Abstract:
Systems and methods for continuously circulating fluid, e.g., drilling mud, through a wellbore tubular string, the systems in certain aspects including a sub positionable in fluid communication with the tubular string, the sub with a body, a plug releasably closing off a side opening of the body, and a closure apparatus for selectively closing off flow from the top of the sub into and through the body, while flow is permitted below the closure apparatus through the side opening down through the body into the tubular string; and, in certain aspects, such systems and methods including tubular manipulation apparatus, e.g. an iron roughneck and working with wellbore tubulars with the tubular manipulation apparatus. This abstract is provided to comply with the rules requiring an abstract which will allow a searcher or other reader to quickly ascertain the subject matter of the technical disclosure and is submitted with the understanding that it will not be used to interpret or limit the scope or meaning of the claims, 37 CFR 1.72( b ).

Description:
CROSS-REFERENCE TO RELATED INVENTION 
       [0001]    The present invention and application claim the benefits of priority, under the Patent Laws, of U.S. Application Ser. No. 61/011,849 filed Jan. 22, 2008. 
     
    
     BACKGROUND OF THE INVENTION 
       [0002]    1. Field of the Invention 
         [0003]    This invention is directed to wellbore operations with strings of tubulars and, in certain particular aspects, to tubular subs and related systems useful for maintaining continuous circulation during joint make-up and break-out. 
         [0004]    2. Description of Related Art 
         [0005]    There are a variety of known continuous circulation systems; for example, and not by way of limitation, the following U.S. Pat. Nos. and application present exemplary systems and components thereof: 7,350,587; 7,107,875; 6,412,554; 6,315,051; 6,591,916; 3,298,385; 1,491,986; and U.S. application Ser. No. 11/449,662 filed Jun. 9, 2006. 
         [0006]    These are a variety of known wellbore, subs, continuous circulation systems, and related components, including, for example, the disclosures of U.S. Pat. Nos. 2,102,555; 2,158,356; 4,310,050; 4,448,267; 4,646,844; 6,253,861; 6,688,394; 6,739,397; 7,028,787; 7,134,489; and 7,281,582; and U.S. Applications Publication Nos. 2002/0157838 published Oct. 31, 2002; and 2006/0254822 published Nov. 16, 2006—all said patents and said applications incorporated fully herein for all purposes. 
         [0007]    In the drilling industry, e.g. in the field of drilling for oil, natural gas and other hydrocarbons, drill strings are used that include a large number of tubular sections, referred to as “tubulars”, which are connected by male threads on the pin ends and female threads on the box ends. In many operations such tubulars are added to the drill string, one-by-one, or in “stands” of two or three connected tubulars, as the string carrying a drill bit drills into the ground. Often it is necessary to withdraw the drill string, in whole or in part. Again, each tubular or stand is unscrewed, one-by-one, as the drill string is brought up to the extent required. 
         [0008]    With some prior systems, each time that a tubular is added or removed, the drilling process is stopped and the circulation of drilling fluid ceases. Resulting delays in the overall drilling operation are expensive. The circulation of drilling fluids can be extremely critical to maintaining a steady down hole pressure and a steady and near constant equivalent circulating density. Often when tripping a drill string into or out of a well, the lack of continuous circulation of a drilling fluid can cause pressure changes in the well which increase the probability of undesirable “kicks”. The connection of sections of casing in a wellbore present similar problems with circulating fluids. 
         [0009]    Various prior systems have a variety of disadvantages and problems associated with their use; for example, in some prior systems valves internal to a sub are sent down a well where they are susceptible to wear and failure. Many items (e.g. fishing tool, logging equipment, downhole tools, etc.) to be located in a wellbore beneath a sub are limited in diameter to a diameter which will pass through the sub. In certain aspects, a valve seat portion of a sub will have a relatively small diameter which limits the size of items which can be inserted through the sub. 
         [0010]    “Iron roughnecks,” combine a torque wrench and a spinning wrench to connect and disconnect tubulars, e.g. drilling components, e.g. drill pipe, in running a string of tubulars into or out of a well. Prior art iron roughnecks are shown. e.g., in U.S. Pat. Nos. 4,023,449; 4,348,920; 4,765,401; 6,776,070; 7,062,991; 7,188,547; and 7,313,986, all of which are incorporated herein by reference in their entirety. Certain prior art iron roughnecks have a spinning wrench and a torque wrench mounted together on a carriage. For making or breaking threaded connections between two tubulars, e.g. joints of drill pipe, certain iron roughnecks have a torque wrench with two jaw levels. An upper jaw of the torque wrench is used to clamp onto a portion of an upper tubular, and a lower jaw clamps onto a portion of a lower tubular, e.g. upper and lower threadedly connected pieces of drill pipe. After clamping onto a tubular, the upper and lower jaws are turned relative to each other to break or make a connection between the upper and lower tubulars. A spinning wrench, mounted on the carriage above the torque wrench, engages the upper tubular and spins it until it is disconnected from the lower tubular (or in a connection operation, spins two tubulars together prior to final make-up by the torque wrench). 
