Back-up tong clamping and torque measuring device of drill rod power tong

Abstract

The utility model provides a back-up tong clamping and torque measuring device of drill rod power tongs, which relates to the technical field of power tongs and comprises a power tong shell and a back-up tong head, the back-up tong head is arranged in the center of a jaw of the power tong shell, and a tong handle of the back-up tong head is hinged with a clamping driving device. And the clamping driving device is used for driving the back-up tong head to rotate around the center of the jaw of the power tong shell. The back-up wrench is simple in structure and reliable in performance, and the initial climbing clamping of the back-up wrench is driven by the hydraulic cylinder, so that the initial clamping torque is large; the angle of the back-up wrench driven by the spinning of the main wrench to realize secondary climbing is small, so that the swing angle of the back-up wrench shell is small, and the working reliability and safety are improved; meanwhile, the torque applied to the back-up tong by the main tong during working can be accurately measured by directly measuring the hydraulic pressure in the working cavity of the clamping oil cylinder and calculating the product of the hydraulic pressure and the length of the tong handle of the back-up tong, so that the screwing-on and screwing-off working torques of the drill rod power tong can be accurately measured.

Description

Technical Field

[0001] This utility model relates to the field of power clamp technology, specifically to a back clamping and torque measuring device for a drill pipe power clamp. Background Technology

[0002] In oil and gas drilling and workover operations, existing climbing-clamping drill pipe power tongs typically use a cylinder to rotate the tong head, causing the jaw plates to climb and initially clamp the drill string. Because the cylinder's force is relatively small, the initial clamping force is low. As the main tong torque increases, the upper drill string transmits torque to the lower drill string, causing the lower drill string to further widen the tong's slope. This results in a larger rotation angle, causing the tail of the power tong housing to swing during the tong head's climbing process. Furthermore, existing drill pipe power tongs use two methods to measure their working torque. The first method measures the hydraulic motor's working pressure to calculate its working torque, then uses a gear reduction ratio to calculate the drill pipe power tong's working torque. The second method measures the relative torque between the power tong's upper housing and the planetary gearbox housing. Of the two methods above, the first measures the working torque at the input end of the entire transmission chain, while the second measures the working torque in the middle of the entire transmission chain. The transmission chain is long from the output working torque at the end, and is affected by hydraulic efficiency and mechanical efficiency. Therefore, the true working torque of the drill pipe power tong cannot be accurately obtained, which affects the quality of the drill pipe joint. Utility Model Content

[0003] The purpose of this utility model is to provide a back clamping and torque measuring device for a drill pipe power tong, so as to solve one or more problems mentioned in the background art.

[0004] To achieve the above objectives, one of the objectives of this utility model is to provide a back clamping and torque measuring device for a drill pipe power tong, comprising a power tong housing and a back clamp head, wherein the back clamp head is located at the center of the jaws of the power tong housing, and a clamping drive device is hinged to the handle of the back clamp head, the clamping drive device being used to drive the back clamp head to rotate around the center of the jaws of the power tong housing.

[0005] As a preferred and feasible method, the clamping drive device is a clamping cylinder. The cylinder body of the clamping cylinder is hinged to the power clamp housing via a second hinge pin, and the fork of the clamping cylinder is hinged to the handle of the back clamp via a first hinge pin.

[0006] As a preferred and feasible approach, it also includes a control oil circuit, which includes a control valve, a first hydraulic lock, and a second hydraulic lock; the control valve is connected to port B of the clamping cylinder through the first hydraulic lock, and the control valve is connected to port A of the clamping cylinder through the second hydraulic lock.

[0007] When the clamping is engaged, high-pressure oil enters from the control valve P port, flows through the second hydraulic lock and then enters the oil port A of the clamping cylinder. The hydraulic oil in the rod chamber of the clamping cylinder flows back to the control valve return port T through the first hydraulic lock and the control valve in sequence.

[0008] During uncoupling, high-pressure oil enters from the control valve P port, flows through the first hydraulic lock, and then enters the clamping cylinder port B. The hydraulic oil in the rodless chamber of the clamping cylinder flows back to the return port T through the second hydraulic lock and the control valve.

