Research and analysis

Specific environmental risks from repurposing oil and gas wells: summary

Published 28 November 2022

Applies to England

1. Chief Scientist’s Group report summary

This project examined the environmental risks from using onshore oil and gas (OOG) wells for other purposes. It considered the different ways that wells can be repurposed, the challenges in doing this, and assessed the numbers of wells that could be repurposed. These findings will help the Environment Agency and others make decisions about whether repurposing is an acceptable alternative to decommissioning at the end of a well’s life.

1.1 Background

There are about 2100 OOG wells in England, but only active wells (neither partially or fully decommissioned) are likely to be repurposed. All 458 active wells are in North and South East England.

Hydrocarbon wells that have not yet been fully decommissioned can be repurposed and used for extracting geothermal energy, storing hydrogen, carbon dioxide and thermal energy or for testing tools. These technologies could help the UK achieve its net zero goals.

1.2 Approach

This project builds on our existing knowledge about the possible sources, pathways and receptors of pollution from onshore oil and gas wells and other technologies. It considers the ways in which wells can be repurposed and the well attributes that could limit environmental harm, the requirements for specific uses, and possible knowledge gaps. It also demonstrates a screening process for repurposing wells in England.

1.3 Results

The report highlights that active, or recently active, OOG wells are frequently repurposed as part of normal operations of oil and gas fields and there are standard procedures for doing this. However, there could be additional considerations for non-oil and gas purposes, relating to secure containment within a reservoir, operational efficiency or the material used in the wellbore.

The report emphasises that each well would need to be assessed for suitability individually and wells not included in the screening could still be suitable.

1.4 Conclusions

This report outlines how wells can be repurposed and how criteria to identify well integrity can be used to screen for suitability. However, it is important to fully test possible wells for repurposing. The considerations outlined in this report can be used to help decision makers and operators understand the potential environmental risks from repurposing boreholes.

1.5 Project details

This summary relates to information from the following project:

  • Report: SC210009/R
  • Title: Specific environmental risks from repurposing oil and gas wells
  • Project manager: Sian Loveless, Chief Scientist’s Group
  • Contractor: Geoenergy Durham, Eshwood Cottage, New Brancepeth, Durham

This project was commissioned by the Environment Agency’s Chief Scientist’s Group, which provides scientific knowledge, tools and techniques to enable us to protect and manage the environment as effectively as possible.

Enquiries: research@environment-agency.gov.uk

© Environment Agency