         [0011]    Certain iron roughnecks are mounted for movement from a wellbore center to a retracted position which does not interfere with or block performance of other operations relative to the well and rotating or driving apparatuses. Such a prior art system can be used for making and breaking joints in a main string or for connecting to or disconnecting from a tubular section located apart from a wellbore center, e.g. in a mousehole (or rathole) at a side of a well. 
         [0012]    Certain prior art iron roughneck systems include a carriage for rolling on the surface of the rig floor along a predetermined path. In certain prior art systems a spinner and torque wrench are mounted for upward and downward movement relative to a carriage, for proper engagement with tubulars, and for tilting movement between a position in which their axis extends directly vertically for engagement with a vertical well pipe and a position in which the axis of the spinner and torque wrench is disposed at a slight angle to true vertical to engage and act against a pipe in an inclined mousehole. In certain prior art systems, a spinner is movable vertically with respect to a torque wrench. 
         [0013]    There are a variety of known torque wrenches and tongs for use in wellbore operations, e.g., but not limited to, as disclosed in and referred to in U.S. Pat. Nos. 3,892,140; 4,221,269; 4,425,827; 4,446,761; 6,684,737; 6,971,283; 5,161,438; 5,159,860; 5,842,390; 5,245,877; 5,259,275; 5,390,568; 4,346,629; 5,044,232; 5,081,888; 5,167,173; 5,207,128; 5,409,280; 5,868,045; 6,966,385; 6,138,529; 4,082,017; 6,082,224; 6,213,216; 6,330,911; 6,668,684; 6,752,044; 6,318,214; and 6,142,041; 6,253,845; and 7,000,502. 
       BRIEF SUMMARY OF THE INVENTION 
       [0014]    The present invention, in various aspects, discloses a system that includes tubular manipulation apparatus (e.g. tong or tongs, tong and back-up, tong and spinner, or iron roughneck) and a continuous circulation apparatus. In certain such systems, a continuous circulation apparatus is mounted below an iron roughneck, and is extendable therewith toward a tubular manipulation apparatus, e.g. toward and away from a tubular or tubular string and/or toward and away from a well center. 
         [0015]    The present invention, in certain aspects, discloses a sub system for use in continuous circulation wellbore operations, the sub system having a sub positionable in fluid communication with a wellbore tubular string, the sub having a body, the body being generally cylindrical and having a first end, a second end, and an exterior surface, the second end connectible to a wellbore tubular string, a bore through the body from the first end to the second end, the bore having an inner boundary defined by an inner surface of the body, the bore positionable for fluid communication with the wellbore tubular string, a side opening in the body, the side opening extending from the exterior surface of the body to the inner surface, and the sub system having closure apparatus including a housing in fluid communication with the side opening of the body of the sub, the closure apparatus including a closure mechanism outside the body, the closure mechanism including a closure member within the housing and selectively insertable into the side opening and removable from the bore of the body, the closure member movable to selectively close off flow from the first end of the body. 
         [0016]    In one aspect, such a system has a plug removably and sealingly secured in the side opening, the plug having a plug body, and the system including a securement mechanism connected to the plug body for releasably securing the plug in the side opening. 
         [0017]    In one aspect, the present invention discloses such a system with plug movement apparatus to which the plug is connected for moving the plug out of the side opening and away from the side opening. 
         [0018]    In another aspect, in such a system a plug movement apparatus includes stinger apparatus movable to connect with the plug and operate the securement mechanism to release the plug from the side opening. 
         [0019]    In one aspect, in such a system the housing of the closure apparatus has an interior space and fluid is flowable through the interior space of the housing into the bore of the body of the sub through an upper end and out through a lower end of the bore of the body so that continuous fluid circulation can be maintained in a wellbore tubular string. 
         [0020]    The present invention discloses, in certain aspects, systems for continuous circulation wellbore operations, the systems including a sub system having a sub positionable in fluid communication with a wellbore tubular string, the sub having: a body, the body being generally cylindrical and having a first end, a second end, and an exterior surface, the second end connectible to a wellbore tubular string; a bore through the body from the first end to the second end, the bore having an inner boundary defined by an inner surface of the body, the bore positionable for fluid communication with the wellbore tubular string; a side opening in the body, the side opening extending from the exterior surface of the body to the inner surface; and the sub system further including closure apparatus including a housing in fluid communication with the side opening of the body of the sub, the closure apparatus including a closure mechanism outside the body, the closure mechanism including a closure member within the housing and selectively insertable into the side opening and removable from the bore of the body, the closure member movable to selectively close off flow from the first end of the body. In certain embodiments, these systems include tubular manipulation apparatus adjacent the sub system, movable therewith, selectively movable therewith, or independently thereof, with the tubular manipulation apparatus being one of tong, tongs, tong and back-up, tong and spinning wrench, and iron roughneck. 
