Patent Publication Number: US-9410383-B2

Title: Method and apparatus for connecting tubulars of a wellsite

Description:
BACKGROUND 
     The disclosure relates generally to techniques for performing wellsite operations. More specifically, the disclosure relates to techniques, such as tubulars and/or risers, for passage of fluid at a wellsite. 
     Oilfield operations may be performed to locate and gather valuable downhole fluids. Some such oilfield operations are performed at offshore locations. Surface platforms may be used to draw fluids from subsea locations to a surface vessel. A wellbore is drilled into the subsea floor and subsea equipment, such as blowout preventers, may be positioned about the wellbore to access fluid from subsurface formations. 
     A riser may extend from the subsea equipment, such as a blowout preventer stack positioned about the wellbore, to the surface platform. The riser may include a series of tubulars with flanged ends connected end to end by bolts to form an elongate fluid path for passage of fluids. Other tubulars, such as choke and kill lines, may also be provided along the riser for communication between the surface platform and the subsea equipment. 
     Various connection devices, such as spiders and torque wrenches, may be positioned on the surface platform to facilitate connection of the tubulars forming the riser. Examples of connection devices are provided in U.S. Pat. Nos. 8,020,626, 8,157,018 and 8,347,972, the entire contents of which are hereby incorporated by reference herein. 
     SUMMARY 
     In at least one aspect, the disclosure relates to a clam assembly for connecting adjacent tubulars positionable in a wellbore of a wellsite for passing fluid therethrough. The clam assembly includes a plurality of segments, and at least one drive mechanism. The segments are selectively movable between an open position to receive the adjacent tubulars and a closed position positionable around the adjacent tubulars, and are disposable about a periphery of the adjacent tubulars. The drive mechanisms are carried by the segments, and include a driver to drive a connector through the adjacent tubulars. The driver is movable between a retracted and an extended position to drive the connector whereby a connection is formed between the adjacent tubulars. 
     The clam assembly may also include an orienter carried by the segments, and engageable with a reference component of the tubulars whereby the segments are orientable about the tubulars. The orientor may include an upper receptacle and a lower receptacle. The upper receptacle includes a pair of arms defining an inlet to grippingly receive the reference component. The lower receptacle may include a plate defining a fixed inlet to receive the reference component. The segments may be pivotally connectable together. Each of the segments may include an upper plate and a lower plate with the at least one drive mechanism therebetween. The drive mechanism may include an axial mechanism to axial move the driver. The driver may include a rotational driver. 
     In another aspect, the disclosure relates to a connection assembly for connecting adjacent tubulars positionable in a wellbore of a wellsite for passing fluid therethrough. The connection assembly includes a base having a hole to receive adjacent tubulars therethrough, a carrier positionable about the base, and a clam assembly movably positionable along the carrier between a retracted position a distance from the tubulars and an extended position about the adjacent tubulars. The clam assembly includes a plurality of segments, and at least one drive mechanism. The segments are selectively movable between an open position to receive the adjacent tubulars and a closed position positionable around the adjacent tubulars, and are disposable about a periphery of the adjacent tubulars. The drive mechanisms are carried by the segments, and include a driver to drive a connector through the adjacent tubulars. The driver is movable between a retracted and an extended position to drive the connector whereby a connection is formed between the adjacent tubulars. The connection assembly of claim  10 , wherein the carrier comprises rails, the clam assembly operatively connectable to the rails and slidably positionable therealong. 
     The carrier may include a support operatively connectable to the rails, with the clam assembly carried by the support. The base may include a plurality of clamps operatively connectable to the adjacent tubulars. The base may be operatively connectable to a platform at the wellsite. The base may be a spider. The clam assembly may also include an orienting bracket carried by the segments. The orienting bracket may be engageable with a reference component of the adjacent tubulars whereby the clam is orientable about the adjacent tubulars. 
     In yet another aspect, the disclosure relates to a method of connecting adjacent tubulars positionable in a wellbore of a wellsite for passing fluid therethrough. The method includes closing a clam assembly about the adjacent tubulars. The clam assembly includes a plurality of segments and at least one drive mechanism. The clam assembly is selectively movable between an open position to receive the adjacent tubulars and a closed position positionable around the adjacent tubulars. The segments are disposable about a periphery of the adjacent tubulars. The drive mechanism is carried by the segments, and includes a driver to drive a connector through the adjacent tubulars. The method also involves forming a connection between the adjacent tubulars with a connector by advancing the connector between a retracted and an extended position with the driver. 
     The clam assembly may also include an orienting bracket carried by the segments, and the method may also involve orienting a clam assembly about the reference component of the adjacent tubulars by grippingly engaging the reference component with the clam assembly. The method may also involve opening the clam assembly, extending the clam assembly to the adjacent tubulars, retracting the clam assembly from the adjacent tubulars, and/or movably positioning the clam assembly between a retracted position a distance from the adjacent tubulars and an extended position about the adjacent tubulars. The forming may involve rotating the connector and/or axially driving the connector. 
     In another aspect, the disclosure relates to a rotational driver for driving a connector through adjacent tubulars. The adjacent tubulars are positionable in a wellbore of a wellsite for passing fluid therethrough. The rotational driver includes a gearbox housing positionable about the connector, a socket carried by the gearbox housing to receivingly engage the connector, and a plurality of gears driven by at least one motor. The gears are operatively connectable to the socket to transfer torque from the at least one motor thereto, and have interlocking teeth defining a plurality of contacts therebetween whereby load on the gears is distributable therebetween. 
     The gears may include a plurality of pinion gears operatively connectable to a plurality motors and rotationally driven thereby, a drive gear operatively connectable to the pinions and rotationally driven thereby, a plurality of intermediate gears operatively connectable to the drive gear and rotationally driven thereby, and a socket gear operatively connectable to the intermediate gears and rotationally driven thereby. The intermediate gears have a plurality of teeth in constant engagement with the socket gear whereby torque is distributed between the intermediate gears during rotation thereof with the socket gear. 
     The gears may include a plurality of intermediate gears having interlocking teeth defining a plurality of contacts between the intermediate gears and the socket. The pinion gears may have teeth engageable with the drive gear. The drive gear may have a drive shaft. The drive shaft may have splines engageable with the intermediate gears. The pinion gears include two pinion gears. Each of the two pinion gears may have teeth engageable with the socket gear. The socket gear may have an aperture therethrough. A drive end of the socket may be receivable in the aperture. The motor may include a pair of hydraulic motors and the gears may include a pair of pinions. Each of the pinions may be operatively connectable to one of the hydraulic motors. The motors may include a pair of motors. A first of the motors may have a first rotational setting and a second of the motors may have a second rotational setting. The second rotational setting may be greater than the first rotational setting. 
