Abstract:
A method to add a joint of pipe to a conductor string includes securing the conductor string with a spider, grasping an upper end of the joint of pipe with a segmented-ring elevator, engaging a plurality of slips of the elevator with an outer profile of the joint of pipe, raising the grasped joint of pipe from non-vertical to vertical, positioning the vertical joint of pipe atop the secured conductor string, attaching the joint of pipe to the conductor string, releasing the conductor string from the spider, and retaining the joint of pipe and the conductor string with the segmented-ring elevator.

Description:
BACKGROUND OF THE DISCLOSURE 
       [0001]    1. Field of the Disclosure 
         [0002]    The present disclosure relates to apparatuses and methods to lift and install large-diameter tubulars with a drilling rig. More particularly, the present disclosure relates to apparatuses and methods to raise horizontal sections of large-diameter pipe to mount them atop vertical strings of large-diameter pipe. More particularly still, the present disclosure relates to apparatuses and methods to raise horizontal sections of conductor pipe to install them atop vertical strings of conductor pipe extending into a wellbore. 
         [0003]    2. Description of the Related Art 
         [0004]    Referring to  FIG. 11 , a perspective view is shown of a drilling rig  50  used to run tubular members  52  (e.g., casing, drill pipe, etc.) downhole into a wellbore. As shown, drilling rig  50  includes a frame structure known as a “derrick”  54  from which a traveling block  56  and an elevator  58  and/or a top drive (not shown) may be used to manipulate (e.g., raise, lower, rotate, hold, etc.) tubular members  52 . As shown, traveling block  56  is a device that is located at or near the top of derrick  54 , in which traveling block  56  may move up-and-down (i.e., vertically as depicted) to raise or lower tubular members  52 . As shown, traveling block may be a simple “pulley-style” block and may have a hook  60  from which objects below (e.g., elevator  58 ) may be hung. Additionally, elevator  58  may also be coupled below traveling block  56  and/or a top drive (not shown) to selectively grab or release tubular members  52  as they are to be raised or lowered within and from derrick  54 . Typically, elevator  58  includes movable gripping components (e.g., slips) movable between an open position and a closed position (shown in  FIG. 11 ). In the closed position, the movable components form a load bearing ring (or shoulder) about or upon which tubular members  52  may bear and be lifted. In the open position, the movable components of elevator  58  may move away from one another to allow the tubular members  52  to be brought within or removed from elevator  58 . 
         [0005]    When assembling a string of tubular members  52  together, the tubular members  52  may be removed from a pipe rack  62  and pulled, or otherwise transported, towards an access opening  64 , for example, a v-door, within the derrick  54  of the drilling rig  50 . The tubular members  52  may be loaded onto a pipe ramp  66  adjacent to the access opening  64 , in which a rigidly mounted end stop  68  may abut the ends of the tubular members  52  to support the tubular members  52  up against access opening  64 . 
         [0006]    Tubular-shaped goods have a variety of uses in oilfield operations including, but not limited to, drill pipe, drill collars, casing, continuous coiled tubing, and the like. One such tubular-shaped good used in exploration and drilling is conductor pipe. Generally, conductor pipe (e.g., drive pipe) is large-diameter pipe (e.g., between about 75 cm to about 100 cm or about 50 cm to about 182 cm in diameter), usually constructed of steel, that extends from the wellhead into the earth or ocean floor. As such, a string of conductor pipe sections (i.e., a conductor string) is typically the first string of “casing” run into the wellbore, and serves to stabilize the sediment surrounding the wellbore to prevent it from caving-in. 
         [0007]    Installation of the conductor string may be performed any number of ways. On land, the conductor string may be driven into the ground from above with an impact loading hammer apparatus. In certain locations, excavation may be necessary prior to driving the conductor string into the uncovered sediment. Offshore, conductor strings may similarly be installed, using impact driving and excavation techniques. In undersea environments, conductor strings may be “jetted in”, for example with a pressurized fluid discharged (e.g., seawater) at a distal end of the conductor string displacing the sediment as the conductor string is advanced into the sea floor. Following such a jetting process, an impact driving process may be performed to force the conductor string further into the sea floor, if desired. Additionally or alternatively, in undersea environments, conductor strings may be “sucked” into the sea floor by filling the string with water, sealing the conductor string, and then pumping, or evacuating, the trapped water from the inner bore of the conductor string. As the water is removed from the sealed bore of the conductor string, the conductor is plunged deeper into the sea floor as the sea floor sediment replaces the evacuated water. Following such a suction process, an impact driving process may be performed to force the conductor string further into the sea floor, if desired. Alternatively, impact driving may be performed simultaneously as the conductor string is jetted or sucked into the sea floor. 
