Patent Publication Number: US-10774609-B2

Title: String assembly system and method

Description:
BACKGROUND 
     This section is intended to introduce the reader to various aspects of art that may be related to various aspects of the presently described embodiments. This discussion is believed to be helpful in providing the reader with background information to facilitate a better understanding of the various aspects of the present embodiments. Accordingly, it should be understood that these statements are to be read in this light, and not as admissions of prior art. 
     In order to meet consumer and industrial demand for natural resources, companies often invest significant amounts of time and money in searching for and extracting oil, natural gas, and other subterranean resources from the earth. Once a desired subterranean resource is discovered, drilling and production systems are employed to access and extract the resource. These systems may be located onshore or offshore depending on the location of a desired resource. Such systems generally include a wellhead assembly through which the resource is extracted. These wellhead assemblies may include a wide variety of components, such as various casings, valves, fluid conduits, that control drilling or extraction operations. 
     These wellhead assemblies may also include a fracturing tree and other components to facilitate a fracturing process and enhance production from a well. As will be appreciated, resources such as oil and natural gas are generally extracted from fissures or other cavities formed in various subterranean rock formations or strata. To facilitate extraction of these trapped resources, a well may be subjected to a fracturing process that creates one or more man-made fractures in a rock formation. These man-made fractures may connect to pre-existing fissures and cavities enabling oil and gas to flow into the wellbore. The fracturing process may include perforating the rock formation with charges and then injecting a pressurized fracturing fluid into the well. The high pressure of the fluid increases crack size and crack propagation through the rock formation to release oil and gas, while the proppant prevents the cracks from closing once the fluid is depressurized. In order to create the perforations, a tool lowers the charges to a desired well depth. After perforating the rock formation with the charges, the tool is removed from the well and the well is pressurized to increase crack propagation. The tool is inserted into and withdrawn from the well through a series of connected pipes coupled to the fracturing tree. These connected pipes may be referred to as a lubricator. Unfortunately, assembly and disassembly of the lubricator may be cumbersome and time consuming. 
     SUMMARY 
     Certain aspects of some embodiments disclosed herein are set forth below. It should be understood that these aspects are presented merely to provide the reader with a brief summary of certain forms the disclosure might take and that these aspects are not intended to limit the scope of the disclosure. Indeed, the disclosure may encompass a variety of aspects that may not be set forth below. 
     In one embodiment, a string assembly system includes a first conduit defining a first end and a second end, and a second conduit defining a third end and a fourth end. A first connector assembly is coupled to the second end of the first conduit. The first connector assembly includes a first connector shaft that rotates relative to the first conduit and the second conduit, and a first alignment shaft that axially aligns the first conduit and the second conduit. A second connector assembly is coupled to the third end of the second conduit. The second connector assembly couples to the first connector shaft, and the first conduit rotates relative to the second conduit. 
     In another embodiment, a string assembly system includes a first connector assembly that couples to a first conduit. The first connector assembly includes a first connector shaft that rotates relative to the first conduit and to a second conduit. A second connector assembly is coupled to the second conduit. The second connector assembly couples to the first connector shaft to enable the first conduit to rotate relative to the second conduit. 
     In another embodiment, a method of assembling a string includes rotating a first conduit relative to a second conduit. The first conduit and the second conduit couple together with a first connector shaft. The method axially aligns the first conduit and the second conduit along a longitudinal axis of the first conduit. The method drives the first alignment shaft into a first receptacle. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       These and other features, aspects, and advantages of certain embodiments will become better understood when the following detailed description is read with reference to the accompanying drawings in which like characters represent like parts throughout the drawings, wherein: 
         FIG. 1  is an illustration of a hydraulic fracturing system with a lubricator in accordance with an embodiment of the present disclosure; 
         FIG. 2  is a side view of a string assembly system in accordance with an embodiment of the present disclosure; 
         FIG. 3  is a side view of the string assembly system of  FIG. 2  in accordance with an embodiment of the present disclosure; 
         FIG. 4  is a top view of the string assembly system of  FIG. 2  in accordance with an embodiment of the present disclosure; 
         FIG. 5  is a perspective view of a portion of a string assembly system in accordance with an embodiment of the present disclosure; and 
         FIG. 6  is a perspective view of a portion of a string assembly system in accordance with an embodiment of the present disclosure. 
