Differences Between BTC and LTC Casing and Their Applications

Overview

BTC (Buttress Thread Casing) and LTC (Long Thread Casing) differ in thread design, sealing performance, and load-bearing capacities, which makes them suited for distinct applications.

Technical Differences

BTC (Buttress Thread Casing)

• Thread Design: Flat thread profile with 0° load flank angle, optimized for axial loads.
• Seal Performance: Relies on thread engagement for sealing under high pressure.
• Strength: Higher tensile and axial strength, making it suitable for deeper wells.
• Applications:
  • High-pressure environments.
  • Deeper and extended-reach wells.

LTC (Long Thread Casing)

• Thread Design: Rounded thread profile with extended engagement length.
• Seal Performance: Moderate sealing strength, effective for shallow wells.
• Strength: Lower tensile and axial strength compared to BTC.
• Applications:
  • Standard drilling and production scenarios.
  • Shallow and medium-depth wells.

Application Scenarios

BTC

BTC's robust tensile and axial capabilities make it indispensable in challenging environments:

• Oil and Gas Production: Handles high-pressure loads in ultra-deep wells.
• Corrosive Environments: When combined with protective coatings, BTC is effective against chemical wear.

LTC

LTC is often chosen for its simplicity and versatility:

• Standard Wells: Suited for shallow to medium-depth wells requiring moderate load capacities.
• Geothermal Energy Exploitation: Its affordability and compatibility make it ideal for geothermal projects.

Advanced Options for Both

• Premium Threads: Options like MS-5T and MS-2T enhance both BTC and LTC for harsher conditions, offering better sealing and resistance to torsion and bending.
• Stainless Steel Lining: Provides excellent corrosion resistance, extending the life of the casing.

BTC and LTC cater to different operational needs, with BTC favored for extreme depths and pressures, while LTC is optimal for cost-effective and general-purpose applications.