CCS in Onshore Deep Carbonate Saline Aquifer: Fast-Track from Feasibility to Project Implementation
Authors: Xu Siqing , Al Keebali A. , Baslaib M. , BinAmro A. A. , Ali I. , Vantala A. , Para H. , Karim M. , El Yosef B. , Abdelazim M. Farouk , Mason J. , Al Shehhi Zayed , Ahmed Dilshad , Anwar Mohamed , Arbadov Gurbandurdy , Mourad Muhammad , Ibrahim Al Marzouqi Khalid , Rizwan Mohammed 
Published: October 2023

As a key milestone of ADNOC sustainability initiative and to support the UAE’s net-zero goals, a major CCS project was initiated focusing on permanent CO2 storage in deep carbonate saline aquifers Onshore Abu Dhabi. Following a comprehensive feasibility study, an appraisal and injection well site was selected. The first CO2 injection well was spudded. The project is the world’s first deep carbonate saline aquifers commercial CCS project! This paper aims to present the work completed taking the project from feasibility study to execution with clear technical and business drivers. Key challenges and innovations are presented, enabling the project to progress within a short record time of less than two years.

A multi-discipline integrated approach embedding specialized external service providers was adopted throughout the project stages, aiming at ensuring CO2 containment, cost optimization and technology innovation. The comprehensive feasibility study was completed with international CCS project benchmarking. The de-risking program included data acquisition from offset wells and associated geo-mechanical and geo-chemical laboratory tests. For appraisal well site location, a new high resolution 3D seismic and offset wells data were used. Extensive risk analysis was performed covering full project life cycle. Well injection and MMV plan was designed to meet short and long term technical (especially CO2 containment) business requirements.

The integrated project feasibility study identified several deep carbonate saline aquifer formations offering significant CO2 storage potential. High level study was carried out including surface facilities design and storage development plan. De-risking for CO2 containment assurance targeted open hole logs and core from offset wells, and associated comprehensive geo-mechanical and geo-chemical laboratory tests. The findings lead to the recommendation of drilling the first carbonate deep saline aquifer CO2 sequestration well, within the framework of a low carbon business development strategy.

A high resolution 3D seismic and offset well geological data were used to screen and select well location. 3D geo-mechanical study helps well injection design to safeguard cap-rock integrity and minimize the risks of far-field fault re-activation.

Significant challenges in well design were addressed, for example, potential J-T cooling effect from CO2 injection. CO2 injection design was aimed at de-risking long term injectivity and reducing overall storage capacity uncertainties.

The MMV plan was designed to meet short term and long term requirements. Innovative monitoring technologies such as shallow soil tracers, CO2 in air laser detection, and DAS/DTS/DSS are implemented.

For this the world’s first onshore carbonate deep saline aquifer commercial CCS project, the work completed under full-value-chain process are presented covering amongst others CCS feasibility, site selection, well and injection test design, MMV plan, risk assessment and low carbon business case. Key technical and design challenges are highlighted and addressed together with technology innovations. It is hoped that the multi-discipline integrated and commercial-driven approach can provide discernment for operators planning similar studies/projects.