power tong operator quotation

Texas International Oilfield Tools (TIOT) offers a free standing test stand for testing of hydraulic casing and tubing power tongs. The test stand is designed to resist torque applied by a power tong through a test mandrel.

The test stand is an air operated device that utilizes a hydraulic active dual spring disc brake chamber in order to apply friction force (“brake” action) to the rotating (or stationary) test mandrel mechanism. The power tong is tested by applying torque to the test stand’s mandrel. The test stand’s brake is activated by pushing and twisting clockwise the red control box button on the control box. A brake foot pedal is supplied as backup for the mini power unit. Using the control box mounted on the test stand, the black knob regulates pressure.

The tong should be secured for both make-up or break-out operation, by utilizing the snub line. If this is not done, the tong may be thrown against operator causing physical harm.

When using the mechanical shift lever to change speeds, the power tong must first come to a complete stop before shifting. When using tongs hydraulic shift two-speed motor to change speeds, the tong may be shifted "On the Run."

Eckel tongs have proven to basically to last forever with minimal maintenance as all they are manufactured with the highest quality of steel. Using Eckel equipment tells your customer that you have the highest quality equipment on the market.

Tong size is determined by range of tubulars you will run. For example a 5-1/2 Hydra-Shift® is capable of running tubulars 5-1/2-inches and smaller while the 14 UHT is capable of running tubulars 14-inches and smaller. It is important not to use a large range of sizes with just one tong. If you have a 10-3/4 Standard and you regularly run 4-1/2-inch tubing with this tong, you might consider using a smaller tong.

PSI pressure determines the maximum torque the tong will safely be able to reach. Eckel rates all their tongs at the industry standard 2500 PSI. A competitor with a similar size tong may show more or the same torque as an Eckel tong due to a higher PSI from the power unit (which is in fine print) in an effort to fool you, thinking there tong is equal to the industry standard (Eckel tong.)

Gallons Per Minute determines the rotational speed of the tong. A low GPM will cause the tong to operate at a lower speed while a high GPM will result in the tong to rotate at a higher speed. Eckel offers an RPM (Revolutions per minute) Control which is a flow divider to decrease the amount of hydraulic fluid that reaches the tong if needed, the remaining fluid is returned to the power unit reservoir. By decreasing the amount of fluid reaching the tong the operator is able to control the maximum RPM of the tong.

Field tests have shown depending on several factors most power units used in above 32 degrees Fahrenheit conditions no matter if your hydraulic oil tank holds 200 gallons of oil, will exceed 150 degrees during a short 8 hour job. Most power units without hydraulic oil coolers exceed 170 degrees which is way past the recommended guide lines.

Radial Lock Door: A patented door locking system (US Patent 6,279,426) for Eckel tongs that allows for latchless locking of the tong door. The tong door swings easily open and closed and locks when torque is applied to the tong. When safety is important this locking mechanism combined with our safety door interlock provides unparalleled safety while speeding up the turn around time between connections. The Radial Door Lock is patented protected in the following countries: Canada, Germany, Norway, United Kingdom, and the United States.

Sliding Head: A type of head used in specific Eckel tongs that slides out from a pocket within the tong. This head biting system utilizes our wide angle wrap-around type dies and is considered the best choice of power tong biting systems for use on small tubular and drill pipe.

Tong Line Pull Gauges and Tong Torque Gauges both tell the operator the amount of torque being applied to oilfield tongs; however, they perform this necessary task differently.  Although they both measure the force applied to the pipe in make up and break out situations, how they measure this force is what makes these two gauges different.  Knowing which tong gaugewill work best for your application and employees is all important in selecting a tong gauge.

The biggest difference between these two gauges is how and what they measure.  A tong line pull gauge measures true force (force/pounds), so what you see on the gauge is exactly what’s being applied to the pipe.  Basically, it’s the what-you-see-is-what-you-get gauge.  A tong torque gauge, on the other hand, measures the force that is being applied to the load cell and reads this force in foot/pounds. A more detailed explanation of both gauges follows.

A tong line pull gauge is universal.  As long as the tong is a manual tong, a tong line pull gauge will fit on any hydraulic tong system.  No matter what the tong’s handle length, a tong line pull gauge will measure force/pounds.  The advantage to these gauges is that because they are universal, they can be used on any manual tong system. For example, you have two tongs, one with a 48 inch handle, and one with a 36 inch handle. You can use a tong line pull gauge with each tong, either the 48 inch handle or 36 inch handle, and measure the force pounds being applied to the drill pipe.  Having this gauge on hand can be very useful when you have to move from different manual tong systems with different handle lengths. These systems, consisting of gauge, hose, and load cell, are great for the driller who wants to measure force/pounds on a variety of manual tongs.

Handle lengths are measured from the center of the tong to the end of the handle.  If this measurement is in inches, it will need to be converted to feet in order to find max torque.

Tong torque gauges can be used on manual tongs or power tongs, but the handle length must never change because these gauges are not universal.  A tong torque gauge is calibrated to a specific tong handle length and thus reads in foot/pounds instead of force/pounds.  The advantage to the gauge readings being foot/pounds is that the driller does not have to convert the gauge measurement in order to know the foot pounds being imposed on the drill string. By doing the math beforehand, the driller will avoid any miscalculations that could cause possible twistoffs.  The calculations are completed when the system is calibrated, taking the worry out of the driller’s hands and making the measurement of torque easier in the field. These systems, consisting of gauge, hose, and load cell, are great for the driller who wants to measure foot pounds without calculations in the field.

Straight Tong Die Driver: Used for die slot redressing, the straight tong die driver is the simplest of type of rig tong. Though it is also the simplest type of rig tong to use, it is also the least safe of the three. Its handle and handguard protect hammer blows from falling onto the grip. Straight tong die drivers are lightweight—under eight pounds—and measure in at around 1”.

Angled Tong Die Driver: The angled tong die driver has a grip that’s angled away from the perpendicular tong as well as brass guards for the tong tip and handle, making this rig tong safer than the straight tong die driver. While this tong is safer, however, it’s actually harder to keep the angle tong die driver in place. This driver is similar in length to the straight tong die driver, but is about two pounds heavier, weighing in at over nine pounds.

