for example. Instead of a rupture disc, various other types of removable temporary seals  130  may also be used. Removal or opening of the temporary seal  130  may be accomplished by a variety of different methods, including mechanically, hydraulically, chemically, electrically, explosively, combustively, or a combination thereof. In one embodiment, the temporary seal  130  comprises a material that degrades over time due to exposure to the fluid  115 , for example. In another embodiment, one or more components of the isolation tool  100 , for example body  140 , is made from an acid dissolvable material such as aluminum. 
         [0031]    In other embodiments, the temporary seal  130  is designed not only to be selectively opened, but also to be selectively closed and re-opened as desired to perform additional maintenance or repair on the pipeline  190 . In such embodiments, the temporary seal  130  may comprise an electromechanical valve, for example, or another type of open/close device. Actuation of such a temporary seal  130  may be achieved by a variety of different methods, including mechanically, hydraulically, electrically, or a combination thereof In various embodiments, the temporary seal  130  is actuated using a pressure pulse, a pressure differential, a temperature increase or decrease, a magnetic signal, an electronic signal, an electromagnetic signal, a timer, an acoustic signal, an ultrasonic signal, or other through-wall communication. 
         [0032]    The tracking device  125  permits monitoring of the pipeline tool  100  as it traverses the pipeline  190 . In an embodiment, the tracking device  125  is a mechanical fixture attached to the exterior surface of the body  140 , which is operable to engage a similar mechanical stop  185  extending into the pipeline  190  at or near the final destination of the pipeline tool  100 . The mechanical stop  185  may be installed using a hot tap fixture  195 , for example. In this embodiment, when the tracking device  125  on the pipeline tool  100  contacts the mechanical stop  185  extending into the pipeline  190 , such contact indicates that the pipeline tool  100  has reached its intended destination, and the mechanical interaction also stops the pipeline tool  100  at the location. In another embodiment, the tracking device  125  may be connected to the exterior of the swellable component  120  such that as swelling occurs, the tracking device  125  will engage the inner pipe wall  180  first, and such engagement may stop the pipeline tool  100  at or near that location. Then the swellable component  120  continues swelling around the tracking device  125  until it forms a seal with the inner pipe wall  180  of the pipeline  190 . Alternatively, in other embodiments, the tracking device  125  may comprise a device that emits a tracking signal, such as a magnet, a radioactive isotope, an electronic transmitter, an acoustic transmitter, and an ultra-sonic device, for example, thus revealing the position of the pipeline tool  100  inside the pipeline  190 . 
         [0033]    The pipeline sealing and isolation tool  100  may be used operationally for a variety of different purposes.  FIGS. 3A through 3D  schematically depict one embodiment of a pipeline operation wherein the pipeline sealing and isolation tool  100  illustrated in  FIG. 1  may be used to seal an external leak  300  in a pipeline  190 . Referring to  FIG. 3A , upon discovery and location of a pipeline leak  300 , the pipeline tool  100  may be inserted into the pipeline  190  via a pipeline pig launcher  710  or another means, including placing the pipeline tool  100  into an open-ended area of the pipeline  190 . The pipeline tool  100  is then propelled along the pipeline  190  by the fluid  115  towards the leak  300  location, while the position of the pipeline tool  100  is monitored using the tracking device  125 . 
         [0034]    In alternative embodiments, the pipeline tool  100  may be moved through the pipeline  190  via a force or transport means other than fluid flow. For example, the pipeline tool  100  may comprise a propulsion system and may thereby be self propelled. The propulsion system may be any suitable means for propulsion such as motorized propulsion, for example a motor coupled to a propeller, wheel, tracks, crawler/creeper arms, and the like. Alternatively, the pipeline tool  100  may be conveyed to a desired location in pipeline  190  via another tool such as a pig. For example, the pipeline tool  100  may be pushed or pulled along the pipeline via a tow unit, and the tow unit may be powered by fluid flow or other conveyance means, including self propulsion. 