         [0008]    While conductor strings are relatively the largest (diameter) and shortest (length) strings of casing used to case a wellbore, the strings are still long enough to be assembled from several sections, or joints, of conductor pipe. As such, because of their large diameter and desired permanent placement about the wellbore, conductor strings are typically assembled, on site, from several joints of conductor pipe 20-40 feet long, and may be threaded or welded together end-to-end. 
         [0009]    Historically, assembling strings of conductor pipe on the rig floor has been a difficult and time-consuming process. In one example method, to install a new joint of conductor pipe atop a string conductor pipe already engaged into the wellbore, a series of lifting eyes and handling eyes are affixed to the outer periphery of the large diameter and heavy-walled joint of conductor pipe to be added. In particular, a pair of heavy-duty lifting eyes are attached, typically 180° apart near the upper-most end of conductor pipe while it remains horizontal, either in the pipe rack or in another location on or near the drilling rig. Next, at least one pair of handling eyes are added to the joint of conductor pipe to be added, typically at opposite ends of the joint, but at similar radial positions. 
         [0010]    As such, using various rigging and sling mechanisms, a crane may secure the bottom end of the horizontal conductor pipe (from a handling eye) while another crane (or the rig draw works) raises the upper end so that the formerly horizontal joint of conductor pipe may be held in a vertical position. Once moved into place atop the string of conductor pipe already engaged into the wellbore (and held in location by its lifting eyes), the joint of conductor pipe to be added may be threaded together and/or welded in place. With the new joint of conductor pipe attached, the lifting eyes of the former topmost joint may be removed and the entire string of conductor pipe may be supported and lowered by the lifting eyes affixed to the outer profile of the newly-added joint. Once the string of conductor pipe is supported by the lifting eyes of the new joint, the handling eyes of the new joint are removed, e.g., to minimize resistance in running the conductor string into the wellbore. 
         [0011]    However, the installation and removal of the lifting and handling eyes may be problematic in itself. In many cases, bosses, pre-fabricated with the joint of conductor pipe, contain tapped holes to receive the lifting and handling eyes so that high-strength bolts may be used to transfer the load from the eyes to the joint of conductor pipe. Bosses are typically an external protrusion on the outer surface of the conductor pipe. When it comes time to remove the lifting and handling eyes, the bolts may be removed, however the boss remains. As a machining and welding process, the installation and manufacture of the bosses is both time consuming and expensive. Further, as an upset on the outer profile of the joint of conductor pipe, the bosses may add undesired resistance as the conductor string is driven further into the ground about the proposed wellbore and/or may prevent the sediment from re-settling around the conductor string, e.g., not allowing the sediment to sufficiently retain the conductor string in place. As the bosses are typically welded on and bolted to the lifting and handling eyes, they represent possible failure mechanisms that may disrupt operations should a boss, bolt, or lifting eye fail during the installation procedure. 
         [0012]    Alternatively, lifting and handling eyes may be directly welded to the outer profile of the joints of conductor pipe. Following use, the welds may be ground off and the outer profile of the conductor pipe may be ground smoother such that little or no resistance to being driven remains. However, depending on regulations for the particular location, “hot work” such as welding and grinding may not be allowed to be performed at particular times on the rig floor. Additionally, the processes to weld, remove, and grind smooth the outer profiles of the joints of conductor pipe may represent a tremendous amount of time investment. Furthermore, during the removal and grinding process, there is opportunity for the outer profile of the joint of conductor pipe to become damaged to the point where it must be replaced or repaired. Repairing a lower joint of conductor pipe following the installation of an upper joint of conductor pipe would be highly undesirable, and would consume tremendous amounts of time and rig resources. 
         [0013]    Apparatuses and methods to simplify the lifting, assembly, and installation of strings of conductor pipe would be well received in the industry. In particular, apparatuses and methods to assemble and install joints of conductor casing without requiring the installation and removal of lifting and handling eyes would be a significant benefit to the industry. 
