Patent Description:
The present disclosure relates to improved automated floor wrenches for use on a drilling rig. More specifically, an improved automated floor wrench having power tong blocks for centering and gripping the drilling pipe around its circumference is provided.

Automated floor wrenches for drilling rigs are known. Conventionally, automated floor wrenches can comprise two rams opposed to one another, each ram having a pair of tong dies to contact and grip the drilling pipe, or three rams spaced <NUM> degrees apart around the circumference of the drilling pipe, each ram having a tong die to contact and grip the pipe.

To date, however, known wrenches have various deficiencies and shortcomings. For example, the force required for the dies to contact and grip the pipe can score or damage the pipe surface, resulting in premature pipe wear. The use of two or three rams also requires significant force placed on two, three or even four points on the drill pipe, which can cause the pipe to be squashed or deformed at those points, also resulting in premature wear and service life for the pipe.

Some drilling rig floor wrenches have been developed that can comprise an improved tong assembly having a plurality of articulated tong block, each tong block capable of being interlocked and interchangeable one with another, and each tong block having at least one die ram assembly, such as described in <CIT>. <CIT> teaches a floor wrench with a multicomponent upper tong and multicomponent lower tong. The floor wrench of <CIT> teaches the use of multiple hydraulic rams, including one set for opening and closing the wrench and a different set of hydraulic wrenches for rotating the upper tong assembly relative to the lower tong assembly.

According to a broad aspect of the present disclosure, there is provided a wrench comprising a tong assembly, the tong assembly comprising: an upper tong comprising a first upper tong half pivotably connected to a second upper tong half at their first ends, the first and second upper tong halves being releasably connectable at their second ends; a lower tong comprising a first lower tong half pivotably connected to a second lower tong half at their first ends, the first and second lower tong halves being releasably connectable at their second ends; a central bearing operatively coupling the upper tong and the lower tong to allow the upper tong to rotate relative to the lower tong; and a ram assembly for pushing or pulling the upper tong at a tangential location thereof; and wherein the ram assembly is configured to move the tong assembly between an open position where the second ends of the first and second upper tong halves and the second ends of the first and second lower tong halves are separated to define a mouth therebetween, and a closed position where the second ends of the first and second upper tong halves and the second ends of the first and second lower tong halves are engaged to defined an opening between the first upper and lower tong halves and the second upper and lower tong halves; wherein the ram assembly is fully retractable to place the tong assembly in the open position; and wherein the ram assembly is partially retractable to place the tong assembly in the closed position.

According to another broad aspect of the present disclosure, there is provided a method of operating a tong assembly of a wrench, the method comprising: opening a tong assembly to provide access to a pipe opening defined therein by retracting a ram assembly coupled to the tong assembly, the tong assembly comprising an upper tong and a lower tong and a central bearing operatively coupling the upper and lower tongs to allow relative rotational movement therebetween, and the ram assembly being coupled to the upper tong and the lower tong; closing the tong assembly by extending the ram assembly, thereby pushing the upper tong at a tangential location thereof; and locking the upper and lower tongs.

According to embodiments herein, an improved automated floor wrench used on a drilling rig floor is provided. The present wrench or improved apparatus <NUM> comprises a powerful, modular automated floor wrench operative to enhance accuracy and consistency of torque on the drill pipe, enabling easier and faster maintenance, and reducing downtime.

In some embodiments, the present apparatus <NUM> may provide <NUM> degrees of radial contact with the drill pipe, reducing slippage, tool joint wear and pipe distortion, and facilitating pipe alignment. Due to the large radial contact around the pipe circumference, the force required to be exerted by each die ram on the pipe during the operation of the wrench is reduced, thereby minimizing potential damage to both the pipe and the wrench itself. It is an advantage that the present apparatus <NUM> may accommodate varying pipe sizes and longer tool joints, while providing accurate torque on each section of drill pipe. It is a further advantage that the present apparatus <NUM> may be fully or partially automated, providing a wireless hands-free operating system, increasing overall safety, and allowing for remote measurement and monitoring of data at each pipe connection (thereby improving diagnostics and enabling preventative maintenance). The present apparatus will now be described having regard to <FIG>.

Having regard to <FIG>, the present apparatus <NUM> can be mounted to a drilling rig floor. Broadly, in some embodiments, the present apparatus <NUM> may be mounted to the drilling rig floor by a rotatable positioning system <NUM>, configured to receive and accommodate a tong assembly <NUM> of apparatus <NUM>, such positioning system <NUM> comprising a rotatable base <NUM> and having a pivot arm configuration with at least two pivot arms 3a,3b pivotable about a first joint <NUM>. Positioning system <NUM> further comprises a lift assembly <NUM> positioned at one end of the pivot arm 3b and the tong assembly <NUM> is supported and mounted on the lift assembly <NUM> via a carrier <NUM> and side mounts <NUM>. The lift assembly <NUM> is configured to contain and control the movement of the tong assembly <NUM> disposed therein.

Having further regard to <FIG>, base <NUM> may include a downwardly protruding male shaft (not shown) that can be extended into a rig floor pocket and base <NUM> may further include a base plate that can be secured to a receiving plate mounted on the rig floor. Base <NUM> can thereby be rotatably positioned on the drilling rig floor, such that positioning system <NUM> is rotatable about a first axis (e.g. substantially perpendicular to the rig floor). Full rotation of the positioning system <NUM> about the first axis enables more precise and efficient alignment of the tong assembly <NUM> with a drill pipe (not shown), which may be located at the well center or at an additional mouse hole position on the rig floor. For example, where tong assembly <NUM> is misaligned with the drill pipe, positioning system <NUM> may be rotated (by any degree required) and carefully guided into alignment with the pipe.