     
    
    
     DETAILED DESCRIPTION OF SPECIFIC EMBODIMENTS 
     Reference will now be made in detail to specific embodiments illustrated in the accompanying drawings and figures. In the following detailed description, numerous specific details are set forth in order to provide a thorough understanding of the disclosure. However, it will be apparent to one of ordinary skill in the art that embodiments may be practiced without these specific details. In other instances, well-known methods, procedures, components, have not been described in detail so as not to unnecessarily obscure aspects of the embodiments. 
     It will also be understood that, although the terms first, second, etc. may be used herein to describe various elements, these elements should not be limited by these terms. These terms are only used to distinguish one element from another. For example, a first object could be termed a second object, and, similarly, a second object could be termed a first object, without departing from the scope of the present disclosure. 
     The terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting. As used in the description and the appended claims, the singular forms “a,” “an” and “the” are intended to include the plural forms as well, unless the context clearly indicates otherwise. It will also be understood that the term “and/or” as used herein refers to and encompasses any and possible combinations of one or more of the associated listed items. It will be further understood that the terms “includes,” “including,” “comprises” and/or “comprising,” when used in this specification, specify the presence of stated features, integers, steps, operations, elements, and/or components, but do not preclude the presence or addition of one or more other features, integers, operations, elements, components, and/or groups thereof. Further, as used herein, the term “if” may be construed to mean “when” or “upon” or “in response to determining” or “in response to detecting,” depending on the context. 
     The description below includes a string assembly system that facilitates assembly of a plurality of conduits (e.g., pipes) into a string that define a common passage. For example, the string assembly system may enable rapid assembly of a lubricator for fracing, a string for drilling, etc. The string assembly system may also facilitate disassembly, transportation, storage, etc. of a plurality of conduits. As will be explained below, the string assembly system includes connector assemblies that enable multiple conduits to couple together prior to complete assembly of a string. The connector assemblies also facilitate alignment and rapid final assembly of the conduits into a string. 
       FIG. 1  is an illustration of a hydrocarbon extraction system  10  capable of hydraulically fracturing a well  12  to extract various minerals and natural resources (e.g., oil and/or natural gas). The system  10  includes a frac tree  14  coupled to the well  12  via a wellhead hub  16 . In embodiments, the wellhead hub  16  includes a large diameter hub disposed at the termination of a well bore  18  and is designed to connect the frac tree  14  to the well  12 . The frac tree  14  may include multiple components that enable and control fluid flow into and out of the well  12 . For example, the frac tree  14  may route oil and natural gas from the well  12 , regulate pressure in the well  12 , and inject chemicals into the well  12 . 
     The well  12  may have multiple formations at different locations. In order to access each of these formations (e.g., hydraulically fracture), the hydrocarbon extraction system may use a downhole tool coupled to a tubing (e.g., coiled tubing, conveyance tubing). In operation, the tubing pushes and pulls the downhole tool through the well  12  to align the downhole tool with each of the formations. Once the tool is in position, the tool prepares the formation to be hydraulically fractured by plugging the well  12  and boring through the casing. For example, the tubing may carry a pressurized cutting fluid that exits the downhole tool through cutting ports. After boring through the casing, frac fluid (e.g., a combination of water, proppant, and chemicals) may be pumped into the well  12  at high pressures. 
     As the frac fluid pressurizes the well  12 , the frac fluid fractures the formations releasing oil and/or natural gas by propagating and increasing the size of cracks  20 . Once the formation is hydraulically fractured the well  12  is depressurized by reducing the pressure of the frac fluid and/or releasing frac fluid through valves  22  (e.g., wing valves). In operation, the valves  22  control the flow of pressurized fluid into and out of the well  12 , as well as the insertion and removal of tools. 