       SUMMARY OF THE CLAIMED SUBJECT MATTER 
       [0014]    In one aspect, the present disclosure relates to a method to add a joint of pipe to a conductor string including securing the conductor string with a spider, grasping an upper end of the joint of pipe with a segmented-ring elevator, engaging a plurality of slips of the elevator with an outer profile of the joint of pipe, raising the grasped joint of pipe from non-vertical to vertical, positioning the vertical joint of pipe atop the secured conductor string, attaching the joint of pipe to the conductor string, releasing the conductor string from the spider, and retaining the joint of pipe and the conductor string with the segmented-ring elevator. 
         [0015]    In another aspect, the present disclosure relates to a lifting elevator including a first elevator segment, a second elevator segment, at least one pivot about which at least one of the elevator segment of the lifting elevator may rotate with respect to each other, a latch connecting the first elevator segment to the second elevator segment, and a plurality of slips to engage a conductor string surrounded by the first and second elevator segments. 
         [0016]    In another aspect, the present disclosure relates to an apparatus to lift non-vertical pipe sections including a first lifting ring connected to a lifting point through a first lifting line, a second lifting ring connected to the lifting point through a second lifting line, and an inner profile of the first and second lifting rings configured to receive and secure a joint of horizontal pipe. 
         [0017]    In another aspect, the present disclosure relates to a method to install a joint of conductor pipe to a conductor string including raising the joint of conductor pipe from a non-vertical position with a lifting apparatus, engaging a segmented ring elevator about the raised non-vertical joint of conductor pipe, closing the segmented ring elevator about the raised non-vertical joint of conductor pipe, activating at least one powered slip of the segmented ring elevator to grip the joint of conductor pipe, raising the segmented ring elevator until the joint of conductor pipe is in a vertical position, positioning the joint of conductor pipe atop the conductor string, and connecting the joint of conductor pipe to the conductor string. 
     
    
     
       BRIEF DESCRIPTION OF DRAWINGS 
         [0018]    Features of the present disclosure will become more apparent from the following description in conjunction with the accompanying drawings. 
           [0019]      FIG. 1  is a schematic view drawing of a horizontal lifting apparatus in accordance with embodiments of the present disclosure. 
           [0020]      FIG. 2  is a schematic view drawing of a joint of conductor pipe being raised from a horizontal position to a vertical position in accordance with embodiments of the present disclosure. 
           [0021]      FIG. 3  is a schematic view drawing of the joint of conductor pipe of  FIG. 2  in the vertical position in accordance with embodiments of the present disclosure. 
           [0022]      FIG. 4  is a schematic view drawing of the joint of conductor pipe of  FIGS. 2 and 3  being connected to a string of conductor pipe in accordance with embodiments of the present disclosure. 
           [0023]      FIG. 5  is a schematic view drawing of the joint of conductor pipe of  FIGS. 2-4  engaged into the wellbore along with the string of conductor pipe in accordance with embodiments of the present disclosure. 
           [0024]      FIG. 6  is a schematic view drawing of an elevator of  FIGS. 2-5  being removed from the string of conductor pipe in accordance with embodiments of the present disclosure. 
           [0025]      FIG. 7  is a detailed perspective view drawing of the elevator of  FIGS. 2-6  in accordance with embodiments of the present disclosure. 
           [0026]      FIG. 8  is a schematic view of the elevator of  FIG. 7  in an open position about to engage a joint of conductor pipe in accordance with embodiments of the present disclosure. 
           [0027]      FIG. 8A  is a schematic view of a first embodiment of an actuated latch mechanism of the elevator of  FIG. 8 . 
           [0028]      FIG. 8B  is a schematic view of a second embodiment of an actuated latch mechanism of the elevator of  FIG. 8 . 
           [0029]      FIG. 9  is a schematic view of the elevator of  FIG. 8  in a closed position around the joint of conductor pipe in accordance with embodiments of the present disclosure. 
           [0030]      FIG. 10  is a schematic view of the elevator of  FIG. 9  in a closed position with slips engaged into the joint of conductor pipe in accordance with embodiments of the present disclosure. 
           [0031]      FIG. 11  is a prior-art schematic drawing of a typical drilling rig. 
