Abstract:
The present invention provides a rapid rig-up and rig-down pipe stand building and racking system that is capable of being retrofit to an existing drilling rig. In particular, the invention relates to a horizontal to vertical pipe delivery machine that is mountable to a drilling rig. The horizontal to vertical machine delivers sections of pipe to a pair of drilling rig mounted elevators. The elevators receive and vertically translate the sections of pipe. A power tong may be used to make connections between the sections of pipe to form a pipe stand, and may also break the connections of the pipe stand. A drill floor mounted pipe racking system receives the connected drill pipe from the elevators. A pipe racking system that may be used in conjunction with the stand building system is capable of controlled, rapid, and precise movement of multiple connected sections of pipe.

Description:
TECHNICAL FIELD OF INVENTION 
       [0001]    The present invention relates to a new apparatus and method for use in subterranean exploration. The present invention provides a rapid rig-up and rig-down pipe stand building system that is capable of being retrofit to an existing drilling rig. In particular, the invention relates to a drilling rig mountable horizontal to vertical pipe delivery machine. The pipe delivery machine delivers pipe to a pair of drilling rig mounted elevators. A drill floor mounted pipe racking system receives the drill pipe from the elevators. The pipe racking system is capable of controlled, rapid, and precise movement of multiple connected sections of pipe. The elevator system is mounted in between for make-up of the single pipe joints into a pipe stand. 
       BACKGROUND OF THE INVENTION 
       [0002]    In the exploration of oil, gas and geothermal energy, drilling operations are used to create boreholes, or wells, in the earth. Subterranean drilling necessarily involves the movement of long lengths of tubular sections of pipe. At various intervals in the drilling operation, all of the drill pipe must be removed from the wellbore. This most commonly occurs when a drill bit wears out, requiring a new drill bit to be located at the end of the drill string. It can also be necessary to reconfigure the bottom-hole assembly or replace other downhole equipment that has otherwise failed. When the drill pipe has to be removed, it is disconnected at every second or third connection, depending on the height of the mast. On smaller drilling rigs used in shallower drilling, every other connection is disconnected, and two lengths of drill pipe, known as “doubles,” are lifted off of the drill string, aligned in the fingers of the rack by the derrickman, and then lowered onto the drill floor away from the well center. On larger drilling rigs used for deeper drilling, every third connection is disconnected and three lengths of drill pipe, known as “triples,” are lifted off of the drill string, aligned in the fingers of the rack by the derrickman, and then lowered onto the drill floor away from the well center. The doubles and triples are called a stand of pipe. The stands are stored vertically on the rig floor, aligned neatly between the fingers of the rack on the mast. 
         [0003]    Removing all of the drill pipe from the well and then reconnecting it to run back into the well is known as “tripping the pipe” or “making a trip,” since the drill bit is making a round trip from the bottom of the hole to the surface and then back to the bottom of the hole. Tripping the drill pipe is a very expensive and dangerous operation for a drilling rig. Most injuries that occur on a drilling rig are related to tripping the pipe. Additionally, the wellbore is making no progress while the pipe is being tripped, so it is downtime that is undesirable. This is why quality drill bits are critical to a successful drill bit operation. Drill bits that fail prematurely can add significant cost to a drilling operation. Since tripping pipe is “non-drilling time,” it is desirable to complete the trip as quickly as possible. Most crews are expected to move the pipe as quickly as possible. The pipe stands are long and thin (about ninety feet long). 
         [0004]    There are a number of variables that contribute to irregular and hostile movement of the pipe stand as it is disconnected and moved to the rack for setting on the drill floor, as well as when it is being picked up for alignment over the wellbore center for stabbing and connection to the drill string in the wellbore. For example, the vertical alignment and travel of the elevator and hoist connection which lift the drill string from the wellbore is cable connected, and capable of lateral movement which is translated to the drill string rising from the wellbore. Also, the drill string is supported from the top, and as the derrickman moves the drill string laterally, the accelerated lateral movement of the long length of the pipe stand away from the well center generates a wave form movement in the pipe itself. As a result of the natural and hostile movement of the heavy drill stand, which typically weighs between 1,500 and 2,000 pounds, and drill collars which weigh up to 20,000 pounds, it is necessary for the crew members to stabilize the drill pipe manually by physically wrestling the pipe into position. The activity also requires experienced and coordinated movement between the driller operating the drawworks and the derrickman and floorhands. Needless to say, many things can and do go wrong in this process, which is why tripping pipe and pipe racking is a primary safety issue in a drilling operation. 
         [0005]    Attempts have been made to mechanize all or part of the pipe racking operation. On offshore platforms, where funding is justifiable and where drill floor space is available, large Cartesian racking systems have been employed, in which the pipe stands are gripped at upper and lower positions to add stabilization, and tracked modules at the top and bottom of the pipe stand coordinate the movement of the pipe stand from the wellbore center to a racked position. Such systems are very large and very expensive, and are not suitable for use on a traditional land-based drilling rig. 
         [0006]    A previous attempt to mechanize pipe racking on conventional land-based drilling rigs is known as the Iron Derrickman® pipe-handling system. The apparatus is attached high in the mast, at the rack board, and relies on a system of hydraulics to lift and move stands of drill pipe and collars from the hole center to programmed coordinates in the racking board. This cantilever mast mounted system has a relatively low vertical load limit, and therefore requires assistance of the top drive when handling larger diameter collars and heavy weight collars. 
         [0007]    The movement of the pipe with this system is somewhat unpredictable and requires significant experience to control. It grasps the pipe from above the center of gravity of the tubular and fails to control the hostile movement of the pipe stand sufficiently to allow for safe handling of the stands or for timely movement without the intervention of drilling crew members. In particular, the system is not capable of aligning the lower free end of the drill stand accurately for stabbing into the drill string in the wellbore. As a result of these and other deficiencies, the system has had limited acceptance in the drilling industry. 
         [0008]    An alternative system that is known provides vertical lifting capacity from the top drive and a lateral movement only guidance system located near the rack. The system still requires a floorman for stabbing the pipe to the stump as well as to the set-back position. 
         [0009]    A primary difficulty in mechanizing pipe stand racking is the hostile movement of the pipe that is generated by stored energy in the stand, misaligned vertical movement, and the lateral acceleration and resultant bending and oscillation of the pipe, which combine to generate hostile and often unpredictable movements of the pipe, making it hard to position, and extremely difficult to stab. 
         [0010]    A conflicting difficulty in mechanizing pipe stand racking is the need to move the pipe with sufficient rapidity so that cost savings are obtained over the cost of manual manipulation by an experienced drilling crew. The greater accelerations required for rapid movement store greater amounts of energy in the pipe stand, and greater attenuated movement of the stand. 
         [0011]    Another primary obstacle in mechanizing pipe stand racking is the prediction and controlled management of the pipe stand movement sufficient to permit the precise alignment required for stabbing the pipe to a first target location on the drill floor and to a second target location within the fingers of the racking board. 
         [0012]    An even greater obstacle in mechanizing pipe stand racking is the prediction and controlled management of the pipe stand movement sufficient to achieve the precise alignment required for stabbing the tool joint of the tubular held by the racking mechanism into the receiving tubular tool joint connection extending above the wellbore and drill floor. 
         [0013]    Another obstacle to land-based mechanizing pipe stand racking is the lack of drilling floor space to accommodate a railed system like those that can be used on large offshore drilling rigs. 
         [0014]    Another obstacle to mechanizing pipe stand racking is the several structural constraints that are presented by the thousands of existing conventional drilling rigs, where the need to retrofit is constrained to available space and structure. For example, existing structures require orthogonal movement of the drill stand over a significant distance and along narrow pathways for movement. 
         [0015]    Another obstacle to mechanizing pipe stand racking is the need to provide a reliable mechanized solution that is also affordable for retrofit to a conventional drilling rig. Still another obstacle to mechanizing pipe stand racking is the need to grip and lift pipe stands within the narrow confines of parallel rows of pipe stands in a conventional rack. 
