Patent Publication Number: US-8118105-B2

Title: Modular electro-hydraulic controller for well tool

Description:
CROSS-REFERENCE TO RELATED APPLICATION 
     This application is a division of prior application serial no. 12/352,892 filed on Jan. 13, 2009. The entire disclosure of this prior application is incorporated herein by this reference. 
    
    
     BACKGROUND 
     The present disclosure relates generally to equipment utilized and operations performed in conjunction with a subterranean well and, in an embodiment described herein, more particularly provides a modular electro-hydraulic controller for a well tool. 
     Typically, electro-hydraulic controls for operation of downhole well tools have been packaged in an annular area between a tubular inner mandrel and a tubular outer housing. Unfortunately, this type of arrangement generally requires that the electro-hydraulic controls, inner mandrel, outer housing, etc., be completely assembled for testing and disassembled for resolution of any problems uncovered in the testing. This can be time-consuming and difficult to accomplish, particularly at a wellsite. 
     In addition, the most failure-prone components (the wires, electronics, connectors, etc.) of the assembly are housed within large, heavy and bulky housings, with the result that these components are frequently damaged during assembly. One reason that the housings are so heavy and bulky is that they must resist large pressure differentials downhole. 
     However, the pressure differential resisting capability of a housing could be enhanced, without increasing the size of the housing, if it were not necessary to contain the electro-hydraulic components of the control system in a large annular area within the housing. An otherwise solid housing could be used instead, with recesses machined into a sidewall of the housing for receiving the components, but this is very expensive and generally requires the use of cross-drilled holes to connect wires, hydraulics, etc. 
     Therefore, it may be seen that advancements are needed in the art of controlling actuation of well tools downhole. 
     SUMMARY 
     In the present specification, a modular controller and associated methods are provided which solve at least one problem in the art. One example is described below in which the controller is separate from a housing assembly which interconnects to one or more actuators. Another example is described below in which the controller incorporates components therein which can be conveniently tested and replaced, apart from any other components of an actuator control system. 
     In one aspect, an actuator control system is provided by the present disclosure. The actuator control system includes a generally tubular housing assembly having at least one line (such as one or more hydraulic lines) therein for controlling operation of an actuator, and a modular controller attached externally to the housing assembly and interconnected to the line. 
     In another aspect, a method of constructing an actuator control system is provided which includes the steps of: assembling a modular controller, the modular controller including a control valve therein for controlling operation of an actuator via one or more hydraulic lines; testing the modular controller, including functionally testing the control valve; and then attaching the modular controller to a housing assembly having the hydraulic line formed therein. This allows control of the actuator via the control valve of the controller. 
     In yet another aspect, an actuator control system is provided which includes a generally tubular housing assembly having at least one line therein for controlling operation of an actuator, and a modular controller attached separately to the housing assembly and interconnected to the line via a manifold of the modular controller. The manifold includes a concave interface surface which receives the housing assembly therein. 
     The housing assembly may be provided with an uninterrupted interior profile for retrievable bi-directional running tools. 
     These and other features, advantages and benefits will become apparent to one of ordinary skill in the art upon careful consideration of the detailed description of representative embodiments below and the accompanying drawings, in which similar elements are indicated in the various figures using the same reference numbers. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is a schematic partially cross-sectional view of a well system embodying principles of the present disclosure; 
         FIG. 2  is an enlarged scale schematic partially cross-sectional view of an actuator control system which may be used in the well system of  FIG. 1 , the control system embodying principles of the present disclosure; 
         FIG. 3  is a side elevational view of a housing assembly and modular controller of the control system; 
         FIG. 4  is an enlarged scale cross-sectional view of the housing assembly and a manifold of the modular controller, taken along line  4 - 4  of  FIG. 3 ; 
         FIGS. 5A  &amp; B are further cross-sectional views of the housing assembly and manifold, taken along respective lines  5 A- 5 A and  5 B- 5 B of  FIG. 3 ; 
         FIGS. 6A-D  are cross-sectional views of successive axial sections of the modular controller; 
         FIG. 7  is a lateral cross-sectional view of the housing assembly and modular controller; and 
         FIG. 8  is a partial longitudinal cross-sectional view of the control system as connected to an actuator in the well system of  FIG. 1 . 