Positioning system <NUM> may comprise at least two pivot arms 3a,3b; a first at least one pivot arm 3a operatively connected to and extending from base <NUM>, while at least one second pivot arm 3b is configured to receive tong assembly <NUM> via lift assembly <NUM>. In this regard, as the base <NUM> of the positioning system rotates about the first axis, at least two pivot arms 3a,3b and correspondingly the tong assembly <NUM>, also rotates. The at least two pivot arms 3a,3b may be pivotable about pivot joint <NUM>, such pivoting (i.e. extending and retracting) operably powered by at least one hydraulic cylinder, and preferably by at least two hydraulic cylinders 9a,9b.

In this regard, positioning system <NUM> may be operative to open or close (i.e. between extended or retracted positions) about joint <NUM>; rotate about base <NUM>; and move the lift assembly <NUM> up or down, so as to manoeuvre the tong assembly <NUM> about the drilling rig floor (i.e. to and away from the wellbore) with six degrees of freedom. As would be appreciated, the present positioning system <NUM> significantly reduces the overall footprint of the apparatus <NUM>, and provides that when not in use, the apparatus <NUM> may be retracted into a closed position and rotated away from the wellbore, for example by about <NUM> degrees to about <NUM> degrees from the apparatus' operating position. In <FIG>, wrench <NUM> is shown with the positioning system <NUM> in the extended position.

Still with reference to <FIG>, the present apparatus <NUM> may be used in combination with a spinner assembly <NUM>. It should be appreciated that the spinner may be a conventional spinner known in the art, and having up to <NUM>" of independent vertical travel, and the ability to accommodate varying pipe sizes and longer tool joints.

With reference to <FIG>, wrench <NUM> comprises a tong assembly <NUM>, which may comprise an upper tong <NUM>, a lower tong <NUM>, and carrier <NUM>. Upper tong <NUM> is rotatably disposed on lower tong <NUM>, with a central bearing <NUM> (shown in <FIG>) operatively coupling the two tongs together, thereby enabling upper tong <NUM> to rotate relative to lower tong <NUM> about a common central axis, while lower tong <NUM> is held stationary by carrier <NUM>. In some embodiments, tong assembly <NUM> can comprise one or more pins extending downwardly from lower tong <NUM> that can be inserted into corresponding apertures through carrier <NUM>. Carrier <NUM> may further comprise a mounting pivot <NUM>.

To enable rotational movement between the tongs, tong assembly can comprise a hydraulic ram assembly <NUM> for pushing one tong at a tangential location relative to the other, and for pulling one tong at a tangential location relative to the other. In one embodiment, to rotate upper tong <NUM> counter-clockwise relative to lower tong <NUM> (when viewed from above) to break a pipe joint, the ram assembly <NUM> pushes the upper tong <NUM> tangentially. To rotate upper tong <NUM> clockwise relative to lower tong <NUM> to make a pipe joint, the ram assembly <NUM> pulls the upper tong <NUM> tangentially. It would be understood that the reverse motions could also be used in certain embodiments. The ram assembly <NUM> and the rotation of the tongs <NUM>,<NUM> relative to one another will be described in more detail below.

Referring to <FIG>, in some embodiments, the ram assembly comprises an upper ram 58a and a lower ram 58b. Upper ram 58a is pivotably coupled at one end to upper tong <NUM> via an upper ram mount 57a, which extends outwardly from a main body of the upper tong <NUM>. The other end of the upper ram 58a is pivotably coupled to a rod pin 61b disposed on a lower ram mount 57b, which extends outwardly from a main body of the lower tong <NUM>. Rod pin 61b extends from an upper surface of the lower ram mount 57b. Similarly, lower ram 58b is pivotably coupled at one end to lower tong <NUM> via ram mount 57b. The other end of lower ram 58b is pivotably coupled to a rod pin 61a disposed on the upper ram mount 57a. Rod pin 61a extends from a lower surface of the upper ram mount 57a. In some embodiments, rams 58a,58b are substantially parallel to one another on one plane and an acute angle may be defined therebetween on another plane. Each of the upper and lower rams 58a,58b has an extended position (shown in <FIG>), a partially-retracted position (shown in <FIG>), and a fully retracted position (shown in <FIG>, <FIG>). In operation, both the upper and lower rams 58a,58b extend and retract synchronously such that the rams are always in the same position relatively to one another.

In some embodiments, wrench <NUM> may comprise at least one tong torque sensor (not shown) mounted thereon for measuring axial stresses. The tong torque sensor can be mounted between rod pins 61a, 61b and upper and lower ram mounts 57a,57b. In some embodiments, a load cell is provided at each of the rod pins 61a,61b to measure true torque between the upper and lower tongs <NUM>,<NUM>.

Referring to <FIG>, an embodiment of tong assembly <NUM> is shown. In some embodiments, as best shown in <FIG>, <FIG>, <FIG>, <FIG>, upper tong <NUM> comprises a first upper tong half 56a and a second upper tong half 56b. The first tong half 56a has a body portion having defined therein a substantially semi-circular arc. In some embodiments, the upper ram mount 57a extends outwardly from the first upper tong half 56a near a first end of the arc. The second tong half 56b also has a body portion having defined therein a substantially semi-circular arc, which is substantially a mirror image of the arc in the first tong half 56a. The first and second upper tong halves 56a,56b are hinged together and pivotably connected at their respective first ends via pin <NUM>. In some embodiments, the second end of the arc of the first upper tong half 56a comprises a locking pin assembly 68a and the second end of the arch of the second upper tong half 56b comprises a pin pocket 70a having a bore for receiving a pin of the locking pin assembly 68a therethrough.

