Abstract:
The present invention relates to a transverse bitbreaker plate, which is attached to the lower surface of a power wrench to effect the coupling or decoupling of downhole tools such as bits or stabilizers. The plate is hinged and provides a generally triangular shaped profile along through its transverse surface which mates with the bit or stabilizer, which is to be connected or disconnected. The hinged plate is removably attached below the power wrench with pins so that it may be used and removed in a minimum of time.

Description:
FIELD OF THE INVENTION 
     The present invention relates to an oil tool coupling and decoupling apparatus; more specifically, to an apparatus used for making up or breaking the connection between a downhole tool, such as a drill bit or stabilizer, and the drill string to which either is connected. 
     BACKGROUND OF THE INVENTION 
     In the process of drilling, “tripping” drill pipe into and out of the bore hole primarily requires repetitive connecting and disconnecting of the tubular members, but also less frequently requires repetitive connecting and disconnecting of stabilizers to a tubular drill string, and repetitive connecting and disconnecting the bit from the terminal end of the drill string. Historically, these connections were made by rig personnel moving a set of power wrenches or tongs onto the rig floor to engage the drill pipe and apply torque against the pipe as it was held fixed in location by the rotary table or the topdrive unit. Other devices, referred to as bitbreakers by those in the art, included a fixed metal plate, having the profile of the bit that was attached to the rotary table. Modern drilling rig rental rates dictate that this coupling/decoupling process be performed quickly to minimize the day rental charges for the drilling rig. Various forms of automated machinery have been proposed over the years for moving power tongs into and out of engagement with the drill string to perform these services. None, so far as known to applicant, combine the benefits of the bitbreaker with the automated features of the automated wrenches or tongs. 
     One form of automated wrenches or tongs moves an apparatus on a track into engagement with the drill string. These units move into engagement and automatically spin the tubular members to make up the joint, then torque the pipe to its make-up torque; or, break-out the pipe, then spin out the tubular member to complete disengagement. These units are heavy weighing in excess of 5,000 kg, require drive tracks or rails and are expensive. 
     As previously noted, so far as known to applicant, none of the automatic tong devices permitted the coupling or decoupling of stabilizers and bits to or from the drill string. These actions have historically been accomplished by pulling the drill string out of the well bore and manually engaging the tubular joint to be operated with a set of tongs, which are manipulated onto the rig floor by rig personnel. Applicant has devised tools for both spinning the drill string while holding a lower portion to make-up the tool joint, which also tightens the joint to operating torque after makeup. See for example, U.S. Pat. No. 6,212,976; International Publication WO 99/10130, PCT application number PCT/US98/17868; and U.S. Pat. No. 5,351,767; all of which are hereby incorporated herein by reference in their entireties as if copied verbatim herein. The present invention permits the applicant&#39;s existing tools, which spins and/or torque the drill string, to be used to automatically add and remove either stabilizers and drill bits on the drill string. This operation may be accomplished quickly and easily without additional equipment being moved onto the overcrowded rig floor. The apparatus may be suspended by conventional support means that permit the ready movement of the device out of the way of other rig operations. 
     SUMMARY OF THE INVENTION 
     The present invention is a wrench apparatus having utility to make up and break out a connection between a drill bit or a stabilizer and the drill string. The apparatus comprises an upper assembly having a gripper which is capable of gripping the drill string and a lower assembly which is capable of gripping the drill bit or stabilizer and a torque applicator for turning the upper gripping means and the lower gripping means in selectively opposite directions. 
     In one aspect, the present invention provides a wrench for make up and break out of a connection between a drill bit or stabilizer having a non-circular cross section and a drill pipe joint disposed along an upright axis. The wrench has an upper assembly comprising a first pipe gripper operable along an angle transverse to the upright axis for holding the drill pipe joint against rotation about the upright axis with respect to the upper assembly. A lower assembly depends from the upper assembly and comprises a drill bit- or stabilizer-receiving member having a non-circular opening matching the cross section of the drill bit or stabilizer for securing the drill bit or stabilizer against rotation about the upright axis with respect to the lower assembly. The lower assembly is rotatably secured with respect to the upper assembly to allow rotation of the upper and lower assemblies with respect to each other about the upright axis. A torque applicator is secured to the upper and lower assemblies for rotating the upper and lower assemblies with respect to each other. A lateral gate opening can be formed in the upper assembly for receiving the drill pipe joint in the pipe gripper. 
