Field decommissioning may be a significant economic burden for operators, especially in the case where its cost was not incorporated in a full field development case.
Figure 1 shows some projections of decommissioning expenditures toward 2030, for the UK Continental Shelf. It is possible to see how these cumulative costs are above 1 billion GBP each year.
Figure 1.Decommissioning expenditure forecast for the UK Continental Shelf (Oil and Gas UK 2021).
Isamgeo can offer to its customers a tailor-made strategy for well plugging and abandonment that would seal any potential leak path, for residual reservoir fluids or for any other overburden formation fluids, over a long-term perspective (50 – 100 yrs).
From an operational point of view, several plugs are created along the abandoned well, see Figure 2.
Figure 2. Production well schematic, before and after plugging and abandonment (Vrålstad et al. 2019).
Isamgeo’s strategy for efficient and environmentally friendly plugging and abandonment would consider several crucial factors that otherwise would drastically reduce the reliability of plugs:
Figure 3. Field stress path. It shows the effect of hydrocarbon production and fluids injection on reservoir pressure (Aruffo et al. 2014).
These issues would be addressed, for each distinct field case, through geomechanical modelling at different scales:
Isamgeo’s combined geomechanical modelling at different scales will support the design of the safest and the most cost-effective plugging and abandonment operations.