Patent Abstract:
The present invention provides a return port cover that can close and open a return port separate from tubing movement caused by stretching or contracting under stress or other induced pipe movement from downhole conditions. For example, the return port cover can assist in preventing pack “fluffing” by preventing unintended fluid communication through an associated downhole tool regardless of the position of a circulating valve means. The return port cover can be biased, so that in one position it closes the port and in another position opens the port based on relative tubing placement at different portions of the fracturing operation or other well treatment operations.

Full Description:
FIELD OF THE INVENTION 
     This invention relates to the field of subsurface tools used in hydrocarbon wells. More particularly, the invention relates to cross-over tools. 
     BACKGROUND OF THE INVENTION 
     Hydrocarbon wells such as oil and gas wells frequently need fracturing of the strata to adequately produce hydrocarbons from the strata. Fracturing cracks the strata to allow more surface area to flow the hydrocarbons. Fracturing generally occurs after the well has been drilled, casing has been placed, and various completion tools inserted into the well bore. Proppant through a flowable slurry is filled in the cracks to maintain the cracks in an open position. A screen is typically placed in the well bore to allow hydrocarbons to flow into a production tubing and up to the well surface without allowing the proppant and sand from the strata to flow into the tubing. 
     The typical techniques involved in flowing proppant are to flow it through a central flow path in a tubing string disposed in the casing and divert it to an annulus formed between a completion assembly, attached to the tubing string, and the casing to fill the annulus in the region of the screen. Then, the flow path is reversed to wash out excess proppant remaining in the tubing string and a cross-over tool. 
     To accomplish the flow reversal, the cross-over tool is frequently used by attaching it to the tubing string above the screen region. The cross-over tool is positioned in the completion assembly so that the slurry is initially diverted from the central flow path of the tubing string into the annulus around the screen and into the formation. The flow reversal can occur by repositioning the cross-over tool to the reverse position to create a flow path down an upper portion of the annulus and back up the central flow path of the tubing string. 
     A problem has been realized in the flow reversal. The frac pressures used to treat the well can actually stretch or contract the tubing string, known as tubing movement. Tubing movement can occur by temperature changes, piston effects, ballooning effects, buoyancy effects, and other downhole conditions. A typical length of several thousand feet of tubing that is often placed in the well bore can change length based on the above factors. The tubing movement length change can cause misalignment of the tool structures and inadvertently open and close ports that are not intended. Inadvertently open flow ports can cause the proppant placed in the fracturing operation to become displaced and create other disadvantageous results. 
     For example, if the cross-over tool is in the reverse position, a so-called circulating valve needs to remain closed. If the valve opens, reverse fluid can travel through the circulating valve, out a wash pipe in the completion string, through the screen, and into the frac pack. Fluid movement upward through the pack tends to “fluff” the pack, thus, destroying the integrity of the pack by creating voids. This upward flow can also carry sand or proppant back into the tool assembly, creating other problems. Stated differently, the circulating valve, or in some cases, a reversing ball, must not open while reversing. But if tubing movement enables fluid communication, then “fluffing” can occur. 
     Other problems can also occur from inadvertent opening and closing, such as loss of fluids or misdirected fluids at inappropriate times, and so forth. Further, tubing movement exists with other procedures, such as gravel packing, acidizing, water packing, and other well treatments and can also cause problems. 
     Therefore, there remains a need to increase the reliability of the fracturing operation and other well treatment operations. 
     SUMMARY OF THE INVENTION 
     The present invention provides a return port cover that can close and open a return port separate from tubing movement caused by stretching or contracting under stress or other induced pipe movement from downhole conditions. For example, the return port cover can assist in preventing pack “fluffing” by preventing unintended fluid communication through an associated downhole tool regardless of the position of a circulating valve means. The return port cover can be biased, so that in one position it closes the port and in another position opens the port based on relative tubing placement at different portions of the fracturing operation or other well treatment operations. 
     The present invention provides a method of controlling flow through a return port positioned downhole in a well, comprising providing an engagement surface on a downhole member disposed downhole in the well; engaging a downhole well treatment tool having a return port cover coupled thereto with the engagement surface of the downhole member to move the return port cover from a first position to a second position; disengaging the well treatment tool from the engagement surface of the downhole member; and allowing the return port cover to move from the second position. 