         [0016]    It is also desirable to minimize accessory structure and equipment, particularly structure and equipment that may interfere with transportation or with manpower movement and access to the rig floor during drilling operations. It is further desirable to ergonomically limit the manpower interactions with rig components during rig-up for cost, safety and convenience. 
         [0017]    Thus, technological and economic barriers have prevented the development of a pipe racking system capable of achieving these goals. Conventional prior art drilling rig configurations remain manpower and equipment intensive to trip pipe and rack pipe when tripping. Alternative designs have failed to meet the economic and reliability requirements necessary to achieve commercial application. In particular, prior art designs fail to control the natural attenuation of the pipe and fail to position the pipe with sufficient rapidity and accuracy. 
         [0018]    A goal of the present invention is to achieve rapid and accurate unmanned movement of the pipe between the racked position and the over-well position. Thus, the racker of the present invention must avoid storage of energy within the positioning structure. True verticality is critical to limiting the energy storage of the system. Additionally, controlled movement and positional holding of the stand is critical to allowing rapid movement by adding the stiffness to the system. 
         [0019]    In summary, the various embodiments of the present invention provide a unique solution to the problems arising from a series of overlapping design constraints, including limited drill floor space, and obtaining sufficient stiffness from a retrofittable assembly to provide a controlled and precise automated movement and racking of drill pipe. More specifically, the various embodiments of the present invention provide for lateral movement of the pipe stand independent of assistance from the top drive, and without extension and retraction of the top drive for handing the pipe stand to the racking system. This provides free time for the top drive to move with the racker system in positioning the pipe without assistance from the top drive. Additionally, the various embodiments of the present invention provide a device capable of precise and accurate stabbing of the drill stand, resulting in faster trip time. 
       SUMMARY OF THE INVENTION 
       [0020]    The present invention provides a new and novel pipe stand building and racking system and method of use. In one embodiment, a horizontal to vertical machine is provided. The horizontal to vertical machine is mountable to a conventional drilling rig. The horizontal to vertical machine has a gripper for gripping the exterior of a tubular (such as drill pipe). The horizontal to vertical machine is capable of grasping and raising a tubular from a horizontal position near the ground to a vertical position proximate to the edge of the drilling floor. 
         [0021]    A lower elevator is mounted to the drilling rig for receiving a tubular in a vertical orientation from the horizontal to vertical machine. The lower elevator may be pivotally connected to the drilling rig so that it may be attached in a horizontal position prior to raising the substructure. The lower elevator has at least one gripper that is vertically translatable along the length of the lower elevator. The gripper is capable of clamping onto the exterior of a drilling tubular and supporting the load of the tubular. 
         [0022]    An automatic pipe racker is provided, having a base frame connectable to a drill floor of a drill rig and extending upwards at a position offset to a V-door side of a drilling mast that is also connected to the drill floor. In one embodiment, the base frame is a C-frame design. A mast brace may be connected between the base frame and the drilling mast at a position distal to the drill floor for stabilizing an upper end of the base frame in relationship to the mast. In one embodiment, the mast brace is adjustable for tilting the automatic pipe racker slightly towards the mast. A tensioner may be connected between the base frame and the drilling floor for stabilizing the base frame in relationship to the substructure. 
         [0023]    The automatic pipe racker is capable of moving stands of pipe between the racked position and the over-well position. 
         [0024]    In one embodiment, a lateral extend mechanism is pivotally connectable to the base frame. The lateral extend mechanism is extendable between a retracted position and a deployed position. A rotate mechanism is connected to the lateral extend mechanism and is rotatable in each of the left and right directions. A finger extend mechanism is connected to the rotate mechanism. The finger extend mechanism is laterally extendable between a retracted position and a deployed position. 
         [0025]    A vertical grip and stab mechanism is attached to the finger extend mechanism. The gripping mechanism has grippers to hold a tubular or stand of pipe and is capable of moving the pipe vertically to facilitate stabbing. The lateral extend mechanism is deployable to move the rotating finger extend and gripping mechanisms between a position beneath a racking board cantilevered from the mast and a position substantially beneath the mast. 
         [0026]    In another embodiment, movement of the lateral extend mechanism between the retracted position and the deployed position moves the rotate mechanism along a substantially linear path. In a more preferred embodiment, movement of the lateral extend mechanism between the retracted position and the deployed position moves the rotate mechanism along a substantially horizontal path. 
         [0027]    The rotate mechanism is rotatable in each of a left and right direction. In a more preferred embodiment, the rotate mechanism is rotatable in each of a left and right direction by at least ninety degrees. In another preferred embodiment, the pipe stand gripping mechanism is vertically translatable to vertically raise and lower the load of a stand of pipe. 
         [0028]    In another embodiment, the automatic pipe racking system is series nesting. In this embodiment, the finger extend and grip and stab mechanisms are substantially retractable into the rotate mechanism, which is substantially retractable into the pivot frame of the lateral extend mechanism, which is substantially retractable into the base frame. 
         [0029]    An upper elevator is pivotally connected to the base frame for receiving a tubular in a vertical orientation from a lower elevator. The upper elevator has an upper gripper and a lower gripper. The upper gripper is vertically translatable along the length of the upper elevator. The upper and lower grippers are both capable of clamping onto the exterior of a drilling tubular and supporting the load of the tubular. 
         [0030]    A stand building power tong is provided for rotating tubular to be connected between the upper elevator and the lower elevator. 
         [0031]    In operation, the horizontal to vertical machine grips a first tubular, such as a section of drill pipe, and raises it from a horizontal position near the ground to a vertical position proximate to the drill floor. The lower elevator receives the first tubular from the horizontal to vertical machine. The lower elevator raises the first tubular vertically, where the upper elevator grips and vertically raises the first tubular. 
         [0032]    The horizontal to vertical machine grips a second tubular and raises it from a horizontal position near the ground to a vertical position proximate to the drill floor. The lower elevator receives the second tubular from the horizontal to vertical machine. The lower elevator raises the second tubular vertically, until the female connection of the second tubular engages the male connection of the first tubular. The stand building power tong rotates the one of the tubular in relation to the other to make-up the threaded connection between them. The upper elevator then grips and vertically raises the connected first and second tubulars. 
         [0033]    The horizontal to vertical machine then grips a third tubular and raises it from a horizontal position near the ground to a vertical position proximate to the drill floor. The lower elevator receives the third tubular from the horizontal to vertical machine. The lower elevator raises the third tubular vertically, until the female connection of the third tubular engages the male connection of the second tubular. The stand building power tong rotates the one of the tubular in relation to the other to make-up the threaded connection between them. The upper elevator then grips and vertically raises the connected first, second and third tubulars (referred to as the pipe “stand”) to a position below the racking board. 
         [0034]    The automatic pipe racker receives the connected pipe stand from the upper elevator, wherein the upper elevator releases the connected pipe stand. In one embodiment, the upper elevator may then be rotated with respect to the base frame of the automatic pipe racker such that the upper elevator is no longer in the way. 
         [0035]    In another embodiment, the automatic pipe racker then tilts the connected pipe stand inside the racking board. The automatic pipe racker may be tilted by actuating linearly adjustable mast braces connected to the drilling mast. The automatic pipe racker is then used to locate the pipe stand in the racking boards, and to move the pipe stand between the racking board and the well. 
         [0036]    As will be understood by one of ordinary skill in the art, the sequence of the steps disclosed may be modified and the same advantageous result obtained. For example, the wings may be deployed before connecting the lower mast section to the drill floor (or drill floor framework). 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0037]    The objects and features of the invention will become more readily understood from the following detailed description and appended claims when read in conjunction with the accompanying drawings in which like numerals represent like elements. 
           [0038]    The drawings constitute a part of this specification and include exemplary embodiments to the invention, which may be embodied in various forms. It is to be understood that in some instances various aspects of the invention may be shown exaggerated or enlarged to facilitate an understanding of the invention. 
           [0039]      FIG. 1  is an isometric view of a drilling rig fitted with an automatic pipe racking system having features in accordance with embodiments of the present invention. 
