Drill pipes are essential tools in many fields, such as underground exploration, mining, and oil and gas drilling. Drill pipe is the key component to connect DTH drilling tools and drilling rigs, it is an important part of DTH drilling tools. The drill pipe serves as a guide throughout the drilling process. Because the length of its service life directly affects the entire construction period, the drill pipe quality requirements are so stringent.
What is a drill pipe?
Drill pipe is a steel pipe with a thread at the end, used to connect the surface equipment of the drilling rig and the drilling and grinding equipment or bottom hole device at the bottom of the well. The purpose is to transport drilling mud to the drill bit and raise, lower or rotate the bottom hole device together with the drill bit. Drill pipes must be able to withstand enormous internal and external pressure, twisting, bending, and vibration. Drill pipe can be used multiple times in the extraction and refining of oil and gas. Drill pipe is not a single entity, it is composed of multiple components.
Structural characteristics of drill pipe
Drill pipe includes a rod, a pin adapter, and a box adapter, all of which have axial holes. The back end of the Pin adapter and the front end of the Box adapter are embedded into the axial hole of the rod from both ends by interference fitting. It has a shaft shoulder on the Pin and Box adapters, and the end face of the rod is connected by welding. The DTH drill pipe is a new type of rod. The Pin and Box adapters are connected by radial interference fit and welded from the axial end face, so the torsional strength of the DTH drill pipe is high, which can meet the drilling rig’s requirements. It has the characteristics of less investment in equipment and the light weight of drill pipe.
Although the drill pipe has a lot of advantages, it is easy to cause wear, corrosion, and fatigue due to its poor working environment, and the fracture of the drill pipe is the main form of its failure. Proper maintenance is critical to ensure the efficient operation of the drill pipe and extend its life. Below are some vital steps and tips to help you maintain your drill pipe for efficiency and safety.
The importance of drill pipe maintenance
Drill pipe is a critical tool in the drilling process, and its performance directly affects drilling efficiency and cost. Correct maintenance methods can extend the service life of drill pipes and reduce downtime and repair costs caused by drill pipe damage. In addition, periodic maintenance can promptly detect and solve problems with drill pipes, ensuring the smooth progress of drilling work and reducing drilling deviations and accidents caused by drill pipe problems.
How to maintain drill pipe？
Cleaning and flushing
When a new drill pipe is first in use, wipe off the protective grease on the threads of the drill pipe and clean the inner wall with air or water. Then, thread oil to the internal and external threads of the drill pipe to prevent the threads from being damaged.
Always clean the drill pipe carefully after each use. Use a high-pressure water gun or special cleaning equipment to wash away the mud, rock debris, and other substances on the shaft. Avoid these particles from adhering to the drill pipe and causing damage and corrosion.
Regular lubrication
It is necessary to lubricate the connecting and critical parts of the drill pipe regularly. Choosing a suitable lubricant ensures that it penetrates the connecting threads and the surface of the rod. It helps reduce wear and friction and maintains the flexibility of the drill pipe. At the same time, tighten the drill pipe. Failure to screw the drill pipe may result in the following situations: 1. Loose threaded connection, causing the threads to grind against each other and the tops of the teeth to become sharp, leading to thread damage or bonding. 2. The step of the box adapter is not pressed tightly, resulting in air leakage, and in severe cases, the root of the thread of the pin adapter is fatigued and fractured.
Check for corrosion and wear
Regularly inspect the surface of the drill pipe for corrosion, wear, or cracks. If any problems are detected, take timely measures to repair or replace damaged parts to prevent further expansion of the problem.
Keep dry
Try to avoid exposing the drill pipe to moisture. Moisture can cause corrosion of the drill pipe surface and affect the stability of connected components. When storing drill pipes, choose a dry and ventilated place and use moisture-proof measures.
Pay attention to the operation method
Using drill pipe, the operator should avoid excessive twisting, stretching, or operating at unsuitable working pressures. This mishandling can cause excessive wear and damage to the drill pipe. Always follow the operating instructions provided by the manufacturer.
Store properly
When the drill pipe is not in use, it should be stored vertically on a dedicated shelf or stand to avoid direct contact with the ground. It helps prevent deformation and damage to the drill pipe.