Hammerless Tong Die Driver: This variety of tong die driver is made up of a hand pipe that can be used to apply pressure to the tong’s tip without using a hammer at all. This option is the safest of the three driver types because there’s no hammer required, it’s also the slowest driver for this same reason. The hammerless tong die driver is about as long and weighs as much as the straight tong die driver.

What oilfield tools does your operation need? Keystone Energy Tools has atool to fit your bill.Contact us today to learn more about how rig tongs can make your work environment safer, and to learn more our other oil and gas industry products.

Power tongs are machines that may be used to make-up and break-out threaded connections between adjacent tubular segments by gripping and rotating a first tubular segment relative to a second tubular segment to either make-up or break-out the threaded connection between the two tubular segments. FIG. 1 is a perspective view of an example of an externally gripping power tong 100. The power tong 100 includes a drive motor 110 that may be hydraulically, electrically, and/or pneumatically-powered, and a gripping assembly mechanically coupled to the motor 110 for gripping and rotating a tubular segment received within a bay 106. A generally “C”-shaped gear housing 112 supports a pair of pivoting doors 114. The doors 114 may be closed to secure the bay 106 or swung open (as indicated in FIG. 1) to provide access to the bay 106. The bay 106 is generally surrounded by the gear housing 112. The center of the bay 106 is between a pair of generally opposed pivotable gripping jaws 120, each having a generally arcuate gripping surface disposed radially inwardly toward the center of the bay 119.

Makeup requirements for tubular connections require high torque, such as in the order of thousands, and up to tens of thousands, of ft-lb torque. The components of a power tong must be capable of producing and sustaining the torques required to rotate tubular segments. As such, safely and effectively handling tubular members within an oilfield environment remains a priority to increase the efficiency and effectiveness of such tubular handling equipment.

FIGS. 2A-2C show multiple views of a power tong assembly used to grip and rotate a tubular segment in accordance with one or more embodiments of the present disclosure;

FIGS. 5A and 5B show multiple schematic views of a simplified hydraulic circuit for a power tong assembly in accordance with one or more embodiments of the present disclosure.

In accordance with various aspects disclosed herein, the present disclosure relates to a power tong assembly that may be used to make-up, break-out, and/or torque two or more tubular members, such as within an oilfield exploration and production operation environment discussed above. The power tong assembly includes a power tong is configured to grip and rotate a tubular segment in a first direction, such as to make-up a threaded connection with the tubular segment, and in a second direction, such as to break-out the threaded connection with the tubular segment. The power tong assembly further includes an interlock system operably coupled to the power tong, in which the interlock system may be configured to selectively allow the power tong to rotate the tubular segment in one of the first direction and the second direction while preventing the power tong to rotate the tubular segment in the other of the first direction and the second direction. The interlock system may, additionally or alternatively, be configured to selectively allow the power tong to rotate or not rotate in response to conditions that are sensed by the interlock system.

For example, the power tong may be operated in two directions, such as a make-up direction (e.g., operated in a make-up setting) and a break-out direction (e.g., operated in a break-out setting), in which the make-up setting enables the power tong to rotate a tubular segment in the first direction to make-up a threaded connection with the tubular segment, and the break-out setting enables the power tong to rotate the tubular segment in the second direction to break-out the threaded connection with the tubular segment. Further, the interlock system includes a make-up setting that allows the power tong to rotate the tubular segment in the first direction to make-up the threaded connection with the tubular segment and a break-out setting that allows the power tong to rotate the tubular segment in the second direction to break-out the threaded connection with the tubular segment. As such, the interlock system is configured to prevent the power tong to operate in the make-up setting when the interlock system is in the break-out setting, and further is configured to prevent the power tong to operate in the break-out setting when the interlock system is in the make-up setting.

In one or more embodiments, the power tong may include a high-speed setting to rotate the tubular segment in the first direction and the second direction in a high gear and a low-speed setting to rotate the tubular segment in the first direction and the second direction in a low gear. Accordingly, in one embodiment, the interlock system is configured to allow the power tong to operate in the make-up setting and the high-speed setting only when the interlock system is in the make-up setting, and is configured to allow the power tong to operate in the break-out setting and the high-speed setting only when the interlock system is in the break-out setting. The interlock system may further include a selector mechanism, such as a plug assembly or a three-way valve, which enables the interlock system to move between the make-up setting and the break-out setting. Further, the interlock system may include a power tong gear position sensor. The power tong gear position sensor may be used to sense and determine if the power tong is configured to operate in high gear (e.g., a high-speed setting) or operate in low gear (e.g., a low-speed setting). Accordingly, as discussed more below, the interlock system may use the selector mechanism and/or the power tong gear position sensor to sense the setting or mode of operation of the power tong, in which the interlock system may be configured to selectively allow the power tong to rotate or not rotate in response to conditions that are sensed by the selector mechanism and/or the power tong gear position sensor of the interlock system. Furthermore, the interlock system may be operably coupled to a bi-directional hydraulic motor of the power tong such that the interlock system disables the hydraulic motor to prevent the power tong to rotate the tubular segment in the other of the first direction and the second direction.

In one or more embodiments, the interlock system may include a selector mechanism, in which the selector mechanism may be used as a tong operator interface to switch and move the interlock system between the make-up setting and the break-out setting. In such an embodiment, if the selector mechanism is in the make-up setting (e.g., a make-up position) and the power tong is actuated in the make-up direction, the interlock system may permit the power tong to operate. In particular, the interlock system may permit the power tong to operate in the make-up direction in high-speed (e.g., the high-speed setting) and low-speed (e.g., the low-speed setting) if the selector mechanism of the interlock system is in the make-up position. Further, in such an embodiment, the interlock system may prevent or block the power tong to operate in the break-out direction in high-speed and only permit the power tong to operate in the break-out direction in low-speed if the selector mechanism of the interlock system is in the make-up position.

Further, if the selector mechanism is in the break-out setting (e.g., a break-out position) and the power tong is actuated in the break-out direction, the interlock system may permit the power tong to operate. In particular, the interlock system may permit the power tong to operate in the break-out direction in high-speed and low-speed if the selector mechanism of the interlock system is in the break-out position. Further, in such an embodiment, the interlock system may prevent or block the power tong to operate in the make-up direction in high-speed and only permit the power tong to operate in the make-up direction in low-speed if the selector mechanism of the interlock system is in the break-out position.