           [0040]      FIG. 2  is an isometric view of the racking mechanism illustrating the mechanism fully retracted within the base frame. 
           [0041]      FIG. 3  is an isometric view of the racking mechanism illustrating the lateral extend mechanism partially deployed. 
           [0042]      FIG. 4  is an isometric view of the racking mechanism illustrating the lateral extend mechanism partially deployed, and further illustrating the rotate mechanism rotated 90 (ninety) degrees, and the finger extend mechanism partially deployed, such as in position to receive or to set back a stand of drill pipe in a racking board. 
           [0043]      FIG. 5  is an isometric view of the base frame of the racking mechanism illustrating the base frame in isolation of the remaining components of the racking mechanism and of the drilling rig. 
           [0044]      FIG. 6  is an isometric view of the lateral extend mechanism of the racking mechanism illustrating the lateral extend mechanism in isolation of the remaining components of the racking mechanism and of the drilling rig. 
           [0045]      FIG. 7  is an isometric view of the pivot frame illustrated in isolation of the remaining components of the racking mechanism and of the drilling rig. 
           [0046]      FIG. 8  is an isometric view of the rotate mechanism, finger extend mechanism and vertical grip and stab mechanism of the racking mechanism. 
           [0047]      FIG. 9  is a top view of the rotate mechanism illustrating the rotate mechanism in the non-rotated position, and having the finger extend and gripping mechanisms retracted. 
           [0048]      FIG. 10  is a top view of the rotate mechanism illustrating the rotate mechanism rotated 90 (ninety) degrees, and having the finger extend and gripping mechanisms retracted. 
           [0049]      FIG. 11  is an isometric view of the finger extend mechanism and vertical grip and stab mechanism of the racking mechanism. 
           [0050]      FIGS. 12 through 22  are top views illustrating operation of the automatic pipe racker and illustrating the automatic pipe racker moving from a fully retracted position, to retrieve a stand of pipe (or other tubular) from the pipe rack, to an extended position and delivering the pipe stand into alignment for vertical stabbing into the stump over the wellbore. 
           [0051]      FIG. 23  is a side view of the automatic pipe racking mechanism in the position illustrated in the top view of  FIG. 13 . 
           [0052]      FIG. 24  is a side view of the automatic pipe racking mechanism in the position illustrated in the top view of  FIG. 15 . 
           [0053]      FIG. 25  is a side view of the automatic pipe racking mechanism in the position illustrated in the top view of  FIG. 17 . 
           [0054]      FIG. 26  is a side view of the automatic pipe racking mechanism in the position illustrated in the top view of  FIG. 22 . 
           [0055]      FIG. 27  is a top view illustrating potential paths of a tubular or pipe as manipulated by the pipe racking mechanism. 
           [0056]      FIG. 28  is an isometric view of a drilling rig floor fitted with a tubular stand building system having features in accordance with the present invention. 
           [0057]      FIG. 29  is an isometric view of a drilling rig floor fitted with a tubular stand building system having features in accordance with the present invention, and generally illustrated from a side opposite that of  FIG. 28 , and illustrating only the base frame and braces of the pipe racking mechanism. 
           [0058]      FIG. 30  is an isometric exploded view of the horizontal to vertical pipe feeding mechanism of the present invention used to bring a tubular such as a drill pipe section from beneath the drill rig floor for delivery to a lower elevator attached near the edge of the V-door side of the drill rig floor. 
           [0059]      FIG. 31  is an isometric view of the horizontal to vertical pipe feeding mechanism, illustrating the mechanism at the bottom of its motion, having gripped a pipe section from a horizontal rack on the ground. 
           [0060]      FIG. 32  is an isometric view of the horizontal to vertical pipe feeding mechanism, illustrating the mechanism moving upwards from its bottom position upon extension of the boom cylinder, and illustrating the upward movement of the pipe being retained in a generally horizontal position. 
           [0061]      FIG. 33  is an isometric view of the horizontal to vertical pipe feeding mechanism, illustrating the continued upward movement of the mechanism, and the translation of the pipe from a horizontal position to a vertically inclined position. 
           [0062]      FIG. 34  is an isometric view of the horizontal to vertical pipe feeding mechanism, illustrating the mechanism in its fully raised position, and with the pipe being fully vertical. 
           [0063]      FIG. 35  is an isometric view of the tubular stand building system, illustrating the collective actuator control movements of the system during operation. 
       
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
       [0064]    The following description is presented to enable any person skilled in the art to make and use the invention, and is provided in the context of a particular application and its requirements. Various modifications to the disclosed embodiments will be readily apparent to those skilled in the art, and the general principles defined herein may be applied to other embodiments and applications without departing from the spirit and scope of the present invention. Thus, the present invention is not intended to be limited to the embodiments shown, but is to be accorded the widest scope consistent with the principles and features disclosed herein. 
         [0065]      FIG. 1  is an isometric view of a racking mechanism  100  including features of the automatic stand building system  1 . As it pertains to the present invention, racking mechanism  100  is one component of automatic stand building system  1 . Although significant detail is provided below for racking mechanism  100 , it will be appreciated that many variations and modifications may be considered desirable by those skilled in the art based upon a review of the following description of one preferred embodiment. 
         [0066]    As seen in  FIG. 1 , a drilling rig  10  is located over a wellbore  12 . Drilling rig  10  has a drill floor  14  and a drilling mast  16  extending upwards above drill floor  14  and located over wellbore  12 . Drilling mast  16  has an open V-door side  18 . A racking board  20  extends horizontally outward on V-door side  18 . Racking board  20  has a plurality of fingers  22  extending horizontally for supporting drill pipe  50  when it is removed from wellbore  12 . Racking mechanism  100  is mounted to drill floor  14 , on V-door side  18  of drilling mast  16 . 
         [0067]      FIG. 2  is an isometric view of racking mechanism  100  in accordance with one embodiment of the invention, illustrating racking mechanism  100  in the fully retracted position. Racking mechanism  100  is comprised of a base frame  200  that is connected to drill floor  14  by floor pins  202 . In one embodiment, base frame  200  is a tapered C-frame that extends upwards from drill floor  14  at a position offset to V-door side  18  of drilling mast  16 . A mast brace  204  is connected between base frame  200  and drilling mast  16  at a position distal to drill floor  14  for stabilizing an upper end of base frame  200  in relationship to drilling mast  16 . In one embodiment, a pair of tensioning members  206  is connected between drill floor  14  and base frame  200 . Tensioning members  206  provide further support and stability to the base frame  200  with respect to the drill floor  14 . 
         [0068]    In one embodiment, base frame  200  comprises a pair of deployable wings  208  (not shown), pivotally attached to base frame  200 . When wings  208  are deployed outward, deployed ends of wings  208  are connected to base frame  200  by struts  210  (not shown). In this embodiment, mast braces  204  are connected to the deployed ends of wings  208 , increasing the spacing between mast braces  204  to facilitate conflict free operation of racking mechanism  100 . Retraction of wings  208  provides a narrower transport profile for transporting racking mechanism  100  between drilling sites. 
         [0069]    As seen in  FIG. 2 , wellbore  12  has a vertical well centerline  70  that extends through and above the entrance of wellbore  12 . Well centerline  70  represents the theoretical target location for stabbing drill pipe  50 . Mast brace  204  stabilizes an upper end of base frame  200  in relationship to drilling mast  16 . In a preferred embodiment, the length of mast brace  204  is adjustable to compensate for deflection of racking mechanism  100  under different payloads which vary with the size of the tubular being handled. Adjustment is also advantageous to accommodate non-verticality and settling of drilling rig  10 . Adjustment is also useful for connectivity to other mechanisms that deliver or receive pipe from racking mechanism  100 . 
         [0070]      FIG. 3  is an isometric view of racking mechanism  100 , illustrating racking mechanism  100  partially deployed. In  FIG. 3  and  FIG. 4 , drilling mast  16  of drilling rig  10  has been removed for clarity. 
