Casing string for gas transmission in corrosive (CO₂/H₂S) environments.
Combining L80-13Cr metallurgy with a premium metal-to-metal seal connection represents the standard engineering solution for CO₂-dominated corrosive gas wells where BTC thread leakage is unacceptable. This supply to a Libyan operator (WAHA Oil Company) reflects the operational reality: 13Cr provides the corrosion resistance, but without a gas-tight connection the casing string will leak at the box–pin interface under thermal cycling and pressure excursions.
Why ZC-2 (VAMTOP equivalent)? VAMTOP is a VAM-proprietary flush-joint connection with a double-step metal seal and torque shoulder. The ZC-2 connection replicates this geometry under ZC Steel Pipe's proprietary designation, manufactured on the same thread-cutting equipment using API-certified gauges. Compared to BTC on 13Cr: - BTC relies on thread compound for sealing — compound degrades in high-temperature gas environments - ZC-2 achieves a positive metal-to-metal seal independent of compound - ZC-2 passes ISO 13679 CAL III gas-tightness testing; BTC is rated for liquid service only
ZC Steel Pipe supplied this project with EN 10204 3.1 MTC, third-party inspection, and ZC-2 thread gauge calibration certificates. Projects with H₂S involvement require NACE MR0175 / ISO 15156 compliance documentation — available on request.