Referring now to FIGS. 2A, 2B, and 2C, multiple views of a power tong assembly 200 used to grip and rotate a tubular segment 202 in accordance with one or more embodiments of the present disclosure are shown. In particular, FIG. 2A shows a perspective view of the power tong assembly 200 when in use to make-up and/or break-out a threaded connection between a first upper tubular segment 202A and a second lower tubular segment 202B, FIG. 2B shows an above schematic view of the power tong assembly 200 when in use to make-up a threaded connection with the tubular segment 202, and FIG. 2C shows another above schematic view of the power tong assembly 200 when in use to break-out a threaded connection with the tubular segment 202.

In one or more embodiments, when making-up and breaking-out threaded connections between tubular segments, a mechanism or component is used to hold reaction torque on one tubular segment while the power tong is used to rotate the other tubular segment. One or more power tong assemblies may include with integral backup wrenches, in which the backup wrench may hold reaction torque on a tubular segment while the power tong makes-up and breaks-out threaded connections by rotating an adjacent tubular segment. In an embodiment in which a power tong assembly does not include an integral backup wrench, such as shown in FIG. 2A, reaction torque may be held on the lower tubular segment 202B using a drilling rotary 204 and/or other tubular gripping mechanism (e.g., a manual tong, a spider, a collar load support), while the power tong assembly 200 is used to rotate and apply torque to the upper tubular segment 202A.

As shown in FIGS. 2A-2C, a tong operator 206 may be in close proximity to the power tong assembly 200, such as particularly when making-up and breaking-out connections. For example, a power tong 208 of the power tong assembly 200 includes a make-up setting and a break-out setting, with the power tong 208 switchable between the make-up and break-out settings. In the make-up setting, the power tong 208 is used to rotate the upper tubular segment 202A in the first direction to make-up a threaded connection between the upper tubular segment 202A and the lower tubular segment 202B, and in the break-out setting, the power tong 208 is used to rotate the upper tubular segment 202A in the second direction to break-out the threaded connection between the upper tubular segment 202A and the lower tubular segment 202B. Furthermore, the power tong 208 may include a high-speed setting and a low-speed setting, with the power tong 208 switchable between the high-speed and low-speed settings. In the high-speed setting, the power tong 208 is used to rotate the upper tubular segment 202A in the first direction or in the second direction in a high gear. In the low-speed setting, the power tong 208 is used to rotate the upper tubular segment 202A in the first direction or in the second direction in a low gear. Accordingly, the tong operator 206 may operate and switch the power tong 206 between each of these different settings.

FIG. 2B shows an example of the power tong 208 when in the make-up setting, in which the power tong 208 is used in this embodiment to rotate the tubular segment 202A in a first direction (e.g., clockwise direction) when making-up threaded connections with the tubular segment 202A. As the power tong 208 rotates the tubular segment 202A in the clockwise direction, the power tong 208 will have the tendency to move and rotate from a reactive torque 210A in the counter-clockwise direction. In one or more embodiments, to prevent movement and rotation of the power tong 208, a snub line 212A may be attached to the power tong 208 in a direction opposite to the reactive torque 210A to prevent movement of the power tong 208 in response to the reactive torque 210A. As such, the snub line 212A may be used in the orientation shown to prevent rotation of the power tong 208 when making-up threaded connections with the tubular segment 202A.

Similarly, FIG. 2C shows an example of the power tong 208 when in the break-out setting, in which the power tong 208 is used in this embodiment to rotate the tubular segment 202A in a second direction (e.g., counter-clockwise direction) when breaking-out threaded connections with the tubular segment 202A. As the power tong 208 rotates the tubular segment 202A in the counter-clockwise direction, the power tong 208 will have the tendency to move and rotate from a reactive torque 210B in the clockwise direction as well. In one or more embodiments, to prevent movement and rotation of the power tong 208, a snub line 212B may be attached to the power tong 208 in a direction opposite to the reactive torque 210A. As such, the snub line 212B may be used to prevent rotation of the power tong 208 when breaking-out threaded connections with the tubular segment 202A.

As shown in FIGS. 2B and 2C, the direction of the attachment of the snub line 212 to the power tong 208 depends on if the power tong 208 is in the make-up setting or the break-out setting. However, as the power tong 208 may not include an integral backup wrench, and is shown to only include the rotary 204 to hold reaction torque, the power tong 208 may present a risk to the tong operator 206. In particular, in the embodiment shown in FIG. 2B, if the tong operator 206 switches the power tong 208 to operate in the break-out setting instead of the make-up setting, the snub line 212A will be ineffective in preventing rotation of the power tong 208. This will allow the power tong 208 to rotate and spin around the tubular segment 202A in the clockwise direction and strike the tong operator 206. This inefficiency is even further magnified if the tong operator 206 is operating the power tong 208 in the high-speed setting, as opposed to the low-speed setting. Similarly, in the embodiment shown in FIG. 2C, if the tong operator 206 switches the power tong 208 to operate in the make-up setting instead of the break-out setting, the snub line 212B will be ineffective in preventing rotation of the power tong 208. This will allow the power tong 208 to rotate and spin around the tubular segment 202A in the counter-clockwise direction and strike the tong operator 206.

Though not shown, the tong operator 206 often operates the power tong 208 from scaffolding or within confined spaces, in which the power tong 208 may then knock the tong operator 206 from the scaffolding and/or smash the tong operator 206 against the structure of a drilling rig, both of which are life-threatening injuries to the tong operator 206. Accordingly, the present disclosure relates to a power tong assembly, in which the power tong assembly includes a power tong and includes an interlock system operably coupled to the power tong, in which the interlock system is configured to selectively allow the power tong to rotate the tubular segment in one of the first direction and the second direction while preventing the power tong to rotate the tubular segment in the other of the first direction and the second direction.

As discussed above, the power tong 208 includes a make-up setting and a break-out setting, which may be operated through one or more handles or levers included with the power tong 208. The make-up setting enables the power tong 208 to rotate the tubular segment 202A in the first direction to make-up a threaded connection with the tubular segment 202A, and the break-out setting enables the power tong 208 to rotate the tubular segment 202A in the second direction to break-out the threaded connection with the tubular segment 202A.