     The rotational driver may also include a retainer operatively connectable to the gearbox and engageable with the connector whereby the connector is retainable in the socket during the advancing. The may include comprises a pivotal retainer bracket, a cylinder, a piston, and a wedge. The retainer bracket may be operatively connectable to the gearbox. The cylinder may be operatively connectable to the gearbox by the bracket. The piston may be extendable from the cylinder by the pivotal retainer bracket. The wedge may be engageable with the connector. The gearbox housing may be operatively connectable to an axial driver. 
     In another aspect, the disclosure relates to a drive assembly for connecting adjacent tubulars with connectors. The adjacent tubulars are positionable in a wellbore of a wellsite for passing fluid therethrough. The drive assembly includes an axial rail operatively connectable to a carrier and positionable thereby, a cylinder positioned on the base (the cylinder having a piston extendable therefrom), a bracket operatively connectable to an end of the piston and slidably positionable along the axial rail, and a rotational driver carried by the bracket. The rotational driver includes a gearbox positionable about the connector, a socket carried by the gearbox housing to receivingly engage the connector, a plurality of gears driven by at least one motor, and a socket having a receptacle to receivingly engage the connector. The gears are operatively connectable to the socket to transfer torque from the at least one motor thereto, and have interlocking teeth defining a plurality of contacts therebewteen whereby load on the gears is distributable therebetween, The socket is operatively connectable to the socket gear and driven thereby. 
     The carrier includes a frame and a plurality of rails. The carrier includes a bracket, a rolling frame, and a crane. The drive assembly may also include a clam assembly carried by the carrier. The axial rail may be operatively connectable to the clam assembly. 
     In yet another aspect, the disclosure relates to a method of connecting adjacent tubulars positionable in a wellbore of a wellsite for passing fluid therethrough. The method involves positioning the rotational driver about the tubulars. The rotational driver including a gearbox housing positionable about the connector, a socket carried by the gearbox housing to receivingly engage the connector, and a plurality of gears driven by at least one motor. The gears are operatively connectable to the socket to transfer torque from the at least one motor thereto, and have interlocking teeth defining a plurality of contacts therebewteen. The method also involves engaging the connector with the socket, and driving the connector through the adjacent tubulars by rotating the connector with the rotational driver and axially moving the rotational driver. 
     The may also involve selectively applying torque to the connector by rotating the gears with a first motor and applying additional torque to the connector by rotating the gears with a second motor, distributing load between the plurality of gears by engaging the gears along the plurality of contacts with the socket, and/or transferring torque from the motors to the socket with the gears. 
     Finally, in another aspect, the disclosure relates to a rotational driver for driving a connector through adjacent tubulars. The adjacent tubulars are positionable in a wellbore of a wellsite for passing fluid therethrough. The rotational driver includes a ratchet support positionable about the adjacent tubulars. a pawl housing slidably positionable along the ratchet support, a socket carried by the pawl housing to receivingly engage a connector (the socket rotationally driven by a motor), and a pawl selectively extendable from the pawl housing to engage the socket whereby the connector is rotatable. 
     The rotational driver may also include a ratchet lift operatively connectable to the ratchet support. The ratchet lift may also include a cylinder with a piston extendable therefrom. The piston may have a piston end operatively connectable to the ratchet support. The ratchet support may have a slot therethrough. The pawl housing may have a guide slidably positionable in the slot. 
     The rotational driver may also include a ratchet actuator operatively connectable to the pawl housing and the ratchet support. The pawl housing may be movable about the ratchet support by the ratchet actuator. The ratchet actuator may include a cylinder operatively connectable to the ratchet support and an actuator piston operatively connectable to the pawl housing. The pawl housing may have a pawl pocket to slidingly receive the pawl. The rotational driver may also include a motor having motor gears operatively connectable to the socket. The socket may be rotatable by the motor. The gears may include a motor gear driven by the motor and a ratchet gear. The ratchet gear may be operatively connectable to the socket to translate torque therebetween. 
    
    
     
       BRIEF DESCRIPTION DRAWINGS 
       So that the above recited features and advantages can be understood in detail, a more particular description, briefly summarized above, may be had by reference to the embodiments thereof that are illustrated in the appended drawings. It is to be noted, however, that the appended drawings illustrate only typical embodiments and are, therefore, not to be considered limiting of its scope. 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. 
         FIGS. 1A and 1B  are schematic views of an offshore wellsite having a riser extending from a surface platform to subsea equipment, the adjacent tubulars of the riser extending through a connection assembly on the surface platform. 
         FIGS. 2A and 2B  are schematic side and perspective views of the connection assembly disposed about adjacent tubulars, the connection assembly including a clam assembly and a carrier. 
         FIGS. 3A and 3B  are schematic perspective and exploded views of the clam assembly and carrier. 
         FIGS. 4A and 4B  are schematic top views of an orienting bracket of the clam assembly in an open and a closed position, respectively, about the tubular. 
         FIGS. 5A-5B through 8A-8B  are schematic top and perspective views, respectively, of the connection assembly in various positions during engagement about the adjacent tubulars. 
         FIGS. 9A and 9B  are schematic top and perspective views, respectively, of an alternate clam assembly and carrier. 
         FIGS. 10A and 10B  are schematic perspective and exploded views of the alternate clam assembly and carrier. 
         FIGS. 11A-11E  are schematic perspective and exploded views of a drive mechanism. 
         FIGS. 12A-12C  are schematic front perspective, back perspective and assembly views of the drive mechanism. 
         FIGS. 13A-13C  are schematic cross-sectional views of the drive mechanism in various positions for connecting the adjacent tubulars with a connector. 
         FIG. 14  is a flow chart depicting a method of connecting adjacent tubulars of a riser. 
         FIGS. 15A-15C  are perspective, cross-sectional, and exploded views, respectively, of a gearbox drive assembly carried by a carrier and positioned about a connector. 
         FIGS. 16A and 16B  are perspective views of the gearbox drive assembly of  FIG. 15A  in the disengaged and engaged positions, respectively, about the connector. 
         FIG. 17  is a side view of the gearbox drive assembly. 
         FIGS. 18A and 18B  are cross-sectional views of the gearbox drive assembly of  FIG. 17  taken along lines  18 A- 18 A and  18 B- 18 B, respectively. 
         FIG. 19  is a top view of the gearbox drive assembly of  FIG. 17 . 
         FIG. 20  is a cross-sectional view of the gearbox drive assembly of  FIG. 19  taken along line  19 - 19 . 
         FIGS. 21A and 21B  are perspective views of a ratchet drive assembly in a disengaged and an engaged position, respectively, about the connector of adjacent tubulars. 
         FIGS. 22A and 22B  are top and cross-sectional views of the ratchet drive assembly positioned about the connector of adjacent tubulars. 
