Quintessa has developed a generic database of features, events and processes (FEPs) for the decommissioning of wells or boreholes. The FEP database was developed to support the transition to a net zero-carbon-emitting economy which will require multiple uses of the subsurface, all requiring the use and subsequent decommissioning of wells and/or boreholes.
The chosen FEPs have been included for their relevance to the long-term behaviour of wells once they have been decommissioned. Some FEPs associated with the well drilling, construction and operation phases, in addition to the FEPs associated with natural and man-made systems surrounding wells, are nevertheless considered where these can affect the long-term behaviour of decommissioned wells.
The FEP list provides a centralised source of information on relevant technical and scientific considerations relating to the long-term behaviour of decommissioned wells. It can be used as part of systemic assessments of decommissioned well safety and performance.
The database currently includes around 240 FEPs in a hierarchical structure, with individual FEPs grouped into six categories. Each FEP has a text description and an associated discussion of its relevance to the long-term behaviour of a decommissioned well. Key references from the published literature are included to enable the retrieval of more detailed information for each FEP.
The OECD/Nuclear Energy Agency FEP database for radioactive waste disposal and Quintessa’s generic FEP database for the geological storage of carbon dioxide provided the inspiration for this generic well decommissioning FEP database, although the aims and content of the database have been developed significantly from the aforementioned databases.
This FEP database is one of the key parts of well decommissioning workflow which Quintessa has been developing, consisting of the:
- Well Decommissioning FEP database;
- Decision Trees to support an informed decision on developing an assessment tool for risk-based approach to well decommissioning, which takes into account the information available and uncertainties in a specific well system; and
- development of the modelling tools of different levels of complexity, appropriate to the specific well type and geological conditions.
Please contact Richard Metcalfe if you would like a copy of the Well Decommissioning FEP Database and to discuss its use further.