Similarly, lower tong <NUM> comprises a first lower tong half 66a and a second lower tong half 66b. The first tong half 66a has a body portion having defined therein a substantially semi-circular arc. The second tong half 66b also has a body portion having defined therein a substantially semi-circular arc, which is substantially a mirror image of the arc in the first lower tong half 66a. In some embodiments, the lower ram mount 57b extends outwardly from the second lower tong half 66b near a first end of the arc. The first and second lower tong halves 66a,66b are hinged together and pivotably connected at their respective first ends via pin <NUM>. In some embodiments, the second end of the arc of the second lower tong half 66b comprises a locking pin assembly 68b and the second end of the arch of the first lower tong half 66a comprises a pin pocket 70b having a bore for receiving a pin of the locking pin assembly 68b therethrough. In some embodiments, pin <NUM> may extend into the mounting pivot <NUM> of carrier <NUM> (shown in <FIG>).

Of course, the configuration of the second ends of each of the first and second upper and lower tong halves 56a,56b,66a,66b described above is only one possible configuration. In other embodiments, the placement of the locking pin assemblies and pin pockets may be reversed. In alternative embodiments, the ends of the upper and lower tong halves may comprise connectable male and/or females ends. As one skilled in the art can appreciate, a number of different configurations is possible as long as the second ends of the first and second upper tong halves 56a,56b are connectable and the second ends of the first and second lower tong halves 66a,66b are connectable.

The tong assembly <NUM> has an open position, shown in at least <FIG>, <FIG>, a closed position, shown in at least <FIG>, and a rotated closed position, shown in at least <FIG>, and <FIG>. In both the open and closed positions, the second ends of the first upper tong half 56a is aligned with that of the first lower tong half 66a and the second end of the second upper tong half 56b is aligned with that of the second lower tong half 66b. In an illustrative embodiment, in both the open and closed positions, the pin pocket 70a of the second upper tong half 56b is aligned with the locking pin assembly 68a of the first upper tong half 56a; the locking pin assembly 68b of the second lower tong half 66b is aligned with the pin pocket 60b of the first lower tong half 66a; and the upper and lower locking pin assemblies 68a,68b and the upper and lower pin pockets 70a,70b are substantially aligned with one another. In the rotated closed position, the pin pocket 70a of the second upper tong half 56b is aligned with the locking pin assembly 68a of the first upper tong half 56a; the locking pin assembly 68b of the second lower tong half 66b is aligned with the pin pocket 60b of the first lower tong half 66a; and the upper and lower locking pin assemblies 68a,68b and the upper and lower pin pockets 70a,70b are not aligned with one another.

In the open position, the second ends of the first upper and lower tong halves 56a,66a are separated from the second ends of the second upper and lower tong halves 56b,66b to define a mouth <NUM> therebetween. In the open position, the upper and lower rams 58a,58b are in the fully retracted position. In other words, the upper and lower rams 58a,58b are fully retracted to place the tong assembly <NUM> in the open position.

In the closed position and the rotated closed position, the second ends of the first upper and lower tong halves 56a,66a can be releasably coupled to the second ends of the second upper and lower tong halves 56b,66b, respectively. In the illustrated embodiment, as best shown in <FIG>, when the tong assembly <NUM> is in the closed position, a pin of the locking pin assembly 68a of the first upper tong half 56a can be received in the pin pocket 70a of the second upper tong half 56b, and a pin of the locking pin assembly 68b of the second lower tong half 66b can be received in the pin pocket 70b of the first lower tong half 66a, to thereby lock the upper and lower tongs <NUM>,<NUM>, respectively.

In the closed position and the rotated closed position, the arcs of the first and second upper tong halves 56a,56b form a substantially circular opening 89a. Similarly, the arcs of the first and second lower tong halves 66a,66b form a substantially circular opening 89b.

In the closed position, as shown for example in <FIG>, the upper and lower rams 58a,58b are in the partially-retracted position. In the illustrated embodiment, when the second ends of the upper tong halves 56a,56b and the second ends of the lower tong halves 66a,66b are aligned, the upper and lower rams 58a,58b are in the partially-retracted position. In the rotated closed position, as shown for example in <FIG>, the upper and lower rams 58a,58b are in the extended position. In the illustrated embodiment, when the second ends of the upper tong halves 56a,56b and the second ends of the lower tong halves 66a,66b are not aligned (i.e. when the upper tong <NUM> is rotated relative to the lower tong <NUM>), the upper and lower rams 58a,58b are in the extended position.

In some embodiments, with reference to <FIG>, <FIG>, <FIG>, and <FIG> each of the first and second upper tong halves 56a,56b and the first and second lower tong halves 66a,66b comprises one or more die rams. The die rams in the upper and lower tongs <NUM>, <NUM> are substantially identical so only the die rams in the upper tong <NUM> will be described in detail. Referring to <FIG>, a cross-sectional view of the upper tong <NUM> is shown. In the illustrated embodiment, the first upper tong half 56a comprises three die rams <NUM> and the second upper tong half 56a also comprises three die rams <NUM>. However, as one skilled in the art can appreciate each tong half may comprise fewer or more die rams. The die ram <NUM> operates to extend or retract a die in a die cartridge, which will be described in detail below.