         FIGS. 23A and 23B  are perspective and exploded views, respectively, of the ratchet drive assembly. 
         FIG. 24  is a side view of the alternate drive assembly of  FIG. 23A . 
         FIGS. 25A and 25B  are cross-sectional views of the alternate drive assembly of  FIG. 24  taken along line  25 - 25  in the extended and retracted positions, respectively. 
         FIG. 26  is a top view of the alternate drive assembly of  FIG. 23A . 
         FIG. 27A  is a vertical cross-sectional view of the alternate drive assembly of  FIG. 26  taken along line  27 A- 27 A.  FIG. 27B  is a horizontal cross-sectional view of the alternate drive assembly of  FIG. 26A  taken along line  27 B- 27 B. 
         FIGS. 28A and 28B  are flow charts depicting methods of connecting adjacent tubulars of a riser. 
     
    
    
     DETAILED DESCRIPTION 
     The description that follows includes exemplary systems, apparatuses, methods, and instruction sequences that embody techniques of the inventive subject matter. However, it is understood that the described embodiments may be practiced without these specific details. 
     A connection assembly for connecting adjacent tubulars, such as tubulars forming a riser extending between a platform and subsea equipment of a wellbore, is provided. The connection assembly includes a clam assembly movably positionable about the platform by a carrier. The clam assembly includes a plurality of segments movable between an open position and a closed position about the adjacent tubulars. The clam assembly includes an orienting bracket for locating the clam assembly about a reference component of the adjacent tubulars. The connection assembly also includes a drive mechanism to advance a connector between the adjacent tubulars to form a connection therebetween. 
     The connection assembly may be used to provide manual and/or automated make-up and/or break-up of tubular connections, such as connections between adjacent tubulars forming the riser. The clam assembly may be extendable and retractable for selective placement about the riser for connecting the adjacent tubulars. The connection assembly may be retractable from the tubulars at the platform to provide visual and/or physical access to the wellbore. Retraction may permit the connection assembly to be positioned for connection of the adjacent tubulars and/or moved away from equipment to prevent interference therewith. 
       FIGS. 1A and 1B  depict an example environment in which subject matter of the present disclosure may be utilized. These figures depict a wellsite  100  having a platform  102  and subsea equipment  104 , with a riser  106  therebetween. The platform  102  has a rig  108  and other surface equipment  110  for operating the wellsite  100 . The subsea equipment  104  is positioned about a wellhead  112  located on sea floor  114  adjacent a wellbore  116 . The subsea equipment  104  is schematically depicted as a box adjacent the wellhead  112 , but may be positioned about the sea floor  114  and may include various subsea components, such as strippers, blowout preventers, manifolds and/or other subsea devices for performing subsea operations. 
     The riser  106  is a system of tubulars  118  that form the riser  106  for joining the rig  108  on the platform  102  to the subsea equipment  104  on the sea floor  114 . The riser  106  may be used to extend the wellbore  116  through the water and/or for allowing drilling mud to be captured as it returns to surface. The riser  106  may be a drill through umbilical line between the subsea equipment and the rig  108  at the surface. 
     The riser  106  may also be provided with one or more external conduits  122 , such as electrical or fluid conduit (e.g., choke and kill, glycol, hydraulics, and/or riser-fill-up, etc.), for performing various functions, such as passing electrical signals and/or fluids between the platform  102  and the subsea equipment  104 . The conduits  122  may include various tubing, cables or other communication mechanisms. The conduit(s)  122  may run along the riser  106  from the platform  102  to the subsea equipment  104 . 
     The tubulars  118  may be tubular members with flanged ends joined to form the tubular connection  120  therebetween. The tubulars  118  may be, for example, tubing having a length of about 75 feet (22.86 m) in length. The tubular connections  120  may also support one or more of the conduits  122  in a desired configuration about the riser  106 . The tubulars  118  and the tubular connections  120  may be modular for use with selected combinations of conduits  122 . Each tubular connection  120  may be configured and selected for use with a selected tubular  118 . The tubulars  118  and the tubular connections  120  may be configured to support the riser  106  and the conduits  122  in position in subsea conditions. 
     The surface equipment  110  may include a control room  124 , draw works  126 , a transporter  128 , a storage facility  130 , and a connection assembly  132 . The control room  124  may include processing, control and/or communication equipment for operation of the wellsite  100 . The control room  124  may be used to send/receive data, communication and/or control signals to/from the connection assembly. 
     The draw works  126  may include, for example, a Kelly, top drive, elevator, and/or other equipment, capable of supporting tubulars  118  during connection. The transporter  128  may be, for example, a riser delivery truck, used to carry the tubulars  118  from the storage facility  130  to a position on the platform  102  and/or to the draw works  126  for connection. One or more tubulars  118  may be pre-assembled for connection to the riser  106 . 
     The connection assembly  132  is positioned on the surface platform  102  about an upper end of the riser  106  for supporting the tubulars  118  during connection. The connection assembly  132  may be positioned about a hole extending through the platform  102 . The connection assembly  132  may be positionable about an upper end of the riser  106  for automatic and/or manual connection of tubulars  118  to the riser  106 . The connection assembly  132  may be capable of moving to a position on the platform  102  for performing the connecting and to a position that avoids interference with equipment on the surface platform. 
     The tubulars  118  may be supported on the platform  102  by the draw works  126  and connected by the connection assembly  132  to an adjacent tubular extending through the platform. A series of tubulars  118  may be connected by the connection assembly to form the riser  106  extending below the platform  102 . 
     While  FIGS. 1A and 1B  show a series of tubulars  118  forming a riser  106  in a subsea application, it will be appreciated that the connection assembly  132  may be used to connect tubulars  118  and tubular connections  120  may be used in a variety of land or water based oilwell applications. 
     Connection Assembly 
       FIGS. 2A and 2B  show side and perspective views of the connection assembly  132  positionable about tubulars  118  for connection thereof. The connection assembly  132  includes a riser support (e.g., a spider)  234 , a carrier  236 , and a clam assembly  238 . The riser support  234  is positionable on the platform  102  for supporting the tubular  118  at a surface end of the riser  106  extending below the platform  102 . The riser support  234  includes a flanged body  240  with a hole extending therethrough and clamps  242 . The hole of the riser support  234  is aligned with a hole of the platform  102  for passing tubulars  118  therethrough. The clamps  242  may be engageable with the tubular  118  of the riser  106  for supporting the tubular  118  during connection. Examples of devices usable as the riser support  234  are provided in U.S. Pat. Nos. 8,020,626, 8,157,018 and 8,347,972, previously incorporated by reference herein. 