Regular maintenance
Establish a regular maintenance program based on how often the drill pipe is in use and the environment in which it is working. It can include lubrication, inspection, cleaning, and more to ensure the drill pipe is always in good working condition.
Training operators
Making the operators receive the necessary training on proper drill pipe operation and maintenance procedures. It helps to reduce the risk of damage to the drill pipe by minimizing operational errors.
Precautions
- Drill holes vertically as far as possible. Avoid premature drill pipe wear caused by drilling deflection or bending.
- The starting rod should be connected between the DTH hammer and the drill pipe. Otherwise, the drill pipe will be damaged prematurely.
- When connecting the drill pipe, the Pin adapter cannot collide with the shoulder and thread of the Box adapter, and ensure that the Pin and Box adapters are aligned. If they are not aligned, do not force the hook. Make sure the drill power head spindle is coaxially aligned with the connecting drill pipe.
- When the drill pipe shackle is difficult, use a small hammer to gently vibrate the threaded part of the joint. Do not use a sledgehammer to hit the joint violently, resulting in thread deformation and damage.
- If the drill pipe thread has local small-scale damage, it should be repaired with a file in time before use.
- Avoid long-term open storage of drill pipes. Before storage, wipe the drill pipe clean, apply anti-rust grease to the thread parts, wear a protective cap, and avoid impact damage to the pin when carrying the drill pipe.
How to develop a maintenance program for drill pipe
Understand the environment and working conditions of the drill pipe
Before formulating a drill pipe maintenance plan, you must understand the drill pipe’s usage environment and working conditions. Including geological conditions, drilling depth, drilling speed, etc. These factors will directly affect the use and wear of the drill pipe and are an essential basis for formulating a maintenance plan.
Determine maintenance intervals
Determine a reasonable maintenance cycle based on the drill pipe’s usage environment and working conditions. We should consider the maintenance cycle according to the wear and tear, the use frequency of drill pipe, the working environment, and other factors. Generally speaking, drill pipes should undergo basic cleaning and inspection after each use and determine the regular maintenance of drill pipes based on actual usage.
Clarify maintenance content
The maintenance plan should list the specific content of each maintenance, including but not limited to the following aspects:
- Cleaning: remove oil, mud, and other impurities on the surface of the drill pipe to keep the appearance of the drill pipe clean.
- Inspection: check the threads, joints, and other critical parts of the drill pipe for wear, cracks, and other damage, and find and deal with problems promptly.
- Lubrication: lubricate and maintain critical parts of the drill pipe to reduce friction and increase the service life of the drill pipe.
- Storage: ensure that the drill pipe is kept in a dry, ventilated, dust-free environment during storage, away from direct sunlight and moisture.
Designated maintenance personnel
To guarantee the quality and effectiveness of maintenance tasks, it’s crucial to assign professional maintenance personnel to execute the maintenance plan. Maintenance personnel should have some knowledge and experience in drilling engineering, be familiar with the structure and performance of drill pipes, and be able to skillfully perform cleaning, inspection, lubrication, and other maintenance work.
Create maintenance records
To track the maintenance and performance changes of the drill pipe, we should establish a detailed maintenance record. The record should include information such as maintenance date, maintenance content, maintenance personnel, problems found, and treatment methods. Through the analysis of maintenance records, issues with drill pipes can be promptly identified, enabling the implementation of appropriate measures for improvement.
Regularly evaluate and adjust the maintenance plan
As the project evolves and drill pipe usage patterns shift, it’s essential to regularly assess and adapt the maintenance plan accordingly. When evaluating, we can adjust the maintenance period and content according to the wear and tear of the drill pipe, the frequency of use, the working environment, and other factors. At the same time, we can make targeted improvements and optimizations based on the problems found in the maintenance records.
Conclusion
By following the maintenance guidelines above, you can extend the service life of your drill pipe, improve work efficiency, reduce repair and replacement costs, and ensure job safety. Whether in geological exploration, mining, or oil and gas drilling, proper drill pipe maintenance will bring long-term benefits to your work.