Accordingly, an interlock system in accordance with the present disclosure that is operably coupled to the power tong 208 also includes a make-up setting and a break-out setting, in which the interlock system may be operated using a selector mechanism included within the interlock system. The make-up setting of the interlock system allows the power tong 208 to rotate the tubular segment 202A in the first direction, such as in both the high-speed setting and the low-speed setting, to make-up the threaded connection with the tubular segment 202A, and the break-out setting of the interlock system allows the power tong 208 to rotate the tubular segment 202A in the second direction, such as in both the high-speed setting and the low-speed setting, to break-out the threaded connection with the tubular segment 202A. FIG. 3A shows a flow chart of operation of a power tong assembly in accordance with the present disclosure. As shown, the interlock system may be set in either an interlock system make-up setting 302A or an interlock system break-out setting 302B. When in the interlock system make-up setting 302A, the power tong is enabled/allowed to operate in a power tong make-up setting 304A and is disabled/prevented to operate in a power tong break-out setting 304B. When in the interlock system break-out setting 302B, the power tong is disabled/prevented to operate in a power tong make-up setting 304C and is enabled/allowed to operate in a power tong break-out setting 304D.

As such, with reference to FIGS. 2A-2C, the interlock system is configured to prevent the power tong 208 to operate in the make-up setting when the interlock system is in the break-out setting, and further is configured to prevent the power tong 208 to operate in the break-out setting when the interlock system is in the make-up setting. Such a configuration may provide an additional safety feature to the power tong assembly 200, thereby helping prevent the tong operator 206 from unintentionally making-up and/or breaking-out of threaded connections that may lead to accidents within a drilling environment.

Further, as also discussed above, the power tong 208 may include a high-speed setting and a low-speed setting, which may be operated through one or more handles or levers included with the power tong 208. The high-speed setting enables the power tong 208 to rotate the tubular segment 202A in the first direction and/or the second direction in a high gear, and the low-speed setting enables the power tong 208 to rotate the tubular segment 202A in the first direction and/or the second direction in a low gear.

Accordingly, an interlock system in accordance with the present disclosure may be configured to allow the power tong 208 to operate in the make-up setting and the high-speed setting only when the interlock system is in the make-up setting, and may further be configured to allow the power tong 208 to operate in the break-out setting and the high-speed setting only when the interlock system is in the break-out setting.

FIG. 3B shows a flow chart of operation of a power tong assembly with an interlock system in a make-up setting in accordance with the present disclosure. The interlock system may be set in an interlock system make-up setting 306A, and the power tong may be set in either a power tong high-speed setting 308A or a power tong low-speed setting 308B. When in the interlock system make-up setting 306A and the power tong high-speed setting 308A, the power tong is enabled/allowed to operate in a power tong make-up setting 310A and is disabled/prevented to operate in a power tong break-out setting 310B. When in the interlock system make-up setting 306A and the power tong low-speed setting 308B, the power tong is enabled/allowed to operate in a power tong make-up setting 310C and is also enabled/allowed to operate in a power tong break-out setting 310D.

Further, FIG. 3C shows a flow chart of operation of a power tong assembly with an interlock system in a break-out setting in accordance with the present disclosure. The interlock system may be set in an interlock system break-out setting 306B, and the power tong may be set in either a power tong high-speed setting 308C or a power tong low-speed setting 308D. When in the interlock system break-out setting 306B and the power tong high-speed setting 308C, the power tong is disabled/prevented to operate in a power tong make-up setting 310E and is enabled/allowed to operate in a power tong break-out setting 310F. When in the interlock system break-out setting 306B and the power tong low-speed setting 308D, the power tong is enabled/allowed to operate in a power tong make-up setting 310G and is also enabled/allowed to operate in a power tong break-out setting 310H.

FIG. 3D shows a flow chart of operation of a power tong assembly in accordance with the present disclosure. In one or more embodiments, the interlock system may include a selector mechanism 312, in which the selector mechanism 312 may be used as a tong operator interface to switch and move the interlock system between operating the power tong in a make-up direction 314 or a break-out direction 316. Further, the interlock system may include a power tong gear position sensor 318. The power tong gear position sensor 318 may be used to sense and determine if the power tong is configured to operate in high gear (e.g., a high-speed setting) or operate in low gear (e.g., a low-speed setting). If the selector mechanism 312 is in the make-up setting (e.g., a make-up position) and the power tong gear sensor 318 detects that the power tong is in high gear, the interlock system may permit the power tong to operate in the make-up direction in high gear 320A and prevent or block the power tong to operate in the break-out direction in high gear 320B. If the selector mechanism 312 is in the make-up setting and the power tong gear sensor 318 detects that the power tong is in low gear, the interlock system may permit the power tong to operate in the make-up direction in low gear 320C and permit the power tong to operate in the break-out direction in high gear 320D.

Further, If the selector mechanism 312 is in the break-out setting (e.g., a break-out position) and the power tong gear sensor 318 detects that the power tong is in high gear, the interlock system may prevent or block the power tong to operate in the make-up direction in high gear 320E and permit the power tong to operate in the break-out direction in high gear 320F. If the selector mechanism 312 is in the break-out setting and the power tong gear sensor 318 detects that the power tong is in low gear, the interlock system may permit the power tong to operate in the make-up direction in low gear 320G and permit the power tong to operate in the break-out direction in high gear 320H.

An interlock system in accordance with the present disclosure may have one or more different types of configurations. For example, as shown and discussed below, the interlock system may be hydraulically controlled, in which the interlock system may include one or more hydraulic components and/or actuators and may be used to selectively control hydraulic fluid flow through the power tong. In particular, the interlock system may be used to selectively provide and control a supply of hydraulic fluid to a hydraulic motor of the power tong. However, in another embodiment, the interlock system may additionally or alternatively be magnetically controlled, electrically controlled, mechanically controlled, and/or pneumatically controlled. Accordingly, the present disclosure contemplates other methods and configurations for an interlock system than only those discussed herein, and therefore the present disclosure should not be so limited.