     The carrier  236  may be any transport mechanism capable of transporting the clam assembly  238  into and out of position about the riser  106  for connecting of the tubulars  118 . The carrier  236  may be mounted to the riser support  234  via any method that provides movement (e.g., linear movement) of the clam assembly  238 . The clam assembly  238  is removably connectable to the carrier  236 . As shown, the carrier  236  includes a pair of rails  244  with a frame  246  thereon. The rails  244  are positionable on the riser support  234  with the frame  246  slidably positionable therealong. The riser support  234  is configured to carry the clam assembly  238  between a retracted position a distance from the riser  106  and an engagement position about the riser  106 . The carrier  236  may also be used to move the clam assembly  238  away from and/or out of the way of the surface equipment  110  and/or tubulars  118 . 
     As shown in greater detail in  FIGS. 3A and 3B , the frame  246  includes a brace  245  with rail supports  247  slidably positionable along the rails  244  ( FIGS. 2A and 2B ). The brace  245  has vertical side portions with a bottom portion  249  extending therebetween for supporting the clam assembly  238  thereon. A locking plate  251  is positionable on the vertical side portions of the brace  245  for securing the clam assembly  238  therebetween. 
     As also shown in  FIGS. 3A and 3B , the clam assembly  238  includes a plurality of segments  248  pivotally connected and movable between an open and a closed position. The clam assembly  236  may be hinged and separated into two or more portions with the ability to open and clear the tubulars  118  as it approaches, and to close about the tubulars  118  (see, e.g.,  FIG. 2B ) for forming connections  120  between the tubulars. 
     Segment plates  254  are provided for connection between the segments  248 . Each of the segments  248  includes upper and lower segment brackets  250  with at least one drive mechanism  252  therebetween. As shown, the clam assembly  238  includes three curved segments  248 , a central segment with two lateral segments pivotally connected thereto. The central segment  248  of the clam assembly  238  is supported between the vertical side portions and bottom portion of the brace  245 . The lateral segments  248  are pivotally movable about the central segment  248  of the clam assembly  238 . 
     The clam assembly  238  contains as many drive mechanisms  252  as there are connectors to be driven through the tubulars  118 . Each of the drive mechanisms  1152  may have independent axial movement to independently respond to variations, such as variable advancing and retracting of the connectors due to, for example, friction, lubrication, fluid flow, etc. 
     The clam assembly  238  is also provided with an orienter  254  for positioning the clam assembly  238  about the tubulars  118  for connection. As shown, the orienter  254  includes a support key  256   a  and a position key  256   b . The support key  246   a  may have a fixed inlet to receivingly engage a reference component, such as one of the conduits  122 , of the tubulars  118 . The position key  256   b  includes pivoting arms  258   a  supported by a linear arm  258   b . The pivot arms  258   a  may grippingly engage the reference component. 
     The engagement of the support key  246   a  and the position key  256   b  may be used to orient the clam assembly  238  about the tubulars  118  during connection.  FIGS. 4A and 4B  show the orienter  254  in an open and closed position, respectively, about a reference component  460  of a riser  106 . In this example, the reference component  460  may be one of the conduits  122  (e.g., a choke or kill line) extending along the tubulars  118  and the riser  106 . 
     In  FIG. 4A , the pivoting arms  258  are in the open position to define an inlet for receivingly engaging the reference component  460 . The pivoting arms  248  may be movably positionable for grippingly engaging the reference component  460 . Once secured in position with the orienter  254 , the segments  248  of the clamshell assembly  238  may close to surround the tubulars  118 . 
     In  FIG. 4B , the pivoting arms  258  are in the closed position to grippingly receive the reference component  460 . In this position, the clam assembly  238  is secured to the riser  106  at a known orientation. With the support key  256   a  and the position key  256   b  locked about the reference component  460 , the clam assembly  238  is oriented about a known position on the tubulars  118 . Other components of the riser  106 , such as connectors (e.g., bolts)  462  and openings  463  in the tubular, are now also in known positions relative to the orienter  254 . With the clam assembly  238  positioned about the tubulars  118 , the drive mechanisms  252  may be disposed in predetermined positions about the tubulars  118 . For known dimensions of the tubulars  118  and connectors  462 , the drive mechanisms  252  may be positioned on the clam assembly  238  such that, when oriented about the reference component  460 , the drive mechanisms  252  are positionable about holes of the tubular  118  for driving connectors  462  therein. 
       FIGS. 5A-5B through 8A-8B  depict the connection assembly  132  in various positions during operation.  FIGS. 5A-8A  show top views of the connection assembly  132  in the various positions.  FIGS. 5B-8B  show perspective views of the connection assembly  132  in the various positions. 
     As shown in  FIGS. 5A-5B , the clam assembly  238  is in a retracted position along the carrier  236  away from the riser  106  with the segments  248  in a closed position. The riser support  234  is clamped about the riser  106 , and an additional tubular  118  is positioned adjacent to tubular  118  of the riser  106  for forming the connection  120  therebetween. 
     As shown in  FIGS. 6A-6B , the segments  248  of the clam assembly  238  have pivotally moved to an open position to receive the tubulars  118 . As shown in  FIGS. 7A-7B , the carrier  236  has moved the clam assembly  238  to an extended position for engagement with the tubulars  118 . With the segments  248  in the open position, the clam assembly  238  slides along the rails  244  of the carrier  236  to a position adjacent the tubular  118 . The arms  258   a  of the orienter  254  receive the reference component  460 , and the segments  248  begin surrounding the tubular  118 . 
     As shown in  FIGS. 8A-8B , the segments  248  are moved to a closed position surrounding the tubular  118 , and the orienter  254  grippingly engages the reference component  460 . In this position, the clam assembly  238  is secured about the tubular  118  in a known position relative to the reference component  460 . The drive mechanisms  252  are positioned along the segments  248  such that, when the segments  248  are closed about the tubular  118  and oriented by orienter  254 , the drive mechanisms  252  are positioned about openings  463  for driving connectors  464  therethrough (see, e.g.,  FIGS. 4A and 4B ). Adjacent tubulars  118  may be fastened together by disposing the connectors (e.g., bolts)  462  through the flanged ends of the tubulars  118  using the drive mechanism  252 . 
     Sensors may be disposed about the connection assembly to monitor parameters thereof during operation. The control room  124  or other surface equipment  110  ( FIG. 1B ) may be provided with processing and/or control units for collecting data, performing analysis, sending control signals, and generating reports (e.g., control curve plots). The surface equipment  110  may be used, for example, to provide real time feedback for automatic or manual operation and/or adjustment. For example, sensors may be positioned about the orienter, plurality of segments and/or carrier to provide information about position that may be used to adjust placement as needed. 
     A time period for forming a riser  106  may include a length of time it takes to fasten each tubular  118  of the riser  106  together. For example, 100 tubulars connected at 30 minutes per tubular may take a total of about 50 hours to connect. The connection may be performed manually (e.g., by an operator equipped with a hydraulic torque wrench/driver) or automatically. An automated process may be used to provide a predetermined connection time, for example, of about five minutes for bolting the tubulars and about five minutes to lower the tubular, for a total time of about 16.7 hours for forming a riser of 100 tubulars. 