         [0021]    The present invention discloses, in certain aspects, a system for continuous circulation wellbore operations, the system having: a sub system positionable in fluid communication with a wellbore tubular string; the sub system for selectively closing off flow to the wellbore tubular string; and tubular manipulation apparatus adjacent the sub. In certain aspects, the tubular manipulation apparatus is one of tong, tongs, tong and back-up, tong and spinning wrench, and iron roughneck. 
         [0022]    Accordingly, the present invention includes features and advantages which are believed to enable it to advance continuous circulation technology. Characteristics and advantages of the present invention described above and additional features and benefits will be readily apparent to those skilled in the art upon consideration of the following detailed description of preferred embodiments and referring to the accompanying drawings. 
         [0023]    Certain embodiments of this invention are not limited to any particular individual feature disclosed here, but include combinations of them distinguished from the prior art in their structures, functions, and/or results achieved. Features of the invention have been broadly described so that the detailed descriptions that follow may be better understood, and in order that the contributions of this invention to the arts may be better appreciated. There are, of course, additional aspects of the invention described below and which may be included in the subject matter of the claims to this invention. Those skilled in the art who have the benefit of this invention, its teachings, and suggestions will appreciate that the conceptions of this disclosure may be used as a creative basis for designing other structures, methods and systems for carrying out and practicing the present invention. The claims of this invention are to be read to include any legally equivalent devices or methods which do not depart from the spirit and scope of the present invention. 
         [0024]    What follows are some of, but not all, the objects of this invention. In addition to the specific objects stated below for at least certain preferred embodiments of the invention, other objects and purposes will be readily apparent to one of skill in this art who has the benefit of this invention&#39;s teachings and disclosures. It is, therefore, an object of at least certain preferred embodiments of the present invention to provide the embodiments and aspects listed above and: 
         [0025]    New, useful, unique, efficient, non-obvious continuous circulation systems and methods of their use; and, in certain aspects, new, useful, nonobvious and efficient systems for wellbore operations, with a sub that permits continuous circulation of drilling fluid, the system providing selective opening of a sub side opening and selective prevention of fluid flow from the top of the sub to and through the sub, while fluid is flowable from the side of the sub down into a tubular string below the sub; and any such system and method used with tubular manipulation apparatus, e.g. but not limited to, a tong, tongs, a tong and back-up, a tong and a spinner, or an iron roughneck. 
         [0026]    The present invention recognizes and addresses the problems and needs in this area and provides a solution to those problems and a satisfactory meeting of those needs in its various possible embodiments and equivalents thereof. To one of skill in this art who has the benefits of this invention&#39;s realizations, teachings, disclosures, and suggestions, various purposes and advantages will be appreciated from the following description of certain preferred embodiments, given for the purpose of disclosure, when taken in conjunction with the accompanying drawings. The detail in these descriptions is not intended to thwart this patent&#39;s object to claim this invention no matter how others may later attempt to disguise it by variations in form, changes, or additions of further improvements. 
         [0027]    The Abstract that is part hereof is to enable the U.S. Patent and Trademark Office and the public generally, and scientists, engineers, researchers, and practitioners in the art who are not familiar with patent terms or legal terms of phraseology to determine quickly from a cursory inspection or review the nature and general area of the disclosure of this invention. The Abstract is neither intended to define the invention, which is done by the claims, nor is it intended to be limiting of the scope of the invention or of the claims in any way. 
         [0028]    It will be understood that the various embodiments of the present invention may include one, some, or all of the disclosed, described, and/or enumerated improvements and/or technical advantages and/or elements in claims to this invention. 
         [0029]    Certain aspects, certain embodiments, and certain preferable features of the invention are set out herein. Any combination of aspects or features shown in any aspect or embodiment can be used except where such aspects or features are mutually exclusive. 
     
    
     
       BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS 
         [0030]    A more particular description of embodiments of the invention briefly summarized above may be had by references to the embodiments which are shown in the drawings with 
           [0031]      FIG. 1A  is a perspective view of a continuous circulation sub according to the present invention and a continuous circulation system according to the present invention. 
           [0032]      FIG. 1B  is a side cross-section view of a continuous circulation sub and a continuous circulation system of  FIG. 1A . 
           [0033]      FIG. 2A  is a top cross-section view of the continuous circulation sub and a continuous circulation system of  FIG. 1A . 