     The present invention also provides a well treatment tool, comprising a wall having a return port formed therethrough to establish a fluid flow path between an exterior portion and an interior portion of the well treatment tool; a return port cover coupled to the wall proximal the return port, the return port cover having a first position and a second position, wherein one position comprises an at least partially closed position on the return port and the other position comprises an at least partially open position on the return port; an engagement surface coupled to the return port cover and adapted to engage another engagement surface disposed downhole and independent from the well treatment tool for actuation of the return port cover. 
     The invention further provides a system for controlling flow through a port, comprising a well treatment tool having a return port and a means for at least partially opening and closing the return port at selective times in a well treatment operation. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       A more particular description of the invention, briefly summarized above, can be realized by reference to the embodiments thereof that are illustrated in the appended drawings and described herein. However, it is to be noted that the appended drawings illustrate only some embodiments of the invention. Therefore, the drawings are not to be considered limiting of its scope, for the invention may admit to other equally effective embodiments. 
         FIG. 1  is a schematic cross-sectional side view of a portion of a tool string in an initial “run in” position. 
         FIG. 2  is a schematic cross-sectional side view of a return port cover in an at least partially opened position on a return port and associated elements. 
         FIG. 3  is a schematic cross-sectional side view a return port cover in an at least partially closed position on the return port and associated elements. 
         FIG. 4  is a schematic cross-sectional side view of a portion of a tool string in a “circulation” position. 
         FIG. 5  is a schematic cross-sectional side view of a portion of a tool string in a “reverse” position. 
     
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
       FIG. 1  is a schematic cross-sectional side view of a portion of a tool string in an initial “run in” position. A well bore  10  is established in various strata of the earth, whether on land or subsea. A casing  12  is generally placed in the well bore, although a casingless well can be formed in some strata. A work string  14  is used to carry a series of tools, known as a “tool string,” into the well and position the tool string at the correct location. Generally, the work string can include several thousand feet of drill pipe or tubing, depending on the depth of the well bore and location of production zones. The work string  14  establishes a central flow path  15  through the bore of the work string and an annular flow path  17  between the work string and the casing  12 . Each flow path is used at various stages of the well treatment process. 
     Generally, a completion work string can be used to suspend various downhole tools to form a tool string  14 A used to complete the preparation of the well prior to production. A tool string  14 A is a general term describing a plurality of downhole tools and sections mounted to the work string  14  for performing various operations from drilling to completing the well to producing the well. A work string may be run initially or at a later time and allow subsequent maintenance operations. Completion string tools can be used to perforate the casing to allow production fluids to flow into the casing, set various packers at appropriate depths, frac or gravel pack appropriate areas, and other well treatment operations. The completion work string is removed with various tools, such as packers being left in the well bore, and a production work string is set in the hole for production of the fluids to the surface. In some operations, the completion work string and production work string are combined, so that reduced trips into the well bore are possible. For the purposes herein, the term “work string” is meant to at least include any string of pipe, tubing, or wireline used to suspend tools used for completing a well or other well treatments, including pre-production and post-production well treatments. 
     The tool string  14 A described herein is representative of an assembly that can be used with the present invention, but is not limiting of the invention because the invention can be used with a variety of tool assemblies. For the purposes of illustration, the tool string described below includes a setting tool  18 , a packer  20 , a cross-over tool  26 , a multi-service sliding sleeve  32 , a polished bore receptacle (“PBR”)  44 , another casing spacer  46 , a circulating valve means  50 , a cross-over reducer  80 , and a screen  84 . Each of the various tools with their subparts are described below as appropriate. 
     A setting tool  18  is shown coupled to the work string  14 . The term “coupled,” “coupling,” and like terms are used broadly herein and can include any method or device for securing, binding, bonding, fastening, attaching, joining, inserting therein, forming thereon or therein, communicating, or otherwise associating, for example, mechanically, magnetically, electrically, chemically, directly or indirectly with intermediate elements, one or more pieces of members together and can further include integrally forming one functional member with another. The coupling can occur in any direction, including rotationally. Often, the setting tool is hydraulically actuated by pressurizing the central flow path  15  with fluid, so that various pistons and other devices move to actuate other assemblies. 
     A packer  20  is selectively coupled to the setting tool  18 . The packer can be hydraulically actuated in conjunction with a hydraulic setting tool or it can be mechanically actuated by movement of the assemblies in the well bore or a combination thereof. A flexible packing element  22  is radially extended to sealingly engage the walls of the casing  12 . The extension of the packing element can be controlled with the movement of the setting tool and various subassemblies. One or more slips  24  are used to assist the packer in retaining its placement at an appropriate depth by expanding and gripping the walls of the casing. 