In some embodiments, with reference to <FIG>, each die ram <NUM> comprises a die ram housing <NUM>, a ram piston <NUM>, a ram rod <NUM>, and a cover <NUM> having defined therein an aperture <NUM>. The cover <NUM> is mounted on an open end of the die ram housing <NUM> and the ram piston <NUM> and the ram rod <NUM> are disposed inside die ram housing <NUM>, with one end of the ram rod <NUM> extending through aperture <NUM>. The piston <NUM> operates to extend or retract the ram rod <NUM> axially through the aperture <NUM>.

Each die ram <NUM> is disposed in the body portion of each of the tong halves 56a,56b,66a,66b between the first and second ends thereof. The die rams <NUM> may be evenly spaced throughout the tong halves such that the space between adjacent die rams is substantially the same in each of the upper and lower tongs <NUM>,<NUM>. In the illustrated embodiment, as shown in <FIG>, the body portion of each of the first and second upper tong halves 56a,56b comprises an upper tong plate <NUM> and a lower tong plate <NUM>, each plate having at least one recess defined therein. The housing <NUM> is received in the respective recesses in the upper and lower plates and is secured between the upper and lower plates <NUM>,<NUM>, with cover <NUM> facing inwardly towards the center of circular opening 89a such that the ram rod <NUM> is extendable radially inwardly in circular opening 89a. In some embodiments, the upper and lower plates <NUM>,<NUM> may be bolted or otherwise secured together using spacer assemblies throughout the upper and lower tongs <NUM>,<NUM>. This allows the die rams <NUM> therebetween to be removed and/or replaced, as desired or as necessary, from the outer circumference of the tong assembly <NUM>. Further, the upper and lower plates <NUM>,<NUM> are configured to accommodate a die cartridge, as described in more detail below.

In some embodiments, as best shown in <FIG>, the upper and lower tongs <NUM>,<NUM> comprise one or more torque reaction bars <NUM>, each extending between the upper and lower plates <NUM>,<NUM>.

With reference to <FIG>, <FIG>, <FIG>, <FIG>, each tong half 56a,56b,66a,66b is configured to removably receive a die cartridge <NUM>. As best shown in <FIG>, <FIG>, <FIG>, and <FIG>, each die cartridge <NUM> comprises one or more dies <NUM> and two or more die guides <NUM>. Each die <NUM> comprises a die pad <NUM> removably mounted on a die holder <NUM> in a slot disposed on a front face thereof. Each die <NUM> is disposed between two die guides <NUM>. In the illustrated embodiment, the die cartridge <NUM> has three dies <NUM> and four die guides <NUM>, in an alternating arrangement and secured between two arc-shaped cartridge plates <NUM>. The die cartridge <NUM> may further comprise locking clips <NUM> for engaging ram rod <NUM> to allow die <NUM> to move together with ram rod <NUM>. The die cartridge <NUM> is configured to allow dies <NUM> to move radially inwardly towards the center of the semicircular space defined by the inner arcs of the cartridge plates <NUM>.

In some embodiments, the upper and lower cartridge plates <NUM> have one or more aligning pairs of torque reaction pockets <NUM>, each pair for matingly receiving a corresponding torque reaction bar <NUM> of the upper or lower tong <NUM>,<NUM>. The torque reaction pockets <NUM> and torque reaction bars <NUM> are for facilitating the transfer of torque from the cartridge <NUM> to the upper and lower tongs <NUM>,<NUM> when the wrench <NUM> is in operation, as will be explained in more detail below. More specifically, in operation, torque is transferred from the dies <NUM> through the die guides <NUM> into cartridge plates <NUM> and then into the upper and lower tongs <NUM>,<NUM>.

With reference to <FIG>, <FIG>, and <FIG>, each die cartridge <NUM> may be inserted in an axial direction into a tong half by aligning the torque reaction pockets <NUM> with the torque reaction bars <NUM> such that each bar <NUM> is received in a pair of pockets <NUM>, thereby restricting any relative rotational movement between the die cartridge and the tong half. Once inserted, the die cartridge <NUM> can be further removably secured to the tong half by at least one latch-type mechanism comprising, for example, a fastener <NUM> and a corresponding anchor <NUM>. In the illustrated embodiment, when the at least one fastener <NUM> of the tong half is received in its corresponding anchor <NUM> of the die cartridge, and when the torque reaction bars <NUM> are matingly received in the corresponding torque reaction pockets <NUM>, the die cartridge <NUM> is secured to the tong half. When the fastener <NUM> is removed from the anchor <NUM>, the die cartridge <NUM> is removable axially from the tong half by slidingly removing torque reaction bars <NUM> from the corresponding torque reaction pockets <NUM>. As a person in the art can appreciate, other ways of securing die cartridge <NUM> to a tong half are possible.

When a die cartridge <NUM> is received in each of the tong halves 56a,56b,66a,66b, and when the tong assembly <NUM> is in the closed position and the rotated closed position, the die cartridges in the upper and lower tongs <NUM>, <NUM> define an open cylindrical space or "pipe opening" <NUM> therebetween. The diameter of the pipe opening <NUM> depends on the inner radius of the die cartridges <NUM>. Preferably, all four die cartridges <NUM> used in the tong assembly <NUM> at any one time are similarly sized such that they all have about the same inner radius to provide concentric closure into opening <NUM>. Accordingly, the diameter of pipe opening <NUM> can be increased or decreased by selecting die cartridges <NUM> with a larger or smaller inner radius, respectively.