Referring now to FIGS. 4A-4G, multiple views of a power tong assembly 400 in accordance with one or more embodiments of the present disclosure are shown. The power tong assembly 400 includes a power tong 402 used for gripping and rotating tubular segments, particularly for making-up and breaking-out threaded connections, and also includes an interlock system 410. The interlock system 410 is operably coupled to the power tong 402 to selectively allow the power tong to rotate the tubular segment in one of the make-up and the break-out direction while also preventing the power tong 402 from rotating the tubular segment in the other of the make-up and the break-out direction. Accordingly, in this embodiment, the interlock system 410, or at least portions or components thereof, are positioned upon and operably coupled to a motor 404 of the power tong 402. The motor 404 may be a bi-directional hydraulic motor, in which the interlock system 410 may be used to disable the motor 404, such as by limiting hydraulic fluid supply to the motor 404, to prevent the power tong 402 from rotating the tubular segment in an undesired direction or at an undesired speed.

Along with the motor 404, the power tong 402 may include one or more handles 406 to set the power tong 402 in the make-up setting or the break-out setting. For example, in FIG. 4A, one of the handles 406 may be moved to set the power tong 402 in either the make-up setting or the break-out setting, while the other of the handles 406 may be moved to operate a lift cylinder operably coupled to the power tong 402 to selectively raise and lower the power tong 402. The power tong 402 may further include a handle 408 (e.g., speed shifting shaft) to set the power tong 402 in the high-speed setting or the low-speed setting. For example, in FIG. 4A, the handle 408 may be moved in one direction to set the power tong 402 in the high-speed setting or may be moved in another direction to set the power tong 402 in the low-speed setting.

As the interlock system 410 may include multiple portions or components, the interlock system 410 is shown in this embodiment as including a manifold 412, which may be formed as one or more housings, and a speed detection mechanism 414 (e.g., power tong gear position sensor 318). FIG. 4B shows a detailed view of the manifold 412, and FIG. 4C shows a detailed view of the speed detection mechanism 414. The manifold 412 may be positioned on the motor 404 of the power tong 402 and may have hydraulic fluid pumped through the manifold 412. As such, the manifold 412 may include hydraulic logic elements to selectively divert hydraulic fluid flow therethrough, such as including one or more valves, plugs, and/or switches to selectively divert the flow through the manifold 412. In particular, in this embodiment, the manifold 412 may include therewith or therein a selector mechanism 416, a check valve, an orifice or a needle valve, and an unloader valve.

The selector mechanism 416 may be included within the interlock system 410, and may be used as a tong operator interface to switch and move the interlock system 410 between the make-up setting and the break-out setting. Examples of the selector mechanism 416 are shown in FIGS. 4D-4F. In FIGS. 4D and 4E, the selector mechanism 416 is shown as a plug assembly 418 that includes one or more plugs. The plugs of the plug assembly 418 may be rearranged and positioned within the manifold 412 to set the interlock system 410 in a make-up setting (e.g., high-speed make-up setting), as shown in FIG. 4D, or to set the interlock system 410 in a break-out setting (e.g., high-speed break-out setting), as shown in FIG. 4E. Alternatively, the selector mechanism 416 is shown as a three-way valve 420 in FIG. 4F, such as a three-way ball valve, in which the three-way valve 420 may be set and moved between the make-up setting and the break-out setting.

The speed detection mechanism 414 may be operably coupled to the handle 408 that shifts the power tong 402 between the high-speed setting and the low-speed setting. Accordingly, the speed detection mechanism 414 may be positioned adjacent the handle 408, such as positioned on the bottom of the power tong 402. In this embodiment, the speed detection mechanism 414 may include a cam-operated valve 422. FIG. 4G shows a cross-sectional view of the cam-operated valve 422. As such, the cam-operated valve 422 is activated and moved between an open position and a closed position based on movement of a camming rod 424. The camming rod 424 may be coupled to the handle 408, and therefore the camming rod 424 may move with the handle 408 when shifting the power tong 402 between the high-speed setting and the low-speed setting. Accordingly, the cam-operated valve 422 may detect the speed of the power tong 402, such as if the power tong 402 is in the high-speed setting or the low-speed setting, based upon the position and movement of the camming rod 424.

Referring now to FIGS. 5A and 5B, multiple schematic views of a simplified hydraulic circuit 500 for a power tong assembly in accordance with one or more embodiments of the present disclosure are shown. As shown in this embodiment, the hydraulic circuit 500 includes a hydraulic motor 502 (e.g., bi-directional hydraulic motor), such as the motor 404 shown in FIG. 4A, and a directional control valve 504 (e.g., four-way, three-position directional control valve) that controls fluid flow to the hydraulic motor 502. The directional control valve 504 may include or be operably coupled to the handles 406 of the power tong 402. As such, the directional control valve 504 may be used to control the direction of rotation of the hydraulic motor 502, and therefore may be used to move the power tong 402 between the make-up setting and the break-out setting. Hydraulic fluid may be provided along a pressure flow path 550 and flow through a motor inlet flow path 552 into the directional control valve 504. The directional control valve 504 may then be used to selectively flow the hydraulic fluid into either the A-side or the B-side of the hydraulic motor 502, depending on the desired rotation of the power tong 402. Hydraulic fluid may then return from the hydraulic motor 502 back into the directional control valve 504, in which hydraulic fluid may then be provided to a return flow path 556 through a motor outlet flow path 554.

The directional control valve 560, as shown in the embodiment in FIGS. 5A and 5B, may be opened from operation of either a directional control valve 564 or a directional control valve 566 fluidly coupled in parallel to the directional control valve 560 along the case drain flow path 562. The directional control valve 564 (e.g., two-way, two-position directional control valve) may include an interlock valve that is movable between the open and closed position based upon an open or closed position of a door of the power tong 402. If the door of the power tong 402 is opened, the directional control valve 564 may relieve pilot pressure to the directional control valve 560 along the case drain flow path 562, thereby opening the directional control valve 560 and preventing operation of the hydraulic motor 502.

The hydraulic circuit 500 may further include a directional control valve 576 (e.g., three-way, two-position directional control valve), which may be the cam-operated valve 422 of the speed detection mechanism 414 shown in FIGS. 4A, 4C, and 4G. The directional control valve 576 may be movable between the open and closed position based upon if the power tong 402 is in the high-speed setting and the low-speed setting. As such, in this embodiment, the directional control valve 576 may be in the open position when the power tong 402 is in the high-speed setting, thereby fluidly coupling the pilot flow path 574 to the pilot flow path 568. Further, as shown in FIGS. 5A and 5B, the directional control valve 576 may be in the closed position when the power tong 402 is in the low-speed setting, thereby preventing fluid from flowing from the pilot flow path 574 to the pilot flow path 568. Furthermore, the hydraulic circuit 500 may include a check valve 578 and an orifice or a needle valve 580. The check valve 578 and the needle valve 580 may be in parallel with each other, as shown, and may be fluidly coupled to the pilot flow path 574 or the pilot flow path 568.

