Elemental Energies was appointed as project manager for the integrated decommissioning of wells and facilities as part of Atlantis Holdings offshore decommissioning campaign in the United Arab Emirates.

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Project Overview

The scope covered full lifecycle decommissioning support, including conceptual and detailed engineering, tendering and contracting, logistics and mobilisation, QHSE management, and the development of decommissioning-specific standards ahead of offshore execution, which commenced in Q2 2023.

The project focused on the permanent abandonment of deep wells exhibiting conditions comparable to those encountered in the North Sea. Key challenges included sustained annulus pressure (SAP), high mud weights, potential gas migration, and the risk of casing contamination. These complex conditions required a technically robust and fully integrated decommissioning solution.

To address these challenges, a tailored engineering approach was developed, incorporating milling optimisation, hydraulic analysis, and the deployment of an innovative barrier system. A key element of the solution was the installation of a 6-ft Bismuth alloy plug at the base of the well prior to cementing, providing a gas-tight primary barrier and protecting cement integrity during setting.

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Scope of Work

The scope covered integrated facilities and wells decommissioning, including:

• Development of decommissioning strategy, standards, and execution plans
• Conceptual and detailed engineering for complex well abandonment conditions
• Tendering, contracting, and supply chain management
• Logistics planning and offshore mobilisation
• QHSE management and regulatory compliance
• Engineering and delivery of a bespoke well abandonment solution

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Well-specific technical considerations included:

• Milling depth: 7,400 ft – 7,600 ft MDBRT
• Minimum P&A barrier requirement: 100 ft cement
• Resulting minimum milled window length: ~200 ft per casing size
• Casing sizes and grades:
• 9 578", 62.8 ppf, P-110
• 7 5/8", 51.2 ppf, P-110

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“This project demonstrated the value of fully integrated decommissioning planning. By aligning wells and facilities early and applying proven technology in a new context, we delivered a safe, efficient, and regulator-approved abandonment solution under challenging well conditions.”
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Technical Director
Elemental Energies

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Key Highlights

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• Deployment of Bismuth plugging technology based on prior project experience
• Strong integration between wells and facilities decommissioning planning and contracting
• Fully integrated project management team operating between the UK and Dubai
• Successful permanent abandonment of the well in line with regulatory requirements
• Complete elimination of Sustained Annulus Pressure (SAP)

The Designed Solution

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A combined barrier system was designed and executed, consisting of an inflatable plug, a 6-ft Bismuth alloy plug, and a minimum 100-ft cement plug.

This approach avoided the need for extensive milling of long window sections and mitigated the risks associated with cement placement in a mobile gas environment. The Bismuth alloy expanded and solidified on cooling, forming a gas-tight barrier that protected cement integrity and delivered a robust primary seal.

The solution reduced operational complexity, managed equipment constraints, and achieved a reliable abandonment outcome on the first deployment – significantly improving efficiency compared with conventional approaches typically requiring multiple attempts in similar environments.