         [0071]    A lateral extend mechanism  300  is pivotally connected to base frame  200 . Lateral extend mechanism  300  is extendable between a retracted position, substantially within base frame  200 , and a deployed position which extends in the direction of well centerline  70 . In  FIG. 3 , as compared to  FIG. 2 , lateral extend mechanism  300  is partially deployed. 
         [0072]    Lateral extend mechanism  300  includes a pivot frame  400 . A rotate mechanism  500  is connected to pivot frame  400 . A finger extend mechanism  700  (not visible) is connected to rotate mechanism  500 . A grip and stab mechanism  800  is connected to rotate mechanism  500 .  FIG. 3  illustrates rotate mechanism  500  rotated 90 (ninety) degrees, with finger extend mechanism  700  in the retracted position. This position is intermediate of positions for receiving or setting back a stand of drill pipe in racking board  20 . 
         [0073]    In a preferred embodiment (best seen in  FIG. 1 ), lateral extend mechanism  300  is particularly configured such that upon deployment towards well centerline  70 , rotate mechanism  500 , finger extend mechanism  700 , and grip and stab mechanism  800  are movable to a position beneath racking board  20 , and further to a position substantially within drilling mast  16 . Also in a preferred embodiment, lateral extend mechanism  300  is particularly configured to be force-balanced, such that upon partial extension, lateral extend mechanism  300  is not inclined to retract or extend, as contrasted to a parallelogram linkage. The benefit of this configuration is that a low pushing force is required to actuate lateral extend mechanism  300  into deployment or retraction. 
         [0074]    In another embodiment, racking mechanism  100  is further balanced such that upon failure of the power supply and/or hydraulic pressure, lateral extend mechanism  300  will be slightly more inclined to retract under gravitational force than to extend. 
         [0075]      FIG. 4  is an isometric view of racking mechanism  100 , illustrating lateral extend mechanism  300  partially deployed, and further illustrating rotate mechanism  500  rotated 90 (ninety) degrees and finger extend mechanism  700  partially deployed. As best seen in  FIG. 2 , finger extend mechanism  700  (not shown) may be retracted into the interior space of rotate mechanism  500  (not shown) to permit passage through the narrow alley formed between stands of pipe  50  stacked on drill floor  14  when tripping drill pipe  50  out of wellbore  12 , such as when changing the drill bit. As contrasted, the position illustrated in  FIG. 4  is exemplary of a position for receiving or setting back a stand of drill pipe in racking board  20 . 
         [0076]      FIG. 5  is an isometric view of base frame  200  of racking mechanism  100 , illustrating base frame  200  in isolation of the remaining components of racking mechanism  100  and of drilling rig  10 . Base frame  200  is pivotally connected to drill floor  14  (not shown) by floor pins  202 . A mast brace  204  connects each side of base frame  200  to drilling mast  16  (not shown) of drilling rig  10  (not shown). Mast braces  204  stabilize base frame  200  of racking mechanism  100 . In a preferred embodiment, mast braces  204  are adjustable to compensate for verticality of drilling mast  16  and for the variable deflection of racking mechanism  100  when handling different sizes of drill pipe  50 . 
         [0077]    In another preferred embodiment, a tensioning member  206  connects each side of base frame  200  to drill floor  14  (not shown) of drilling rig  10  (not shown). Tensioning members  206  stabilize base frame  200  of racking mechanism  100 . In a preferred embodiment, tensioning members  206  are adjustable to compensate for verticality of racking mechanism  100 , and for the variable deflection of racking mechanism  100  when handling different sizes of drill pipe  50 . 
         [0078]      FIG. 6  is an isometric view of lateral extend mechanism  300  of  FIG. 1 , illustrating lateral extend mechanism  300  in isolation of the remaining components of racking mechanism  100  and of drilling rig  10 . As shown in  FIG. 6 , lateral extend mechanism  300  has a mast side  302  and a base connect side  304 . Base connect side  304  of lateral extend mechanism  300  is pivotally connected to base frame  200  (not shown). Mast side  302  of lateral extend mechanism  300  is pivotally connected to pivot frame  400  at connections  420  and  450 . 
         [0079]    In the preferred embodiment illustrated, lateral extend mechanism  300  comprises an extend linkage  320  and a level linkage  350 . In a more preferred configuration, lateral extend mechanism  300  comprises an eight bar linkage as illustrated. 
         [0080]    In the preferred embodiment illustrated, extend linkage  320  is comprised of an upper link  322 , a lower link  324 , and a long link  326 . Also in this embodiment, level linkage  350  is comprised of an inboard link  352 , an outboard link  354 , and a coupler link  356 . 
         [0081]    Extend linkage  320  and level linkage  350  are pivotally connected to base frame  200  (not shown) on base connect side  304 . Extend linkage  320  and level linkage  350  are pivotally connected to pivot frame  400  on mast side  302 . Extend linkage  320  is pivotally connected to pivot frame  400  at connection  420 . Level linkage  350  is pivotally connected to pivot frame  400  at connection  450 . Extend linkage  320  and level linkage  350  are also pivotally connected to each other by coupler link  356 . 
         [0082]    A lateral extend cylinder  390  is pivotally connected between base frame  200  (not shown) and extend linkage  320 . Controllable expansion of lateral extend cylinder  390  moves lateral extend mechanism  300  and thus pivot frame  400  between a retracted position substantially internal to base frame  200  (not shown) and an extended position external to base frame  200 . In a preferred embodiment, inboard link  352  and upper link  322  are substantially the same length. The novel kinematic configuration of extend linkage  320  and level linkage  350  generates extension of pivot frame  400  along a stable and substantially horizontal path above drill floor  14  (not shown) when lateral extend mechanism  300  is deployed. 
         [0083]    The lateral extend mechanism  300  is useful for other drilling rig applications in which it is desirable to horizontally translate another apparatus in a self-balancing manner in which maintaining the vertical alignment of the apparatus is desired. Such applications include positioning a gripping or torque device. 
         [0084]    As seen in  FIG. 6 , pivot frame  400  is in the form of a C-frame, with an opening in the direction of mast side  302  for receiving rotate frame  600  (not shown) and its connected contents. 
         [0085]      FIG. 7  is an isometric view of lateral extend mechanism  300  from  FIG. 6 , shown from the opposite side, with pivot frame  400  in front, and shown from below. Pivot frame  400  has a plurality of sockets for pivotal connection to the linkage of rotate mechanism  500 . 
         [0086]    In one embodiment as shown, at the top of pivot frame  400  is a right lock socket  412 , a right drive link socket  414 , and a right cylinder socket  416  which are located near the top of pivot frame  400 . A left lock socket  422 , a left drive link socket  424 , and a left cylinder socket  426  are also located near the top of pivot frame  400 . 
         [0087]    A right lock socket  452 , a right drive link socket  454 , and a right cylinder socket  456  are located near the bottom of pivot frame  400 , and in respective axial alignment with right lock socket  412 , right drive link socket  414 , and right cylinder socket  416  at the top of pivot frame  400 . 
         [0088]    A left lock socket  462 , a left drive link socket  464 , and a left cylinder socket  466  are located near the bottom of pivot frame  400 , and in respective axial alignment with left lock socket  422 , left drive link socket  424 , and left cylinder socket  426  at the top of pivot frame  400 . 
         [0089]    In one embodiment illustrated in  FIG. 7 , a notch  490  on pivot frame  400  is receivable of level linkage  350  of lateral extend mechanism  300 . A similarly sized notch  410  (not seen) is located on the corresponding side of the pivot frame  400 . Engagement of notch  490  (and notch  410 ) with level linkage  350  stabilizes pivot frame  400  and other components of racking mechanism  100  when lateral extend mechanism  300  is fully retracted. 