       FIGS. 9A-10B  show an alternate carrier  936  and clam assembly  938 .  FIGS. 9A and 9B  show perspective and top views, respectively, of the clam assembly  938  carried by the alternate carrier  936 .  FIGS. 10A and 10B  show perspective and exploded views of the clam assembly  938 . This alternate version employs a rolling carrier  936  positionable about the riser support  234  and/or platform  102  ( FIG. 2B ). This alternate version is similar to the carrier  936  and clam assembly  238  previously described, but demonstrates some possible variations. 
     In this version, the carrier  936  includes car  944 , a frame  946 , and a crane  947 . The car  944  has rollers  945  for movably positioning the clam assembly  938 . The frame  946  is operatively connectable to the clam assembly  938 . The crane  947  is movably connectable between the frame  246  to the car  944 . The crane  947  may be used to lift and/or translate the frame  946 . The frame  946  is movably mounted on the car  946  by the crane  947  to carry the clam assembly  938  into position about the riser support  234  for connection of the adjacent tubulars  118 . 
     As shown in  FIGS. 10A and 10B , the clam assembly  938  includes a plurality of segments  1048  pivotally connected and movable between an open and a closed position. Connector plate  1054  is provided for connection between the segments  1048 . Each of the segments  1048  includes upper and lower brackets  1050  with at least one drive mechanism  252  therebetween. 
     As shown, the clam assembly  1038  includes two curved segments  1048  with the connector plate  1054  therebetween. The segments  1048  are pivotally movable about the connector plate  1054  of the clam assembly  938 . The connector plate  1054  of the clam assembly  938  is operatively connected to a base portion of the frame  1045 . The frame  946  includes the base portion with two lateral wings extending therefrom. Each of the wings is operatively connected to the segments  1048  for supporting the segments about the frame  946 . 
     The clam assembly  938  is also provided with an orienter  1058  for positioning the clam assembly  938  about the reference component  460  on the riser  106  (see, e.g.,  FIGS. 4A and 4B ). As shown, the orienter  254  includes pivoting grip arms  1056  with a spring  1059  therebetween. The grip arms  1056  define an inlet for receiving the reference component  460 . The grip arms  1056  are movably positionable for grippingly engaging the reference component  460 . 
       FIGS. 11A-13C  show various views of a drive mechanism  1152  usable with the clam assemblies  238  and  938 .  FIG. 11A  shows a drive mechanism  1152  carried by the clam assembly  238 ,  938  and positioned adjacent tubulars  118  for driving connectors  462  into the tubulars  118 .  FIGS. 11B-11D  show the drive mechanism  1152  in various positions as the connector  462  is driven into the adjacent tubulars  118 .  FIGS. 12A and 12B  show front and back perspective views of the drive mechanism  1152 .  FIGS. 11E and 12C  show exploded views of the drive mechanism  1152 . 
     The drive mechanism  1152  includes an axial rail  1160 , a lift  1162 , a rail bracket  1164 , and a rotational driver  1166 . The axial rail  1160  is supported between upper and lower brackets  250 ,  1050  of the clam assembly  238 ,  938 . The axial rail  1160  has a track therealong for receiving the rail bracket  1164 . The lift  1162  includes a cylinder  1166  with a piston  1168  extendable therefrom and a piston bracket  1170  on an end of the piston  1168 . 
     The lift  1162  is supported on the lower bracket  250 ,  1150  adjacent the axial rail  1160  with the piston bracket  1170  movably positionable along the axial rail  1160 . The rail bracket  1164  is operatively connectable to the lift cylinder  1166  and movable along the axial rail  1160  thereby. The rail bracket  1164  is also operatively connectable to the rotational driver  1166  for slidably positioning the rotational driver  1166  along the axial rail. The drive mechanisms  1152  may be horizontally positionable along the rail  1160  to adapt to various riser configurations. 
     The rotational driver  1166  may be any driver capable of advancing the connector  462  into the adjacent tubulars  118  of the riser  106  to form a connection  120  therebetween. For example, the rotational driver  1166  may be a torque tool capable of rotationally driving a bolt into threaded openings  463  in the tubulars  118 . The rotational driver  1166  may be, for example, a rotating wrench capable of receiving a hex head of a bolt and rotationally driving the bolt into threads in the openings  463  in tubulars  118 . While a rotational driver  1166  is described and depicted, other drivers may be used to drive the connectors  462 . 
       FIGS. 11A-11C  show perspective views and  FIGS. 13A-13C  show a vertical cross-sectional view of the drive mechanism  1162  in a disengaged, an engaged, and a connected position, respectively, during operation. The positions of  FIGS. 11A-11C and 13A-13C  may be depicted after the drive mechanism  1162  has been positioned about the connectors using, for example, the carriers and clam assemblies described herein. 
     In the disengaged position of  FIGS. 11A and 13A , the piston  1162  is extended and the rotational driver  1166  is positioned in alignment with the connector  462  a distance thereabove. In the engaged position of  FIGS. 11A and 13B , the piston  1162  is partially retracted and the piston bracket  1170  and the rail bracket  1164  move the rotational driver  1166  downward along the rails  1160  to engage the connector  462 . As the piston  1162  retracts, the piston bracket  1170  and the rail bracket  1164  move the rotational driver  1166  downward along the rails  1160  to engage the connector  462 . 
     In the connected position of  FIGS. 11A and 13C , the piston  1162  is fully retracted and the rotational driver  1166  is moved downward along the rails  1160  by the piston bracket  1170  and rail bracket  1164 . As the rotational driver  1166  is moved towards the connected position, the connector  462  may be rotated by the rotational driver  1166  and advanced through the adjacent tubulars  118  to form the connection  120  therebetween. 
     As also shown in  FIGS. 13A and 13B , the tubulars  118  may be threaded and/or contain a retained nut  1311  with threads to threadedly engage the connectors  462 . For example, the tubulars  118  may contain a threaded collar to hold the connector during disconnection (e.g., for storage purposes). The connectors  462  may have mated threads to threadedly engage the threads of the tubulars  108  and/or nuts  1311  therein. Example connectors  462  may be bolts having pre-loads with torque values between 5,000 to 15,000 ft-lbs (6779.09 N-m to 20,337.27 N-M). The drive mechanisms  1162  and/or rotational drivers  1166  may be configured to facilitate connection with the connectors  462 . 