In operation, the selector mechanism 570 may be used to either allow fluid flow through the A-side motor flow path 572A or the B-side motor flow path 572B and into the pilot flow path 574. When the A-side motor flow path 572A is open with fluid allowed to flow therethrough, the A-side of the hydraulic motor 502 is not operational. For example, hydraulic fluid may be provided along the motor inlet flow path 552, into the directional control valve 504, and towards the A-side of the hydraulic motor 502. As the A-side motor flow path 572A is open, hydraulic fluid will flow into the A-side motor flow path 572A and continue along the pilot flow path 574. If the directional control valve 576 is present and open (e.g., the power tong 402 is in the high-speed setting), hydraulic fluid may flow from the pilot flow path 574 to the pilot flow path 568 to provide pilot pressure to the directional control valve 566. When pilot pressure is received along the pilot flow path 568 to the directional control valve 566, the directional control valve 566 will open, thereby relieving pilot pressure to the directional control valve 560 along the case drain flow path 562, opening the directional control valve 560, and preventing operation of the hydraulic motor 502.

In an embodiment in which hydraulic fluid received through the A-side of the hydraulic motor 502 causes the power tong 402 to make-up threaded connections with a tubular segment, the right side of the directional control valve 504 may be used as the make-up setting for the power tong 402, and the opening the B-side motor flow path 572B may be used as the make-up setting for the selector mechanism 570 (e.g., selector mechanism 416). In such an embodiment, the hydraulic motor 570 may, thus, be disabled when the directional control valve 504 is switched to the left side for the break-out setting of the power tong 402, thereby disabling and preventing the hydraulic motor 570, and the power tong 402, from operating in the break-out setting when the interlock system 410 is in the make-up setting.

Similarly, in an embodiment in which hydraulic fluid received through the B-side of the hydraulic motor 502 causes the power tong 402 to break-out threaded connections with a tubular segment, the left side of the directional control valve 504 may be used as the break-out setting for the power tong 402, and the opening the A-side motor flow path 572A may be used as the break-out setting for the selector mechanism 570 (e.g., selector mechanism 416). In such an embodiment, the hydraulic motor 570 may, thus, be disabled when the directional control valve 504 is switched to the right side for the make-up setting of the power tong 402, thereby disabling and preventing the hydraulic motor 570, and the power tong 402, from operating in the make-up setting when the interlock system 410 is in the break-out setting.

Further, as discussed above, the directional control valve 566 (e.g., unloader valve) may be used as a disabling portion within the interlock system to disable and prevent rotation of the power tong based a speed detection portion (e.g., a directional control valve 576 and/or a cam-operated valve 422) and the direction detection portion (e.g., selector mechanism 570). For example, when pilot pressure is received along the pilot flow path 568 to the directional control valve 566, the directional control valve 566 will open, thereby relieving pilot pressure to the directional control valve 560 along the case drain flow path 562. This enables the directional control valve 560 to open, in which hydraulic fluid then flows along the bypass flow path 558 instead of the motor inlet flow path 552, thereby disabling and preventing the hydraulic motor 502 from operation.

Accordingly, a power tong assembly including a power tong and an interlock system in accordance with the present disclosure may include one or more advantages, such as by decreasing the likelihood of an accident when operating a power tong. In particular, the interlock system is configured to selectively allow the power tong to rotate the tubular segment in one of the first direction and the second direction while preventing the power tong to rotate the tubular segment in the other of the first direction and the second direction. As such, the interlock system may be used to prevent the power tong from operating in a direction unintended by a tong operator, thereby preventing damage to the power tong, to the tubular segments handled by the power tong, and the tong operator.

The Model 300 Sucker Rod Tongs made to make getting on and off the rods easier and to reduce weariness and mishaps. The Model 300 accelerates tripping the pipe, protects rods, and all while simply using the same power unit as a tubing tong. The Model 300 comes with a modifiable relief valve to set the torque; 95 RPM and 850ft/lbs. of torque at high range. Situated by a firm torque arm, this tong can engage automatically and release automatically by a reversing tong.

The Model 300M Sucker Rod Tongs made to make getting on and off the rods easier and to reduce weariness and mishaps.  The Model 300 accelerates tripping the pipe, protects rods, and all while simply using the same power unit as a tubing tong. The Model 300 comes with a modifiable relief valve to set the torque; 95 RPM and 850ft/lbs. of torque at high range. Situated by a firm torque arm, this tong can engage automatically and release automatically by a reversing tong. A feature unique to this model is the ability to breakout and make-up 1-1/8” rods without over torqueing.

The Model 500 Power Tubing Tong has a size range of 1-5/16” to 7”, joint make-up in 5 seconds, and joint break-out in 7 seconds. With a split glide ring, both safer and more convenient access to jaws and final drive gear components is attainable, while pressurized oil baths ensure that the Model 500 is properly lubricated. The Model 500 also features an adjustable clutch and air or hydraulic assist for the back-up tool. Also fitted with a “Power Shift” Transmission, the operator is able to adjust gears during operation while the Improved Drive Alignment minimizes wasted power.

The Model 600 Power Tubing Tongs feature an adjustable clutch and is available in either air or hydraulic assist for the back-up tool. Also fitted with a “Power Shift” Transmission, the operator is able to adjust gears during operation while the Improved Drive Alignment minimizes wasted power. The Model 600 permits joint make-up in 5 seconds and joint break-out in 7 seconds. With a split glide ring, both safer and more convenient access to jaws and final drive gear components is attainable, while pressurized oil baths ensure that the Model 500 is properly lubricated.

The Model RSHD Power Tubing Tongs are truly a heavy duty piece of equipment that is for the tough jobs. The Model RSHD has more steel weight and gussets added to the bottom in order to diminish chance of case spreading. This model features a customary chain-driven design, integral sprocket, and outer ring. Lastly, the Model RSHD utilizes a familiar jaw-and-bushing biting system.

