Bentonites

Publieke samenvatting / Public summary

Aanleiding
The issue of high well abandonment costs and safe long-term sealing of oil and gas wells is an important topic which receives increasing attention both, in related industry and society. Billions of euros are needed for abandonment, which will have substantial economic impact on the economic value of sustainable hydrocarbon production. Furthermore, under certain conditions existing abandonment techniques may not be able to demonstrate long term integrity to ensure sealing for the post abandonment phase. If required, the costs for future, additional and unplanned remediation of leaking plugs will be significant. The same accounts for the cost of long term monitoring since dedicated and specified methods are currently not available.
If the costs of abandonment can be reduced significantly, the overall profitability of gas operations will strongly increase and will strengthen the future use of the subsurface for large scale energy storage, CCUS and geothermal exploitation.

Doelstelling
The overall objective of this project is maintaining long-term sealing properties after abandonment by ensuring that the well remains its zonal isolation for geological timeframes and simultaneously providing a cost-efficiency plugging operation.

Korte omschrijving
Focus is on exploring and testing the feasibility of the application of bentonite for O&G wellbore plugging by (a) conducting in-situ lab experiment(s) on bentonite sealing behavior, (b) studying tailored placement and long-term monitoring options and (c) evaluating financial benefits of the approach and preparing a field test.

Resultaat
The work will generate extended knowledge on the in-situ mechanisms of the bentonite sealing process for wellbore abandonment, thereby ensuring safe and cost-efficient well plugging. The project will develop plugging concepts, placement options and verification methods in compliance with regulations and industry practices in force. Overall, this idea could be a game-changing approach, providing long term zonal isolation and economic abandonment procedures at the same time.