           [0034]      FIG. 2B  is an enlargement of part of the sub and system as shown in  FIG. 2A . 
           [0035]      FIG. 3A  is a top cross-section view of the continuous circulation sub and a continuous circulation system of  FIG. 1A . 
           [0036]      FIG. 3B  is an enlargement of part of the sub and system as shown in  FIG. 3A . 
           [0037]      FIG. 3C  is a cross-section view of part of the sub of  FIG. 1A . 
           [0038]      FIG. 3D  is a cross-section view of part of the sub of  FIG. 1A . 
           [0039]      FIG. 4A  is a top cross-section view of the continuous circulation sub and a continuous circulation system of  FIG. 1A . 
           [0040]      FIG. 4B  is an enlargement of part of the sub and system as shown in  FIG. 4A . 
           [0041]      FIG. 5  is a side cross-section view of a continuous circulation sub and a continuous circulation system of  FIG. 1A . 
           [0042]      FIG. 6  is a side cross-section view of a continuous circulation sub and a continuous circulation system of  FIG. 1A . 
           [0043]      FIG. 7  is a side cross-section view of a continuous circulation sub and a continuous circulation system of  FIG. 1A . 
           [0044]      FIG. 8  is a side cross-section view of a continuous circulation sub and a continuous circulation system of  FIG. 1A . 
           [0045]      FIG. 9  is a side cross-section view of a continuous circulation sub and a continuous circulation system of  FIG. 1A . 
           [0046]      FIG. 10  is an enlargement of part of the sub and system as shown in  FIG. 9 . 
           [0047]      FIG. 10A  is a cross-section view of the part shown in  FIG. 10  with a seated closure member. 
           [0048]      FIG. 11A  is a side view illustrating a system according to the present invention. 
           [0049]      FIG. 11B  is a side view showing the system of  FIG. 11A  extended. 
           [0050]      FIG. 11C  is a perspective view of the system of  FIG. 11B . 
           [0051]      FIG. 11D  is a perspective view of the system of  FIG. 11B , with an iron roughneck removed. 
           [0052]      FIG. 12A  is a top schematic view of a system according to the present invention in a non-extended “parked” position. 
           [0053]      FIG. 12B  is a top view showing a step in a method using the system of  FIG. 12A . 
           [0054]      FIG. 12C  is a top view showing a step in a method using the system of  FIG. 12A . 
           [0055]      FIG. 12D  is a top view showing a step in a method using the system of  FIG. 12A . 
           [0056]      FIG. 13A  is a perspective view of part of the system as shown in  FIG. 12A . 
           [0057]      FIG. 13B  is a perspective view of part of the system as shown in  FIG. 12A . 
       
    
    
       [0058]    Presently preferred embodiments of the invention are shown in the above-identified figures and described in detail below. Various aspects and features of embodiments of the invention are described below and some are set out in the dependent claims. Any combination of aspects and/or features described below or shown in the dependent claims can be used except where such aspects and/or features are mutually exclusive. It should be understood that the appended drawings and description herein are of preferred embodiments and are not intended to limit the invention or the appended claims. On the contrary, the intention is to cover all modifications, equivalents and alternatives falling within the spirit and scope of the invention as defined by the appended claims. In showing and describing the preferred embodiments, like or identical reference numerals are used to identify common or similar elements. The figures are not necessarily to scale and certain features and certain views of the figures may be shown exaggerated in scale or in schematic in the interest of clarity and conciseness. 
         [0059]    As used herein and throughout all the various portions (and headings) of this patent, the terms “invention”, “present invention” and variations thereof mean one or more embodiment, and are not intended to mean the claimed invention of any particular appended claim(s) or all of the appended claims. Accordingly, the subject or topic of each such reference is not automatically or necessarily part of, or required by, any particular claim(s) merely because of such reference. So long as they are not mutually exclusive or contradictory any aspect or feature or combination of aspects or features of any embodiment disclosed herein may be used in any other embodiment disclosed herein. 
       DETAILED DESCRIPTION OF THE INVENTION 
       [0060]      FIGS. 1A and 1B  show a continuous circulation sub  10  according to the present invention and a continuous circulation system  100  according to the present invention. The continuous circulation sub  10  has a body  12  with a flow bore  14  from top to bottom, a threaded pin end  16 , and a threaded box end  18 . The continuous circulation sub  10  is in a tubular string TS (parts TS 1  and TS 2  shown schematically,  FIG. 1B ; e.g. a string from a rig or platform extending down into the earth). The continuous circulation system  100  has a housing  102 . 