     The wrench preferably also includes a spinner yieldably mounted on the upper assembly for rotating the drill pipe joint about the upright axis with respect to the lower assembly. Springs can be provided between the upper assembly and the spinner. The lower assembly can include a housing for a second pipe gripper operable along an angle transverse to the upright axis for holding a drill pipe joint against rotation about the upright axis with respect to the lower assembly, and a lateral gate opening formed in the housing for receiving a drill pipe joint in the second pipe gripper. 
     The pipe gripper is preferably a jaw assembly. The jaw assembly can include a housing, a seating jaw and an opposed locking jaw movable toward the seating jaw along an operating axis of the jaw assembly at a transverse angle to the upright axis for securing the drill pipe joint between the jaws. 
     The drill bit- or stabilizer-receiving member is preferably supported by torque stabilizers removably supported from the housing in torque transmitting relation thereto. The opening is preferably formed in a transverse plate securely attached to the torque stabilizers. The transverse plate preferably has left and right sections hingedly connected at one side of the opening and lockable at an opposite side of the opening. The drill bit- or stabilizer-receiving member can include a drill bit lock secured to the transverse plate and movable into and from locking relation with the drill bit or stabilizer. 
     The vertical support is preferably movable transversely with respect to the upright axis between a first position wherein the pipe gripper is aligned with a drill string of a drilling rig and a second position disposed away from the drill string. 
     In another aspect, the present invention provides a method for breaking out a connection between a drill bit or stabilizer and a drill pipe section having a complementary threaded coupling. The method includes the steps of: 
     (a) positioning the drill bit or stabilizer in the opening of the drill bit- or stabilizer-receiving member of the wrench described above to secure the drill bit or stabilizer against rotation with respect to the lower assembly; 
     (b) inserting the drill pipe section through the lateral gate and into alignment with the pipe gripper in the upper assembly; 
     (c) holding the drill pipe section in the pipe gripper against rotation with respect to the upper assembly; 
     (d) actuating the torque applicator to rotate the upper assembly with respect to the lower assembly and loosen the connection. 
     The method can also include the steps of releasing the pipe gripper and spinning the drill pipe, while continuing to secure the drill bit or stabilizer against rotation with respect to the lower assembly, to disconnect the drill pipe from the drill bit or stabilizer. 
     In a further aspect, the present invention provides a method for making up a connection between a drill bit or stabilizer and a drill pipe section having a complementary threaded coupling. The method includes the steps of: 
     (a) positioning the drill bit or stabilizer in the opening of the drill bit- or stabilizer-receiving member of the wrench described above to secure the drill bit or stabilizer against rotation with respect to the lower assembly; 
     (b) engaging a lower end of the drill pipe section in the drill bit or stabilizer and spinning the drill pipe with respect to the lower assembly to shoulder the connection between the drill pipe and the drill bit or stabilizer; 
     (c) engaging the pipe gripper in the upper assembly to hold the drill pipe section in the pipe gripper against rotation with respect to the upper assembly; 
     (d) actuating the torque applicator to rotate the lower assembly with respect to the upper assembly to tighten the connection. 
     Where the wrench includes the spinner yieldably mounted on the upper assembly thereof, the spinning step preferably includes operation of the spinner. 
     In yet another aspect, the present invention provides an apparatus for coupling and decoupling downhole tools from a drill string on the rig floor. The apparatus has a plate providing a hole in the center having a non-circular geometric profile suitable for engagement of an exterior surface of the downhole tool. One or more arms extend upwardly from the plate for attaching the plate in spaced, torque-transmitting relationship below a hydraulically actuated wrench. The apparatus can also include a power wrench having brackets on a lower end thereof for attachment to the at least one upwardly extending arms of the hinged lockable plates, whereby torque may be applied to the drill string while holding the downhole tool in a relatively fixed position. The plate is preferably made of a pair of hinged, lockable sections that have opposing mating surfaces that form the geometric profile. 
    
    
     DETAILED DESCRIPTION OF THE DRAWINGS 
     FIG. 1 is a front elevation of the spinner/power wrench apparatus engaging a drill pipe and drill bit. 
     FIG. 2 is a side elevation of the spinner/power wrench apparatus engaging a drill pipe and drill bit. 
     FIG. 3 is a top view of the bit breaker plate showing the location of the hinge and lock pin. 
     FIG. 4 is schematic representation (both front and side) of the bitbreaker after installation around the drill bit and before engagement with the power wrench apparatus. 
     FIG. 5 is a top view of the hinged plate portion of the apparatus through the line  3  with the pin and hinge attached in its open position ready to be placed around the bit or stabilizer body to be connected. 
     FIG. 6 is a frontal view of the hinged plate portion of the apparatus in the closed position with the pin inserted. 