     To facilitate insertion of tools into the well  12 , a lubricator  24  couples to the fracturing tree  14 . The lubricator  24  is an assembly of conduits coupled together to form a passage (e.g., axial passage). Various tools may be placed within this passage for insertion into and retrieval from the well  12 . These tools may include logging tools, perforating guns, plugging tools, among others. For example, a perforating gun may be placed in the lubricator  24  for insertion in the well  12 . After performing downhole operations (e.g., perforating the casing), the tool is withdrawn back into the lubricator  24  with a wireline  26 . 
     The wireline  26  extends and retracts in response to rotation of a reel  28 . In operation, the reel  28  rotates to wind and unwind the wireline  26 . In embodiments, the wireline  26  and reel  28  may be carried on a wireline truck  30  along with a motor that controls rotation of the reel  28 . In order to position and orient the wireline  26 , the wireline  26  may pass through one or more pulley&#39;s  32 ,  34 . As illustrated, the pulley  34  is suspended with a crane  36  above the lubricator  34 . In this position, the wireline  26  is able enter and exit the lubricator  34  in a vertical orientation, which facilitates insertion and retraction of tools while also reducing friction and wear on the wireline  26 . 
     As explained above, the lubricator  24  is an assembly of multiple conduits that couple together to form a string with a common passage that receives the wireline  26  and tools. To facilitate assembly of the lubricator  24 , the lubricator  24  may be formed with a string assembly system  38 . As will be explained below, the string assembly system  38  includes connector assemblies that enable multiple conduits to couple together in a non-axial layout (e.g., not end-to-end), while still sequentially ordering the conduits. More specifically, the string assembly system  38  enables the conduits  60  to couple together prior to complete assembly of a string, such as the lubricator  24 . And during assembly, the string assembly system  38  facilitates alignment and rapid final assembly of the conduits into a string. 
       FIG. 2  is a side view of a string assembly system  38 . The string assembly system  38  includes a plurality of conduits  60  numbered  62 ,  64 ,  66 ,  68 , and  70 . While five conduits  60  are illustrated, it should be understood that the string assembly system  38  may include additional conduits (e.g., 10, 20, 50, 100, 1000, or more). The string assembly system  38  may also include less than the illustrated five conduits  60  (e.g., 2, 3, 4). The conduits  60  are supported on a base  69  that organizes the conduits  60 , facilitates transport, and enables rapid assembly of the conduits  60  into a string. 
     In order to couple the conduits  60  together, the string assembly system  38  includes first connector assemblies  72  (e.g., first clamp assemblies) and second connector assemblies  74  (e.g., second clamp assemblies), and connector  76  (e.g., threaded connector). As illustrated, the first connector assemblies  72  couple to first ends  78  (e.g., end portions) of the conduits  60 , the second connector assemblies  74  couple to second ends  80  (e.g., end portions) of the conduits  60 , and the connectors  76  couple to the second ends  80  of the conduits  60 . In some embodiments, the first conduit  62  and the last conduit  70  may not include a respective first connector assembly  72  and a second connector assembly  74 . The absence of these connector assemblies may facilitate coupling of the first conduit  62  and the last conduit  70  to other components of the mineral extraction system  10 . 
     As illustrated, the conduits  60  are coupled together in sequential order with connector shafts  82  (e.g., telescoping shafts) that couple to and extend between the respective first connector assemblies  72  of a conduit and the second connector assemblies  74  of the following one. More specifically, in embodiments, the connector shafts  82  are coupled to respective pins  84  of the first connector assembly  72  and respective pins  86  of the second connector assemblies  74 . In this way, the conduits  60  may be coupled together without the need for being axially aligned (e.g., without being coaxial or arranged end-to-end) and/or completely assembled. For example, the conduits  60  may be placed next to each other in a parallel layout or substantially parallel layout when not in use. This may facilitate transport of the conduits  60  while simultaneously coupling the conduits  60  together (i.e., in sequential order) for rapid assembly at a designated site. 