[0009] As a preferred and feasible approach, the control circuit also includes an upper catch replenishing valve (8) and a lower catch replenishing valve. The oil ports A and B of the clamping cylinder are respectively equipped with a lower catch replenishing valve (7) and an upper catch replenishing valve. The oil inlet of the lower catch replenishing valve is connected to the oil return port T of the hydraulic system, the oil outlet of the lower catch replenishing valve is connected to the oil port A of the clamping cylinder, the oil inlet of the upper catch replenishing valve is connected to the oil return port T of the hydraulic system, and the oil outlet of the upper catch replenishing valve is connected to the oil port B of the clamping cylinder.

[0010] As a preferred and feasible approach, a shuttle valve is connected between port A and port B of the clamping cylinder, and the shuttle valve is connected to a pressure gauge.

[0011] Compared with the prior art, the present invention has the following beneficial effects:

[0012] 1) This utility model has a simple structure and reliable performance. The initial climbing clamping of the back clamp is driven by a hydraulic cylinder, resulting in a large initial clamping torque. 2) The angle at which the main clamp rotates and drives the back clamp to climb the second slope is small, thereby reducing the swing angle of the back clamp housing and improving work reliability and safety. 3) The torque applied to the back clamp by the main clamp during operation can be accurately measured by directly measuring the hydraulic pressure in the working chamber of the clamping cylinder and calculating the product of the hydraulic pressure and the length of the back clamp handle. Attached Figure Description

[0013] Figure 1 This is a schematic diagram of the back clamping and torque measuring device of a drill pipe power tong according to the present invention. Detailed Implementation

[0014] The technical solutions of the present utility model will be clearly and completely described below with reference to the accompanying drawings of the embodiments. Obviously, the described embodiments are only some embodiments of the present utility model, and not all embodiments. Based on the embodiments of the present utility model, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the protection scope of the present utility model.

[0015] like Figure 1As shown, a back clamping and torque measuring device for a drill pipe power tong is provided, including a housing 1, a back tong head 2, a first hinge pin 3, a second hinge pin 4, a unhooking torque setting valve 5, a first hydraulic lock 6, a unhooking oil replenishing valve 7, an upper hook oil replenishing valve 8, a clamping drive device, a pressure gauge 10, a shuttle valve 11, an upper hook torque setting valve 12, a second hydraulic lock 13, and a control valve 14. Specifically, the back tong head 2 is located at the center of the jaws of the power tong housing 1, and the clamping drive device is hinged to the handle of the back tong head 2. The clamping drive device is used to drive the back tong head 2 to rotate around the center of the jaws of the power tong housing 1. The clamping drive device is a clamping cylinder 9, the cylinder body of which is hinged to the power tong housing 1 via the second hinge pin 4, and the fork of the clamping cylinder 9 is hinged to the handle of the back tong head 2 via the first hinge pin 3.

[0016] The measuring device also includes a control oil circuit, which includes a control valve 14, a first hydraulic lock 6, and a second hydraulic lock 13. The clamping cylinder 9 includes port A and port B, and a shuttle valve is connected between ports A and B. The shuttle valve is connected to a pressure gauge, and the higher pressure value between the rod-side and rodless-side chambers of the clamping cylinder 9 is automatically selected and displayed on the pressure gauge 10. The control valve 14 is connected to port B of the clamping cylinder 9 via the first hydraulic lock 6, and the control valve 14 is connected to port A of the clamping cylinder 9 via the second hydraulic lock 13.

[0017] When the clamping is engaged, high-pressure oil enters from the P port of control valve 14, flows through the second hydraulic lock 13 and then enters the oil port A of clamping cylinder 9. The hydraulic oil in the rod chamber of clamping cylinder 9 flows back to the return oil port T of control valve through the first hydraulic lock 6 and control valve 14 in sequence.

[0018] During unhooking, high-pressure oil enters from the control valve P port, flows through the first hydraulic lock 6, and then enters the oil port B of the clamping cylinder 9. The hydraulic oil in the rodless chamber of the clamping cylinder 9 flows back to the return port T through the second hydraulic lock 13 and the control valve 14 in sequence.