       
    
    
     DETAILED DESCRIPTION 
       [0032]    Apparatuses and methods disclosed herein relate to the assembly and installation of strings of large-diameter tubulars. While strings of conductor pipe are discussed in conjunction with the embodiments described below, it should be understood that various types (and sizes) of tubular items may be handled, assembled, and installed in accordance with the embodiments described below. 
         [0033]    Referring initially to  FIG. 1 , a horizontal lifting apparatus  100  is shown schematically lifting a horizontally-stored joint of conductor pipe  102 . As shown, lifting apparatus  100  includes a pair of lifting rings  104 A and  104 B extending from a pair of lifting lines  106 A and  106 B to a single lifting point  108 . As shown, lifting lines  106 A,  106 B may be of equal length so that when rings  104 A,  104 B are positioned at equal distances from ends of conductor pipe  102 , vertical lifting at point  108  will result in a horizontal lift of joint of conductor pipe  102 . However, in certain circumstances, it may be advantageous to lift joint of conductor pipe  102  at an angle (e.g., when required by available on rig floor, so those having ordinary skill in the art will appreciate that the relative positions of lifting rings  104 A,  104 B and lengths of lifting lines  106 A,  106 B may be varied to achieve the desired angle of joint of conductor pipe  102  as it is lifted. 
         [0034]    Further, it should be understood that lifting rings  104 A,  104 B may be constructed as continuous circular (or other) profiles such that they are simply slid over the ends of conductor pipe  102  and moved into position. Similarly, the internal profiles of lifting rings  104 A,  104 B may comprise friction elements to prevent conductor pipe  102  from sliding out of the grasp of rings  104 A,  104 B during lifting operations. As such, the inner profiles of lifting rings  104 A,  104 B may comprise rubber or hardened metal dies to prevent undesired movement of conductor pipe  102  relative thereto. Furthermore, as shown in  FIG. 1 , when lines  106 A,  106 B are pulled at point  108 , lifting rings  104 A,  104 B may be tilted with respect to an axis  110  of the joint of conductor pipe  102  at an angle α. As such, lifting rings  104 A,  104 B may be constructed such that enough diametrical slack exists relative to the outer profile of joint of conductor pipe  102  that lifting rings  104 A,  104 B may “bite” into the conductor pipe  102  to more securely retain it. 
         [0035]    Additionally, lifting rings  104 A,  104 B may be constructed as hinged and segmented rings such that they may be opened and closed laterally around the joint of conductor pipe  102  without needing to be slid over the ends. In particular, in cases where joints of conductor pipe  102  are laying directly on the floor of the rig or in the pipe rack, it may not be possible to slide rings  104 A,  104 B over the ends of layed pipe without lifting the conductor pipe  102  a sufficient amount to allow the thickness of lifting rings  104 A,  104 B thereunder. As such, segmented, openable, and closeable lifting rings  104 A,  104 B may allow the joint of conductor pipe  102  to be “grabbed” from above and lifted. Furthermore, the mechanisms of lifting rings  104 A,  104 B may be such that the segments of each ring  104 A,  104 B are tended to be closed as tension from lines  106 A,  106 B increases. Thus, for a joint of conductor pipe  102  laying on the floor, lifting rings  104 A and  104 B may be hingedly placed around the joint of pipe  102 , but may not be able to fully close with pipe  102  laying on the floor. As lines  106 A,  106 B are pulled from point  108 , rings  104 A,  104 B may be pulled fully closed as pipe  102  is lifted from the floor. 
         [0036]    Finally, while lifting lines  106 A,  106 B and lifting point  108  are shown schematically, it should be understood that various lifting methods and apparatus, for example, but not limited to, lifting slings, chains, and other rigging may be used in place of the simple schematic view shown in  FIG. 1 . Furthermore, depending on location and the resources available, the horizontal lifting of joint of conductor pipe  102  from a pipe rack or the rig floor and next to be run may be performed by an auxiliary crane, a separate lifting apparatus, or by the drilling rig&#39;s draw works. After a “to be added” joint of conductor pipe  102  is disposed from its position in the pipe rack (or other location on the rig), it must be rotated to vertical before it may be assembled to the remainder of the string of conductor pipe  112 . 