     In embodiments, in order to assemble the conduits  60  into a string, the first conduit  62  and/or the second conduit  64  might be rotated about their respective hinge pins  86  and  84  (e.g., rotated about an axis perpendicular to a central axis of the respective conduit  62 ,  64 ) until the second end  80  of the first conduit  62  is substantially aligned with (e.g., coaxial) the first end  78  of the second conduit  64 . Once substantially aligned, the first conduit  62  is driven in axial direction  88 . As the first conduit  62  moves in axial direction  88 , an alignment shaft  90  on the second connector assembly  74  slides into a receptacle  92  on the first connector assembly  72 . The alignment shaft  90  and corresponding receptacle  92  facilitate axial alignment of the second end  80  of the first conduit  62  with the first end  78  of the second conduit  64 . After aligning the first conduit  62  with the second conduit  64 , the connector  76  couples the second end  80  with the first end  78 . For example, a rotating drive  94  may rotate the connector  76  (clockwise or counterclockwise) to threadingly engage the first end  78  of the second conduit  64 , thereby coupling the first conduit  62  to the second conduit  64 . 
     It should be understood that instead of the first conduit  62  moving in direction  88 , the second conduit  64  may be driven in direction  98  in order to drive the alignment shaft  90  into the receptacle  92 . In some embodiments, both the first conduit  62  and the second conduit  64  may be axially driven towards one another. That is, the first conduit  62  may be driven in axial direction  88  and the second conduit  64  may be driven in axial direction  98  in order to drive the alignment shaft  90  into the receptacle  92 . It should also be understood that the alignment shaft  90  may couple to the first connector assembly  72  and the second connector assembly  74  may define the receptacle  92 . In some embodiments, the connectors  76  may couple to the second ends  80  of the conduits  60  instead of the first ends  78 , prior to the coupling of the conduits  60  into a string. 
       FIG. 3  is a side view of the string assembly system  38 . As illustrated, the first conduit  62  and the second conduit  64  are coupled together with the connector  76 . After assembling the first conduit  62  to the second conduit  64 , both the first conduit  62  and the second conduit  64  are driven in direction  98 . As the second conduit  64  moves in axial direction  98 , the second conduit  64  separates from the base  69  via a track outlet  124  of a track  122 . 
     As the first conduit and second conduits  62 ,  64  continue to move in direction  98 , the second connector assembly  74  at the second end  80  of the second conduit  64  pulls the first connector assembly  72  coupled to the first end  78  of the third conduit  66  with the connector shaft  82 . In response, the third conduit  66  may rotate as well as slide in direction  120  along the track  122  towards the track outlet  124 . The movement of the third conduit  66  in direction  120  likewise pulls the remaining conduits  60  in direction  120 , as the connector shafts  82  block separation of the first connector assemblies  72  from the second connector assemblies  74 . 
     The first and second conduits  62  and  64  continue to move in direction  98  to rotate the third conduit  66  about the pin  84  until the third conduit  66  is substantially aligned (e.g., coaxial) with the second end  80  of the second conduit  64 . Once aligned, the first conduit  62  and the second conduit  64  are driven in axial direction  88 . As the first and second conduits  62 ,  64  move in axial direction  88 , an alignment shaft  90  on the second connector assembly  74  of the second conduit  64  slides into a receptacle  92  on the first connector assembly  72  of the third conduit  66 . As alignment shaft  90  enters the corresponding receptacle  92 , the second end  80  of the second conduit  64  aligns with the first end  78  of the third conduit  66 . After aligning the second conduit  64  with the third conduit  66 , the connector  76  couples the second end  80  of the second conduit  64  with the first end  78  of the third conduit  66 . For example, a rotating drive  94  may rotate the connector  76  in circumferential directions  96  (e.g., clockwise or counterclockwise) to threadingly couple the second conduit  64  to the third conduit  66 . 
     After coupling the second conduit  64  to the third conduit  66 , the first conduit  60 , the second conduit  64 , and the third conduit  66  are driven in axial direction  98 . As the third conduit  66  moves in axial direction  98 , the third conduit  66  separates from the base  69  via the track outlet  124  of the track  122 . The same process described above, occurs with the fourth conduit  68 , the fifth conduit  70 , and any number of additional conduits  60  enabling the string assembly system  38  to rapidly form a string from the conduits  60 . For example, the string assembly system  38  may rapidly form a lubricator  24  for the mineral extraction system  10 . 
