Applying Makeup Torque Using a Rig Tong: Explanation and Calculation Example

In oil and gas drilling operations, torque is a crucial factor in ensuring that drill pipes, casings, and other tubular components are securely connected. Makeup torque is the force applied to tighten the connection between two pipes, ensuring a proper seal and structural integrity during drilling. Understanding how to calculate and apply makeup torque is essential for maintaining safe and efficient operations, and rig tongs play a vital role in this process.

This article will explain how makeup torque is applied using a rig tong and provide a calculation example to illustrate the process.

What is Torque?

Torque is the measure of the rotational force applied to an object. In the context of oil and gas drilling, it refers to the twisting force used to connect two sections of pipe. Proper makeup torque ensures that the pipes are joined tightly, preventing leakage and maintaining the strength of the connection under high-pressure and high-stress conditions.

The formula for torque (T) is expressed as:

T=F×L

Where:

T = Torque (measured in foot-pounds or Newton-meters)

F = Force applied (measured in pounds or Newtons)

L = Length of the lever arm (measured in feet or meters)

Applying Makeup Torque with Rig Tongs

Rig tongs are large, heavy-duty tools used to apply torque to pipes during drilling operations. They function similarly to a wrench but are designed to handle the extreme forces required for oil and gas applications. The amount of torque generated depends on the force applied to the tong’s arm and the arm’s length.

The arm length (L) refers to the distance from the point where the pulling force is applied to the center of the connection being tightened. The line pull (F) is the force exerted at the end of the tong arm, and it creates the necessary torque to screw the pipes together. To achieve the desired torque, the pulling force must be applied at a 90° angle to the tong arm as shown in the diagram below.

Calculation Example

Let’s go through a calculation example to demonstrate how to determine the pulling force needed for a specific makeup torque.

Given Information:

• Pipe: 7 3/4” Drill Collar (DC) with a 6 5/8” regular connection
• Recommended makeup torque: 58,500 ft-lbs (79,315 Nm)
• Tong type: HT 65
• Tong arm length: 4.25 ft (1.29 m)

The formula to calculate the required force is:

F=T÷L

Substituting the given values:

F (lb) = 58,500 ft-lbs ÷ 4.25 ft

F (lb) = 13,765 lbs

Therefore, a pulling force of approximately 13,765 lbs is required to achieve the recommended makeup torque using the HT 65 tong with a 4.25 ft arm length.

Key Points to Consider

1. Proper Torque Application: Applying the correct makeup torque is essential to prevent connection failure, leakage, or damage to the pipes during drilling operations. Insufficient torque can lead to loose connections, while excessive torque can cause thread damage or even pipe breakage.
2. Torque Equipment: The choice of rig tong is critical, as it must be capable of delivering the required torque. In our example, the HT 65 tong is appropriate for the specified torque requirements.
3. Safety: When applying makeup torque, ensure all personnel maintain a safe distance from the rig tong and pull line to avoid injuries due to sudden movements or slippage.

Conclusion

Understanding how to calculate and apply makeup torque is a fundamental aspect of drilling operations in the oil and gas industry. By using the formula F=T÷L, operators can determine the exact pulling force required to achieve the desired torque, ensuring a secure and reliable connection between pipes. Proper application of torque using rig tongs like the HT 65 ensures the safety, efficiency, and longevity of drilling equipment, contributing to the overall success of drilling operations.

<p>The post Applying Makeup Torque Using a Rig Tong: Explanation and Calculation Example first appeared on Drilling Formulas and Drilling Calculations.</p>