         [0037]    Referring now to  FIGS. 2 and 3 , the rotation and assembly of joint of conductor pipe  102  to the remainder of a string of conductor pipe  112  is shown schematically. As depicted, the drilling rig includes a rig floor  114  and a spider  116  holding string of conductor pipe  112  in the well. A segmented elevator  118  grasps a first end of the joint of conductor pipe  102  to be added to string  112 , such that joint of conductor pipe  102  may be tilted from a non-vertical position, e.g., the horizontal position in  FIG. 1 , or an intermediate position, e.g., as shown in  FIG. 2 , and to a vertical ( FIG. 3 ) position. As will be described below in further detail, elevator  118  includes slips to grip the outer profile of joint of conductor pipe  102  and lifting lugs to allow elevator  118  to be lifted from a horizontal position to a vertical position so that lower end  120  of joint of conductor pipe  102  may be connected (e.g., threaded, welded, etc.) to the upper end  122  of the string of conductor pipe  112 . 
         [0038]    Referring now to  FIG. 4  the joint of conductor pipe  102  to be added is shown atop string of conductor pipe  112  where it may be connected in place at  124 . Prior to completion of the welding, spider  116  supports the weight of pipe string  112  and elevator  118  supports the weight of joint of conductor pipe  102 . With joint  102  securely connected to (and now integrally part of) conductor pipe string  112 , the slips of spider  116  may be released so that the entire weight of the conductor pipe string  112  (including add on joint  102 ) may be carried by elevator  118 . 
         [0039]    Referring now to  FIG. 5 , conductor pipe string  112  may be engaged into the formation surrounding the wellbore (e.g., through driving, suction, jetting, etc.) from its full height ( FIG. 4 ) to it&#39;s new, lowered height such that upper end of joint  102  of conductor string  112  is adjacent and above rig floor  114 . In this new position, the slips of spider  116  may be re-engaged so that spider  116  again holds the entire weight of string of conductor pipe  112 . Referring briefly now to  FIG. 6 , the slips of elevator  118  may be de-activated so that elevator  118  may be lifted, e.g., by the rig&#39;s draw works, and removed from upper end of added on joint  102  of conductor string  112  so that the process may be repeated with a new joint of conductor pipe to be added. 
         [0040]    Referring now to  FIG. 7 , a more detailed view of the elevator  118  depicted in  FIGS. 2-6  is shown. Elevator  118  is shown constructed as a segmented ring comprising a first half  126 A, a second half  126 B, a hinge,  128 , and a latch  130 . Latch  130  may be constructed as a pin, a hinge, or any other mechanism through which a connection between half  126 A and half  126 B may be coupled and de-coupled. While elevator  118  is shown segmented into two halves  126 A,  126 B, those having ordinary skill will appreciate that more than two segments may be used. Furthermore, it should be understood that the segments of elevator  118  need not be equal in size or angle swept. For example, in one embodiment, segmented elevator  118  may comprise three segments, two segments having 150° swept angles, and a third (e.g., non-pivoting) segment having an angle of 60°. 
         [0041]    Furthermore, when in the closed position (shown), the inner profile  132  of the halves  126 A,  126 B of the segmented ring is generally circular in shape and includes a plurality of slip assemblies  134  spaced at generally equal radial positions (at a common axial location) thereabout. As shown, each slip assembly  134  includes a die, e.g., gripping surface,  136  configured to “bite” into contact with joints of conductor pipe (e.g.,  102 ) and assembled conductor pipe string  112 . Those having ordinary skill in the art will appreciate that slip assemblies  134  may be designed on inclined planes such that the grip diameter (i.e., the average inner diameter among the slip assemblies  134 ) of the slip assemblies  134  decreases as the slip assemblies are thrust downward. In one embodiment, a single “timing ring” axially actuates all slip assemblies  134  simultaneously so that the grip diameter of the elevator  118  is relatively consistent. The timing ring may be thrust hydraulically, pneumatically, mechanically, or through any type of actuator known to those having ordinary skill in the art. Thus, as slip assemblies  134  (and dies  136 ) are activated to engage the outer profile of conductor pipe string  112 , additional downward thrusting of the conductor string  112  (e.g., from the weight of the string  112 ) acts to increase the amount of “bite” dies  136  exhibit into conductor pipe string  112 . Those having ordinary skill in the art will appreciate that slip assemblies  134  of elevator  118  may be activated and actuated using various methods and mechanisms available including, but not limited to, electrical activation, hydraulic activation, pneumatic activation, and mechanical activation. 