         [0061]    A plug apparatus  20  is removably secured in an opening  13  of the body  12 . When secured in place, the plug apparatus  20  prevents fluid flow through the opening  13  (e.g. see  FIGS. 1B ,  2 B,  3 B). A plug movement device  15  (shown schematically,  FIGS. 1A ,  1 B) selectively activates and moves the plug apparatus  20 . A control system  17  controls the plug apparatus  20  and a closure apparatus  40  (described below). The control system  17 , in certain aspects, is directed to the type of controls used for the system; for example, and not by way of limitation, a control system can include: controls for a manual hydraulic valve system that operates the plug apparatus  20  and the closure apparatus  40 ; an electro-hydraulic control system; and a mechanical control system. In certain aspects the control system can employ linear motion devices (hydraulic, pneumatic, electric) which manipulate a closure apparatus and plug apparatus and other system components. The devices can be functional manually and/or via a computer system. Any such control system can have one or more computers, PLC&#39;s, and/or single board computers. 
         [0062]    As shown in  FIGS. 1B and 2A , the plug movement device  15  moves a stinger structure  19  toward and away from the plug apparatus  20 . The stinger structure  19  has a body  19   a  and a stinger  19   b  with a tip  19   c.    
         [0063]    The plug apparatus  20  has a plug  21  with a concave body portion  21   a  which has no part which projects into the bore  14  (it can be recessed from the inner bore surface of flush with it). Seals  22  (made, e.g., of rubber or of any suitable seal material) seal an opening- 13 /plug-apparatus- 20  interface. An anti-extrusion steel device  23  is on each side of the seals and helps to maintain the seals in place when pressure is applied to them. Fluid pressure pushing on the plug  21  pushes on the steel devices  23  which in turn push on the seals  22  to enhance sealing at the opening/apparatus interface. In one aspect, the outer surface of the plug is flush with the inner surface of the bore (i.e., the curvature of the outer surface of the plug matches the curvature of inner surface of the bore). 
         [0064]    Two spaced-apart locking dogs  24  are movable into and out of corresponding side opening recesses  13   a . With the dogs  24  within the recesses  13   a , the plug apparatus  20  is secured in place. Retracting the dogs  24  from the recesses  13   a  with a dog movement device  25  releases the plug apparatus  20  so it can be removed from the opening  13  (as in  FIGS. 4A ,  4 B,  5 ). 
         [0065]    The plug  21  has an outer part  21   o  and a bore piece  21   b  with a bore  21   r  through which the stinger  19   b  can pass. Lock pins  21   c  hold the parts of the plug together. 
         [0066]    The closure apparatus  40  has a closure structure  42  described in detail below. 
         [0067]    As shown in  FIGS. 4A and 4B , the stinger structure  19  has moved so that the stinger  19   b  with tip  19   c  has activated the dog movement device  25 , retracting the dogs  24  from the recesses  13   a . The stinger structure  19  is movable with respect to the plug apparatus  20 . With the plug apparatus  20  freed from the body  12  of the continuous circulation sub  10 , the plug movement device  15  can remove the plug apparatus  20  from the opening  13  as shown in  FIG. 5 . 
         [0068]    As shown in  FIG. 6  the plug apparatus  20  is rotated away from the opening  13  by the plug movement device  15  and as shown in  FIG. 7  the plug apparatus  20  has been rotated out of the way of the opening  13 , e.g. about ninety degrees from its position in  FIG. 5 , and has been retracted so that a portion thereof is in a chamber  102   a  of the housing  102  of the continuous circulation system  100 . Upon removal of the plug apparatus  20  from the opening  13  (e.g. see  FIG. 5 ), fluid is flowable through the opening  13  into the bore  14  of the body  12  of the continuous circulation sub  10 . 
         [0069]    The opening  13  provides access to the bore  14  so that the closure structure  42  can be moved into position to close off flow through the bore  14 . As shown in  FIG. 8 , the closure apparatus  40  has been activated and has moved a shaft  41  (an extendable shaft, e.g., a telescoping shaft or other extendable shaft) toward the opening  13  so that the closure structure  42  is passing through the opening  13 . A piston  43  of a piston/cylinder assembly  44  is retracted to effect this movement of the shaft  41 . The shaft  41  moves in a bore  44   a  of a body  44 . The bore  44   a  is in communication with the interior of the housing  102 . The shaft- 41 /body- 44  interface is sealed with seals  45  and an end  44   e  of the body  44  is sealing secured in an opening  102   b  of the housing  102 . An end  41   e  of the shaft  41  is secured to a pivot member  46  which is pivotably connected to an end  44   g  of the piston/cylinder assembly  44 . Another end  44   f  of the piston/cylinder assembly  44  is pivotably connected to the housing  102 . The closure structure  42  is rotatably mounted to the shaft  41  with a pin  47 . A rotation mechanism  49 , shown schematically in  FIG. 1B , rotates the closure apparatus  42  by rotating a shaft  42   s  of the closure apparatus  42 . 