         [0090]      FIG. 8  is an isometric view of the components of racking mechanism  100 , shown without lateral extend mechanism  300  and pivot frame  400 . As illustrated in  FIG. 9 , a rotate mechanism  500  is shown for connection to pivot frame  400 . A rotate frame  600  comprises the body of the rotate mechanism  500 . A top rotate mechanism  510  and bottom rotate mechanism  560  are also shown connected to the rotate mechanism  500 , and used for connection to the pivot frame  400 . A finger extend mechanism  700  is connected to rotate mechanism  500 . A grip and stab mechanism  800  is connected to rotate mechanism  500  via the finger extend mechanism  700 .  FIG. 3  illustrates rotate mechanism  500  rotated 90 (ninety) degrees; with finger extend mechanism  700  in the retracted position. This position is intermediate of positions for receiving or setting back a stand of drill pipe in racking board  20 . 
         [0091]      FIG. 9  is a top view of rotate mechanism  500 , illustrating top rotate mechanism  510  (not shown) in the non-rotated position.  FIGS. 9 and 10  illustrate one embodiment in which pivot frame  400  (not shown) is operably connected to rotate mechanism  500 . 
         [0092]    As best seen in  FIG. 9 , top rotate mechanism  500  comprises a right driver  532  pivotally connected to pivot frame  400  (not shown) at right drive socket  414  (not shown) on one end and pivotally connected to a right coupler  534  on its opposite end. Right coupler  534  is pivotally connected between right driver  532  and rotate frame  600 . An expandable right cylinder  536  has one end pivotally connected to pivot frame  400  at right cylinder socket  416  (not shown). The opposite end of right cylinder  536  is pivotally connected to right driver  532  between its connections to pivot frame  400  and right coupler  534 . A right rotate lock pin  530  is provided for engagement with pivot frame  400  at right lock socket  412 . 
         [0093]    As also seen in  FIG. 9 , top rotate mechanism  500  comprises a left driver  542  pivotally connected to pivot frame  400  at left drive link socket  424  (not shown) on one end and to a left coupler  544  on its opposite end. Left coupler  544  is pivotally connected between left driver  542  and rotate frame  600 . An expandable left cylinder  546  has one end pivotally connected to pivot frame  400  at left cylinder socket  426 . The opposite end of left cylinder  546  is pivotally connected to left driver  542  between its connections to pivot frame  400  and left coupler  544 . A left rotate lock pin  540  is provided for engagement with pivot frame  400  at left lock socket  422  (not shown). 
         [0094]    A substantially matching configuration to the linkage and sockets of top rotate mechanism  510  is provided for bottom rotate mechanism  560 . In this manner, top rotate mechanism  510  and bottom rotate mechanism  560  work in parallel relation to turn rotate frame  600  of rotate mechanism  500  in the desired direction. 
         [0095]    To provide selectable rotation direction, or non-rotated direction, rotate mechanism  500  is connected to pivot frame  400 , in part, by selectable rotate lock pins  530  and  540 . Rotate frame  600  is clockwise rotatable about a first vertical axis centered on right lock socket  452  of pivot frame  400 . Rotate frame  600  is counterclockwise rotatable about a second vertical axis centered on left lock socket  462  of pivot frame  400 . 
         [0096]    As illustrated in  FIG. 9 , right rotation of rotate mechanism  500  is caused by actuation of right rotate lock pin  530  into right lock socket  440  (not shown) of pivot frame  400 . Subsequent expansion of right cylinder  536  forces right driver  532  to push right coupler  534 , which pushes out one end of rotate frame  600 . Since the other end of rotate frame  600  is pivotally attached to pivot frame  400  by right rotate lock pin  530  in right lock socket  412 , rotate frame  600  rotates to the right. 
         [0097]    Similarly, left rotation of rotate mechanism  500  is caused by actuation of left rotate lock pin  540  into left lock socket  422  (not shown) of pivot frame  400 . Subsequent expansion of left cylinder  546  forces left driver  542  to push left coupler  544 , which pushes out one end of rotate frame  600 . Since the other end of rotate frame  600  is pivotally attached to pivot frame  400  by left rotate lock pin  540  in left lock socket  462 , rotate frame  600  rotates to the left. 
         [0098]    Rotate frame  600  can be locked into non-rotated position by actuation of right rotate lock pin  530  into right lock socket  412  of pivot frame  400 , and actuation of left rotate lock pin  540  into left lock socket  422  of pivot frame  400 . 
         [0099]    As previously stated, the same kinematic relationships are engaged in top rotate mechanism  510  and bottom rotate mechanism  560  so that they may work in parallel relation to turn rotate frame  600  in the desired direction. 
         [0100]      FIG. 10  is a top view of rotate mechanism  500 . Rotate mechanism  500  comprises a rotate frame  600 , a top rotate linkage  510  and a bottom rotate linkage  560  (not shown). Top rotate linkage  510  and bottom rotate linkage  560  pivotally connect rotate frame  600  to pivot frame  400  (not shown). Top rotate linkage  510  and bottom rotate linkage  560  work in parallel relation to turn rotate frame  600  at least 90 (ninety) degrees in a selectable clockwise or counterclockwise direction in relation to pivot frame  400 . 
         [0101]      FIG. 11  is an isometric view of finger extend mechanism  700  and vertical grip and stab mechanism  800 . Finger extend mechanism  700  is pivotally connected to rotate frame  600  (not shown). Finger extend mechanism  700  is extendable between a retracted position substantially within rotate frame  600  and a deployed position, which extends outward in the selected direction of rotate mechanism  500 , away from rotate frame  600 . Referring back to  FIG. 4 , as compared to  FIG. 3 , finger extend mechanism  700  is partially deployed. 
         [0102]    In the preferred embodiment, finger extend mechanism  700  is collapsible within rotate frame  600  such that rotate frame  600 , finger extend mechanism  700  and vertical grip and stab mechanism  800  are collectively 180 (one hundred eighty) degrees rotatable within a 48 inch distance. 
         [0103]    Finger extend mechanism  700  includes an upper finger extend frame  702  pivotally connected on its upper end to rotate frame  600  and pivotally connected on its lower end to a vertical stab frame  802  of vertical grip and stab mechanism  800 . Finger extend mechanism  700  includes a lower finger extend frame  704  pivotally connected on its upper end to rotate frame  600  and pivotally connected on its lower end to vertical stab frame  802 . A finger extend cylinder  710  is pivotally connected on a first end to vertical stab frame  802 , and connected on a second end to rotate mechanism  500 . Extension of finger extend cylinder  710  causes extension of finger extend mechanism  700  and movement of vertical grip and stab mechanism  800  away from rotate frame  500  to position pipe  50  in the desired position. 
         [0104]    As stated, vertical grip and stab mechanism  800  has a vertical stab frame  802 . Vertical stab frame  802  has a lower end and an opposite upper end. A stab cylinder  804  is located on vertical stab frame  802 . 
         [0105]    A lower load gripper  820  is mounted in vertically translatable relation to vertical stab frame  802 . A spacer  806  is attached above lower load gripper  820 . An upper load gripper  830  is mounted above spacer  806 , in vertically translatable relation to vertical stab frame  802 . Load grippers  820  and  830  are capable of clamping onto the exterior of a drilling tubular and supporting the load of the tubular. Extension of stab cylinder  804  moves lower load gripper  820 , spacer  806 , and upper load gripper  830  vertically upwards in relation to vertical stab frame  802 . 
         [0106]    A spring assembly  808  is located between stab cylinder  804  and centering gripper  840 . Spring assembly  808  is preloaded with the weight of the lower load gripper  820  and upper load gripper  830 . The spring is further loaded when lower load gripper  820  and upper load gripper  830  are used to grip pipe  50 , and stab cylinder  804  is extended. This reduces the power required for extending stab cylinder  804  to raise pipe  50 . In one embodiment, spring assembly  808  is designed to achieve maximum compression under a weight of approximately 2,000 pounds, which is approximately the weight of a standard drill string. 
         [0107]    Preloading spring assembly  808  allows for a gradual load transfer of the vertical forces from stab cylinder  804  to the target support of pipe  50 , being either a receiving toll joint of drill pipe stump  52  located in wellbore  12 , or on drill floor  14  for setting back the stand of drill pipe  50 . 