       FIG. 4  is a top view of the string assembly system  38 . The conduits  60  are supported on the base  69  that organizes the conduits  60 , facilitates transport, and enables rapid assembly of the conduits  60  into a string. In this way, the conduits  60  may be coupled together without being axially aligned and/or assembled. For example, the conduits  60  may be placed next to each other in a parallel layout or substantially parallel layout when not in use. The base  69  includes the track  122  that receives respective pins  140  coupled to the conduits  60 . The pins  140  enable the conduits to couple to the base  69  (e.g., for transport, for storage) while simultaneously enabling the conduits  62  to slide in direction  120  towards the track outlet  124 . As explained above, the conduits  60  are assembled in sequential order and then progressively disconnected from the base  69  as they are assembled into a string. Accordingly, the pins  140  enable the conduits  60  to slide towards the track outlet  124  as each conduit  60  is progressively added to the string. In some embodiments, instead of pins  140  the conduits  60  may magnetically couple to the base  69 . A magnetic coupling may enable the conduits  60  to slide and/or rotate while blocking separation of the conduits  60  from the base  69  prior to assemble into the string. 
       FIG. 5  is a perspective view of a string assembly system  160 . The string assembly system  160  includes the first connector assembly  72  (e.g., a first clamp assembly), the second connector assembly  74  (e.g., a second clamp assembly), and the connector  76 . As illustrated, the first connector assembly  72  couples to the first end  78  of the conduit  64 , the second connector assembly  74  couples to the second end  80  of the conduit  62 , and the connector  76  couples to the second end  80  of the conduit  62 . 
     The first connector assembly  72  includes a first bracket  162  and a second bracket  164  that couple together about the conduit  64  with pins  84  and  166 . In addition to coupling to the first bracket  162  and the second bracket  164 , the pin  84  couples to the rod or shaft  82 . In operation, the pin  84  is configured to rotate about its axis  169  in either circumferential direction  168  or  170  to enable the conduit  62  to rotate relative to the conduit  64  while remaining connected. In contrast, the pin  166  is configured to be fixed (e.g., does not rotate) relative to the first bracket  162  and the second bracket  164 . The pin  166  defines a recess or receptacle  172  that is configured to receive an end  174  of the alignment shaft  90 . In some embodiments, the alignment shaft  90  may have a tapered end  176  that engages a tapered surface  178  of the receptacle  172 . These tapered surfaces may facilitate alignment and coupling of the alignment shaft  90  with the first connector assembly  72 . 
     The second connector assembly  74  similarly includes a first bracket  180  and a second bracket  182  that couple together about the conduit  62  with pins  86  and  184 . The pin  86  couples to the rod or shaft  82 , which couples the first connector assembly  72  to the second connector assembly  74 . The pin  86  is able to rotate about its axis  186  in either circumferential direction  188  or  190  to enable the conduit  64  to rotate relative to the conduit  62 . However, in some embodiments, the pin  184  is fixed (i.e., does not rotate) relative to the first bracket  180  and the second bracket  182 . The pin  184  may be fixed in order to facilitate coupling of the alignment shaft  90  to the pin  166 . The alignment shaft  90  couples to the pin  166  by lowering the conduit  62  in direction  88  and/or by lifting the conduit  64  in direction  98 . 
     As the alignment shaft  90  enters the receptacle  172 , the first and second connector assemblies  72 ,  74  align the connector  76  with the end  78  of the conduit  64 . The connector  76  may then couple the conduit  62  to the conduit  64 , which adds conduit  64  to the string. For example, the connector  76  may be threadingly coupled to threads  192  on the first end  78  of the conduit  64 . It should be understood that while a single first connector assembly  72 , second connector assembly  74 , and connector  76  are illustrated in  FIG. 5 , the string assembly system  160  may include additional first connector assemblies  72 , second connector assemblies  74 , and connectors  76  to couple additional conduits  60  together to form a string. 
