Legacy well re-entry services

Supporting safe re-entry into legacy well formations for offshore storage of CO2 for carbon capture and storage developments.


We have designed our legacy well re-entry service suite to be a specialised resource for facilitating safe re-entry into well formations for the offshore storage of CO2; crucial for advancing carbon capture and storage (CCS) initiatives. At Aquaterra, we are wholly committed to safe and efficient CO2 storage. Our recent contract with INEOS on Project Greensand highlights our commitment to meeting worldwide CCS goals. 

Repurposing depleted oil reservoirs and saline aquifers makes practical sense, as they are typically situated within mature basins and come with detailed geological data. However, they do present unknown leakage risks. Before CO2 injection can begin, these wells must undergo re-entry to establish an environmental and pressure-retaining barrier, ensuring safe re-abandonment and readiness for storage.

Drawing upon decades of expertise in well re-entry and tieback engineering from the oil and gas industry, we provide tailored solutions for repurposing depleted reservoirs and saline aquifers to store CO2 effectively.

Cost-effective vertical well re-entry

  • Our approach prioritises vertical re-entry, offering a cost-effective and expedited alternative to traditional relief well drilling methods
  • We conduct thorough casing string logging and testing above and below during or after abandonment, ensuring integrity and safety throughout the process
  • We can repurpose wells as monitoring points by incorporating advanced seismic monitoring technologies
  • Watch our webinar on the engineering challenges for CCS to learn more about the role of wells and platforms in CCS projects.

Expert well locating and feasibility studies

Our well re-entry and feasibility studies assist CCS operators in identifying suitable wells for re-entry, mitigating risks, and devising optimal methodologies for re-abandonment.  This includes:

  • Assessing risks linked to re-entering abandoned wells
  • Analysing factors like Date of Abandonment, Water Depth, Soil Conditions, and well depth below the mudline for vertical re-entry
  • Developing methods for locating the well efficiently
  • Evaluating re-entry options and proposing suitable approaches
  • Creating strategies to establish Environmental and Pressure Retaining barriers for re-abandonment

Tailored solutions for pressure-retaining barriers

We specialise in creating robust pressure-retaining barriers below the mudline, utilising our tieback engineering expertise to ensure the long-term integrity of CO2 storage wells.

Our experienced team of engineers specialise in developing robust well re-entry plans and providing the necessary, recoverable equipment and expertise to ensure a successful re-entry and tieback operation. The outcome is a properly re-abandoned well that facilitates long-term CO2 storage. This is just one example of exciting CCS technology that will help the UK achieve its goal of capturing 10Mt of carbon dioxide a year by 2030.

In-house offshore analysis team

Our dedicated team of offshore tieback analysts provides site-specific reviews, incorporating legacy well re-entry data and information, environmental conditions, and rig specifications to optimise strategies and approaches.

Discover how heritage oil and gas expertise can play a crucial role in advancing CCS.

For more information about how our we can support your offshore carbon capture and storage project and re-entering legacy wells for CO2 storage, get in touch with our CCS specialists.

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