         [0035]    As the pipeline tool  100  approaches its intended destination within the pipeline  190 , in this case the location of the leak  300 , the flow of fluid  115  may be slowed or discontinued. Without fluid  115  to push the pipeline tool  100  via contact with the guide discs  110 ,  170  and the closed temporary seal  130 , the pipeline tool  100  will cease to traverse the pipeline  190 . Then the position of the pipeline tool  100  may be determined relative to its intended destination. If the pipeline tool  100  has stopped upstream of its intended destination, fluid  115  flow may be resumed briefly to push the pipeline tool  100  closer to that position. If, on the other hand, the pipeline tool  100  has traveled beyond its intended destination, fluid  115  flow may be injected in the opposite direction to push the pipeline tool  100  upstream to the desired position. The guide discs  110 ,  170  are bidirectional such that they are designed to permit the pipeline tool  100  to traverse the pipeline  190  in either direction. 
         [0036]    During the time that the pipeline tool  100  is traveling, and upon arrival at the leak  300  location, as shown in  FIG. 3B , the swellable component  120  is absorbing the fluid  115  and expanding across the annulus  135 , towards the inner pipe wall  180  of the pipeline  190  and the leak  300 . As shown in  FIG. 3C , once the swellable component  120  fully expands, it forms a permanent, fluid-tight seal across the annulus  135  and against the inner pipe wall  180  of the pipeline  190  such that the leak  300  is also sealed. 
         [0037]    Once the swellable component  120  is set, the temporary internal seal  130  may be opened as described above using some method of actuation. In an embodiment, the temporary seal  130  is opened by pressuring up the fluid  115  within the pipeline  190 . In such an embodiment, the seal formed by the swellable component  120  against the inner pipe wall  180  of the pipeline  190  is designed to withstand the higher pressure of the fluid  115  operable to open the temporary internal seal  130 . When the temporary internal seal  130  is opened, fluid  115  flow can resume inside the pipeline  190 , as shown in  FIG. 3D . Although fluid  115  flow is reestablished, the pipeline tool  100  remains firmly in position and the leak  300  is sealed due to the expanded swellable component  120 . The pipeline tool  100  may comprise a permanent leak repair, or may remain in position for an extended period of time until this section of the pipeline  190  may be cut out and replaced. 
         [0038]    The pipeline sealing and isolation tool  100  may also be used to seat and isolate one section of pipeline  190  to perform maintenance operations on the pipeline  190 .  FIGS. 4A through 4D  schematically depict one embodiment of a sequence for isolating an upstream section  192  of pipeline  190  from a downstream section  194  using the pipeline sealing and isolation tool  100  illustrated in  FIG. 1  so that maintenance operations maybe performed on the isolated section  192  of pipeline  190 . In an embodiment, the pipeline tool  100  used to perform maintenance operations on the pipeline  190  comprises dual temporary internal seals  130  to ensure fluid-tight isolation between the upstream section  192  and the downstream section  194 . 