     Frequently, the packer is set and released from the setting tool and left in the well bore. The packer can be coupled to other tools described herein that become fixedly positioned when the packer is set. Still other tools can be moved longitudinally or rotationally relative to the fixedly positioned tools, such as when completing the well prior to production. One such tool, a cross-over tool  26 , is moved to change flow paths in the well in conjunction with some of the fixedly positioned tools. Other well treatment tools having various flow paths can also be used. 
     The cross-over tool  26  can be coupled to the work string  14  and selectively coupled to the packer  20  through the setting tool  18 . The cross-over tool  26  can form a significant piece of the tool string when changes are needed in the flow paths to perform various operations in the well. The cross-over tool  28  includes several subsections and openings in one or more walls of the cross-over tool that move relative to each other to control the various flow paths, described below. 
     One such subsection and opening includes a return port  28  formed in a wall of the cross-over tool and a cross-over tool return port cover  90  disposed adjacent and proximal to the return port. The return port  28  is useful for returning flow to the surface between an interior portion and an exterior portion of the cross-over tool and can also provide pressure monitoring during the fracturing or other well treatment processes. However, the tubing movement described above caused by pressure stretching of the work string allows the return port and other ports below the return port to unintentionally be opened or closed at unintended times. This unintended opening or closing can damage the placement of the proppant in the fracturing process and cause other challenges. 
     A solution provided by the present invention is to use and provide a return port cover  90 , so that it opens on engagement with a known surface and closes at other times. Further, it is operational in the proximal area of the return port  28 . The known engagement surface can unintentionally move by tubing movement described above. However, the work string and the return port cover coupled thereto can be adjusted independently of the tubing movement, so that the return port cover engages and disengages the engagement surface at wherever the engagement surface has been displaced. Thus, the opening and closing of the return port can be controlled. The tubing movement has little ultimate effect on the ability to open and close the port  28 , because the return port cover  90  in a broad sense does not depend on a constant positioning with other tools for proper operation. Further details of the return port cover  90  are provided in  FIGS. 2 and 3 . 
     The cross-over tool  26  also includes a frac port  38 , through which proppant and other fluids can flow when aligned with other openings. The tool string  14 A can move the cross-over tool  26  longitudinally and/or rotationally relative to other tools and openings to create the changes in flow paths. Seals above and below the frac port  38  assist in directing flow to the window  34 . 
     A passageway sealing surface  40  is used to seal the central flow path  15 , often in cooperation with a dropped ball or other movable object, so that flow is directed through the upstream frac port  38  and window  34 . Frequently, the central flow path  15  is pressurized by using the passageway sealing surface  40  at selected times to cause various tooling assemblies to shift or move as described herein. 
     A circulating valve means  50  can be coupled to the cross-over tool  26 . The circulating valve means  50  is sometimes referred to as a “shifting tool,” because it can be used to move other tools to shifted positions. The circulating valve means can also be used to replace the traditional reversing ball in the cross-over tool. The circulating valve means advantageously allows the monitoring of pressure on the annulus while fracing the well, in contrast to the reversing ball. However, in some embodiments, where the monitoring is secondary, the reversing ball can be used. 
     The circulating valve means  50  includes a passageway sealing surface  51  to restrict flow in the central flow path  15  for the various shifting operations using the circulating valve means, as would be known to those with ordinary skill in the art. The circulating valve means  50  also includes a collet assembly  52  having a collet head  54  and a detent collet  61 . The collet head  54  includes at least one collet finger  56  that is generally biased radially outward to engage other tools as it is moved longitudinally in the well. The movement of the collet finger  56  is limited between a stroke tab  58  and a corresponding shoulder  59 . The collet finger  56  can also include a shifting tab  60  to assist in engaging and shifting other tools as the collet assembly  52  is moved longitudinally. The detent collet  61  can also include at least one collet finger  62  with a detent tab  64 . The collet finger  64  can be biased inwardly to engage a detent  66  formed in the circulating valve means  50  to assist in maintaining a shifted position of the collet assembly  52 . 