     
    
    
     DETAILED DESCRIPTION 
     It is to be understood that the various embodiments described herein may be utilized in various orientations, such as inclined, inverted, horizontal, vertical, etc., and in various configurations, without departing from the principles of the present disclosure. The embodiments are described merely as examples of useful applications of the principles of the disclosure, which are not limited to any specific details of these embodiments. 
     In the following description of the representative embodiments of the disclosure, directional terms, such as “above”, “below”, “upper”, “lower”, etc., are used for convenience in referring to the accompanying drawings. In general, “above”, “upper”, “upward” and similar terms refer to a direction toward the earth&#39;s surface along a wellbore, and “below”, “lower”, “downward” and similar terms refer to a direction away from the earth&#39;s surface along the wellbore. 
     Representatively illustrated in  FIG. 1  is a well system  10  which embodies principles of the present disclosure. In the well system  10 , a drill stem test is performed utilizing, in part, well tools  44 ,  46  for controlling flow between an interior flow passage  48  of a tubular string  50 , an annulus  52  formed between the tubular string and a wellbore  54 , and a formation  56  intersected by the wellbore. The wellbore  54  could be cased, as depicted in  FIG. 1 , or it could be uncased. 
     An actuator control system  12  is interconnected in the tubular string  50 . The control system  12  is used to control operation of actuators of the well tools  44 ,  46  during the drill stem test. The actuators of the well tools  44 ,  46  may be of conventional design and so are not described further herein, but a schematic actuator  18  which may be used in the well tools  44 ,  46  is depicted in  FIG. 2 . 
     Alternatively, an actuator for operating both of the well tools  44 ,  46  could be as described in the U.S. patent application Ser. No. 12/352,901 filed concurrently herewith, entitled MULTI-POSITION HYDRAULIC ACTUATOR, the entire disclosure of which is incorporated herein by this reference. 
     The control system  12  controls operation of the actuators by selectively applying pressure to pistons of the actuators. For this purpose, the tubular string  50  may also include pressure sources  20 ,  22 . 
     For example, a relatively low pressure source could be an atmospheric chamber or a low pressure side of a pump. A relatively high pressure source could be a pressurized gas chamber, hydrostatic pressure in the well, or a high pressure side of a pump. Any type of pressure source could be used, and it is not necessary for any of the pressure sources to be interconnected in the tubular string  50 , in keeping with the principles of the invention. For example, if hydrostatic pressure is used as a pressure source, the annulus  52  or passage  48  could serve as the pressure source. 
     The well tool  44  is depicted in  FIG. 1  as being a circulating valve, and the well tool  46  is depicted as being a tester valve. However, actuation of any other type or combination of well tools could be controlled using the control system  12 . 
     At this point, it should be reiterated that the well system  10  is merely one example of an application of the principles of this disclosure. It is not necessary for a drill stem test to be performed, for the control system  12  to be interconnected in the tubular string  50 , for fluid communication between the formation  56 , passage  48  and annulus  52  to be controlled, or for well tools  44 ,  46  to be actuated. The principles of this disclosure are not limited in any manner to the details of the well system  10 . 
     Referring additionally now to  FIG. 2 , a schematic hydraulic circuit diagram of the control system  12  is representatively illustrated apart from the well system  10 . In this view, it may be seen that a control valve  14  of the control system  12  is interconnected between the pressure sources  20 ,  22  and chambers  24 ,  26  on opposite sides of a piston  28  in the actuator  18 . 
     The control valve  14  could comprise a single valve with multiple inputs and outputs, or it could comprise multiple individual valves. The control valve  14  may be operated in any manner (e.g., electrically, hydraulically, magnetically, etc.). A specific example of a motor-driven rotary control valve is described below, but it should be understood that any type of control valve or valves (such as, a linear actuator-operated spool valve, pressure-operated pilot valves, an array of solenoid-operated valves, etc.) may be used in keeping with the principles of this disclosure. 
     An example of an acceptable control valve is described in U.S. patent application Ser. No. 11/199,093, filed Aug. 8, 2005 and published as US2007-0029078. The entire disclosure of this prior application is incorporated herein by this reference. 
     As depicted in  FIG. 2 , the chambers  24 ,  26  are in fluid communication with respective opposing surface areas  30 ,  32  on the piston  28 . However, in other embodiments, it would not be necessary for the chambers  24 ,  26  and surface areas  30 ,  32  to be on opposite sides of the piston  28 . 