         [0108]    A centering gripper  840  is located on the lower end of vertical stab frame  802 . Centering gripper  840  stabilizes pipe  50 , while allowing it to translate vertically through its centering grip. 
         [0109]    In an alternative embodiment (not illustrated), a gripper assembly is mounted in vertically translatable relation to vertical stab frame  802 . At least one load gripper  830  is mounted on the gripper assembly. In this embodiment, extension of stab cylinder  804  moves the gripper assembly, including load gripper  830 , vertically upwards in relation to vertical stab frame  802 . 
         [0110]      FIGS. 12 through 22  are top views illustrating the operation of racking mechanism  100  and illustrating racking mechanism  100  moving from a fully retracted position to retrieve a stand of pipe  50  (or other tubular) from pipe rack  20 , and delivering pipe stand  50  into alignment for vertical stabbing into drill pipe stump  52  located over wellbore  12 . In each of  FIGS. 12 through 22 , substantial structure has been removed for the purpose of more clearly illustrating the operation of racking mechanism  100 , with emphasis of the relationship between racking mechanism  100 , pipe rack  20 , pipe stand  50 , and drill pipe stump  52 . 
         [0111]    In  FIG. 12 , racking mechanism  100  is illustrated in the fully retracted position. In this position, the lateral extend mechanism  300  (not seen), rotate mechanism  500 , finger extend mechanism  700  (not seen), and grip and stab mechanism  800  are all fully retracted. In this position, racking mechanism  100  can be serviced. Rotate mechanism  500  can also be rotated and lateral extend mechanism  300  can be extended to permit racking mechanism  100  to be used to lift other drilling rig equipment. It is possible to replace grip and stab mechanism  800  with an alternative gripping device for this purpose. 
         [0112]      FIG. 13  illustrates racking mechanism  100  having lateral extend mechanism  300  partially extended. In this position, racking mechanism  100  can be parked for immediate access to pipe  50  in racking board  20  when needed. 
         [0113]      FIG. 14  illustrates racking mechanism  100  in a partially extended position as racking mechanism  100  progresses towards pipe  50  which is resting in racking board  20 . In this position, the lateral extend mechanism  300  is partially extended and rotate mechanism  500 , finger extend mechanism  700 , and grip and stab mechanism  800  are extended to a position beneath diving board  24 . 
         [0114]      FIG. 15  illustrates racking mechanism  100  with rotate mechanism  500  partially rotated to the right towards pipe  50 .  FIG. 16  illustrates rotate mechanism  500  rotated 90 (ninety) degrees and now orienting grip and stab mechanism  800  such that grippers  820 ,  830 , and  840  are open and facing pipe  50 . 
         [0115]      FIG. 17  illustrates racking mechanism  100  having finger extend mechanism  700  fully extended to position grip and stab mechanism  800  adjacent to pipe  50 . Grippers  820 ,  830 , and  840  are closed around pipe  50 . Stab cylinder  804  is extended and pipe  50  is raised off of drilling floor  10 , suspended vertically by upper load gripper  830  and lower load gripper  820 . Centering gripper  840  resists undesirable bending and oscillation of pipe  50 . 
         [0116]      FIG. 18  illustrates racking mechanism  100  having finger extend mechanism  700  retracted to position pipe  50  between diving board  24  and the ends of fingers  22  of racking board  20 . Rotate mechanism  500  remains rotated clockwise. A corridor  26  is formed in this space through which pipe  50  must be navigated to avoid conflict with the structure of racking board  20 . 
         [0117]      FIG. 19  illustrates racking mechanism  100  having the lateral extend mechanism  300  further extended to guide pipe  50  through corridor  26  towards drill pipe stump  52  in wellbore  12 . 
         [0118]      FIG. 20  illustrates racking mechanism  100  having delivered pipe  50  along a substantially horizontal path by the extension of lateral extend mechanism  300 . In this position, pipe  50  is now past diving board  24  in the direction of wellbore  12 . Rotate mechanism  500  is now rotated counterclockwise to position pipe  50  in alignment with drill pipe stump  52  in wellbore  12 . 
         [0119]      FIG. 21  illustrates racking mechanism  100  having rotate mechanism  500  returned to the forward and non-rotated position, thus aligning pipe  50  for delivery to a position directly above drill pipe stump  52 . It is possible to simultaneously actuate rotate mechanism  500  while lateral extend mechanism  300  continues to extend in the direction of drill pipe stump  52  in wellbore  12  to save delivery time. 
         [0120]      FIG. 22  illustrates racking mechanism  100  having delivered pipe  50  in a vertical position directly above drill pipe stump  52  in wellbore  12 . In this position, stab cylinder  804  of grip and stab mechanism  800  is lowered to vertically lower upper load gripper  830  and lower load gripper  820 , and thus pipe  50 , until the male pin connection of pipe  50  (or other tubular) engages female box connection of drill pipe stump  52 . In this position, pipe  50  may be fully connected by rotation and the proper torque into drill pipe stump  52 . 
         [0121]      FIGS. 23 through 26  are selected side views that correspond to the top views provided in  FIGS. 12 through 22 . 
         [0122]      FIG. 23  is a side view of racking mechanism  100  in the position illustrated in the top view of  FIG. 13 . In this view, racking mechanism  100  is mostly retracted. 
         [0123]      FIG. 24  is a side view of racking mechanism  100  in the position illustrated in the top view of  FIG. 15 . In this view, lateral extend mechanism  300  is partially extended in the direction of pipe  50 , and rotate mechanism  500  is partially rotating to the right towards pipe  50 . 
         [0124]      FIG. 25  is a side view of racking mechanism  100  in the position illustrated in the top view of  FIG. 17 , in which racking mechanism  100  has finger extend mechanism  700  fully extended to position grip and stab mechanism  800  adjacent to pipe  50 . Grippers  820 ,  830 , and  840  are closed around pipe  50 . Stab cylinder  804  is extended and pipe  50  is raised off of drilling floor  14 , suspended vertically by upper load gripper  830  and lower load gripper  820 . Centering gripper  840  resists undesirable bending and oscillation of pipe  50 . 
         [0125]      FIG. 26  is a side view of racking mechanism  100  in the position illustrated in top view of  FIG. 22 , in which automatic pipe racking mechanism  100  has delivered pipe  50  in a vertical position directly above stump  52  in wellbore  12 . In this position, stab cylinder  804  of grip and stab mechanism  800  is lowered to vertically lower upper load gripper  830  and lower load gripper  820 , and thus pipe  50 , until the male pin connection of pipe  50  (or other tubular) engages female box connection of drill pip stump  52 . In this position, pipe  50  may be fully connected by rotation and the proper torque into drill pipe stump  52 . 
         [0126]      FIG. 27  is a top view illustrating potential paths of pipe racking mechanism  100  with the dotted line representing the path of drill pipe  50 . As seen in  FIG. 27 , pipe racking mechanism  100  is capable of navigating the narrow space between diving board  10  (see  FIG. 24 ) and fingers  20 . 
         [0127]      FIG. 28  is an isometric view of a drilling rig floor  14  fitted with automatic stand building system  1  having features in accordance with the present invention. As seen in  FIG. 28 , automatic stand building system  1  comprises a horizontal to vertical mechanism  900 , which feeds sections of drill pipe  50  to a lower elevator  1000 . 
         [0128]    Lower elevator  1000  has at least one gripper  1002  for supporting the load of drill pipe  50 . Gripper  1002  of lower elevator system  1000  is vertically translatable along lower elevator  1002 . This capability allows gripper  1002  to vertically raise drill pipe  50  to an upper elevator  1100 . In one embodiment, the upper end of lower elevator  1000  is pivotally connected to drill rig  10  along a horizontal axis. This connection permits horizontally positioned attachment of lower elevator  1000  in a horizontal position to drill rig  10  prior to raising the substructure of drill rig  10  during rig up. After raising the substructure, lower elevator  1000  may be pivoted into its normal, vertical position. 
