Firstgas Completes Complex Pipeline Repair with STATS BISEP Technology

New Zealand gas transmission operator First Gas Limited (Firstgas) has successfully completed a major pipeline remediation project on its critical 400 Pipeline, maintaining uninterrupted gas supply throughout the operation using STATS Group's patented BISEP isolation technology.

The 30-inch pipeline transports over 80% of New Zealand's natural gas production from Taranaki to the upper North Island. Following an in-line inspection, a wrinkle defect was identified on the pipeline, requiring remediation to ensure its long-term integrity.

Two 30-inch BISEPs were deployed approximately 500 meters apart between the Mokau Compressor Station and the Mahoenui Scraper Station, providing localised, fail-safe double block and bleed (DBB) isolation while an integrated 12-inch bypass line maintained uninterrupted gas flow around the repair location.

The project marked New Zealand's first deployment of the BISEP on a large diameter transmission pipeline incorporating a 0.5km bypass. According to Firstgas, the decision to utilise the BISEP technology was driven by both safety and operational considerations.