     It is also not necessary for the piston  28  to have a cylindrical shape as depicted in  FIG. 2 . The piston  28  could instead have an annular shape or any other shape. If the actuator described in the incorporated concurrently filed application referenced above is used in the control system  12 , the actuator  18  would include multiple annular pistons for operating both of the well tools  44 ,  46 . 
     In the example of  FIG. 2 , the pressure source  20  will be described as a high pressure source, and pressure source  22  will be described as a low pressure source. In other words, the pressure source  20  supplies an increased pressure relative to the pressure supplied by the pressure source  22 . 
     For example, the pressure source  20  could supply hydrostatic pressure and the pressure source  22  could supply substantially atmospheric pressure. The preferable condition is that a pressure differential between the pressure sources  20 ,  22  is maintained, at least during operation of the actuator  18 . 
     When it is desired to displace the piston  28  to the right as viewed in  FIG. 2 , the control valve  14  is operated to permit fluid communication between the pressure source  20  and the chamber  24 , and to permit fluid communication between the pressure source  22  and the chamber  26 . When it is desired to displace the piston  28  to the left as viewed in  FIG. 2 , the control valve  14  is operated to permit fluid communication between the pressure source  22  and the chamber  24 , and to permit fluid communication between the pressure source  20  and the chamber  26 . 
     Such displacement of the piston  28  can be reversed and repeated as desired. However, the number of times the piston  28  can be displaced may be limited by some resource (e.g., electrical power, hydraulic fluid, pressure differential, etc.) available to the control system  12 . 
     Although only one actuator  18 , one piston  28  and two pressure sources  20 ,  22  are depicted in the control system  12  of  FIG. 2 , it will be appreciated that any number or combination of these elements may be provided in a control system incorporating principles of this disclosure. 
     Referring additionally now to  FIG. 3 , a side elevational view of a housing assembly  34  and modular controller  36  of the control system  12  is representatively illustrated. The housing assembly  34  is preferably interconnected in the tubular string  50  in the well system  10  by means of externally and internally threaded connectors  38 ,  40  so that the flow passage  48  extends longitudinally through the housing assembly. However, it should be clearly understood that the control system  12 , housing assembly  34  and modular controller  36  can be used in well systems other than the well system  10  of  FIG. 1 , in keeping with the principles of this disclosure. 
     In one unique feature of the control system  12 , the modular controller  36  is received in a longitudinally extending recess  42  formed externally on the housing assembly  34 . The controller  36  is retained in the recess  42  by an elongated retainer  58  which presses the controller against sides of the recess for enhanced acoustic coupling when acoustic telemetry is used for communicating between the controller and a remote location. The manner in which the retainer  58  secures the controller  36  in the recess  42  can be more clearly seen in  FIG. 7 . 
     In another unique feature of the control system  12 , the controller  36  is separately attached to the housing assembly  34  and is connected to control lines  60 ,  82  therein (see  FIG. 7 ) by a manifold  64 . The manifold  64  provides sealed fluid communication between the lines  60 ,  62 ,  80 ,  82  in the housing assembly  34  and the control valve  14  in the controller  36 . 
     In yet another unique feature of the control system  12 , the controller  36  (including each of the components thereof described more fully below) can be functionally and pressure tested separately from the housing assembly  34 , so that any problems uncovered in the controller testing can be conveniently remedied without use or handling of the housing assembly. For example, operation of the control valve  14  can be confirmed prior to connecting the controller  36  to the housing assembly  34 . 
     Likewise, the housing assembly  34  can be tested, maintained, repaired, etc. apart from the controller  36 . Furthermore, the assembled downhole tool assembly can be function tested, operating well tools  44 ,  46 , apart from the controller  36 . 
     If, for example, a problem is uncovered in the controller  36 , this configuration of the control system  12  permits relatively rapid detection and resolution of the problem. In addition, the external attachment of the controller  36  on the housing assembly  34  means that the controller can be easily and conveniently replaced, if necessary, without substantial downtime or interruption of wellsite activities. 