The Model 700 features the highest torque of all the Power Tubing/Casing Tongs at 20,000 ft./lbs. at 2000 PSI. This model consists of a light drill pipe, tubing, and casing.

Contact our expert sales staff for pricing, availability and product specifications for the Gill Power Tong right for your application at the link provided on this page.

The present invention relates to open-head power tongs used in drilling operations, and more particularly, is directed to an improved means of actuating and deactuating the operation of the power tong drive means in response to the opened and closed positions of an access door.

As well known in the drilling industry, power tongs are employed in making-up and breaking-out operations of casings, tubings, rods, pipes and the like. More particularly, power tongs are used to grip and rotate lengths of drill pipe or the like to connect or join several lengths of pipe together to thereby form a drill string in a make-up operation, and in the alternative, to grip and rotate a length of drill pipe to disconnect it from the drill string in a break-out operation.

One type of power tong commonly used today is the open-head tong, such as the one shown and described in U.S. Pat. No. 4,060,014. The open-head tong has a bifrucated frame defining a central opening and a side opening communicating with the central opening for the passing therethrough of a drill pipe or the like. Due to the extreme costs of drilling, open-head tongs have become very popular, in that, they can easily and readily be moved into and out of an operative position when they are needed in the making up and breaking out of drill strings.

In operation, the open-head power tong exerts large rotational torques on the drill pipes, usually the larger the tong, the larger the torque output. Due to these large torque outputs and the resulting forces generated therefrom, the open-head tongs have been provided with an access door that bridges the gap between the bifrucated ends of the tong. The primary purpose of such an access door is to strengthen the tong structure so as to prevent, during the operation of the tong, the bifrucated ends from separating or springing apart, which not only results in damage to the tong, but could also inflict injury to the operating personnel. The access door, in addition to providing structural rigidity to the tong, also provides the operator with safety in bodily protecting him from the rotating pipe gripping and engaging jaws.

Such access doors perform very satisfactorily in providing structural rigidity to the tong and do provide protection to the operators from the rotating components of the tong when the door is properly latched in position during the make-up and break-out operations; however, in an effort to save time, operators have been known to operate the tong with the access door open, and in some instances, the operators have even removed the access door from the tong. Such operator"s carelessness not only causes costly structural damage to the tong, but also results in personal injury to the operator.

In U.S. Pat. No. 2,705,614 there is shown an open-head power tong having an automatic hydraulically powered access door, operably interconnected to the hydraulic cylinders that actuate the jaw gripping mechanism, which must be closed before the jaws can be actuated so as to rotate a drill pipe. Such door interlock mechanism has been specifically designed for the type of tong disclosed and is not readily adaptable to other types of power tongs, such as the one shown in the above-mentioned U.S. Pat. No. 4,060,014. Further, the hydraulic circuitry that is involved with such a powered access door is not only complicated, having expensive components, but is also, costly to maintain and repair. Still further, such door interlock mechanism does not provide adequate safety to an operator, in that, although the operator is protected from the pipe gripping and engaging mechanism when the door is closed, he is also subjected to the risk of having the power operated door being automatically swung into him as it is being closed, thus, creating a potentially dangerous and unsafe condition under which the operator must work.

The present invention obviates the problems experienced with access doors and disadvantages associated with the prior art door-interlock mechanisms by providing, as one of its principle objects, an improved door-interlock mechanism for an open-head power tong that ensures the access door is in a closed position before the tong can be operated, thereby preventing possible structural damage to the tong from operating the tong with the door open, as well as, preventing personal injury to the operators by protecting them from the various rotating components of the tong.

Another object of the present invention is to provide a door-interlock mechanism for an open-head power tong that is simple in structure and adaptable to all types of open-head power tongs.

Accordingly, the present invention, sets forth in an open-head power tong having an access door mounted on the tong and moveable between opened and closed positions, an improved door-interlock mechanism that includes means for controlling the operation of the tong in response to the opened and closed position of the door. More particularly, the control means preferably includes a pneumatic contact valve interconnected with a pneumatically piloted diverter valve operably associated with the power means of the tong such that the power means is placed in either an operative or inoperative condition in response to respective closed and opened positions of the door. Specifically, the pneumatic contact valve is so positioned in the vicinity of the side opening that the door, in its closed position, engages the contact valve thereby actuating the diverter valve to permit operation of the power means, and when, the door is moved from its closed position out of engagement with the contact valve, the contact valve causes the diverter valve to deactuate the power means, thus stopping the operation thereof.

FIG. 1 is a top plan view of an open-head power tong incorporating the improved door-interlock mechanism of the present invention with the access door being in its closed position in engagement with the contact valve which actuates the diverter valve.

FIG. 2 is a diagrammatic fragmentary view of the power tong showing the side edge portion of the access door with the door latch removed and with the contact valve being in disengagement with the door which is partly open.

Referring to the drawings, and particularly, to FIG. 1, there is shown, for illustration purposes only, an open-head power tong, being generally indicated by the numeral 10, incorporating the principles of the present invention. The tong illustrated in FIG. 1 is of the type shown and described in U.S. Pat. No. 4,060,014, and thus, for the sake of brevity, since the tong itself forms no part of this invention, only a brief description of the tong will follow.

Briefly, as best seen in FIG. 1, the power tong 10 is comprised of a bifrucated frame structure 12 defining a central drill pipe receiving opening, and a side opening that communicates to the central opening for laterally passing a drill pipe therewithin. Rotatably supported within the frame structure 12 is a pipe engaging and gripping means that includes jaws 14 that swing into and out of the central opening for gripping and rotating a drill pipe disposed within the central opening during make-up and break-out operations of a drill string. The pipe engaging and gripping means with its associated jaws 14 are rotatably driven through a suitable drive train (not shown) by power means such as the hydraulic motor 16 which receives fluid under pressure from a suitable hydraulic pump (not shown) and through a hydraulic control valve 17. The valve 17 is conventional, being moveable between three spool positions; one position being such that the fluid drives the motor in a forward clockwise direction, another position being such that the hydraulic fluid drives the motor in a reverse counterclockwise direction, and the third position being a neutral position wherein fluid passes through the valve to the return line that returns the fluid to a reservoir (not shown) for recirculation thereof.