         [0042]    Referring now to  FIG. 8 , elevator  118  is shown in an open position as it is lowered over a horizontally-laying joint of conductor pipe  102 . A lifting sling (not shown) or an alternative form of rigging may attach to elevator at lifting lugs  138 A and  138 B. Such a lifting apparatus may include swivels or other devices so that elevator  118  may switch from vertical position (e.g.,  FIGS. 3 and 4 ) to horizontal position ( FIG. 8 ) with relative ease. In certain embodiments, elevator  118  may be suspended directly from the hook (e.g.,  60  of  FIG. 11 ) of a traveling block (e.g.,  56  of  FIG. 11 ) of the rig&#39;s draw works. As shown, elevator  118  is lowered about horizontal joint of conductor pipe  102  such that a back stop  140  of elevator abuts the top of joint of conductor pipe  102 . Optionally, a pair of cylinders  144 A,  144 B may be used to open and close halves  126 A,  126 B of elevator  118 . Similarly, referring briefly to  FIG. 8A , a cylinder  146  may be used to open and close latch  130  between halves  126 B and  126 A. While hydraulic cylinders are depicted in  FIGS. 8 and 8A  as  144 A,  144 B, and  146 , it should be understood that pneumatic cylinders, mechanical ball screws, or any other type of powered actuator may be used. Alternatively still, referring to  FIG. 8B , a torsion spring  148  in conjunction with an upset portion  150  of latch  130  may be used to bias latch  130  in a closed or open direction. 
         [0043]    Referring now to  FIG. 9 , the two halves  126 A,  126 B of elevator  118  may rotate about hinge  128  to the closed position and latch  130  may rotate about pin  142  to lockably engage half  126 B with half  126 A. Because joint of conductor pipe  102  is non-vertical and elevated (e.g., with lifting apparatus  100  of  FIG. 1 ), two halves  126 A,  126 B of elevator  118  may rotate about hinge  128  to the closed position, e.g., encircling the joint  102 . Depicted latch  130  has sufficient clearance to reach around the bottom of joint of conductor pipe  102  and engage with half  126 A of segmented ring of elevator  118 . With latch  130  secured closed, elevator may be lifted up (in direction Z) without concern that halves  126 A,  126 B will separate and release joint of conductor pipe  102 . As such, slips  134  may be activated to secure (and center) joint of conductor pipe  102  within the inner profile of elevator  118 . In alternative embodiments, latch  130  may function without pivot pin  142  and may have a lower profile. It should be understood that embodiments disclosed herein should not be limited to a particular latch mechanism. Furthermore, it should be understood that latch mechanism (e.g.,  130 ) may not be necessary at all, for example, powered actuators used to open and close halves  126 A,  126 B of elevator  118  may be used to keep halves  126 A,  126 B together when lifting joint of conductor pipe  102 . 
         [0044]    Referring now to  FIG. 10 , a top-view schematic of elevator  118  is shown with slips  134  activated into the engaged position and securing joint of conductor pipe  102  within the inner profile of segmented ring elevator  118 . As such, elevator may be used to raise and lower the joint of conductor pipe  102  in the vertical position, the horizontal position, and all positions in-between. 
         [0045]    Advantageously, embodiments disclosed herein allow an elevator to engage and lift a (e.g., horizontally laying) joint of conductor pipe without requiring the elevator to be slid over a free end of the joint of conductor pipe. Furthermore, embodiments disclosed herein depict a method by which joints of conductor pipe may be assembled and thrust into the wellbore without the need for welded and/or bolted lifting eyes to be installed and removed from each joint of conductor pipe. Pursuant thereto, embodiments disclosed herein reduce likelihood that individual joints of conductor pipe may become damaged during assembly and installation processes. Advantageously still, embodiments disclosed herein allow cylindrical joints of conductor pipe having no lifting features, e.g., upsets on the outer diameter of the pipe) to be lifted from a non-vertical position in a pipe rack or another rig location, grasped by a lifting elevator, rotated into a vertical position, and installed atop a string of conductor pipe. 
         [0046]    While the disclosure has been presented with respect to a limited number of embodiments, those skilled in the art, having benefit of this disclosure, will appreciate that other embodiments may be devised which do not depart from the scope of the present disclosure. Accordingly, the scope of the invention should be limited only by the attached claims.