         [0039]    The pipeline tool  100  is inserted into the pipeline  190  and propelled along the pipeline  190  by the fluid  115 . The position of the pipeline tool  100  inside the pipeline  190  may be monitored using the tracking device  125 . As shown in  FIG. 4A , when the pipeline tool  100  reaches its intended destination, it is stopped by discontinuing fluid  115  flow through the pipeline  190 . During the time that the pipeline tool  100  is traveling, and upon arrival at the intended location, the swellable component  120  is absorbing the fluid  115  and expanding across the annulus  135 , towards the inner pipe wall  180  of the pipeline  190 . As shown in  FIG. 4B , once the swellable component  120  fully expands, it forms a permanent fluid-tight seal across the annulus  135  and against the inner pipe wall  180  of the pipeline  190 . Determining when the swellable component  120  has fully expanded and is set in the pipeline  190  may be accomplished in a number of ways. In one embodiment, laboratory testing of the core  230  material and the membrane  210  may be performed to estimate the rate of expansion for the given fluid  115 . Then, the amount of time needed to fully expand or set the swellable component  120  may be calculated as a function of the rate of expansion of the core  230  and membrane  210  materials in the given configuration. In another embodiment, a field test may be performed. In particular, when it is estimated that enough time has elapsed for the swellable component  120  to set, the flow of fluid  115  may be resumed to pressure up the pipeline  190  upstream of the pipeline tool  100 , and if the pipeline tool  100  moves in response to that pressure, the swellable component  120  is not set. In another embodiment, strain gauges may be affixed to the body  140  of the pipeline tool  100 , and strain levels in the body  140  of the pipeline tool  100  may then be monitored. As the swellable component  120  sets, strain levels in the body  140  will increase, and strain measurement behavior will indicate when the swellable component  120  is set. 
         [0040]    Once the swellable component  120  is set as shown in  FIG. 4B , the upstream section  192  of the pipeline  190  is hereby isolated from the downstream section  194  of the pipeline  190  by virtue of the fully-expanded swellable component  120  sealing with the pipeline  190  and the closed dual temporary seals  130 . In one embodiment, the isolated upstream section  192  of the pipeline  190  may then be depressurized to allow for maintenance operations to be performed. The downstream section  194  of the pipeline  190  may remain pressurized because the swellable component  120  and the dual temporary seals  130  ensure isolation between the depressurized and pressurized sections of the pipeline  190 . As shown in  FIG. 4C , upon completion of maintenance operations, the isolated section  192  of the pipeline  190  may be re-pressurized. Finally, as shown in  FIG. 4D , the temporary internal seals  130  may be opened, as described above, allowing the flow of fluid  115  to resume inside the pipeline  190 . Although the flow of fluid  115  is reestablished, the pipeline tool  100  remains firmly in position due to the expanded swellable component  120 . The pipeline tool  100  may remain in position indefinitely to allow for similar subsequent maintenance operations wherein the dual seals  130  may be re-actuated to close, and thereby isolate the upstream section  192  of the pipeline  190  from the downstream section  194 . 
         [0041]    In an alternative embodiment, two our more pipeline tools  100  may be used to isolate a section of pipeline  190  between the tools. For example, first and second pipeline tools  100  may be positioned on either side of a leak  300  and set, thereby isolating the section of pipe between the tools  100 , which thereafter may be depressurized and repaired accordingly. In alternatively embodiments, more than one pipeline tool  100  may be used one or both sides of a portion of pipeline to be isolated. For example, a first pair of pipeline tools  100  may be positioned on the downstream side of a leak and a second pair of pipeline tools  100  may be positioned on the upstream side of the leak, thereby isolating the section of pipeline containing the leak upon setting of the tools. Placement and positioning of a plurality of pipeline tools  100  can be carried out using the methods described herein. For example, a first pipeline tool  100  may be placed in the pipeline  190  followed by a sufficient flow of fluid to space the first pipeline tool  100  a desired distance in front of a second pipeline tool  100  that is subsequently placed in the pipeline. Additional fluid may be used to convey both tools to a desired location, which may be located as described herein. 
         [0042]    The pipeline sealing and isolation tool  100  may also be used to install permanent devices, such as a valve, for example, at a particular location within the pipeline  190 .  FIGS. 5A through 5C  schematically depict a sequence wherein the pipeline sealing and isolation tool  100  illustrated in  FIG. 1  may be used to install a permanent device  500  positioned internally of the flow cavity  160  in the body  140 . In an embodiment, the permanent device  500  is a ball valve that may be actuated by through-wall communication. In another embodiment, the permanent device  500  is a check valve. In another embodiment, the permanent device is a submersible pump, for example an electrical submersible pump (ESP). In an embodiment, an ESP is pumped into a production riser, for example an offshore production riser. The ESP may be placed in the production riser, for example, near the base of a deep water production riser, where the pump may be used to boost production by removing all or a portion of the hydrostatic head back pressure from the well head located on the sea floor. 