       FIG. 14  is a flow chart depicting a method  1400  of connecting adjacent tubulars of a riser. The method  1400  involves positioning  1472  a clam assembly about a platform, The clam assembly includes a plurality of segments selectively movable between an open position to receive the adjacent tubulars and a closed position positionable around the adjacent tubulars (the segments disposable about a periphery of the adjacent tubulars), an orienting bracket carried by the segments and engageable with a reference component of the adjacent tubulars, and a driver carried by the segments, the drive mechanism including a socket to engage the connector (the drive mechanism movable between a retracted and an extended position). 
     The method further involves  1474 —orienting a clam assembly about a reference component of the adjacent tubulars,  1476 —closing the clam assembly about the adjacent tubulars, and  1478 —forming a connection between the adjacent tubulars with the connector by advancing the connector between a retracted and an extended position with the drive mechanism. The method may also involve  1480 —opening the clam assembly and  1482 —retracting the clam assembly from the adjacent tubulars. 
     The steps may be performed in any order, and repeated as desired. 
     Rotational Driver 
     A rotational driver carried by an oilfield connection assembly for connecting adjacent tubulars, such as tubulars forming a riser extending between a platform and subsea equipment of a wellbore, is provided. The rotational driver may be configured for carrying by a carrier for placement about the adjacent tubulars. The rotational driver may receivingly engage a connector, such as a bolt, and advance the connector through adjacent tubulars to form a connection therebetween. The rotational driver may have, for example, a gearbox or a ratchet configuration. 
     1. Gearbox Configuration 
     The gearbox configuration uses motor driven gears to rotate the connector as the rotational driver is axially moved. The rotational driver may be reversible to provide installation and removal of the connectors without requiring a change of equipment. The gears may be provided in a stacked, compact gearbox configuration to transfer torque from the motors to the connector. The gearbox configuration may be used to provide for reversibility, durability, simple controls, compact design, reduced peak loading, variable teach loading, etc. 
       FIGS. 15A-20  show various views of a gearbox configuration of a rotational driver  1566 .  FIGS. 15A-15C  show perspective, cross-sectional, and exploded views, respectively, of the rotational driver  1566 . One or more of the rotational driver  1566  may be carried by a carrier, such as clam assembly  238  of  FIGS. 2A-8B . The rotational drivers are positionable for driving the connectors  462  in holes  463  to connect tubulars  118  of a riser  106 . The rotational driver  1566  includes a gearbox  1567 , gears  1569 , motors  1571 , a socket  1573 , and a retainer  1575 . 
     The gearbox  1567  may be provided with a handle, box bracket or other device for supporting and/or carrying the rotational driver  1566  during operation. As shown, the gearbox  1567  is operatively connectable to the axial rail  1160  of the clam assembly  238  by the rail bracket  1164 . The gearbox  1567  may be sized to fit compact spaces about the clam assembly  238  and/or the tubulars  118  for connection. The gearbox  1567  has the gears  1569  therein rotationally driven by motors  1571 . The motors  1571  may be, for example, one or more motors operatively connected to a power source for selectively activating portions of the drive assembly  1566 . The gearbox  1567  may be made of a deflectable material, such as aluminum, that may deflect under load to compensate for positional tolerances. 
     The gears  1569   a - f  are coupled to the socket  1573  for rotation thereof. The socket  1573  may have an inlet for receiving a head of the connector  462 . The socket  1573  may be, for example, a wrench socket for receivingly engaging a hex head of a bolt. Rotation of the socket  1573  may be used to rotate the connector  462  as the rotational driver  1566  is advanced, thereby extending the connector  462  through threaded holes  463  in the tubulars  118 . Optionally, nuts  1561  may be positioned in holes  463  the tubulars  118  to facilitate connection with connector  462 . The retainer  1575  may optionally be provided to secure the connector  462  in the socket  1573 . 
       FIGS. 16A and 16B  depict operation of the retainer  1575 . These figures show bottom perspective views of the rotational driver  1566  before and after engagement, respectively, with the connector  462 . As shown in these views, the retainer  1575  may include a retainer bracket  1577 , a cylinder  1579 , a piston  1581 , and a wedge  1583 . The retainer bracket  1575  is operatively connectable to the gearbox  1567 . The cylinder  1579  is supported by the retainer bracket  1575  with the piston  1581  extendable therefrom. The wedge  1583  is positioned on an end of the piston  1581 . 
     The retainer bracket  1575  includes a base with a pivoting end operatively connected to the wedge  1583 . As the piston  1581  extends and retracts, the pivoting end rotates to selectively extend and retract the wedge  1583 . The wedge  1583  is movable by the piston  1581  and retainer bracket  1577  between a retracted position away from the connector  462  and an extended position in engagement with the connector  462 . As shown, the connector  462  is a bolt with a shoulder to receivingly engage the wedge  1583 . In the extended position, the wedge  1583  pinches a head of the connector  1583  against the socket  1573  thereby retaining the connector  462  in the socket  1573  of the rotational driver  1566 . 
     The retainer  1575  may be used to lift and lower the connector  462 . The lifting may be performed gently so as not to damage threads and/or nuts  1561  in the tubular  118  ( FIG. 15B ). The retainer  1575  may be pneumatically or hydraulically actuated by the motors  1571 . 
     The rotational driver  1566  may be provided with other components, such as directional control valves and position sensors to monitor the connection process, determine when to active the motors  1571 , and indicate a direction of rotation for the gears  1569   a - f . Guided positioning of the rotational driver  1566  may be provided using, for example, the clam assembly  238  and/or the carrier  236 . For example, a proximity sensor may be provided about teeth of the gears  1569  to measure rotation. 
     The rotational driver  1566  may be manually and/or automatically operated. The control room  124  or other surface equipment  110  ( FIG. 1B ) may be provided with processing and/or control units for collecting data, performing analysis, sending control signals, and generating reports (e.g., control curve plots). The surface equipment  110  may be used, for example, to provide real time feedback for automatic or manual operation and/or adjustment. For example, where multiple drive assemblies  1566  may be provided about the tubulars  118 , multiple connectors  462  may be engaged to connect multiple tubulars  118  (see, e.g.,  FIG. 15B ). Simultaneous, automatic connections  120  may be provided based on real time data. 
       FIGS. 17-20  show additional views depicting operation of the gears  1569   a - f .  FIG. 17  shows a side view of the rotational driver  1566 .  FIGS. 18A and 18B  are cross-sectional views of the rotational driver  1566  taken along lines  18 A- 18 A and  18 B- 18 B, respectively.  FIG. 19  is a top view of the rotational driver  1566 .  FIG. 20  is a cross-sectional view of the rotational driver  1566  of  FIG. 19  taken along line  20 - 20 . As shown in these views, the gears include a pair of pinion gears  1569   a  operatively coupled to the motors  1571  for rotation thereby. 