     This is a significant advantage over conventional control systems in which an annular space between an inner mandrel and an outer housing of a housing assembly is used to contain components of the control system, some of which extend completely around the annular space and encircle a flow passage extending through the housing assembly. In such conventional control systems, the components in the annular space must be tested while positioned in the housing assembly, and the housing assembly cannot be pressure tested apart from the components therein. Thus, a problem with one component, or with a seal in the housing assembly, typically requires the entire control system to be disassembled, the problem resolved, the control system reassembled, the control system re-tested, etc. 
     Referring additionally now to  FIG. 4 , an enlarged scale cross-sectional view of the control system  12  is representatively illustrated. In this view, the manner in which the manifold  64  is externally attached to the housing assembly  34  is representatively illustrated. 
     Note that fasteners  66  are used to secure the manifold  64  externally to the housing assembly  34 . The fasteners  66  are depicted in  FIG. 4  as being threaded bolts, but other types of fasteners, and other types of attachments, may be used in keeping with the principles of this disclosure. 
     Note, also, that a concave interface surface  68  formed on the manifold  64  receives the housing assembly  34  therein, and that the manifold thus extends partially circumferentially about the passage  48 . This shape of the interface between the manifold  64  and the housing assembly  34  enhances the differential pressure resisting capabilities of the manifold and housing assembly. In particular, a sidewall  70  of the housing assembly  34  has an arch shape which is advantageous for its differential pressure resisting capabilities. 
     The circumferential profile of the manifold  64  further allows larger fluid passageways for increased flow area, and an uninterrupted contour within the housing assembly  34 , preventing the possibility of jarring the controller  36  during run-in or pulling out of the well. Furthermore, this profile allows convenient and reliable fluid communication methods between the manifold  64  and the housing assembly  34 , thereby aiding controller  36  and system  12  modularity as depicted in  FIG. 5  and described below. 
     Referring now to  FIG. 5 , another enlarged scale cross-sectional view of the control system  12  is representatively illustrated. In this view, the manner in which sealed communication between the controller  36  and the housing assembly  34  is provided may be clearly seen. 
     Relatively small tubes  72 ,  74  having seals  76  thereon are received in seal bores  78  formed in the manifold  64  and housing assembly  34 . Although only two of the tubes  72 ,  74  are visible in  FIG. 5 , this example of the control system  12  preferably includes four such tubes for providing sealed communication between each of the pressure sources  20 ,  22  and the actuator  18  via the control valve  14 , as described more fully below. 
     The pressure sources  20 ,  22  are in communication with respective lines  80 ,  62  in the housing assembly  34 , and the actuator  18  is in communication with additional lines  60 ,  82  in the housing assembly. The manifold  64  provides convenient sealed communication between the controller  36  and each of the lines  60 ,  62 ,  80 ,  82  in the housing assembly  34  via the tubes  72 ,  74 ,  75 ,  77  and passages  84 ,  86 ,  87 ,  89  formed in the manifold. Tubes  75 ,  77  and passages  87 ,  89  are visible in  FIG. 5B . 
     The passages  84 ,  86 ,  87 ,  89  are specially constructed for routing fluid and pressure between the lines  60 ,  62 ,  80 ,  82  and the control valve  14  in the controller  36 . Preferably, the manifold  64  is constructed with the passages  84 ,  86 ,  87 ,  89  therein using a progressive material deposition process, but any method may be used for constructing the manifold in keeping with the principles of this disclosure. 
     Note that, as depicted in  FIGS. 4 &amp; 5 , the housing assembly  34  is provided with an uninterrupted interior profile which is especially advantageous for use with retrievable bi-directional running tools. 
     Referring additionally now to  FIGS. 6A-D , longitudinal cross-sectional views of the modular controller  36  are representatively illustrated apart from the remainder of the control system  12 . In these views, the manner in which the various components of the controller  36  are arranged and interconnected can be conveniently seen. 
     In  FIG. 6A , an upper portion of the controller  36  includes the manifold  64 , the control valve  14  and a motor  88  for operating the control valve. Note that it is not necessary for the control valve  14  to be motor-operated, since any other type of control valve or valves may be used, if desired. 
     As described above, the manifold  64  provides sealed communication between the control valve  14  and the lines  60 ,  62 ,  80 ,  82  in the housing assembly  34 . The control valve  14  is used to operate the actuator  18  by providing selective communication between the lines  80 ,  62  and the lines  60 ,  82  to thereby selectively connect the pressure sources  20 ,  22  to the chambers  24 ,  26  of the actuator  18 . 