         [0070]    As shown in  FIG. 9 , the closure apparatus  42  has been rotated to seat against a shoulder  12   s  of the body  12  of the continuous circulation sub  10 . 
         [0071]    It is within the scope of the present invention for the shaft  41  (and its parts or pieces) to be solid so that no fluid flow through the shaft  41  is possible. Optionally, the shaft  41  has a bore  41   r  therethrough from one end to the other; with a top end opening  41   t  and, via a port  46   p  in the pivot member  46  and a line  51 , is in fluid communication with a reservoir system  50  or rig mud system (e.g., like the system ARS,  FIG. 1A ). Valve apparatus  52  selectively controls flow in the line  51 . Any suitable control system, including, but not limited to the control system  17 , can control the valve apparatus  52 . Any fluid, e.g. drilling fluid, that enters the top of the continuous circulation sub  10  is vented to the reservoir  50 . 
         [0072]    Any suitable seal or seal structure may be used to seal the closure apparatus  42  against the shoulder  12   s  of the body  12  of the continuous circulation sub  10 . Optionally, as shown in  FIGS. 9 and 10 , a pressure energized seal apparatus  54  may be used which includes a seal member  56  (made, e.g. of rubber or of any suitable seal material) on top of which is a hard member  57  (e.g. made of metal, steel, hard plastic, composite, etc.). Fluid pressure on the hard member  57  pressurizes and thereby energizes the seal member  56 . The snap ring  59  maintains the member  57  and the seal member  57  in place. optionally, as shown in  FIG. 10A , a closure member such as a plug, seal, or valve member  60  may be located to seal against a seal seat  62  of the body  12  of the sub  10  so that two barriers are provided within the body  12 . The member  60  can be inserted from above or through the side opening. 
         [0073]    For continuous circulation of fluid down a wellbore WB ( FIG. 1B , shown schematically), e.g. when it is desired to add a new piece or stand of pipe above the sub  10 , the plug  21  is removed from the opening  13  and then (with the plug  21  moved out of the way and the closure apparatus  42  positioned as shown in  FIG. 9 ) fluid is pumped from an active rig mud system ARS ( FIG. 1A ; shown schematically) into the housing  102  of the system  100  via a channel  11   a , through the opening  13  and downhole in the wellbore WB, thus providing continuous circulation. 
         [0074]    It is within the scope of the present invention, among other things, to use a system according to the present invention (e.g. like the system  100 ) in combination with a sub according to the present invention (e.g. like the sub  10 ) with a tong (“tong” including tongs and spinners), with tongs, or with an iron roughneck. In one aspect a system according to the present invention has an independent support and an independent movement apparatus for moving the system with respect to a tubular or a tubular string, and with respect to a tong, tongs, or an iron roughneck. In other aspects, a system according to the present invention is supported from the same support or frame that supports a tong, tongs, or an iron roughneck and an extension apparatus connected to the support or frame moves the system according to the present invention with the iron roughneck, or independently with respect thereto. 
         [0075]    A system  200  according to the present invention shown in  FIGS. 11A and 11B  has, shown schematically, a tubular manipulation apparatus  202  (which may be any such apparatus, including, but not limited to, a tong, tongs, a tong and a back-up tong, a tong and a spinning wrench or spinner, or an iron roughneck) which, in one particular aspect, is an iron roughneck (any suitable known iron roughneck system or apparatus) with an extension apparatus  204  (shown schematically,  FIG. 11B ) for extending and retracting the apparatus  202  with respect to a support frame  206 . 
         [0076]    A system  100   a  according to the present invention (like any system described herein according to the present invention including, but not limited to, the system  100 ) is connected to an extension apparatus  210  for extending and retracting the system  100   a  with respect to the frame  206 . Conduit apparatus  220  is in communication with the system  100   a  and with an active rig mud system (e.g. like the system ARS,  FIG. 1A ). 
         [0077]    A sub  10   a  (e.g. like the sub  10  described above) is used with the system  200 . The sub  10   a  is connected to a string SG extending down into a wellbore. 
         [0078]    As shown in  FIGS. 11B and 11C , the iron roughneck  202  and the system  100   a  have been moved toward and then adjacent the sub  10   a . The system  100   a  is operatively coupled to the iron roughneck  202  which is positioned to operate on a tubular above the sub  10   a . The iron roughneck  202  can move with or independent of the system  100   a.    