     In some embodiments, the circulating valve means  50  can also include at least two circulation ports  68 ,  70  for flowing fluids through the valve around the passageway sealing surface  51 . The ports can be selectively opened and closed by location of the collet assembly  52 . The collet assembly  52  can include circulation seals  72 ,  74 ,  76  to assist in restricting the flow through the ports  68 ,  70 . The circulation seal  74  can be selectively disposed between the ports  68 ,  70 , as shown in  FIG. 5 , so that any flow is restricted therethrough and flow is restricted outside of the collet assembly by the two circulation seals  72 ,  76  to the sides of the circulation seal  74 , respectively. 
     A sealing member  78  having at least one seal can be coupled to the circulating valve means  50 . The sealing member  78  is used to selectively engage various portions of the tools, such as the PBR  44 , as selected times in the operations to control flow below or above the sealing member  78 . 
     The tool string  14 A can further include a multi-service sliding sleeve (“MS sliding sleeve”)  32  coupled to the packer  20  through a casing spacer  30 . A casing spacer can be of variable length depending on the needs of the particular assembly of tools and well. The MS sliding sleeve  32  is generally mounted external to the cross-over tool  26 . The MS sliding sleeve  32  is used to isolate the zone after the flow of proppant slurry through a window  34 . As shown, the window  34  can be, but not required, initially aligned with the frac port  38  in the cross-over tool as a “run in” position. 
     The MS sliding sleeve  32  generally includes a window  34  that communicates with other openings, such as the frac port  38  in the cross-over tool  26 , for flow therethrough. Seals to either side of the window  34  assist in restricting undesired flow. 
     A sliding sleeve  42  of the MS sliding sleeve  32  is used to slide over the window  34  to restrict flow from other ports even when the frac port  38  of the cross-over tool is not aligned with the window. The sliding sleeve  42  functions in conjunction with the collet assembly  52 , described below. 
     The PBR  44  can be coupled to the MS sliding sleeve  32 . The PBR  44  has an internal smooth bore that is used as a sealing surface for various portions of the cross-over tool and other tools with seals as the tools move longitudinally in the well. The PBR  44  provides a sealing surface to restrict unintended flow at portions of the well process, such as in conjunction with the cross-over tool  26  that is moved internally thereto. 
     A casing spacer  46  can be coupled to the PBR  44  to allow for appropriate spacing between components. The length and use is known to those with ordinary skill in the art and depends on the relative length of the particular tools in the work string and other known factors. 
     A cross-over reducer  80  can be coupled to the casing spacer  46  to reduce the diameter of the completion assembly and serve as a coupler to a screen  84 . The screen  84  can be coupled to the completion assembly below the cross-over tool  28 . The screen allows production fluids from the formation into the central flow path  15  while restraining the entrance of the proppant and particles from strata, once the cross-over tool is moved and production tubing and seal assembly is positioned for well production. Other assemblies not shown include a lower packer also known as a “sump packer” for restricting fluid flow past the packer. 
     Having described the general assembly and various portions in the tool string  14 A, further attention is directed to the return port cover  90 . 
       FIGS. 2 and 3  are schematic cross sectional views of details of the return port  28 , the return port cover  90 , and surrounding elements.  FIG. 2  is a schematic cross-sectional side view of a return port cover  90  in an at least partially opened position on a return port  28 .  FIG. 3  is a schematic cross-sectional side view a return port cover  90  in an at least partially closed position on the return port  28 .  FIGS. 2 and 3  will be described in conjunction with each other. In general, the work string  14  with a central flow path  15  can be coupled to a setting tool  18 , as described above. The setting tool can be coupled to a packer  20  having a packing element  22 . A cross-over tool  26  can be releasably coupled to the packer  20 , generally near to the top of the packer. The cross-over tool  26  includes a return port  28  for fluid flow therethrough. The return port  28  can be formed as a return port subsection  88  of the cross-over tool  26 . 
     The return port cover  90  is generally mounted external relative to the return port  26  so that external surfaces and/or devices can actuate the cover. For example, the return port cover includes an engagement surface  92 , such as a shoulder in this embodiment, another protrusion or a recess. Other engagement surfaces on the return port cover could be used. The engagement surface  92  can be sized to interact with an engagement surface  94 , such as a shoulder, formed on the packer  20 . The engagement surface  94  is advantageously formed on or otherwise coupled to an uphole portion of the packer  20  to allow the return port cover  90  to be raised and lowered with minimal interference with other tooling in the well bore. Other surfaces could be used on the packer and other downhole members. A bias element  96 , such as a spring, can be used to bias the return port cover. The bias element  96  can be housed in a recess  97  formed in the return port subsection  88 . One or more openings  98 ,  100  can also be formed in the return port cover that can assist in washing out debris. 