         [0129]    In one embodiment, upper elevator  1100  is pivotally connected to base frame  200  of pipe racking mechanism  100  along a vertical axis of upper elevator  1100 . Upper elevator  1100  has a lower gripper  1102  and an upper gripper  1104 . Lower gripper  1104  is vertically translatable along the length of upper elevator  1100 . Each of the grippers  1102  and  1104  is capable of supporting the load of three sections of pipe  50 . Grippers  1102  and  1104  are independently operable. 
         [0130]    A torquing mechanism such as a power tong  1200  may be used to rotate a first section of drill pipe  50  in upper elevator  1100  in respect to a second section of drill pipe  50  in lower elevator  1000 . By this procedure, the upper section of the second section of drill pipe  50  and the lower section of the first section of drill pipe  50  are threadedly connected. In an alternative embodiment, one or both of lower elevator  1000  and upper elevator  1100  are fitted with spinning grippers, which are capable of rotating a first section of drill pipe  50  in upper elevator  1100  with respect to a second section of drill pipe  50  in lower elevator  1000 . 
         [0131]    In one embodiment, the verticality of automatic pipe racking mechanism  100  is controllable in relationship to the mast  16  of drilling rig  10 , such as by controllable length adjustment of the mast braces  204 . In this embodiment, tipping base frame  200  of automatic pipe racking mechanism  100 , and thus also upper elevator  1100  towards mast side  302  of base frame  200  permits entry of a pipe stand  50  into the confines of the racking board  20  of drilling rig  10 . 
         [0132]      FIG. 29  is an isometric view of the automatic stand building system  1  shown in  FIG. 28 , as it appears from the opposite side. In this view, the lower elevator  1000  may be more clearly seen as located underneath the drill floor  14 . Furthermore, the overall positional relationship between the horizontal to vertical mechanism  900 , the lower elevator  1000 , the upper elevator  1100 , and the racking mechanism  100  are more clearly illustrated in  FIG. 29 . 
         [0133]      FIG. 30  is an isometric exploded view of the horizontal to vertical pipe feeding mechanism  900  of the present invention, used to bring tubulars such as drill pipe  50  from beneath drill rig floor  14  for delivery to lower elevator  1000  attached at the edge of the V-door side drill rig floor  14 . In the view provided by  FIG. 30 , the various components which make up the horizontal to vertical mechanism  900  are illustrated in detail, and are further described below. 
         [0134]    Horizontal to vertical mechanism  900  has a base  910 . In the embodiment shown, base  910  has a flange  912  for connection to drill rig  10 . Base  910  is pivotally connected to a boom  930 , a cylinder  950  and a link  952 . In one embodiment, base  910  has a boom flange  922  with a boom pivot  924 . Base  910  has a link flange  914  with a link pivot  916 . Link flange  914  extends outward from flange  912  further than boom flange  924 . Base  910  has a cylinder flange  918  with a cylinder pivot  920 . 
         [0135]    Horizontal to vertical mechanism  900  has an angular boom  930 . In the embodiment shown, boom  930  has a base connect end  934  for pivotal connection to base  910  at boom pivot  924 . Boom  930  has a yoke  936  on its opposite end. Yoke  936  has a brace pivot  944  and an arm pivot  942 . In the embodiment illustrated, boom  930  is pivotally connectable to cylinder  950  at a cylinder pivot  940 . 
         [0136]    Horizontal to vertical mechanism  900  has a lever  960 . Lever  960  is pivotally connected to boom  930 , link  952 , and arm  980 . In the embodiment shown, lever  960  has an outer lobe  962  and an inner lobe  964 . In this embodiment, inner lobe  964  is shorter than outer lobe  962 . Outer lobe  962  has a pivot connection  966  for pivotal connection to link  952 . A pivot connection  968  is provided between outer lobe  962  and inner lobe  964  for pivotal connection to boom  930  at pivot connection  942 . A pivot connection  970  is provided between outer lobe  962  and inner lobe  964  for pivotal connection to arm  980  at pivot connection  988 . 
         [0137]    Horizontal to vertical mechanism  900  has a brace  954 . Brace  954  is pivotally connected between boom  930  and arm  980 . In the embodiment shown, brace  954  is pivotally connected at one end to pivot point  944  on yoke  936  of boom  930 . Brace  954  is pivotally connected at its opposite end to pivot  990  of arm  980 . 
         [0138]    Horizontal to vertical mechanism  900  has an arm  980 . Arm  980  is pivotally connected to lever  960  and to boom  930  through brace  954 . In the embodiment shown, arm  980  is pivotally connected to lever  960  between inner lobe  964  and outer lobe  962  at pivot point  968 . Arm  980  is pivotally connected to brace  954  at pivot  990 . 
         [0139]    Arm  980  has an upper arm portion  982  and a lower arm portion  984 . Lower arm  984  is angularly disposed to upper arm  982  in a direction that extends beneath inner lobe  964  of lever  960 . Arm  980  has a gripper head  986  on the free end of lower arm  984 . Gripper head  986  has attached at least one gripper  992  capable of clamping onto the exterior of a drilling tubular such as a section of drill pipe  50  and of supporting the load of the tubular  50 . In the embodiment shown, a second gripper  994  is provided for increased lifting and support capability. In another embodiment, not shown, grippers  992  and  994  are controllably and rotatably attached to arm  980 , for additional positioning control of drill pipe  50 . 
         [0140]    Cylinder  950  is pivotally connected between base  910  and boom  930 . Cylinder  950  is pivotally connected at one end to base  910  at cylinder pivot  920  on cylinder flange  918 . Cylinder  950  is pivotally connected at its opposite end to boom  930  at cylinder pivot  940 . 
         [0141]    Link  952  is pivotally connected between base  910  and lever  960 . Link  952  is pivotally connected at one end to base  910  at link pivot  916  on link flange  914 . Link  952  is pivotally connected at its opposite end to lever  960  at pivot point  966  on outer lobe  962 . 
         [0142]    Although the above description discloses horizontal to vertical mechanism  900  as a six-bar mechanism, it has been recognized that an eight-bar mechanism may also be developed for this purpose by taking advantage of the unique geometry and kinematic relationships disclosed for horizontal to vertical mechanism  900 . This may be preferred depending upon other variables such as the height of the drilling floor  14  of a particular drilling rig  10 , or the total length of the stand of drill pipe  50  being utilized. In particular, such mechanism could include an additional linkage between base  910  and boom  930 . An example of this mechanism is illustrated in  FIG. 35  for comparison. 
         [0143]      FIG. 31  is an isometric view of the horizontal to vertical pipe feeding mechanism  900 , illustrating mechanism  900  at the bottom of its motion, having gripped a section of drill pipe  50  from a horizontal rack near the ground. 
         [0144]      FIG. 32  is an isometric view of the horizontal to vertical pipe feeding mechanism  900 , illustrating mechanism  900  moving upwards from its bottom position upon extension of cylinder  950 , and illustrating the upward movement of drill pipe  50 , being advantageously retained in a generally horizontal position at this stage of the movement, thus clearing an optional V-door ramp, and accommodating variable heights of conventional drill floors  14 . 
         [0145]      FIG. 33  is an isometric view of the horizontal to vertical mechanism  900 , illustrating the mechanism&#39;s continued upward movement, and the translation of drill pipe  50  from a horizontal position to a vertically inclined position. 
         [0146]      FIG. 34  is an isometric view of the horizontal to vertical mechanism  900 , illustrating mechanism  900  in its fully raised position, and with drill pipe  50  being fully vertical for gripping by gripper  1002  of lower elevator  1000  (see  FIG. 35 ). 
         [0147]      FIG. 35  is an isometric view of the tubular stand building system  1 , illustrating the collective actuator control movements of tubular stand building system  1  in operation, as is described further below. In  FIG. 35 , the internal components of the racking mechanism  100  are excluded for visibility of the remaining components of tubular stand building mechanism  1 , illustrating only base frame  200  of racking mechanism  100 . In this view it is seen that upper elevator  1100  can be pivotally attached to base frame  200  with hinge-type or other pivots  1106 . It can also be seen that extendable mast braces  204  can be used to alter the verticality of base frame  200  with respect to mast  16  (not shown) via extension or retraction of the mast braces  204 . 
