Work

Optimization approach for sustainable decommissioning of unpiggable subsea pipelines: Insights from the Arabian Gulf

Year: 2025

Type: article

Abstract: Unpiggable pipelines, often inaccessible for traditional pigging operations, pose significant risks due to residual hydrocarbons and limited inspection options. This paper presents an optimized methodology for flushing, de-oiling, and abandoning unpiggable subsea pipelines, specifically designed to address the unique environmental and regulatory challenges in the Arabian Gulf. The paper introduces an innovative approach that integrates advanced modeling tools ‒ OLGA for internal flow assurance and CORMIX for pollutant dispersion analysis ‒ to manage oil-in-water (OIW) concentrations effectively, ensuring compliance with the stringent 15-ppm discharge limit. The proposed methodology not only mitigates residual contamination risks but also enhances operational efficiency and regulatory compliance through adaptive measures. By addressing plateauing contaminant removal rates and leveraging region-specific environmental data, the current study provides actionable guidance for sustainable decommissioning of subsea pipelines. The findings hold broad applicability for projects in environmentally sensitive marine ecosystems, hence, supporting global efforts toward environmentally responsible decommissioning practices. • Environmental Compliance Focus : Introduces a flushing method to meet strict discharge rules, such as 15 ppm oil-in-water (OIW). • Innovative Methodology : Uses OLGA and CORMIX models to enhance pollutant dispersion and minimize environmental impact. • Case Study Insights : Explores a real-world case in the Arabian Gulf, addressing challenges in decommissioning unpiggable pipelines. • Comprehensive Analysis : Evaluates costs and benefits of decommissioning methods, focusing on sustainability and efficiency. • Long-Term Impact : Suggests monitoring frameworks to ensure environmental safety and regulatory compliance after decommissioning.

Source: Journal of Environmental Management

DOI: 10.1016/j.jenvman.2025.124180

Authors: Ahmed Reda, Chiemela Victor Amaechi, Mohamed A. Shahin

Institutions: The University of Western Australia, Curtin University, Global Banking School, Lancaster University

Language: English

Topic: Marine and Offshore Engineering Studies

Subfield: Ocean Engineering

Field: Engineering

Domain: Physical Sciences

SDGs: Responsible consumption and production, Clean water and sanitation, Industry, innovation and infrastructure, Climate action

Open Access status: hybrid

Estimated APC paid: $3,750