[0019] The control oil circuit also includes an upper latching oil replenishing valve 8 and an upper latching oil replenishing valve 7. The oil ports A and B of the clamping cylinder are respectively equipped with the upper latching oil replenishing valve 8 and the lower latching oil replenishing valve 7. The oil inlet of the upper latching oil replenishing valve 7 is connected to the return oil port T of the hydraulic system, and the oil outlet of the upper latching oil replenishing valve 7 is connected to the oil port A of the clamping cylinder. The oil inlet of the upper latching oil replenishing valve 8 is connected to the return oil port T of the hydraulic system, and the oil outlet of the upper latching oil replenishing valve 8 is connected to the oil port B of the clamping cylinder.

[0020] On the other hand, a method for back clamping and torque measurement of a drill pipe power tong, employing a back clamping and torque measurement device, includes the following steps:

[0021] S100. When the power tongs are engaged, after the drill bit enters the center of the power tong jaws, the valve core of the control valve 14 is reversed, so that the control valve 14 is in the right position. The high-pressure oil enters from the P port of the control valve 14 and flows through the second hydraulic lock 13 before entering the oil port A of the clamping cylinder 9, so that the rodless chamber of the clamping cylinder 9 is filled with oil, and the piston rod is extended. At this time, the clamping cylinder 9 drives the back tong jaw 2 to rotate counterclockwise around the center of the jaws of the power tong housing 1 through the first hinge pin 3. The back tong jaw 2 is pushed by the clamping cylinder 9 with the maximum working pressure of the hydraulic system to engage and climb the slope for clamping. At this time, the clamping working pressure value of the back tong jaw of the power tongs is measured by the pressure gauge 10, and the hydraulic oil in the rod chamber of the clamping cylinder 9 flows back to the return port T through the first hydraulic lock 6 and the control valve 14 in sequence.

[0022] S200. The main clamp of the power tong clamps the upper drill bit, causing the upper drill bit to rotate together. If the torque applied by the main clamp is less than the clamping working torque of the back clamp head, the back clamp head will not move.

[0023] When the torque applied by the main clamp is greater than the working torque of the back clamp, the back clamp swings under the action of the torque applied by the main clamp, causing the back clamp to climb a second slope. The handle of the back clamp head 2 reacts to the piston rod of the clamping cylinder 9 through the first hinge pin 3, thereby transmitting the torque applied by the main clamp to the rodless chamber of the clamping cylinder 9. At this time, it is determined whether the working pressure in the rodless chamber of the clamping cylinder 9 reaches the set pressure of the upper clamping torque setting valve 12.

[0024] S300. If the working pressure in the rodless chamber of the clamping cylinder 9 reaches the set pressure of the upper clamping torque setting valve 12, the piston rod of the clamping cylinder 9 will squeeze the hydraulic oil in the rodless chamber of the clamping cylinder 9 out of the upper clamping torque setting valve 12, so that the torque applied by the main clamp and the torque of the back clamp climbing the second slope are balanced. At this time, the piston rod moves to the left, and hydraulic oil is replenished to the rod chamber of the clamping cylinder 9 through the return oil side T and the upper clamping oil replenishment valve 8.

[0025] S400. Determine the pressure in the rodless chamber and the rod chamber of clamping cylinder 9. If the pressure in the rodless chamber of clamping cylinder 9 is greater than the pressure in the rod chamber, measure the pressure value in the rodless chamber of clamping cylinder 9 using the shuttle valve pressure gauge 10.

[0026] S500. The torque borne by the back clamp of the power tong is calculated by measuring the pressure value and the length of the back clamp handle, which is the torque borne by the drill pipe. It should be noted that the working area of ​​the rodless chamber and the rod chamber of the clamping cylinder and the length of the back clamp handle are all constant values. Therefore, the working pressure of the back clamp can be directly calculated by measuring the working pressure of the working chamber of the clamping cylinder. This method is accurate and efficient.