     In some embodiments, the first connector assembly  72  and/or the second connector assembly  74  may include bearings. For example, the first connector assembly  72  may include one or more bearings  194  between the brackets  162  and  164 ; and the conduit  64 . Likewise, the second connector assembly  74  may include one or more bearings  196  between the brackets  180  and  182 ; and the conduit  62 . In operation, the bearings  194  and  196  enable the first and second connector assemblies  72  and  74  to rotate relative to the conduits  62  and  64 . The ability of the string assembly system  160  (e.g., first connector assembly  72  and/or second connector assembly  74 ) to rotate relative to the conduits  60  enables the string assembly system  160  to couple together a drilling string. More specifically, by enabling rotation, the string assembly system  160  is able to couple conduits  60  together while still enabling the drill string to drill as well as enable additional conduits to couple to the drill string (e.g., conduits  60  that have not been added to the string). 
       FIG. 6  is a perspective view of a string assembly system  210 . The string assembly system  210  includes the first connector assembly  72 , the second connector assembly  74 , and the connector  76 . As illustrated, the first connector assembly  72  couples to the first end  78  of the conduit  64 , the second connector assembly  74  couples to the second end  80  of the conduit  62 , and the connector  76  couples to the second end  80  of the conduit  62 . 
     The first connector assembly  72  includes first and second flanges  212 ,  214  that couple to the conduit  64 . For example, the flanges  212 ,  214  may be welded to the conduit  64  or formed integrally with the conduit  64  (e.g., one-piece). As illustrated, the second flange  214  includes a pin  216  that couples to and extends between opposing walls  218  and  220  of the second flange  214 . The pin  216  also couples to the rod or shaft  82 . In operation, the pin  84  is configured to rotate about its axis  222  in either circumferential direction  224  or  226  to enable the conduit  62  to rotate relative to the conduit  64 . 
     As illustrated, the first flange  212  defines a recess or receptacle  228  that is configured to receive an end  174  of the alignment shaft  90 . In some embodiments, the alignment shaft  90  may have a tapered end  176  that engages a tapered surface  230  of the receptacle  228 . These tapered surfaces may facilitate alignment and coupling of the alignment shaft  90  with the first connector assembly  72 . 
     The second connector assembly  74  similarly includes a first and second flange  232  and  234  that couple to the conduit  62 . For example, the flanges  232 ,  234  may be welded to the conduit  62  or formed integrally with the conduit  62  (e.g., one-piece). As illustrated, the second flange  234  includes a pin  236  that couples to and extends between opposing walls  238  and  240  of the second flange  214 . The pin  236  also couples to the rod or shaft  82 . In operation, the pin  236  is configured to rotate about its axis  242  in either circumferential direction  244  or  246  to enable the conduit  64  to rotate relative to the conduit  62 . 
     As illustrated, the second connector assembly  74  couples to the alignment shaft  90 . For example, the alignment shaft  90  may be welded, threadingly coupled, or formed integrally with the first flange  232  (e.g., formed from one-piece). In operation, the alignment shaft  90  is inserted into the recess or receptacle  228  to align the connector  76  with the end  78  of the conduit  64 . Once aligned, the connector  76  couples the conduit  62  to the conduit  64 . For example, the connector  76  may be threadingly coupled to the threads  192  on the end  78  of the conduit  64 . 
     As used herein, the terms “inner” and “outer”; “up” and “down”; “upper” and “lower”; “upward” and “downward”; “above” and “below”; “inward” and “outward”; and other like terms as used herein refer to relative positions to one another and are not intended to denote a particular direction or spatial orientation. The terms “couple,” “coupled,” “connect,” “connection,” “connected,” “in connection with,” and “connecting” refer to “in direct connection with” or “in connection with via one or more intermediate elements or members.” 
     The foregoing description, for purpose of explanation, has been described with reference to specific embodiments. However, the illustrative discussions above are not intended to be exhaustive or to limit the disclosure to the precise forms disclosed. Many modifications and variations are possible in view of the above teachings. Moreover, the order in which the elements of the methods described herein are illustrate and described may be re-arranged, and/or two or more elements may occur simultaneously. The embodiments were chosen and described in order to best explain the principals of the disclosure and its practical applications, to thereby enable others skilled in the art to best utilize the disclosure and various embodiments with various modifications as are suited to the particular use contemplated.