     FIG. 7 is a side view of an embodiment of the hinged plate showing the relative placement of the attaching pinholes. 
     FIG. 8 is a side view of another embodiment of the hinged plate showing multiple attaching pinhole arrangements for accommodating longer bits or stabilizers in the tool. 
     FIG. 9 is a front elevation of the spinner/power wrench engaging a stabilizer connected to a drill pipe. 
     FIG. 10 is a top view of the FIG. 9 embodiment showing a removable bit breaker plate. 
    
    
     DESCRIPTION OF THE INVENTION 
     With reference to the drawings wherein like reference numerals indicate like parts, one embodiment of the present invention involves a novel attachment of a bitbreaker to a wrench device that holds the bit or stabilizer in a locked position while the torque providing jaws of the wrench device either make up or break out the bit from the drill string. This is accomplished by attaching a hinged and lockable set of plates  100 , shown generally in FIG. 1, around either the bit  102  or the stabilizer (shown more clearly in FIG. 9) to be connected or disconnected, while the elevators hold the bit  102  or stabilizer  102 ′ adjacent the rig floor. For the purposes of illustration and clarity, reference is made hereinbelow to the bit  102 , with the understanding that the invention is likewise applicable to stabilizers. 
     The hinged plates  100  are fitted to the profile of the bit  102 , which is usually triangular in shape to accommodate tricone bit profiles and three bladed stabilizers. It should be recognized that the lockable, hinged plate may be made in a number of different geometric shapes to accommodate the geometry of other types of stabilizers and bits. If the bit  102  is circular in cross-section, or if otherwise desired, the bit  102  can be locked in place with a conventional bit lock (more clearly shown in FIGS.  9  and  10 ). The plates  100  are then locked into place over the tricone bit profile while it sits on the rotary table RT. The power wrench device is then lowered into place adjacent the plate  100 , consisting of two cooperating segments  100   a  and  100   b  to permit the attachment of the torque transfer arms  104  of the device. The torque transfer arms  104  of the plate  100  are bolted to bracket  106  provided on the lower torque jaws  108  of the power wrench by pins  110 . The operator then applies hydraulic pressure controlled by the panel  112  located on the device to apply either right-hand torque to makeup either the bit  102 , or left-hand torque to disconnect the bit  102  from the drill string in a manner well known in the drilling industry. 
     The power wrench is composed of two pipe-gripping elements, which operate by gripping the tubular member with two sets of jaws  108 ,  114  along an angle transverse to the longitudinal axis of the pipe. Typically hydraulic elements urge the jaws  108 ,  114  into engagement with the pipe and the operator through the panel  112  may selectively control each. The upper assembly  120  is suspended adjacent the drill pipe by its hoisting harness  120 ′ providing vertical support for the entire assembly. The upper assembly  120  is hingedly connected to the lower assembly  121  which supports the lower jaws  108  and the brackets  106  and plate  100 . The operator will position the spinner assembly  118  by moving the drill pipe into the lateral opening  198  of the spinner assembly  118 . Springs  196  permit longitudinal movement of the upper assembly as the pipe is connected or disconnected. 
     The spinner assembly  118  is used to spin the drill pipe to be connected onto the drill bit or stabilizer in a manner well known to those in the pipe handling art. The torque to complete the connection is applied by engaging the upper torque assembly  114  to impart torque in the drill pipe/drill bit assembly. Regular joints of pipe are connected in the normal manner engaging the upper torque jaws  114  and the lower torque jaws  108  and moving them in the appropriate direction by engaging torque cylinder  116 . The torque cylinder  116  best seen in FIG. 2 is then activated to apply a torquing force to the housings of the jaws  108 ,  114 . In the present invention, the lower jaws  108  are not allowed to engage to grip the pipe so the torque is transmitted through the torque transfer arms  104  to the locked plate  100  to either torque the bit  102  to the operating torque or to disconnect or break the bit  102  from the tubular member. 
     To make up the bit  102  to the drill string, the bit  102  is locked into the plate  100 , and the spinner  118  is activated to spin the drill pipe into engagement with the bit  102 . Then the operator applies the appropriate torque to the bit  102  to make up the tool to its rated make up torque. Once torquing is completed, the hinged plates  100  may be unlocked from the bit  102 , which is then lowered through the plates  100  and rotary table RT into the well bore. 
     To disconnect the bit or stabilizer, torque is applied by the torque cylinder  116  to break the connection and once the seal is broken upon breakout and the torque declines, the spinner mechanism  118  can be activated to complete the disconnection. 