[0027] S600. When the power clamp is unhooking, the valve core of the control valve 14 is in the left position. High-pressure oil flows from the control valve P port through the first hydraulic lock and enters the oil port B of the clamping cylinder. The clamping cylinder 9 drives the back clamp head 2 to rotate clockwise around the center of the jaw of the power clamp housing 1 through the first hinge pin 3. The back clamp head 2 is pulled by the clamping cylinder 9 with the maximum working pressure of the hydraulic system to unhook and climb the slope clamp. At this time, the pressure gauge 10 measures the active clamping working pressure of the current back clamp. At the same time, the hydraulic oil in the rodless chamber of the clamping cylinder 9 flows back to the control valve return port T through the second hydraulic lock 13 and the control valve 14 in sequence. Therefore, when the main clamp drives the back clamp to unscrew, the torque of the main clamp increases, and the back clamp head 2 is driven to rotate by the main clamp. The back clamp handle drives the piston rod of the clamping cylinder to continue to extend forward through the first hinge pin 3. The hydraulic oil in the rod chamber is squeezed out from port B through the unscrew torque setting valve 5 and flows into the low-pressure return oil circuit of the hydraulic system. As the piston rod extends, the piston moves to the right, and a vacuum is formed in the rodless chamber of the clamping cylinder. At this time, the pressure in the low-pressure return oil circuit is greater than the pressure in the rodless chamber of the clamping cylinder. The unscrew replenishing valve 7 opens, and the hydraulic oil is replenished to the rodless chamber through the unscrew replenishing valve.

[0028] The foregoing has shown and described the basic principles, main features, and advantages of this utility model. Those skilled in the art should understand that this utility model is not limited to the above embodiments. The embodiments and descriptions in the specification are merely preferred examples and are not intended to limit the utility model. Various changes and modifications can be made to this utility model without departing from its spirit and scope, and all such changes and modifications fall within the scope of the claimed utility model. The scope of protection of this utility model is defined by the appended claims and their equivalents.

Claims

1. A back clamping and torque measuring device for a drill pipe power tong, characterized in that, It includes a power clamp housing (1) and a back clamp head (2). The back clamp head (2) is located at the center of the jaws of the power clamp housing (1). The handle of the back clamp head (2) is hinged to a clamping drive device. The clamping drive device is used to drive the back clamp head (2) to rotate around the center of the jaws of the power clamp housing (1). The clamping drive device is a clamping cylinder (9). The cylinder body of the clamping cylinder (9) is hinged to the power clamp housing (1) through the second hinge pin (4). The fork of the clamping cylinder (9) is hinged to the handle of the back clamp head (2) through the first hinge pin (3). It also includes a control oil circuit, which includes a control valve (14), a first hydraulic lock (6), and a second hydraulic lock (13); the control valve (14) is connected to the oil port B of the clamping cylinder (9) through the first hydraulic lock (6), and the control valve (14) is connected to the oil port A of the clamping cylinder (9) through the second hydraulic lock (13); When the clamp is engaged, high-pressure oil enters from the P port of the control valve (14), flows through the second hydraulic lock (13), and then enters the oil port A of the clamping cylinder (9). The hydraulic oil in the rod chamber of the clamping cylinder (9) flows back to the return oil port T of the control valve through the first hydraulic lock (6) and the control valve (14) in sequence. When the buckle is released, the high-pressure oil enters from the control valve P port, flows through the first hydraulic lock (6) and then enters the oil port B of the clamping cylinder (9). The hydraulic oil in the rodless chamber of the clamping cylinder (9) flows back to the return port T through the second hydraulic lock (13) and the control valve (14).

2. The back clamping and torque measuring device for a drill pipe power tong as described in claim 1, characterized in that: A shuttle valve is connected between oil port A and oil port B of the clamping cylinder (9), and the shuttle valve is connected to a pressure gauge.

3. The back clamping and torque measuring device for a drill pipe power tong as described in claim 2, characterized in that: The control oil circuit also includes an upper buckle replenishing valve (8) and a lower buckle replenishing valve (7). The oil port A and oil port B of the clamping cylinder are respectively equipped with the lower buckle replenishing valve (7) and the upper buckle replenishing valve (8). The oil inlet end of the lower buckle replenishing valve (7) is connected to the oil return port T of the hydraulic system. The oil outlet end of the lower buckle replenishing valve (7) is connected to the oil port A of the clamping cylinder. The oil inlet end of the upper buckle replenishing valve (8) is connected to the oil return port T of the hydraulic system. The oil outlet end of the upper buckle replenishing valve (8) is connected to the oil port B of the clamping cylinder.

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