     On the portion of the cover that engages the return port, the cover can be formed with a return port cover taper  102 . The taper  102  can engage a corresponding taper  104  formed on the return port area. Thus, as the return port cover  90  covers the return port  28 , the tapers  102  and  104  matingly engage to restrict flow though the return port. The tapers&#39; engagement serves to restrict the travel of the return port cover. In unusual circumstances, a stop  106  formed on the return port subsection can be used to stop the return port cover if the tapers do not engage prior thereto. Similarly, a shoulder  108  formed on the other end of the return port subsection limits the reverse travel of the return port cover  90 . Further, seals could be used as necessary or desired. 
     A slot  110  is formed in the return port cover  90  to further restrict the available travel of the port cover. The slot  110  can work in conjunction with a travel stop  112 , such as a setscrew, bolt, pin, or other device mounted within the slot  110 . 
     The return port cover  90  functions with the engagement surface  94  generally when one or more of the frac packing procedures are being performed. The cross-over tool  26  can be positioned, so that the return port cover  90  being engaged with the engagement surface  94  uncovers and thereby at least partially opens the return port  28  as shown in  FIG. 2 . At other times in the procedures, the cross-over tool  26  can be relocated, for example uphole as shown in  FIG. 3 , so that the return port cover  90  does not engage the engagement surface  94  and the return port cover is allowed to cover and thereby at least partially close the return port  28 . In this embodiment, the return port cover  90  is biased closed over the return port  28  when the return port cover is not engaged with the engagement surface  94 . 
     One advantage of using the engagement surface  94  is that it is located in the packer as one of the most upward engagement surfaces, as in  FIG. 2 . This position generally assures that the port cover is open and flow can occur through port  28  when the tool is in the circulating or frac position. An open port  28  allows monitoring of the frac pressure in the upper annulus during pumping operations, i.e., mini-fracing or fracing with proppant. 
       FIG. 3  shows the tool moved to the reverse position. As surface  92  disengages from surface  94 , the spring  96  at least partially closes the return port cover  90  over port  28  to restrict fluid movement. For example, in the embodiment shown, the flow would be restricted inward toward annular spaces or other flow paths  36   a ,  36   b ,  36   c ,  36   d , and  36   e , outside the screen  36   f , through gravel pack  36   g , back up through flow path  36   h  at the window  34 , and into flow paths  36   i  and  36   j . This flow path is one example of a flow path that can “fluff” the pack, described above. However, the closure of the return port cover  90  with the return port stops or otherwise restricts this flow. 
     Thus, the cross-over tool  26  can be moved away from the engagement surface  94  in the well bore and not interfere with the operation of the return port cover  90 . Further, the return port cover  90  is coupled and controlled in proximity to the return port  28 . Thus, tubing stretch caused by pressures or other downhole conditions on the tubing has little, if any, effect on the ability of the return port cover  90  to at least partially close and open the return port  28 . 
     Returning to  FIG. 1 , the cross-over tool  26  can be “run in” to the well bore in an open position so that the frac port  38  of the cross-over tool  26  is aligned or communicating with the window  34  of the MS sliding sleeve  32 . This alignment allows for subsequent flow through various openings in a “circulating” position to follow the “run in” position. Further, the sliding sleeve  42  of the MS sliding sleeve  32  is open to allow the window to receive flow from the frac port  38 . For simplicity, an initially open position will be described with the understanding that a closed position could be the initial position. 
     The work string  14  with the tool string  14 A coupled thereto is run into the well bore. The packer  20  with the flexible packing element  22  is not “set” in position against the casing wall, so that a clearance is formed between the packing element and the casing  12  through which the packer is longitudinally run. The tool string is placed at an appropriate depth and the packer is set. In one embodiment, the setting tool is pressurized through fluid in the central flow path  15 . The pressure actuates various internal elements to force the packing element  22  radially outward in the annulus  17  to engage the casing  12 . The tools fixedly coupled to the packer  20  are thus also set in position. While the work string with the setting tool  18  and cross-over tool  26  also releases the packer  20  and tools coupled thereto for independent movement, the work string can leave the cross-over tool  26  and various tools in that relative position for the next position, known as a “circulating” or frac position. 
     The return port cover  90  is in a retracted state by engagement of the engagement surface  92  on the port cover with the engagement surface  94  on the packer  20 , described above. Thus, the return port  28  is open to allow flow therethrough. 