As best shown in <FIG> and <FIG>, the spacing of the die rams <NUM> and the dies <NUM> is configured such that when the die cartridge <NUM> is received in a tong half, each die <NUM> is aligned with the ram rod <NUM> of one of die rams <NUM>. In some embodiments, to extend die <NUM> inwardly towards the pipe opening <NUM>, pressurized hydraulic fluid is supplied to the die ram housing <NUM>, as known to those skilled in the art, to move piston <NUM> such that it pushes ram rod <NUM> through aperture <NUM>, thereby pushing die <NUM> through between die guides <NUM>. To retract die <NUM> away from the pipe opening <NUM>, hydraulic fluid is supplied to the die ram housing <NUM>, as known to those skilled in the art, to urge piston <NUM> back and withdraw ram rod <NUM> through aperture <NUM>, thereby retracting die <NUM> back into the space between die holders <NUM>. The die ram <NUM> is configured to extend die <NUM> into opening <NUM> by a range of distances (also referred to as "grip range"), for example from <NUM>% to about <NUM>% of the depth of the die holder <NUM>. Preferably, when die <NUM> is extended into the opening <NUM>, at least a portion of the die holder <NUM> remains between the adjacent die guides <NUM>.

Since the diameter of pipe opening <NUM> depends on the inner radius of the die cartridge <NUM> and/or since the dies <NUM> in the die cartridge have a grip range, one size and configuration of die cartridges <NUM> can be used to handle and manipulate a range of pipes of different sizes, without modifying any component of the wrench <NUM>. In some embodiments, the diameter of pipe opening <NUM> can range from about <NUM>" to about <NUM>¾" to accommodate pipe sizes of about <NUM><NUM>/<NUM>" to about <NUM>". Further, since die cartridges <NUM> are removable, one set of die cartridges can be replaced with another set having a different inner radius and/or grip range to accommodate smaller or larger diameter pipes. In some embodiments, the inner radius and/or the grip range of the die cartridges <NUM> are selected depending on the size of the rig in order to eliminate or minimize the need to switch out the die cartridges.

In some embodiments, hydraulic fluid is supplied to all the die ram housings <NUM> in each tong <NUM>,<NUM> simultaneously such that the corresponding dies <NUM> can all extend synchronously. In further embodiments, hydraulic fluid is supplied to all the die ram housings <NUM> through a volumetric flow divider to each tong <NUM>,<NUM> simultaneously to help equalize the volume of oil delivered to each die ram <NUM>. Referring to <FIG> and <FIG>, one embodiment of locking pin assemblies 68a,68b is shown. In some embodiments, each of the locking pin assemblies 68a,68b of tongs <NUM>,<NUM> comprises a lock pin 72a,72b. Lock pin 72a,72b may be a hydraulically operated pin for engaging an opening 71a,71b of the pin pockets 70a,70b of the tongs <NUM>,<NUM>, respectively. Lock pin 72a operates to extend into the opening 71a of pin pocket 70a of the second upper tong half 56b to effectively lock the first and second upper tong halves 56a,56b together. Similarly, lock pin 72b operates to extend into the opening 71b of pin pocket 70b of the first lower tong half 66a to effectively lock the first and second lower tong halves 66a,66b together. To unlock the first and second tong halves, lock pins 72a,72b are retracted from openings 71a,71b, respectively, so that the first and second tong halves can be separated from one another. In some embodiments, a sensor can be provided at the end of lock pins 72a72b to measure the closure of lock pins 72a,72b into pin pockets 70a, 70b.

To open mouth <NUM> of the tong assembly <NUM> to receive a drill pipe in pipe opening <NUM>, as shown for example in <FIG>, the lock pins 72a,72b are removed from openings 71a,71b and the upper and lower rams 58a,58b are fully retracted to move the second ends of the upper tong halves 56a, 56b and the second ends of the lower tong halves 66a,66b away from one another so that tong assembly <NUM> can be moved towards the drill pipe and receive same within pipe opening <NUM>. Once the drill pipe is received in pipe opening <NUM>, the upper and lower rams 58a,58b are moved to the partially-retracted position to close mouth <NUM>, as shown for example in <FIG>, to thereby place the tong assembly in the closed position. Once mouth <NUM> is closed, lock pins 72a,72b are operated as described above to lock the first and second upper tong halves 56a,56b and the first and second lower tong halves 66a,66b together, respectively, to allow the die cartridges <NUM> in the upper and lower tongs <NUM>,<NUM> to circumferentially surround the section of the drill pipe <NUM> in pipe opening <NUM>, as shown for example in <FIG>.

With reference to <FIG>, the upper tong <NUM> is coupled to lower tong <NUM> by the central bearing <NUM>. In some embodiments, the central bearing <NUM> comprises an upper section 39a, a lower section 39b, a side section <NUM>, a wear section <NUM>, preload spring washers <NUM>, and preload bolt <NUM>. Lower section 39b is secured to the lower tong <NUM> via upper tong plate <NUM>. Upper section 39a and side section <NUM> are secured to the upper tong <NUM> via lower tong plate <NUM>. The central bearing <NUM> is configured to have precise motion as the spring washers <NUM> create a preload to provide sufficient clearance to absorb any anomalies in the upper and lower tong halves 56a,56b,66a,66b during the operation of the wrench. The combination of the upper section 39a, lower section 39b, and side section <NUM> allows for small radial movements and also allows the central bearing <NUM> to self-align.

