LiquiGel® Delivers Subsea Multi-Diameter Solution

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A GoM upstream operator engineered a pre-existing 22” gas pipeline and a pre-existing 8” oil pipeline for common use. This re-engineered scope eliminated CAPEX costs on installing a new pipeline and decommissioning costs on removing the in-service assets by utilizing in-place assets to achieve the new production requirements.

Pipeline: 8” x 6,228’ Liquid Pipeline & 22” x 37,000’ Gas Pipeline

Challenge

1. In-service pipelines required product evacuation and safe pigging solutions that mitigated all risks to internal pipeline integrity or mechanical pig failure.

2. Dewatering procedure for the new multi-diameter pipeline must not exceed a MAOP of 260 psi.

3. Water treatment solutions must comply with Department of Interior (DOI) regulatory standards.

4. Specified flowrate required a minimum 90% efficiency of seawater removal for the commissioning of gas product.

5. Commission the reconfigured multi-diameter pipeline using nitrogen while mitigating additional costs for mechanical pig launchers and receivers.

Solution

• Phase 1: High volume/low pressure seawater flush and water treatment solutions to evacuate pipeline product in preparation of subsea reconfiguration.

• Phase 2: Dewater the reconfigured multi-diameter pipeline with nitrogen and LiquiGel® Pig System for proper commissioning.

Technical Achievements & Benefits

1. LiquiGel® Pig System transversed a multi-diameter pipeline surface while maintaining a proper seal and 100% dewatering efficiency in a single pass.

2. Received the 22” LiquiGel® Pig System through 2” ports, enabling the operator to forego the installation of traditional pig launcher and receiver types.

3. Successfully mitigated the pipelines structural integrity limitations, never exceeding a system pressure of 160 psi.

4. LiquiGel® Pig System maintained a 100% seal during the dewatering phase for a 24-hour unplanned shutdown process.

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