Introduction
The oil and gas industry relies heavily on precise and reliable equipment to ensure efficient and safe drilling operations. Among the critical components used in drilling, rotary shouldered connections play a vital role. Specifically, the Hughes H90 Non Preferred Rotary Shouldered Connection, although not widely recommended, is utilized in certain situations. To maintain the integrity of these connections, Hughes H90 thread plug and ring gages are essential tools for measuring and verifying thread quality and accuracy.
Understanding the Hughes H90 Thread Form
The Hughes H90 thread form is a type of rotary shouldered connection characterized by a 90-degree angle thread with a rounded root and crest. These threads are used to join various components of the drill string, such as drill pipes and drill collars. Despite being a non-preferred connection according to the American Petroleum Institute (API), understanding its application and proper maintenance is crucial for avoiding operational failures.
Why the H90 Thread Form is Non-Preferred
The Hughes H90 thread form is considered non-preferred for several reasons:
- Lower Fatigue Resistance: Compared to other thread forms like NC (Numbered Connections) or REG (Regular) threads, the H90 has lower fatigue resistance, making it more susceptible to wear over time.
- Lower Load Capacity: The load capacity of the H90 thread form is also inferior, which can impact the overall performance of the drilling operation.
- Higher Tendency to Galling: Galling, a form of wear caused by friction and adhesion between the mating surfaces of the threads, is more common with H90 threads. This can lead to damage, seizure, or even loss of the connection.
Given these drawbacks, the use of Hughes H90 threads necessitates rigorous inspection and verification using specialized gages.
Importance of Thread Plug and Ring Gages
Thread plug and ring gages are crucial for ensuring the quality and reliability of Hughes H90 connections. These gages are designed to measure the dimensions, pitch, taper, and profile of the H90 thread form, ensuring they meet the required specifications.
Types of Gages
- Thread Plug Gages: Used to check the internal threads (box end) of the connection. These gages are inserted into the threads to detect any gaps, misalignment, or defects.
- Thread Ring Gages: Used to check the external threads (pin end) of the connection. Similar to plug gages, ring gages are screwed onto the threads to ensure proper alignment and absence of defects.
Both types of gages are made from high-quality steel and are hardened for durability and accuracy. They are also calibrated and certified according to API specifications and tolerances, ensuring they provide reliable measurements.
Application of Hughes H90 Gages in the Field
In the field, the use of Hughes H90 thread plug and ring gages involves several steps:
- Pre-Use Inspection: Before deploying drill pipes or collars with H90 threads, gages are used to inspect the threads for any manufacturing defects or wear from previous use.
- Post-Use Inspection: After each use, the threads are re-inspected to identify any wear or damage that may have occurred during drilling operations. This helps in preventing future failures.
- Regular Maintenance: Regular gaging ensures that the threads remain within acceptable tolerances, thereby extending the lifespan of the equipment and maintaining operational safety.
Benefits of Using Hughes H90 Gages
The primary benefits of using Hughes H90 thread plug and ring gages include:
- Enhanced Safety: Regular inspection and verification of threads help prevent accidents and failures during drilling operations.
- Increased Reliability: Ensuring the threads are within specifications reduces the risk of connection failures, thereby improving the overall reliability of the drilling process.
- Cost Savings: By preventing premature wear and damage, regular gaging can lead to significant cost savings in terms of reduced downtime and equipment replacement costs.
Conclusion
While the Hughes H90 Non Preferred Rotary Shouldered Connection thread form is not the first choice for many drilling operations, its use is still prevalent in specific scenarios. Ensuring the quality and reliability of these connections is paramount, and this is where Hughes H90 thread plug and ring gages play a crucial role. By providing accurate measurements and helping to identify potential issues before they become critical, these gages contribute significantly to the safety and efficiency of drilling operations in the oil and gas industry.
FAQs
Q: What makes the Hughes H90 thread form non-preferred?
A: The H90 thread form has lower fatigue resistance, lower load capacity, and a higher tendency to galling compared to preferred thread forms like NC or REG threads.
Q: What are thread plug and ring gages used for?
A: Thread plug gages check the internal threads (box end), while thread ring gages check the external threads (pin end) of the Hughes H90 connections to ensure they meet the required specifications.
Q: Why is regular inspection with gages important?
A: Regular inspection with gages helps prevent accidents and failures, increases the reliability of drilling operations, and leads to cost savings by reducing downtime and equipment replacement costs.
Q: Are Hughes H90 gages certified?
A: Yes, Hughes H90 thread plug and ring gages are calibrated and certified according to API specifications and tolerances to ensure accuracy and reliability.