     Further, the collet assembly  52  is located in a position that restricts flow through the circulation ports  68 ,  70 . The circulation seal  74  is positioned between the ports  68 ,  70  with the seals  72 ,  76  located to both sides of the seal  74  and the ports, respectively. 
       FIG. 4  is a schematic cross-sectional side view of a portion of a tool string in a “circulation” position. The “circulation” position is similar to the “run in” position. However, the collet assembly  52  can been displaced, so that a flow path is created between the circulation ports  68 ,  70 . The circulation seals  72  and  74  can be moved so that circulation seal  72  is on one side of the ports  68 ,  70  and circulation seal  74  is on the other side of ports  68 ,  70 , allowing flow between the ports, such as from the central flow path  15 . 
     A desired fluid, such as a proppant slurry, can flow through the central flow path  15 , through the annulus  17 , or a combination thereof. In general, the slurry flows downhole through the central flow path  15 , through the frac port  38  of the cross-over tool  26 , through the window  34  of the MS sliding sleeve  32 , into the annulus  17  and down into the area of the screen  84 . The slurry flow is restricted from flowing significantly uphole by the presence of the packing element  22  in the annulus  17 . 
     The liquid portion of the slurry passes from the annulus  17  inwardly through the screen  84  to the flow paths  48   a ,  48   b , through ports  68  and  70 , through flow paths  48   c ,  48   d ,  48   e ,  48   f , port  28 , and into annulus  17 . 
       FIG. 5  is a schematic cross-sectional side view of a portion of a tool string in a “reverse” position. The cross-over tool  26  can be raised and lowered in the well bore independently from the packer, once the packer is set and decoupled from the setting tool  18  and cross-over tool  26 . In the reverse position, the cross-over tool is pulled away from the packer and the flow reversed in the central flow path  15  and annulus  17 . 
     Importantly, the return port cover  90  becomes disengaged with the engagement surface  94  on the packer  20 . In this embodiment, the return port cover is biased closed, so that the cover closes the return port  28  upon disengagement with the packer. Fluid flows in the annulus  17  through frac port  38  and up the central flow path  15  to the surface. The reverse flow assists is washing out extraneous materials above the packer and in the central flow path left during the preceding operations. Sufficient tubing movement, caused by the pressure, temperature, bouyancy, and other downhole conditions on the tubing that leads to stretching can cause unintended opening of the circulating valve means  50  by the collet head  54  and tab  60  engaging surfaces  82 ,  86 , or any other surface engaged by downward movement. This unintentional opening is compensated by the location of the return port cover  90  relative to the return port  28 . The return port cover  90  can be positioned in the tool string, so that as the work string is raised and lowered, the return port cover  90  remains relatively fixed along the tool string with respect to the port  28 . Thus, the return port cover  90  can still open and close the port  28  at the appropriate time, even with tubing movement caused by the extensive length of the work string  14  in the well bore. 
     While the foregoing is directed to various embodiments of the present invention, other and further embodiments can be devised without departing from the basic scope thereof. For example, the present invention can be used with other well treatment operations beside fracturing, including gravel packing, acidizing, water packing, and other treatments. Further, the various methods and embodiments of the invention can be included in combination with each other to produce variations of the disclosed methods and embodiments. Discussion of singular elements can include plural elements and vice-versa. Further, the use of any numeric quantities herein, particularly regarding the claims, such as “a” or “the”, includes at least such quantity and can be more. The use of a term in a singular tense is not limiting of the number of items. Any directions shown or described such as “top,” “bottom,” “left,” “right,” “upper,” “lower,” “down,” “up,” “side,” and other directions and orientations are described herein for clarity in reference to the figures and are not to be limiting of the actual device or system or use of the device or system. The device or system can be used in a number of directions and orientations. 
     The order of steps can occur in a variety of sequences unless otherwise specifically limited. The various steps described herein can be combined with other steps, interlineated with the stated steps, and/or split into multiple steps. Similarly, elements have been described functionally and can be embodied as separate components or can be combined into components having multiple functions. Additionally, any headings herein are for the convenience of the reader and are not intended to limit the scope of the invention. 
     Further, any references mentioned in the application for this patent as well as all references listed in the information disclosure originally filed with the application are hereby incorporated by reference in their entirety to the extent such may be deemed essential to support the enabling of the invention. However, to the extent statements might be considered inconsistent with the patenting of the invention, such statements are expressly not meant to be considered as made by the Applicants.

Technology Classification (CPC): 4