     FIG. 1 shows a complete assembly of the power wrench and spinner assembly  118  in its hoisting harness  120 ′ with the lockable, hinged plate  100  attached by the torque transfer arms  104  to the bottom by brackets  106  below the lower jaws  108 . The bit  102  has been previously locked into place and the hinged plates  100  closed and bolted by attaching pins  110  in holes  110 ′ in the assembly. FIG. 3 more clearly demonstrates the hinged lockable plate after engagement to the bit  102 , but before lowering the power wrench, spinner assembly to be connected to the upper torque transfer arms  104  of the plates  100  by attaching pins  110  which are inserted and engaged in the holes  110 ′. 
     FIG. 2 shows a side view of the apparatus of FIG. 1 with the bit  102  engaged in the lockable plate  100 . Disconnection of the bit  102  would be effected by engaging upper jaws  114  to move with left hand torque. Connection of the bit would be accomplished in a reverse manner. Sixty thousand foot-pounds of torque may be applied to make up a bit  102  to the drill string without damage to either the bit  102  or the drill string. Seventy thousand foot-pounds of torque may be applied to break apart the bit or stabilizer from the drill string without damage to either the bit  102  or the drill string. 
     To operate the device, the hinged plate  100  is locked around the bit  102 , for example, by moving the two cooperating plates  100   a  and  100   b  around the bit  102  and locking them in place by inserting pin  122  in the hole  122 ′ provided on each of the plates  100 . The operator, standing at the console  112  would lower the drill string onto the drill bit  102  and engage the spinner  118  which would spin up the connection. Thereafter, the final operating torque would be applied by applying right hand torque by the upper jaws  114  to the drill string to tighten the bit  102  to the desired torque which is measured on the torque gauge on the operator&#39;s console  112  in a manner well known in the drilling industry. 
     FIG. 3 is a top view of the transverse hinged plates  100  used to couple and decouple the bit  102  from the drill string. As may be readily appreciated, the bottom plates  100  comprises two interconnected pieces  100   a  and  100   b  that are hinged by connector  124  and provide mateable surfaces providing a hole  122 ′ therethrough for a locking pin  122 . In operation, the hinged plate  100  is moved over the bit  102  by ordinary lifting means well known to this industry, such as by an air hoist, and set on the profile (which, in this embodiment, is generally triangular), and manually closed. Thereafter, locking pin  122  is inserted in the hole  122 ′ provided. The upper assembly  120  is lowered over the torque transfer arms  104  to seat on shoulder  126  and the attaching pins  110  are inserted in the holes  110 ′ provided in the bracket  106  provided on the lower surface of the lower torque applicator body  108 . Torque is then applied selectively by manipulation of the upper jaws  114  to either couple or decouple the bit  102 , which is locked in the hinged plate  100 . 
     As may be readily appreciated with reference to FIG. 8, differing lengths of tools or subs may be accommodated within the hinged plates  102  by placing attaching pins  130  through a lower or higher hole location  132  as desired. In this embodiment, the torque transfer arms  104  are elongated and pass through a slot formed in the plates  100  and adjacent a lug  134  attached to a lower side of the plates  100 . If the desired coupling/decoupling desired related to an extended length stabilizer assembly, the longer stabilizer could be loaded in the hinged plate and the locking pin placed in a higher hole  132 ′, intermediate hole  132 ′ or lower hole  132 ′″ as desired. 
     FIG. 9 shows another embodiment of the apparatus of the present invention deployed with a bit lock BL plate that is removably seated in a recess in the bottom plate  100 ′ in a manner well known in the oil and gas industry. Bottom plate  100 ′ is a unitary member attached by torque transfer arms  104  in the same manner as described above, by attachment to the lower surface of the torque applicator body  108  by bracket  106 . FIG. 9 also shows the use of the invention to connect and disconnect a drill pipe stabilizer  102 ′ in a drill pipe. 
     FIG. 10 is a top view of the lower plate of the alternative embodiment of the invention using a bit lock plate BL. The bit lock plate BL is inserted in a recess in the lower plate  100 ′ and the drill pipe lowered or raised to engage the bit in the profile of the plate. 
     It may also be appreciated that the apparatus of the present invention may also be used with a power tong apparatus well known to those in the industry by attaching the hinged plates  100  or the fixed plate  100 ′ with bit lock insert in the foregoing described manner to the lower torque-applying surface of the power tongs. It should also be further appreciated that the spinner/power tong apparatus is not needed to utilize the coupling/decoupling features of the present invention, which may be useful when used solely in conjunction with the power wrenches.