Referring to <FIG>, <FIG>, the operation of tong assembly <NUM> is shown. In <FIG>, mouth <NUM> of the tong assembly <NUM> is opened by fully retracting the upper and lower rams 58a,58b to allow a drill string (not shown) to be placed in pipe opening <NUM>. In some embodiments, the open-mouth tong assembly <NUM> can be positioned by positioning system <NUM> around the drill string. In <FIG>, mouth <NUM> is closed by simultaneously extending the upper and lower rams 58a,58b to the partially-retracted position, thereby overlapping the locking pin assemblies 68a,68b of the upper and lower tongs <NUM>,<NUM> with the pin pockets 70a,70b, respectively. The upper and lower tongs <NUM>,<NUM> are then locked by activating lock pins 72a,72b. In practice, the placement of tong assembly <NUM> relative to the drill string would be such that lower tong <NUM> would be positioned around a box end of a lower drill pipe section and upper tong <NUM> would be positioned around a pin end of an upper drill pipe section so as to make (or connect) or break (or disconnect) a joint between the drill pipe sections that makeup the drill string.

To make a joint, the dies <NUM> in the lower tong <NUM> are extended substantially synchronously by their corresponding die rams <NUM> to contact the drill pipe using a predetermined minimum hydraulic pressure, after the upper and lower tongs are locked. The upper and lower rams 58a,58b are then extended to the extended position, thereby rotating the upper tong <NUM> counterclockwise relative to the lower tong <NUM> and placing the tong assembly in the rotated closed position as best shown in <FIG>. Once the rams 58a,58b are extended, the dies <NUM> in the upper tong <NUM> are extended substantially synchronously by their corresponding die rams <NUM> to contact the drill pipe using a predetermined minimum hydraulic pressure. The rams 58a,58b are then retracted to the partially-retracted position or fully retracted position, which may depend on the torque measured by the load cell in rod pins 61a,61b, thereby rotating the upper tong <NUM> clockwise relative to the lower tong <NUM>, which also rotates the drill pipe section engaged by the upper tong <NUM> in a clockwise direction, when viewed from above, relative to the other drill pipe section gripped by the lower tong <NUM>. The dies <NUM> in the upper and lower tongs <NUM>, <NUM> are then retracted to disengage from the pipe <NUM>.

To break a joint, the dies <NUM> in the lower tong <NUM> are extended substantially synchronously by their corresponding die rams <NUM> to contact the drill pipe using a predetermined minimum hydraulic pressure, after the upper and lower tongs are locked. The dies <NUM> in the upper tong <NUM> are extended substantially synchronously by their corresponding die rams <NUM> to contact the drill pipe, either simultaneously with or immediately after the extension of dies <NUM> in the lower tong <NUM> using a predetermined minimum hydraulic pressure. Once the drill pipe is gripped by both the upper and lower tongs <NUM>,<NUM>, the upper and lower rams 58a,58b are extended to the extended position, as best shown in <FIG>, thereby rotating the upper tong <NUM> counterclockwise relative to the lower tong <NUM>, which also rotates the drill pipe section engaged by the upper tong <NUM> in a counterclockwise direction relative to the other drill pipe section gripped by the lower tong <NUM>. The dies <NUM> in the upper tong <NUM> are then retracted to disengage from the drill pipe <NUM> and the rams 58a,58b are retracted to the partially-retracted position, as shown in <FIG>. The dies <NUM> in the lower tong <NUM> are then retracted to disengage from pipe <NUM>.

The synchronization of the extension of the dies <NUM> in tong assembly <NUM> helps to keep the section of the drill pipe in upper tong <NUM> aligned and concentric with the other section of the drill pipe in the lower tong <NUM>.

After making or breaking the joint, the upper and lower tongs <NUM>,<NUM> are unlocked by deactivating lock pins 72a,7b. Once unlocked, the tong assembly <NUM> can be opened by fully retracting the rams 58a,58b, as shown in <FIG>, thereby opening the mouth <NUM> through which the drill pipe can be removed from pipe opening <NUM> of tong assembly <NUM>.

The incorporation of six die rams <NUM> in each tong, as shown in the illustrated embodiment, can enable the equal distribution of gripping force around the circumference of drill string <NUM> and prevent the crushing or squashing of drill string <NUM> such it becomes out of round when gripped by die rams <NUM>. In addition, by distributing the gripping forces in multiple locations around the circumference of the drill string, less force per die ram <NUM> can be used to prevent deep scoring on the drill string caused by dies <NUM>, which can occur if fewer die rams are used to grip the drill string, such as are found on similar apparatuses using only two or three die rams.

The mounting pivot <NUM> of carrier <NUM> is configured to allow the lower tong <NUM> to rotate in the event of slippage in the interface between the dies <NUM> and the pipe or when the lower tong <NUM> is improperly used as a backup for the spinner assembly (i.e., where the tong assembly <NUM> is used as a backup wrench such that all the torque is transferred to the positioning system <NUM> and into the rig floor).

In some embodiments, wrench <NUM> may comprise at least one carrier torque sensor mounted thereon for measuring rotational stresses. The carrier torque sensor can be mounted between positioning system <NUM> and tong assembly <NUM>. In a sample embodiment shown in <FIG>, the carrier torque sensor <NUM> can be mounted between tong assembly <NUM> and carrier <NUM> at mounting pivot <NUM>.

In some embodiments, wrench <NUM> comprises a control system for controlling the operation of hydraulic rams and motors of the wrench <NUM>. The control system can comprise one or more components selected from the group consisting of hydraulic fluid cylinders, hydraulic fluid pumps, hydraulic fluid tanks, hydraulic fluid coolers, hydraulic fluid filters, hydraulic fluid hoses, hydraulic fluid control valves and programmable logic controllers as well known to those skilled in the art.