       Operation of the Invention 
       [0148]    Referring to  FIG. 35 , lower elevator  1000  is mounted to drilling rig  10  for receiving a section of drill pipe  50  in a vertical orientation from horizontal to vertical mechanism  900 . Lower elevator  1000  may be pivotally attached to drilling rig  10  so that it may be attached in a horizontal position prior to raising the substructure. Lower elevator  1000  has at least one gripper  1002  that is vertically translatable along the length of lower elevator  1000 . Gripper  1002  is capable of clamping onto the exterior of drilling tubular  50  and supporting the load of tubular  50 . 
         [0149]    Referring back to  FIGS. 28-29 , racking mechanism  100  is provided, having base frame  200  connectable to a drill floor  14  of a drill rig  10  and extending upwards at a position offset to a V-door side  18  of a drilling mast  16  that is also connected to drill floor  14 . In one embodiment, the base frame  200  is a C-frame design. A mast brace  204  is connected between base frame  200  and drilling mast  16  at a position distal to drill floor  14  for stabilizing an upper end of base frame  200  in relationship to mast  16 . In one embodiment, mast brace  204  is adjustable for tilting racking mechanism  100  slightly towards mast  16 . A tensioning member  206  may be connected between base frame  200  and drilling floor  14  for stabilizing base frame  200  in relationship to the substructure. 
         [0150]    The racking mechanism  100  is capable of moving stands of pipe between a racked position within the racking board  20  and the over-well position such as well centerline  70 . 
         [0151]    In one embodiment, a lateral extend mechanism  300  is pivotally connectable to base frame  200 . Lateral extend mechanism  300  is extendable between a retracted position and a deployed position. A rotate mechanism  500  is connected to lateral extend mechanism  300  and is rotatable in each of a left and right direction. A finger extend mechanism  700  is connected to rotate mechanism  500 . Finger extend mechanism  700  is laterally extendable between a retracted position and a deployed position. 
         [0152]    A grip and stab mechanism  800  is attached to finger extend mechanism  700 . Grip and stab mechanism  800  has grippers  820 ,  830 ,  840  to hold a drill pipe  50  or stand of pipe and is capable of moving the pipe  50  vertically to facilitate stabbing. Lateral extend mechanism  300  is deployable to move finger extend mechanism  700  and grip and stab mechanism  800  between a position beneath a racking board  20  cantilevered from mast  16  to a position substantially beneath mast  16 , and back. 
         [0153]    In another embodiment, movement of lateral extend mechanism  300  between the retracted position and the deployed position moves rotate mechanism  500  along a substantially linear path. In a more preferred embodiment, movement of lateral extend mechanism  300  between the retracted position and the deployed position moves the rotate mechanism along a substantially horizontal path. 
         [0154]    Rotate mechanism  500  is rotatable in each of a left and right direction. In a more preferred embodiment, the rotate mechanism is rotatable in each of a left and right direction by at least 90 (ninety) degrees. In a preferred embodiment, grip and stab mechanism  800  is vertically translatable to vertically raise and lower the load of a stand of pipe  50 . 
         [0155]    In another embodiment, racking mechanism  100  may be series nesting. In this embodiment, finger extend mechanism  700  and grip and stab mechanism  800  are substantially retractable into rotate mechanism  500 , which is substantially retractable into pivot frame  400  of lateral extend mechanism  300 , which is substantially retractable into base frame  200 . 
         [0156]    An upper elevator  1100  is pivotally connected to base frame  200  for receiving a drill pipe  50  in a vertical orientation from a lower elevator  1000 . Upper elevator  1100  has a lower gripper  1102  and an upper gripper  1104 . Upper gripper  1104  is vertically translatable along the length of upper elevator  1100 . Upper gripper  1104  and lower gripper  1102  are both capable of clamping onto the exterior of a drill pipe  50  and supporting the load of the drill pipe. 
         [0157]    A stand building power tong  1200  is provided for rotating drill pipe  50  to be connected between upper elevator  1100  and the lower elevator  1000 . 
         [0158]    Remaining on  FIGS. 28-29 , in operation, the horizontal to vertical machine  900  grips a first tubular  60 , such as a section of drill pipe  50 , and raises it from a horizontal position near the ground to a vertical position proximate to drill floor  14  and adjacent to lower elevator  1000 . Lower elevator  1000  receives the first tubular  60  from the horizontal to vertical machine  900 . Lower elevator  1000  raises the first tubular  60  vertically, wherein upper elevator  1100  grips and continues to vertically raise the first tubular  60 . 
         [0159]    The horizontal to vertical machine  900  grips a second tubular  62  and raises it from a horizontal position near the ground to a vertical position proximate to drill floor  14  and adjacent the lower elevator  1000 . Lower elevator  1000  receives second tubular  62  from the horizontal to vertical machine  900  and raises the second tubular  62  vertically until the female connection of second tubular  62  engages the male connection of first tubular  60 . Stand building power tong  1200  rotates one of the tubulars in relation to the other to make-up the threaded connection between them. Upper elevator  1100  then grips and vertically raises the connected first tubular  60  and second tubular  62 . 
         [0160]    Depending on the needs of a well operator and the requirements on the length of a pipe stand, horizontal to vertical machine  900  may grip a third tubular  64  and raise it from a horizontal position near the ground to a vertical position proximate to drill floor  14  and adjacent to the lower elevator  1000 . Lower elevator  1000  receives the third tubular  64  from the horizontal to vertical machine  900  and raises the third tubular  64  vertically until the female connection of third tubular  64  engages the male connection of the second tubular  62 . Stand building power tong  1200  then rotates one of the tubulars in relation to the other to make-up the threaded connection between them. Upper elevator  1100  then grips and vertically raises the connected first, second and third tubulars  60 ,  62 ,  64 , which collectively make up a connected pipe stand  66 . 
         [0161]    The racking mechanism  100  receives the connected pipe stand  66  from upper elevator  1100 , whereupon, the upper elevator  1100  releases the connected pipe stand  66 . In one embodiment, upper elevator  1100  may then be rotated with respect to base frame  200  of racking mechanism  100  such that upper elevator  1100  is no longer in the way. 
         [0162]    In another embodiment, racking mechanism  100  then tilts the connected pipe stand  66  inside racking board  20 . Racking mechanism  100  may be tilted by actuating linearly adjustable mast braces  204  connected to drilling mast  16 . (See  FIG. 35 ). The racking mechanism  100  is then used to locate connected pipe stand  66  in racking boards  20 , and to move pipe stand  66  between racking board  20  and the wellbore  12 . 
         [0163]    The references and relationship between first, second and third tubulars  60 ,  62 ,  64  are illustrated in  FIG. 28 , which shows first, second and third tubulars  60 ,  62 ,  64  threaded together as connected pipe stand  66 , and positioned over stump  52  by racking mechanism  100 . 
         [0164]    As will be understood by one of ordinary skill in the art, the sequence of the steps disclosed may be modified and the same advantageous result obtained. For example, the wings may be deployed before connecting the lower mast section to the drill floor (or drill floor framework). 
         [0165]    As described, the relationship of these elements has been shown to be extremely advantageous in providing a racking mechanism  100  that can be mounted to a conventional drill floor, and that is capable of lifting and moving drill pipe between a racked position within a largely conventional racking board and a stabbed position over a wellbore. 
         [0166]    Having thus described the present invention by reference to certain of its preferred embodiments, it is noted that the embodiments disclosed are illustrative rather than limiting in nature and that a wide range of variations, modifications, changes, and substitutions are contemplated in the foregoing disclosure and, in some instances, some features of the present invention may be employed without a corresponding use of the other features. Many such variations and modifications may be considered desirable by those skilled in the art based upon a review of the foregoing description of preferred embodiments. Accordingly, it is appropriate that the appended claims be construed broadly and in a manner consistent with the scope of the invention.