Also supported on the frame structure 12 is an access door 18, adapted to span or bridge the access opening defined between the bifrucated end portions so as to provide structural rigidity to the power tong 10, as well as, to protect the operator from the various moving components, such as the jaws 14. One end of the access door 18 is hinged to an end of one of the frame bifrucations by a pivot pin 20 whereas the free end of the door is provided with a self-latching arm 22 that engages a latch member 24 mounted on the other bifrucation so as to positively latch the door when it is closed. The door and the door latching mechanism are of the type shown and described in a pending U.S. application, bearing U.S. Ser. No. 791,752; filed Apr. 28, 1977; and entitled TONG LOCKING MECHANISM. The door and the latching mechanism forms no part of this invention and thus a further description will not be given.

To ensure that the tong 10 is only operated when the door 18 is closed, closing the access opening, the tong 10 is provided with an interlock mechanism which basically includes a contact valve 26, engageable by the door 18, and a hydraulic diverter valve 28, operably associated with the hydraulic motor 16 so as to permit flow of hydraulic fluid to the motor, or, in the alternative position, to bypass the flow of hydraulic fluid around the motor.

Now turning to FIG. 3 which schematically represents the various operating components as well as the hydraulic and pneumatic circuitry associated therewith, the operation of the door interlock will be further described. First, it should be noted that both the hydraulic source and the pneumatic source are fully operating with respective fluids being under pressure in inlet lines, the access door 18 being closed, engaged with the actuating arm of the contact valve 26, the piloted diverter valve 28 being detented so as to pass the flow of hydraulic fluid around the motor 16, and with the hydraulic spool control valve 17 being in its neutral position such that fluid passes directly therethrough to the reservoir tank via inlet line 34, passageway 36, return line 38. Thus, as the spool valve 17 is shifted to its forward drive position, hydraulic fluid passes from the inlet line 34, through passageway 40, to line 42, through passageway 44 (of diverter valve 28), to line 46 which directs fluid into the left-hand side of the motor 16, and then via lines 48,49 to passageway 50 of valve 18 which is internally connected to the hydraulic return line 38. If the spool valve 17 is shifted in an opposite direction so as to reverse the direction of the motor 16, fluid flows via line 34, through passageway 52 to line 49 and line 48 to the right side of the motor 16, and then returns via lines 46, passageway 44, line 42 to passageway 54 which is internally connected to return line 38. It can be thus seen that when pressure is applied on the diverter valve 28, it is so positioned to pass hydraulic fluid either to one or the other sides of the motor 16 to thereby drive the rotating components of the tong 10 in either forward or reverse directions depending on the forward or reverse positions of the control valve 17. However, when the pneumatic pressure is relieved from the diverter valve 28, the internal spring forces the valve to the right, thus changing the flow path of the hydraulic fluid so as to bypass the motor 16. In such pressure relief position of the diverter valve 28, the fluid flow path is via lines 49,58, passageway 56 and line 42, thereby bypassing the flow of fluid to the motor 16. Since the flow of fluid through line 46 is blocked, no fluid passes to the motor 16, thus rendering it inoperative.

It can be understood from the foregoing that the described interlock-mechanism controls the operation of the hydraulic motor 16, and thus the operation of the tong 10, in response to the open and closed positions of the access door 18, such that the tong 10 can only be operated with the access door 18 in its closed position, and thereby eliminating the possibility of structural damage to the tong from operating same with the door open, as well as, providing safety to the operator from exposure to the various operating components of the tong.

Well pipe is made up by supporting a lower pipe section ("joint") in the well and then threading an upper joint onto it by means of a fluid-driven power tongs. The pipe assembly is lowered as new joints are added, down to depths of several miles. Threaded well joint connections, in order to seal properly and to have maximum tensile strength, must be accurately tightened ("made-up" in the trade) to a design torgue ("make-up torque") specified by the pipe manufacturer. The design torque must not be exceeded, since galling or breakage of the pipe threads may result. This is particularly true with pipe joint materials chosen for considerations other than strength, e.g. corrosion resistance and impermeability. Such materials are not only relatively soft--they can be quite expensive. In one recent case, 1000 joints (each thirty-three feet long) were removed from a well. Every joint had thread damage due to overtorquing and was considered scrap. This was pipe originally costing $2500 per joint. The importance of controlling the torque applied by the power tongs to the pipe can thus be appreciated, and in fact it is a requirement on many jobs that a running record of maximum torque at each joint be kept. (Various systems exist for making torque records during make-up, including applicant"s system described in co-pending applications Ser. Nos. 487,048 and 526,611.) Despite the existence of accurate torque recording systems, improper torquing continues to occur. The industry still seeks a system that will positively prevent thread damage from overtorquing.

The crossed thread problem is aggravated by violent or jerky movement of the tongs when power is first applied. The tongs frequently do not work smoothly--and are hard to control--at very low speeds. Also, the snub line, initially slack, tends to snap tight when power is first applied. These conditions make it difficult to control and/or record torque at the instant tongs operation begins, so that thread damage can occur even if a low-level torque limiter is used.

I have found that the above problems can be overcome by substantially increasing the overall gear reduction ratio within the tongs, for example, by a factor of five, so that the tongs jaw speed is correspondingly reduced, avoiding the problems of irregular start-up. This speed reduction is advantageously combined with a two-stage torque limiter system for (a) preventing the application of substantial torque during the initial phase of make-up and (b) limiting the maximum torque that the tongs can produce at the final make-up stage. Such a system is described in my co-pending application Ser. No. 629,421, supra.

Torque is automatically controlled during both tightening stages. In the final tightening stage, galling and breaking of threads is prevented by slowly turning the pipe and automatically disabling the pipe tongs when a predetermined torque level is reached.

A particularly important feature of the invention is that even after the tongs are disabled, a persistent torque is maintained by an adjustable choke in a shunt line between the high and low pressure sides of the power tongs.

The preferred embodiment of the invention is illustrated diagrammatically in FIG. 1. The major components are a conventional hydraulic power unit A, a power tongs T driven by fluid from the power unit, a tongs torque sensor/recorder B and a torque control module C.

The power unit A, as shown in FIG. 1, comprises an internal combustion engine 10, a hydraulic pump 12 driven thereby, a pressure regulator 14 downstream of the pump, and a fluid reservoir 16 upstream of the pump. In operation, the power unit delivers pressurized fluid through high pressure line 20, and receives fluid exhausted by the tongs via return line 22.

Th