In operation, by placing the carrier torque sensor between one of the pins extending downwardly from tong assembly <NUM> and carrier <NUM> at pivot <NUM>, rotational force between tong assembly <NUM> and carrier <NUM> can be monitored. It is known that when automated floor wrenches are used on drilling rigs using top drives for rotating the drill string, drilling operators have been known to use the top drive to make joints between sections of drill pipe instead of using the automated floor wrench. Top drives can produce large amounts of torque, far more than what is necessary to properly torque sections of drill pipe together. Using the top drive to make the joints can apply excessive rotational force to the automated floor wrench, which is still being used to grip to lower section of drill pipe, and cause damage to the floor wrench. By incorporating the carrier torque sensor in the mounting of tong assembly <NUM> to carrier <NUM> at pivot <NUM>, the carrier torque sensor can be used to sense when excessive rotational force is applied to the wrench <NUM>. When excessive rotational force is applied to lower tong <NUM>, carrier torque sensor can send a signal to the control system that can, in turn, cause tong assembly <NUM> to release any pipe gripped by it. In the instance when wrench <NUM> is used with a top drive drilling rig, and its operators simply use wrench <NUM> to grip the drill string with lower tong <NUM> and use the top drive to make joints with the drill string, the carrier torque sensor can be used to sense when the rotational force is applied to longer tong <NUM> by the top drive exceeds a predetermined threshold, and send a signal to the control system to cause lower tong <NUM> to release the drill string, thereby preventing damage to wrench <NUM>. In further embodiments, the control system can also shut down the operation of the top drive and any other system that was operating prior to the carrier torque sensor sending the signal to the control system.

In other operational situations, such as during break-out operations, it is known that a drill string can slip in a lower tong when the upper tong is trying to break a joint in adjacent sections of pipe in the drill string. When this occurs, excessive rotational forces can occur in lower tong <NUM>, which can damage carrier <NUM> and positioning system <NUM>. By connecting the carrier torque sensor between lower tong <NUM> and carrier <NUM> at pivot <NUM>, such rotational forces can be detected by the carrier torque sensor. When the rotational forces exceed a predetermined threshold, the carrier torque sensor can send a signal to the control system to, in turn, cause tong assembly <NUM> to release the drill string. In further embodiments, the control system also shut down the operation of the top drive and any other system that was operating prior to the carrier torque sensor sending the signal to the control system. Using a single ram assembly to both (i) open and close the tong assembly and (ii) rotate the upper tong relative to the lower tong provides the tong assembly <NUM> of the present disclosure more capacity in terms of rotational engagement and torque than previous floor wrenches of the same footprint. Further, the synchronous movement of the upper and lower rams 58a,58b of the tong assembly <NUM> allows the wrench <NUM> to provide more torque as well as more rotational per grip than its predecessors. In one embodiment, the wrench <NUM> can provide a maximum break out torque of about <NUM>,<NUM> lbs , a maximum make up torque of about <NUM>,<NUM> lbs, a nominal pressure of about <NUM>(dif. ) psi, and a maximum pressure of about <NUM> psi.

The tong assembly <NUM> of the present disclosure only has two tong halves in each tong as opposed to at least four tong sections in each tong of the predecessors. The simplicity of the configuration of tong assembly <NUM> may reduce manufacturing and/or maintenance costs.

Accordingly, a wrench for making up or breaking up a pipe joint is provided. The wrench comprises a tong assembly comprising: an upper tong comprising a first upper tong half pivotably connected to a second upper tong half at their first ends, the first and second upper tong halves being releasably connectable at their second ends; a lower tong comprising a first lower tong half pivotably connected to a second lower tong half at their first ends, the first and second lower tong halves being releasably connectable at their second ends; a central bearing operatively coupling the upper tong and the lower tong to allow the upper tong to rotate relative to the lower tong; and a ram assembly for pushing or pulling the upper tong at a tangential location thereof; and wherein the ram assembly is configured to move the tong assembly between an open position where the second ends of the first and second upper tong halves and the second ends of the first and second lower tong halves are separated to define a mouth therebetween, and a closed position where the second ends of the first and second upper tong halves and the second ends of the first and second lower tong halves are engaged to defined an opening between the first upper and lower tong halves and the second upper and lower tong halves; wherein the ram assembly is fully retractable to place the tong assembly in the open position; and wherein the ram assembly is partially retractable to place the tong assembly in the closed position.

In one embodiment, the tong assembly further comprises a first rotated closed position where the second ends of the first and second upper tong halves are securely connected; the second ends of the first and second lower tong halves are securely connected; and the ram assembly is extended to rotate the upper tong counterclockwise relative to the lower tong.

In one embodiment, the tong assembly further comprises a second rotated closed position where the second ends of the first and second upper tong halves are securely connected; the second ends of the first and second lower tong halves are securely connected; and the ram assembly is partially retractable or fully retractable to rotate the upper tong clockwise relative to the lower tong.

In one embodiment, the wrench further comprises a die cartridge removably receivable in each of the first and second upper tong halves and the first and second lower tong halves, the die cartridge comprising one or more dies, and the one or more dies are extendable radially inwardly substantially toward a center of the opening and retractable therefrom; and wherein when the tong assembly is in the closed position, a pipe opening is defined between the die cartridges.

In one embodiment, each of the first and second upper tong halves and the first and second lower tong halves comprises one or more die rams configured to extend and retract the one or more dies.