     The control valve  14  is preferably a rotary control valve of the type described in U.S. patent application Ser. No. 11/946,332 filed on Nov. 28, 2007, the entire disclosure of which is incorporated herein by this reference. However, other types of control valves may be used for the control valve  14  in keeping with the principles of this disclosure. 
     In  FIG. 6B , it may be seen that a sealed bulkhead  90  is provided between the motor  88  and control electronic circuitry  92  in the modular controller  36 . Preferably, the motor  88  is contained in pressurized fluid (such as dielectric fluid) within its outer housing  94 , and so the bulkhead  90  isolates this fluid from the control circuitry  92 . 
     In  FIG. 6C , it may be seen that the control circuitry  92  is connected to a telemetry device  96  for wireless communication with a remote location (such as the surface or another location in the well). In this example, the telemetry device  96  comprises two acoustic telemetry components, one for receiving acoustic signals from the remote location (e.g., commands to operate the control valve  14 ), and the other for transmitting acoustic signals to the remote location (e.g., data relating to the operation of the controller  36 ). 
     The telemetry device  96  preferably includes a relatively thin and flexible piezoelectric material applied externally to a tubular mandrel  98 , but other types of acoustic telemetry devices, receivers, transmitters, etc. may be used in keeping with the principles of this disclosure. Furthermore, any type of telemetry device (such as electromagnetic, pressure pulse, etc.) may be used instead of, or in addition to, the acoustic telemetry device  96  if desired. For example, the telemetry device  96  could comprise a pressure transducer, hydrophone, antenna, etc. 
     A hydrophone or other type of pressure sensor  100  is also included in the controller  36 , and is connected to the control circuitry  92 . As depicted in  FIG. 6C , the controller  36  is configured so that the pressure sensor  100  is operative to detect pressure in the annulus  52  in the well system  10 . In situations in which the annulus  52  is used as a relatively high pressure source, it is useful to have an indication of the pressure in the annulus at the controller  36 . In addition, or alternatively, the pressure sensor  100  can serve as a telemetry device for receiving signals transmitted from a remote location via pressure pulses and/or pressure profiles in the annulus  52 . 
     In response to the signals received by the telemetry device  96  (and/or the pressure sensor  100  which may serve as a telemetry device), the control circuitry  92  operates the control valve  14 , for example, by appropriately applying electrical power to the motor  88  from a power source  102  (see  FIG. 6D ), and/or otherwise operating the control valve (e.g., actuating one or more solenoid valves, spool valves, pilot valves, etc.). In this example, the power source  102  comprises multiple batteries in an outer housing  104 , with a connector  106  at an upper end. Preferably, when the housing  104  is connected to the remainder of the controller  36 , electrical power is thereby supplied to the control circuitry  92 . 
     Referring additionally now to  FIG. 7 , a cross-sectional view of the control system  12  is representatively illustrated. In this view, the manner in which the controller  36  is received in the recess  42 , and the manner in which the retainer  58  biases the controller against a side of the recess for enhanced acoustic coupling, can be clearly seen. 
     Note that an additional module  108  is received in another longitudinal recess  110  formed externally on the housing assembly  34 , and is retained therein by the retainer  58  which biases the module against a side of the recess. The module  108  could, for example, comprise a relatively long range telemetry device, such as an acoustic telemetry transceiver. In that case, the telemetry device  96  could be used to communicate with the module  108  over the relatively short distance between the controller  36  and the module  108 , and the module could be used to communicate with a remote location over a relatively long distance. 
     Referring additionally now to  FIG. 8 , a cross-sectional view of the control system  12  as connected to the actuator  18  is representatively illustrated. In this view, the manner in which the control system  12  interfaces with the actuator  18  can be more clearly seen. Although various hydraulic lines which provide fluid communication between the manifold  64  and the actuator  18  are not visible in  FIG. 8 , it will be appreciated that these lines do function to appropriately connect the pressure sources  20 ,  22  to the actuator via the manifold  64  and control valve  14  of the controller  36 . 
     It may now be fully appreciated that the above disclosure provides many advancements to the art of controlling operation of well tools downhole. For example, the modular controller  36  is externally accessible and can be tested separately from the housing assembly  34  and other portions of the control system  12 . As another example, the manifold  64  is uniquely configured to provide sealed communication between the controller  36  and the housing assembly  34 , and is configured to enhance the differential pressure resisting capabilities of these elements. 