         [0079]      FIGS. 12A-12D  show various steps in the extension of a system  100   b  (like the system  100   a  or the system  100 ). An extension apparatus  230 , connected to a support frame  228 , has a back arm  232  pivotably connected at one end to the frame  228  and at the other end to a front arm  236 . The front arm  236  is pivotably connected to the system  100   b . A conduit apparatus  250  connects the system  100   b  to a mud system. The support frame  228 , like the frame  206 , can support the system  100   b  and an iron roughneck, or tong(s) and spinner(s). The system  100   b  may be moved by a separate movement system  100   c  (shown schematically,  FIG. 12A ) or it can be selectively connected to an iron roughneck and move as the iron roughneck moves. With a latch  238  engaged, described below, the arm  232  cannot move and the arm  236  can move. 
         [0080]    A latch  238 , held in a latch engaged position with a latch member  238   m  on the frame  228  by the force of a spring  234 , prevents the back arm  232  from moving when the system is in a “parked” position. The latch  238  has one end pivotably connected to the back arm  232  and another end pivotably connected to a linakge member  240  which is connected to the arm  236 . The spring  234  is in the linkage member  240 . Until the arm  236  is moved, while the latch  238  is engaged, the arm  232  is prevented from moving and the spring  234  urges an end rod  240   a  toward the latch  238 . 
         [0081]    As shown in  FIG. 12C , the latch has been disengaged and the system  100   b  has begun its movement toward a well enter. Continued travel of the system  100   b  is shown in  FIG. 12C . 
         [0082]      FIG. 12D  shows the extension apparatus  230  fully extended and the system  100   b  at well center engaged with a sub lob (like the sub 10 a ; like the sub  10 ). 
         [0083]    Via a selective connection apparatus  100   d  shown schematically in  FIG. 12A ), the system  100   b  is selectively connected to an iron roughneck positioned above the system  100   b  (e.g., like the iron roughneck  202 ,  FIG. 11A . Any suitable connection or connections can be used between the system  100   b  and the iron roughneck, e.g., but not limited to, a latch or latches; selectively projecting pins and/or pistons which project from one of the system  100   b  and the iron roughneck to corresponding holes and/or recesses in the other; magnetic apparatuses; a roller or rollers on one of the items and selectively move into corresponding slots on the other item; and/or releasably cooperating fastener material. 
         [0084]      FIGS. 13A and 13B  illustrate operation of the latch  238 . The spring  234  applies latching pressure to maintain the latch in a closed, engaged “parked” position (as in  FIGS. 12A and 13B ). As shown in  FIG. 13A  (and  FIG. 12B ), with the latch disengaged, the arm  232  can move. 
         [0085]    The conduit apparatus  250  extends and retracts with the system  100   b . The conduit apparatus  250  includes sealed, pivotably connected conduits  252 ,  254  and flow line  256  in fluid communication with a mud system. 
         [0086]    The present invention, therefore, provides in some, but not in necessarily all, embodiments a system for continuous circulation wellbore operations, the system including a sub system having a sub positionable in fluid communication with a wellbore tubular string, the sub having: a body, the body being generally cylindrical and having a first end, a second end, and an exterior surface, the second end connectible to a wellbore tubular string; a bore through the body from the first end to the second end, the bore having an inner boundary defined by an inner surface of the body, the bore positionable for fluid communication with the wellbore tubular string; a side opening in the body, the side opening extending from the exterior surface of the body to the inner surface; and the sub system further including closure apparatus including a housing in fluid communication with the side opening of the body of the sub, the closure apparatus including a closure mechanism outside the body, the closure mechanism including a closure member within the housing and selectively insertable into the side opening and removable from the bore of the body, the closure member movable to selectively close off flow from the first end of the body. Such a system may one or some, in any possible combination, of the following: tubular manipulation apparatus adjacent the sub system; wherein the tubular manipulation apparatus is one of tong, tongs, tong and back-up, tong and spinning wrench, and iron roughneck; wherein the sub system is selectively movable with the tubular manipulation apparatus; the sub further having a plug removably and sealingly secured in the side opening, the plug having a plug body, and a securement mechanism connected to the plug body for releasably securing the plug in the side opening; plug movement apparatus to which the plug is connected for moving the plug out of the side opening; the plug movement apparatus including stinger apparatus movable to connect with the plug and operate the securement mechanism to release the plug from the side opening; the sub further having two spaced-apart side opening recesses in communication with the side opening, and the securement mechanism including one or two dogs, the or each of the dogs selectively movable into and out of one of the two spaced-apart side opening recesses; wherein the inner surface of the body of the sub is curved and the plug has an outer curved surface, the outer surface of the plug substantially flush with the inner surface of the body; wherein the housing of the closure apparatus has an interior space and wherein fluid is flowable through the interior space of the housing into the bore of the body of the sub and out through the second end of the bore of the body so that continuous fluid circulation can be maintained in the wellbore tubular string; the closure apparatus including an extendable shaft, the extendable shaft extendable to position the closure member with respect to the bore of the body, the extendable shaft having a shaft channel therethrough, the closure member at an end of the extendable shaft, the closure member having a member channel therethrough, the member channel in fluid communication with the shaft channel so that with the closure member blocking fluid flow down to the second end of the sub fluid is flowable from the first end of the sub to and through the member channel of the closure member and then to and through the shaft channel; and/or wherein the fluid is drilling mud being pumped into the sub and flowing down through the first end of the body, and the shaft channel is in fluid communication with a rig mud system so that the drilling mud flowing out through the shaft channel flows to the rig mud system. 
