How to reduce the size and improve the efficiency of hydraulic tong on workover rigs?

During drilling and workover operation in the oilfield, making up and down of tubing string is a key part in the drilling and downhole operation. At present, making up and down of tubing string in the field mainly relies on the manual push-pull operation on the traditional suspended type workover hydraulic power tong, which has many problems such as high labor intensity, high risk and poor operating environment.


In order to solve low degree of automation when making up and down operation of tubing string. Recent years, iron roughneck technology with high degree of automation has tried to apply. But due to the differences between workover and drilling. Lots of issues of iron roughneck technology exposed in the process of workover operations during workover, such as large size, heavy weight, low efficiency to make it hard to perform industrial popularization and application.

As most of my country’s oilfields enter the middle and late stages of development, the difficulty of oil production is becoming more and more difficult, the process and well conditions are becoming more and more complex, and the workover tasks in oilfields are becoming more and more arduous. However, the technical equipment and operation procedures of the current oilfield workover operation determine that the labor intensity of the wellhead operators in the workover operation is very high, and the manual operation in the work process has great potential safety hazards. Every year, a certain number of oilfield workover operations will occur worker casualties.


The make-up and break-up operation of the pipe string is a key link in the workover operation. The existing oil workover operation of the pipe string is mainly completed by manual operation of open-type hydraulic tongs and switching elevators. The outstanding advantage of the existing open-type hydraulic tongs is that the tong head is open, with good flexibility, and the pipe string is immediately evacuated after each make-up or break-up, which does not hinder other operations at the wellhead, so it is widely used by users at home and abroad.

In the existing workover operations, manually operated open-type hydraulic tongs and switching elevators are used. Since the operation tongs weigh hundreds of kilograms and are suspended on the workover frame, they need to be manually pushed or removed from the wellhead, and the elevators and lifting rings also need to be Frequent switching leads to very high labor intensity. In a word, using the existing work pliers for work has low work efficiency, high labor intensity of workers and poor safety.


Objective disadvantages of existed technology are as follows:

tightening torque change during marking up and down between drill rod and tubing are different. Also different spinner and button punching structure cause the iron roughneck only meet requirements of marking up and down of drill pipe, but for tubing, its efficiency is extremely low. Due to complex structure and large volume, it occupies too large space to meet the production requirements.

At present, the difficulty for workover rig is low degree of automation in China. However, the cost of designing a new automatic workover rig is so high that it is not suitable for the situation of low oil prices, so we need to upgrade the current workover rig to the automatic one. For automatic workover rig, its tubing and rod thread screw on or off automatically is a key.

The hydraulic tong, which applied to the automatic workover rig, is designed. According to its function and the process of action, we also design the hydraulic control system. For two kinds of hydraulic motors, one for elevating and the other for thread screwing on or off, we carry out their parameter calculation and selection. Likewise, we use AMESim to simulate the hydraulic control system of hydraulic tong and the hydraulic system for thread screwing on or off. The simulation results are consistent with the design of action.

Sanjack developed a new designed of hydraulic power tong, which can replace the trial experiment of iron drill man technology in workover operation. It occupies less space of drilling platform, and realizes efficient automatic of marking up and down on both tubing and drill pipe. The invention discloses an automatic hydraulic power tong head, which belongs to the field of oil drilling and workover machinery. During oil drilling, workover wellhead setting, and shattering, the existing practice is that workers operate the liquid and gas tongs at close range, and manually assist to align the position of the tong head and the joint of the drilling tool, and the rotating components are exposed, which is prone to safety accidents. This way of working is labor-intensive and has a high-risk factor.

The automation of the pliers is the focus of changing this way of working. The invention consists of the following: an upper caliper clamping mechanism, an upper caliper braking mechanism, an upper caliper power mechanism, and a lower caliper clamping mechanism. Its structural feature is that the plier head part can realize automatic operation, has high work efficiency, and significantly improves the safety of use.

hydraulic tong

It works as following.

It comprises an outer cylinder, which is fixed vertically on the drilling platform; And a hydraulic clamp body with a cylinder column at the bottom, and the hydraulic clamp body can rotate around the cylinder column, and the fixing sleeve of the cylinder is connected to the outer cylinder.

As mentioned above, the external of the hydraulic power tong connected and fixed on the drill floor in advance. By its holder at the bottom of the column within a fixed socket in the outer tube, which can quickly install the hydraulic power tong to the rig platform. Compared to the iron roughneck of making up and down, structure and design are improved. Also space of drilling platform that hydraulic tong take up is less.

Beneficial effects of the present invention:

  1. The present invention replaces the original liquid-gas caliper brake with a hydraulic motor brake, realizes automatic control, achieves the purpose of controllable braking force, and reduces energy waste.
  2. The present invention replaces the manual observation and operation of the original liquid-gas tong to align the notch direction of the tong head, and adopts the motor to cooperate with the encoder to realize the function of automatically aligning the notch direction.
  3. The present invention can be used in conjunction with the existing iron drill support part, and can realize the integrated installation and transportation of the whole machine, and remote one-key control, which reduces the labor intensity of workers and significantly improves the safety of use.