     The above disclosure describes an actuator control system  12  which includes a generally tubular housing assembly  34  having at least one line  60 ,  62 ,  80 ,  82  therein for controlling operation of an actuator  18 . A modular controller  36  is attached externally to the housing assembly  34  and is interconnected to the line(s)  60 ,  62 ,  80 ,  82 . 
     The housing assembly  34  may include a flow passage  48  extending generally longitudinally through the housing assembly  34 . The modular controller  36  is preferably free of any component which completely encircles the flow passage  48 . 
     The modular controller  36  may include a control valve  14  therein for controlling operation of the actuator  18  via the line(s)  60 ,  62 ,  80 ,  82 . The modular controller  36  may also include a motor  88  and an electrical power source  102  therein for actuating the control valve  14 . 
     The modular controller  36  can include at least one telemetry device  96 ,  100  for wireless communication with a remote location. The modular controller  36  may also include control circuitry  92  which controls actuation of the motor  88  to operate the control valve  14  (or otherwise operate one or more control valves) in response to commands received by the telemetry device(s)  96 ,  100 . 
     The modular controller  36  may be attached to the housing assembly  34  and interconnected to the line(s)  60 ,  62 ,  80 ,  82  via a manifold  64  which extends partially circumferentially about the housing assembly  34 . 
     The above disclosure also describes a method of constructing an actuator control system  12 , which method includes the steps of: assembling a modular controller  36 , the modular controller  36  including at least one control valve  14  therein for controlling operation of an actuator  18  via at least one hydraulic line  60 ,  62 ,  80 ,  82 ; testing the modular controller  36 , including functionally testing the control valve  14 ; and then attaching the modular controller  36  to a housing assembly  34  having the line(s)  60 ,  62 ,  80 ,  82  formed therein. 
     The method may include the step of pressure testing the housing assembly  34 , including pressure testing the line(s)  60 ,  62 ,  80 ,  82 . The well tools  44 ,  46  can furthermore be function tested to verify component tool operation(s), apart from the controller  36 . The modular controller  36  testing step may be performed separately from the housing assembly  34  pressure testing step. 
     The modular controller  36  attaching step may include connecting a manifold  64  of the modular controller  36  to the housing assembly  34 , thereby providing sealed fluid communication between the control valve  14  and the actuator  18  via the manifold  64 . The modular controller  36  testing step may include pressure testing the manifold  64  prior to the step of attaching the modular controller  36  to the housing assembly  34 . 
     The modular controller  36  may also include a motor  88  and an electrical power source  102  therein for actuating the control valve  14 , and the method may include the step of testing the motor  88  and electrical power source  102  prior to the step of attaching the modular controller  36  to the housing assembly  34 . 
     The modular controller  34  may also include at least one telemetry device  96 ,  100  for wireless communication with a remote location, and the method may include the step of testing the telemetry device(s)  96 ,  100  prior to the step of attaching the modular controller  36  to the housing assembly  34 . 
     The modular controller  36  may also include control circuitry  92  which controls actuation of the motor  88  to operate the control valve  14  in response to commands received by the telemetry device(s)  96 ,  100 , and the method may include the step of testing the control circuitry  92  prior to the step of attaching the modular controller  36  to the housing assembly  34 . 
     The above disclosure also describes an actuator control system  12  which includes a generally tubular housing assembly  34  having at least one line  60 ,  62 ,  80 ,  82  therein for controlling operation of an actuator  18 ; and a modular controller  36  attached separately to the housing assembly  34  and interconnected to the line(s)  60 ,  62 ,  80 ,  82  via a manifold  64  of the modular controller  36 . The manifold  64  includes a concave interface surface  68  which receives the housing assembly  34  therein. 
     Of course, a person skilled in the art would, upon a careful consideration of the above description of representative embodiments, readily appreciate that many modifications, additions, substitutions, deletions, and other changes may be made to these specific embodiments, and such changes are within the scope of the principles of the present disclosure. Accordingly, the foregoing detailed description is to be clearly understood as being given by way of illustration and example only, the spirit and scope of the present invention being limited solely by the appended claims and their equivalents.