     The pinion gears  1569   a  drive a drive gear  1569   b . The drive gear  1569   b  has a drive shaft  1569   c  therein rotated by the drive gear  1569   b . The driver shaft  1569   c  has a drive end  1569   d  connected thereto and rotated therewith. The drive end  1569   d  rotates intermediate gears  1569   e . The intermediate gears  1569   e  are coupled to a socket gear  1569   f  for transferring rotation from the secondary gear  1569   e  to the socket gear  1569   f . The socket gear  1569   f  is coupled to the socket  1573  to transfer rotation from the secondary gear  1569   e  thereto. The intermediate gears  1569   e  have teeth  1565  interlockingly engaging teeth of the socket gear  1569   f . Multiple intermediate gears  1569   e  may be used to provide multiple points of engagement with the socket gear  1569   f.    
     Each pinion gear  1569   a  may be connected to one of the motors  1571 . One or more pinion gears  1569   a  and one or more motors  1571  may be used. The motors  1571  may be low speed/high torque hydraulic drive motors capable of turning the pinion gears  1569   a , and the drive gear  1569   b  meshed with the pinion gears  1569   a . A first of the motors  1571  may be used to drive the gears  1569   a - f  during the initial rotation of the connectors  462 . The first motor  1571  may thread or unthread the connector  462  under high flow, low hydraulic pressure. Once the connector  462  is seated in the tubulars  118 , a second of the motors  1571  may be utilized in parallel with the first motor  1571 , both operating with low flow, high hydraulic pressure to tighten the connector  462  in place in the tubulars  118 . The operation may be reversed to break the connector  462  away from the tubulars  118  and/or to retract the connector  462  from the tubulars. 
     The gears  1569  may be provided with a gear ratio to facilitate the transfer of torque while minimizing the effects of loads and/or stresses on the drive assembly  1566 . The pinion gears  1569   a  may be meshed with the drive gear  1569   b  to amplify torque as needed. The drive gear  1569   b  may have a larger diameter than the pinion and intermediate gears  1569   a,d  to transfer torque as needed. The various gears  1569 , as shown, may be stacked to reduce spacing and thereby the overall size of the gearbox  2567 . The stacked gears  1569  may be configured to drive connectors  462  in a location where head room may be limited. 
     Torque from the motors  1571  may be multiplied within reduced space by to the gears  1569  and transferred into a narrow envelope within the gearbox  1567  by loading multiple teeth of the intermediate gears  1569   e  simultaneously on the socket gear  1569   f . One or more of the intermediate gears  1569   e  may be provided to transfer torque to the socket gear  1569   f . In the example shown, two intermediate gears  1569   e  are used to provide multiple contact points for transferring torque. In such cases, at least two gear teeth may be loaded simultaneously to reduce tooth bending stress on the gears  1569 . 
     2. Ratchet Configuration 
     The ratchet configuration may be used to drive the connectors of the tubulars. The ratchet configuration employs a ratchet to rotate the connector as the rotational driver is axially moved. The rotational driver includes a pawl housing rotatable about a ratchet support by a ratchet motor and gears, and a pawl extendable from the ratchet housing to engage a socket and rotate the connector. The pawl may have multiple teeth engageable with the socket to disperse load therealong. The ratchet configuration may be used to provide for reversibility, durability, simple controls, compact design, reduced peak loading, variable teach loading, etc. 
       FIGS. 21A-25B  show the ratchet configuration of a drive mechanism  2152  and a rotational driver  2166  in position about adjacent tubulars  118  and driving a connector  462  therethrough.  FIGS. 21A and 21B  shows the ratchet configuration in a retracted and an extended position, respectively.  FIG. 22A  shows a top view of the drive mechanism  2152 , rotational driver  2166  in the extended position of  FIG. 21B .  FIG. 22B  shows a cross-sectional view of  FIG. 22A  taken along line  22 B- 22 B.  FIGS. 23A and 23B  show perspective and exploded views of the rotational driver  2166  coupled to a drive mechanism  2152 . 
     The drive mechanism  2152  may be a device for axially positioning the rotational driver  2166 , such as those described herein (e.g., drive mechanism  1152  of  FIGS. 11A-11B ). The drive mechanism  2152  may be carried manually and/or by a clam assembly and/or carrier as described herein. The drive mechanism  2152  may include upper and lower drive plates  2153  connected by supports  2151 . Rotational driver  2166  may be supported between the drive plates  2153 . Optionally, a hook  2149  may be provided on the drive plate for carrying the drive mechanism  2152  and/or rotational driver  2166 . 
     The rotational driver  2166  includes a ratchet support  2155 , a pawl housing  2159 , a ratchet actuator  2175 , and a socket  2173 . The ratchet support  2155  is operatively connectable to the drive plates  2153  with the pawl housing  2159  movable thereabout via movement of the ratchet actuator  2175 . The ratchet support  2155  may include a ratchet base  2177  with a ratchet arms  2179  extending therefrom. A slot  2181  extends through at least one of the ratchet arms  2179 . The ratchet support  2155  and arms  2179  movably support the pawl housing  2159  in the slot  2181 . 
     The ratchet support  2155  may be operatively connected to or integral with an axial driver  2183 . As shown, the axial driver  2183  includes a ratchet cylinder  2185  with a ratchet piston  2187  and a piston bracket  2189 . The piston bracket  2189  is operatively connected to or integral with the ratchet support  2155 . The ratchet support  2155 , and, therefore, the rotational driver  2166 , are axially movable along the ratchet support  2155  by movement of the ratchet piston  2187 . 
     The pawl housing  2159  has a pawl pocket  2189  for slidingly receiving the pawl  2169 . The ratchet actuator  2175  includes an actuator cylinder  2191  operatively connecting the pawl housing  2159  to the ratchet support  2155 . The actuator cylinder  2191  is operatively connected to the ratchet support  2155  and has an actuator piston  2193  extending therefrom. The actuator piston  2193  has an actuator end operatively connectable to the pawl housing. 
       FIG. 24  shows a side view of the drive mechanism  2152  and the rotational driver  2166 .  FIGS. 25A and 25B  show a cross-sectional view of the drive mechanism  2152  and rotational driver  2166  in the retracted and extended positions, respectively. Extension and retraction of the actuator piston  2193  permits pivotal and/or sliding movement of the pawl housing  2159  along the slot  2181  in the ratchet support  2155 . The pawl housing  2159  has a guide  2195  extending therethrough and receivably engageable with the slot  2181  of the ratchet support  2155 . The guide  2195  and slot  2181  interact to define a path of travel for the pawl housing  2159 . As shown, the slot  2181  is curved to provide for translation and rotation of the pawl housing  2159  along a predetermined path between the retracted position of  FIG. 25A  and the extended position of  FIG. 25B . 