         [0087]    The present invention, therefore, provides in some, but not in necessarily all, embodiments a system for use in continuous circulation wellbore operations, the system including a sub system having a sub positionable in fluid communication with a wellbore tubular string, the sub having: a body, the body being generally cylindrical and having a first end, a second end, and an exterior surface, the second end connectible to a wellbore tubular string; a bore through the body from the first end to the second end, the bore having an inner boundary defined by an inner surface of the body, the bore positionable for fluid communication with the wellbore tubular string; a side opening in the body, the side opening extending from the exterior surface of the body to the inner surface; and the sub system further including closure apparatus including a housing in fluid communication with the side opening of the body of the sub, the closure apparatus including a closure mechanism outside the body, the closure mechanism including a closure member within the housing and selectively insertable into the side opening and removable from the bore of the body, the closure member movable to selectively close off flow from the first end of the body; plug apparatus having a plug body removably and sealingly secured in the side opening; a securement mechanism connected to the plug body for releasably securing the plug in the side opening; plug movement apparatus to which the plug is connected for moving the plug out of the side opening; the plug movement apparatus including stinger apparatus movable to connect with the plug and operate the securement mechanism to release the plug from the side opening; the housing of the closure apparatus having an interior space and wherein fluid is flowable through the interior space of the housing into the bore of the body of the sub and out through the second end of the bore of the body so that continuous fluid circulation can be maintained in the wellbore tubular string; the closure apparatus including an extendable shaft, the extendable shaft extendable to position the closure member with respect to the bore of the body, the extendable shaft having a shaft channel therethrough; the closure member at an end of the extendable shaft, the closure member having a member channel therethrough, the member channel in fluid communication with the shaft channel so that with the closure member blocking fluid flow down to the second end of the sub fluid is flowable from the first end of the sub to and through the member channel of the closure member and then to and through the shaft channel; wherein the fluid is drilling mud being pumped into the sub and flowing down through the first end of the body; the shaft channel is in fluid communication with a rig mud system so that the drilling mud flowing out through the shaft channel flows to the rig mud system; and tubular manipulation apparatus adjacent the sub system. In such a system, the tubular manipulation apparatus may be one of tong, tongs, tong and back-up, tong and spinning wrench, and iron roughneck. 
         [0088]    The present invention, therefore, provides in some, but not in necessarily all, embodiments a system for continuous circulation wellbore operations, the system having: a sub system positionable in fluid communication with a wellbore tubular string; the sub system for selectively closing off flow to the wellbore tubular string; tubular manipulation apparatus adjacent the sub; and the tubular manipulation apparatus having one of tong, tongs, tong and back-up, tong and spinning wrench, and iron roughneck. 
         [0089]    In conclusion, therefore, it is seen that the present invention and the embodiments disclosed herein and those covered by the appended claims are well adapted to carry out the objectives and obtain the ends set forth. Certain changes can be made in the subject matter without departing from the spirit and the scope of this invention. It is realized that changes are possible within the scope of this invention and it is further intended that each element or step recited in any of the following claims is to be understood as referring to the step literally and/or to all equivalent elements or steps. The following claims are intended to cover the invention as broadly as legally possible in whatever form it may be utilized. The invention claimed herein is new and novel in accordance with 35 U.S.C. § 102 and satisfies the conditions for patentability in § 102. The invention claimed herein is not obvious in accordance with 35 U.S.C. § 103 and satisfies the conditions for patentability in § 103. This specification and the claims that follow are in accordance with all of the requirements of 35 U.S.C. § 112. The inventors may rely on the Doctrine of Equivalents to determine and assess the scope of their invention and of the claims that follow as they may pertain to apparatus not materially departing from, but outside of, the literal scope of the invention as set forth in the following claims. All patents and applications identified herein are incorporated fully herein for all purposes. It is the express intention of the applicant not to invoke 35 U.S.C. § 112, paragraph 6 for any limitations of any of the claims herein, except for those in which the claim expressly uses the words ‘means for’ together with an associated function. In this patent document, the word “comprising” is used in its non-limiting sense to mean that items following the word are included, but items not specifically mentioned are not excluded. A reference to an element by the indefinite article “a” does not exclude the possibility that more than one of the element is present, unless the context clearly requires that there be one and only one of the elements.