         [0043]    As shown in  FIG. 5A through 5C , the closed permanent device  500  provides a seal to replace the temporary seal  130  in previous embodiments. The pipeline tool  100  with the permanent device  500  therein is inserted into the pipeline  190  and propelled along the pipeline  190  by the fluid  115 . The position of the pipeline tool  100  inside the pipeline  190  may be monitored using the tracking device  125 . As shown in  FIG. 5A , when the pipeline tool  100  reaches its intended destination, it is stopped by discontinuing fluid  115  flow through the pipeline  190 . During the time that the pipeline tool  100  is traveling, and upon arrival at the intended location, as shown in  FIG. 5A , the swellable component  120  is absorbing the fluid  115  and expanding across the annulus  135 , towards the inner pipe wall  180  of the pipeline  190 . As shown in  FIG. 5B , once the swellable component  120  fully expands, it forms a permanent fluid-tight seal across the annulus  135  and against the inner pipe wall  180  of the pipeline  190 . Determining when the swellable component  120  is fully expanded and set may be accomplished by methods discussed above, including laboratory testing of the core  230  material and membrane  210  material, pressuring up the pipeline  190  to see if the pipeline tool  100  moves in response to the pressure, or monitoring strain levels in the body  140  of the pipeline tool  100 . As shown in  FIG. 5C , once the swellable component  120  is set, the permanent device  500  may be opened using an electronic signal, another type of through-wall communication, or another method, such as a pressure pulse, for example. Once the permanent device  500  is opened, the flow of fluid  115  may resume inside the pipeline  190 . Although the flow of fluid  115  is reestablished, the pipeline tool  100  remains firmly in position due to the expanded swellable component  120  and may remain so for an indefinite period of time. As a result, the permanent device  500  will also remain fixed in this position and may be actuated to control fluid  115  flow through the pipeline  190  at this location. 
         [0044]    The foregoing descriptions of specific embodiments of pipeline scaling and isolation tools and methods of utilizing such tools to perform maintenance, leak repair, and installation operations on pipelines have been presented for purposes of illustration and description and are not intended to be exhaustive or to limit the invention to the precise forms disclosed. Obviously many other modifications and variations of these embodiments are possible. In particular, maintenance, repair and installation operations may vary. For example, these methods disclose stopping the pipeline device at its intended destination by discontinuing fluid flow in the pipeline. Other methods of stopping the pipeline device may be utilized, such as opening the temporary sealing devices  130  or permanent devices  500  while maintaining the flow of fluid  115 . Moreover, design of the pipeline tool body  140  may vary. Instead of the smooth-walled, solid structure disclosed, the body may comprise a corrugated, flexible housing to permit maneuvering through pipelines with numerous turns and corners. Further, the taper of the flared tail  150  may be optimized to minimize the effects of debris accumulation near the pipeline tool  100  and flow restrictions due to the presence of the pipeline tool  100  in the fluid  115  flowpath. The material comprising the swellable component  120  may vary depending on the type of fluid  115  inside the pipeline  190 , whether a hydrocarbon, water, brine or other aqueous solution. 
         [0045]    While various embodiments of pipeline sealing and isolation tools and methods of utilizing those tools to perform maintenance, leak repair and installation operations on pipelines have been shown and described herein, modifications may be made by one skilled in the art without departing from the spirit and the teachings of the invention. The embodiments described are representative only, and are not intended to be limiting. Many variations, combinations, and modifications of the applications disclosed herein are possible and are within the scope of the invention. Accordingly, the scope of protection is not limited by the description set out above, but is defined by the claims which follow, that scope including all equivalents of the subject matter of the claims.

Technology Classification (CPC): 5