Premium Connections
A premium connection is a proprietary threaded and coupled or integral connection for oil country tubular goods (OCTG) — casing and tubing — that provides performance beyond the capabilities of standard API connections. Premium connections offer metal-to-metal sealing (no thread compound required for gas tightness), higher torque ratings, and better performance under combined axial, bending, and pressure loads than API BTC or LTC connections.
Why Premium Connections Are Specified
Standard API connections (BTC, LTC, STC) were designed for conventional vertical wells with moderate pressure. They rely on thread compound (dope) for gas tightness and have limited torque and combined load capacity. In demanding applications, they fail.
Premium connections are required when:
- The well produces or injects gas — standard API connections are not gas-tight without dope, and dope can fail at temperature
- High axial loads are anticipated — deep wells, heavy casing strings
- Combined loads are high — deviated wells, extended reach
- Elevated temperature reduces thread compound effectiveness — HPHT wells
- H₂S is present — sour service requires specific material and connection design
- Liner drilling or rotating casing applications — high torque requirements
Product Range — Hunting PLC
SEAL-LOCK® Standard
The SEAL-LOCK® is Hunting’s foundational premium connection — a metal-to-metal gas-tight connection providing reliable sealing for gas wells and standard demanding applications. The SEAL-LOCK® uses a proprietary thread form and metal-to-metal seal that is independent of thread compound, providing gas tightness without reliance on dope.
Available for all standard casing sizes and grades. The standard connection for demanding onshore wells throughout the Caspian region.
SEAL-LOCK® XD — Extreme Duty
The SEAL-LOCK® XD is designed for extreme combined load conditions — high compression, high torque, high bending — encountered in extended reach, deviated, and highly loaded well programmes. It provides higher torque-to-yield ratios and greater compression resistance than the standard SEAL-LOCK®.
SEAL-LOCK® FLUSH
The SEAL-LOCK® FLUSH is a flush OD connection — the connection OD does not exceed the pipe body OD. Designed for liner applications where the connection must pass through a smaller casing string, and for wells with tight clearances. Also available in a semi-flush configuration.
SEAL-LOCK® HT — High Temperature
The SEAL-LOCK® HT is engineered for geothermal and HPHT applications where temperature exceeds the performance envelope of standard premium connections. The HT design maintains gas-tight sealing integrity at elevated temperatures where thermal expansion and relaxation would compromise a standard connection.
TEC-LOCK™ — Semi-Premium
The TEC-LOCK™ is a semi-premium connection — providing performance above standard API connections at a lower cost than full premium. Suitable for wells that require improved torque capacity and better sealing than API BTC, but where the full performance envelope of the SEAL-LOCK® family is not required.
Key Specifications
| Connection | Type | Key Feature | Application |
|---|---|---|---|
| — | — | — | — |
| SEAL-LOCK® | Premium | Metal-to-metal seal | Standard gas wells, demanding applications |
| SEAL-LOCK® XD | Premium | Extreme combined load | Extended reach, highly loaded wells |
| SEAL-LOCK® FLUSH | Premium | Flush OD | Liner applications, tight clearances |
| SEAL-LOCK® HT | Premium | High temperature | HPHT, geothermal |
| TEC-LOCK™ | Semi-premium | Improved API performance | Cost-effective step up from API |
All connections available in standard API steel grades and premium grades. Contact Proxima for size, weight, grade, and connection availability.
Why Source Through Proxima
Proxima is the regional distributor of Hunting PLC premium connections in Azerbaijan and the Caspian region. Hunting connections are manufactured at facilities worldwide and supplied to all major oil and gas markets. Proxima provides local technical support for connection selection, thread inspection, and make-up specification, and coordinates supply from Hunting’s international manufacturing network.
Frequently Asked Questions
Q: When does my well require a premium connection instead of API BTC?
The key trigger is gas service — gas wells should not rely on API BTC connections, which require thread dope for gas tightness. Also specify premium connections for wells with high torque requirements (deviated, extended reach), high axial loads, elevated temperatures, or H₂S service. Proxima engineers review your well programme and recommend the appropriate connection.
Q: What is the difference between SEAL-LOCK® and SEAL-LOCK® XD?
The standard SEAL-LOCK® is designed for general demanding well applications — gas wells, moderate combined loads. The XD (Extreme Duty) is for higher combined loads — more compression, more torque, more bending — encountered in extended reach and highly deviated wells. If your well is going to put high compressive loads on the casing, specify XD.
Q: Does Hunting supply the OCTG pipe with the premium connection already applied?
Yes. Hunting sources OCTG from major global mills and applies the premium connection threading at its own facilities, supplying casing and tubing with SEAL-LOCK® or TEC-LOCK™ connections ready for running. Proxima coordinates supply from Hunting’s manufacturing network to Azerbaijan and regional markets.
Q: Are premium connections available with Clear-Run® dope-free thread compound?
Yes. Hunting’s Clear-Run® is an eco-friendly, dope-free thread compound that can be used with premium connections where a thread compound is still specified — for example, where regulations or company standards require a compound even on metal-to-metal seal connections. Contact Proxima for Clear-Run® availability.