     As shown in  FIGS. 24-25B , the rotational driver  2166  also includes a pawl  2169  engageable with the socket  2173 . The pawl  2169  is slidingly movable in the pawl pocket  2189  in response to pressure applied thereto. The pawl  2169  may be hydraulically activated by a hydraulic source fluidly coupled to the pawl pocket  2189 . As shown in  FIGS. 25A and 25B , the pawl  2169  is movable between a disengaged position of  FIG. 25A  to an engaged position of  FIG. 25B . 
     The pawl  2169  has a toothed head  2197  engageable with the socket  2173 . The pawl  2169  may be hydraulically activated and centrally located about a head of the connector  462 . The socket  2173  may be operatively connectable to the connector  462  for rotation thereof by movement of the pawl housing  2159  and the pawl  2169 . The toothed head  2197  of the pawl  2169  may be wide enough to engage multiple teeth for load distribution therebetween. The toothed head  2197  of the pawl  2169  may also be used to restrict rolling that may occur when the pawl  2169  is engaged with the socket  2173 , but does not move relative to it. 
     As shown by  FIGS. 26-27B , a ratchet motor  2157  and ratchet gears  2197   a,b  may be used to drive the rotational driver  2166 . The ratchet motor  2157  may be, for example, spin drive motor, directly or indirectly coupled to the socket  2173  by gears  2197   a,b . The gears  2197   a,b  may include a motor gear  2197   a  rotationally driven by the motor  2157  and a ratchet gear  2197   b  operatively coupled between the motor  2157  and the socket  2197  for transferring movement therebetween. 
     While the motor  2157  is rotating to thread or unthread a bolt, the pawl  2169  is retracted. To apply final (increased) torque or to loosen (breakaway), the actuator piston  2197  applies force and leverage to the pawl housing  2159  for rotation thereof along the slot  2181 . The pawl  2169  may be configured with a first piston area for torqueing down and a second piston area for breaking away (loosening). The pawl  2169  may advance the connector  462  by a tightening or loosening stroke to the pawl housing  2159 , and retracted for return stroke of the pawl housing  2159 . The pawl  2173  retracts and the actuator piston  2197  strokes forward at which point the pawl  2169  may re-engage for a next turn of the connector  462 . 
     Sensors may optionally be provided about the rotational driver  2166  to detect engagement of the pawl  2169  and/or forces on the rotational driver  2166 . When the pawl  2169  engages there may be times when the toothed head  2197  of the pawl  2169  contacts the socket  2173  crest to crest and thus may not properly seat. The sensors may be positioned about the actuator piston  2193  before an end of a stroke to trigger a controller to actuate the pawl  2169  prematurely to ensure teeth of the pawl  2169  and socket  2173  properly engage. 
     In operation, the pawl housing  2157  may be in a start position with the pawl  2169  retracted as shown in  FIG. 25A . The pawl  2169  may be hydraulically activated to engage the socket  2173 . Once engaged, the socket  2173 , and thereby the connector  462  coupled to the socket  2173 , may be rotated by movement of the pawl housing  2159  to the rotated position of  FIG. 25B . The pawl housing  2159  may be selectively rotated by extension and retraction of the actuator piston  2193 . The pawl  2169  may be retracted so that the motor  2157  rotates motor gear  2197   a . The socket  2173 , and the connector  462  therein, is then rotated by the rotation of the ratchet gear  2197   b  by the motor gear  2197   a . The pawl  2169  may be extended for engagement with the socket  2173  and rotated by movement of the pawl housing  2157  to tighten the connector  462 . The process may be reversed for removal of the connector. 
       FIGS. 28A and 28B  are flow charts depicting methods  2800 A and  2800 B of connecting adjacent tubulars of a riser. The method  2800   a  depicts a method using the gearbox configuration of  FIGS. 15A-20 . The method  2800   b  depicts a method using the ratchet configuration of  FIGS. 21-28B . 
     The method  2800   a  involves positioning a rotational driver about the tubulars. The rotational driver includes a gearbox housing, a socket carried by the gearbox housing to receivingly engage a connector, and a plurality of gears driven by at least one motor, the gears interlocking teeth defining at a plurality of contacts therebetween whereby load on the gears is distributable therebetween. The method further involves  2874   a  engaging the connector with the socket,  2876   a —driving the connector through the adjacent tubulars by rotating the connector with the rotational driver and axially moving the rotational driver, and  2878   a —selectively applying torque to the connector by rotating the gears with a first motor and applying additional torque to the connector by rotating the gears with a second motor. 
     The method  2800   b  involves positioning a rotational driver about the tubulars. The rotational driver includes a ratchet support, a pawl housing slidably positionable along the ratchet support, a socket carried by the pawl housing to receivingly engage a connector, the socket rotational driven by a motor, and a pawl selectively extendable from the pawl housing to engage the socket whereby the connector is rotatable by the pawl housing. The method further involves  2874   b —engaging the connector with the socket,  2876   b  driving the connector through the adjacent tubulars by rotating the connector with the rotational driver and axially moving the rotational driver,  2878   b —rotating the connector by retracting the pawl and rotating the socket with the motor, and  2880   b —applying torque to the connector by engaging the socket with the pawl and moving the pawl housing along the ratchet support. 
     The methods may be performed in any order, and repeated as desired. 
     It will be appreciated by those skilled in the art that the techniques disclosed herein can be implemented for automated/autonomous applications via software configured with algorithms to perform the desired functions. These aspects can be implemented by programming one or more suitable general-purpose computers having appropriate hardware. The programming may be accomplished through the use of one or more program storage devices readable by the processor(s) and encoding one or more programs of instructions executable by the computer for performing the operations described herein. The program storage device may take the form of, e.g., one or more floppy disks; a CD ROM or other optical disk; a read-only memory chip (ROM); and other forms of the kind well known in the art or subsequently developed. The program of instructions may be “object code,” i.e., in binary form that is executable more-or-less directly by the computer; in “source code” that requires compilation or interpretation before execution; or in some intermediate form such as partially compiled code. The precise forms of the program storage device and of the encoding of instructions are immaterial here. Aspects of the subject matter may also be configured to perform the described functions (via appropriate hardware/software) solely on site and/or remotely controlled via an extended communication (e.g., wireless, internet, satellite, etc.) network. 
     While the embodiments are described with reference to various implementations and exploitations, it will be understood that these embodiments are illustrative and that the scope of the inventive subject matter is not limited to them. Many variations, modifications, additions and improvements are possible. For example, the clam assembly may be carried by a variety of carriers and have any number of segments and drive mechanism. 
     Plural instances may be provided for components, operations or structures described herein as a single instance. In general, structures and functionality presented as separate components in the exemplary configurations may be implemented as a combined structure or component. Similarly, structures and functionality presented as a single component may be implemented as separate components. These and other variations, modifications, additions, and improvements may fall within the scope of the inventive subject matter.