In one embodiment, the one or more die rams in the first upper tong half and the one or more die rams in the second upper tong half are configured to synchronously extend the one or more dies in the first upper tong half and the one or more dies in the second upper tong half; and the one or more die rams in the first lower tong half and the one or more die rams in the second lower tong half are configured to synchronously extend the one or more dies in the first lower tong half and the one or more dies in the second lower tong half.

In one embodiment, the ram assembly comprises an upper ram and a lower ram, the upper ram being pivotably coupled at a first end to the upper tong and at a second end to the lower tong, and the lower ram being pivotably coupled at a first end to the lower tong and at a second end to the upper tong.

In one embodiment, the upper and lower rams are extendable or retractable substantially synchronously.

In one embodiment, the first end of the upper ram is pivotably coupled to the upper tong at or near the first end of the first upper tong half; and the second end of the upper ram is pivotably coupled to the lower tong at or near the first end of the second lower tong half.

In one embodiment, the first end of the lower ram is pivotably coupled to the lower tong at or near the first end of the second lower tong half; and the second end of the lower ram is pivotably coupled to the upper tong at or near the first end of the first upper tong half.

In one embodiment, the upper ram is coupled to the lower tong by a first rod pin and the lower ram is coupled to the upper tong by a second rod pin.

In one embodiment, the wrench further comprises a torque sensor disposed at the first rod pin and/or the second rod pin.

In one embodiment, the second ends of the first and second uppers tong halves and/or the second ends of the first and second upper tong halves are securably connectable by a lock pin.

In one embodiment, the wrench further comprises a rotatable positioning system, and wherein the tong assembly is secured to and supported on the positioning system, the positioning system being mountable to a drilling rig floor.

In one embodiment, the wrench further comprises a torque sensor disposed between the tong assembly and the positioning system.

In one embodiment, the wrench further comprises a control system for controlling the operation of the tong assembly.

In one embodiment, the wrench further comprises a carrier, and wherein the lower tong is secured to and supported on the carrier.

A method of operating a tong assembly of a wrench is also provided. The method comprises: opening a tong assembly to provide access to a pipe opening defined therein by retracting a ram assembly coupled to the tong assembly, the tong assembly comprising an upper tong and a lower tong and a central bearing operatively coupling the upper and lower tongs to allow relative rotational movement therebetween, and the ram assembly being coupled to the upper tong and the lower tong; closing the tong assembly by extending the ram assembly, thereby pushing the upper tong at a tangential location thereof; and locking the upper and lower tongs.

In one embodiment, the method further comprises inserting and securing a die cartridge in each half of the upper and lower tongs, wherein the die cartridge comprises one or more dies and each half having one or more die rams for operatively engaging the one or more dies.

In one embodiment, the method further comprises, after opening the tong assembly and before closing the tong assembly, receiving a pipe joint in the pipe opening.

In one embodiment, the method further comprises, after locking the upper and lower tongs, securely engaging the pipe joint by extending the one or more dies in the lower tong radially inwardly using the one or more die rams in the lower tong.

In one embodiment, the method further comprises: rotating the upper tong counterclockwise relative to the lower tong by extending the ram assembly; securely engaging the pipe joint by extending the one or more dies in the upper tong radially inwardly using the one or more die rams in the upper tong; rotating the upper tong clockwise relative to the lower tong by retracting the ram assembly; retracting the one or more dies in the upper and lower tongs; unlocking the upper and lower tongs; and reopening the tong assembly to remove the pipe joint from the tong assembly.

In one embodiment, the method further comprises: securely engaging the pipe joint by extending the one or more dies in the upper tong radially inwardly using the one or more die rams in the upper tong; rotating the upper tong counterclockwise relative to the lower tong by extending the ram assembly; retracting the one or more dies in the upper tong; rotating the upper tong clockwise relative to the lower tong by retracting the ram assembly; retracting the one or more dies in the lower tong; unlocking the upper and lower tongs; and reopening the tong assembly to remove the pipe joint from the tong assembly.

Claim 1:
A wrench for making up or breaking up a pipe joint, the wrench comprising: a tong assembly (<NUM>) comprising:
an upper tong (<NUM>) comprising a first upper tong half pivotably connected to a second upper tong half at their first ends, the first and second upper tong halves being releasably connectable at their second ends;
a lower tong (<NUM>) comprising a first lower tong half pivotably connected to a second lower tong half at their first ends, the first and second lower tong halves being releasably connectable at their second ends; and
a central bearing (<NUM>) operatively coupling the upper tong (<NUM>) and the lower tong (<NUM>) to allow the upper tong (<NUM>) to rotate relative to the lower tong (<NUM>); and
a ram assembly (<NUM>) for pushing or pulling the upper tong (<NUM>) at a tangential location thereof, the ram assembly (<NUM>) comprising an upper ram (58a) and a lower ram (58b);
wherein the upper ram (58a) and lower ram (58a) are both configured to move the tong assembly (<NUM>) between an open position where the second ends of the first and second upper tong halves and the second ends of the first and second lower tong halves are separated to define a mouth therebetween, and a closed position where the second ends of the first and second upper tong halves and the second ends of the first and second lower tong halves are engaged;
wherein the upper ram (58a) and the lower ram (58b) are moveable in a first direction to place the tong assembly (<NUM>) in the open position; and
wherein the upper ram(58a) and the lower ram (58b) are moveable in a second direction to place the tong assembly (<NUM>) in the closed position and when the second ends of the first and second upper tong halves are engaged, the upper ram (58a) and the lower ram (58b) are further moveable in the second direction to rotate the upper tong (<NUM>) in a first rotational direction relative to the lower tong (<NUM>).