This webinar presented work performed in the SECURe H2020 EU project addressing assessment of loss of well integrity in subsurface energy operations and ways to remediate such losses. The work combines numerical simulations and laboratory experiments. A probabilistic well integrity modelling workflow was developed in this project. The tool captures the impact of uncertainties in the input parameters for well integrity analysis. The workflow is applied to two case studies to demonstrate the probability of well failure under various operational conditions. The tool can be used by operators and regulators to minimise leakage risk when considering operational strategies and well designs. This is translated in the experiments by creating complex fracture networks in a downscaled realistic assembly of steel casing, cement sheath and surrounding sandstone, where the borehole pressure is varied until fracturing occurs. This cell allows one to independently control borehole pressure, cement curing pressure, pore fluid pressure in the sandstone and confining pressure on the surrounding rubber sleeve, thus recreating in-situ field conditions. Once fractures are obtained, they are characterised by image analysis performed on recorded CT scan reconstructions and by flowing fluid through them to assess leakage propensity. The fracture networks are then utilised to test remediation fluids such as flexible or low-density cement. These fluids are evaluated also in simpler, single fracture set-ups.
Chair: Ed Hough, BGS
Programme (all times are GMT):
- Introduction and overview of the SECURe project - Chair (5 min)
- Probabilistic modelling for assessment of well leakage risk - Al Moghadam, TNO (15 min)
- Testing suitable materials for remediation of CO2 leakage through a fractured cement sheath - Nicolaine Agofack, SINTEF (15 min)
- Q&A (20 min)
- Closing remarks - Chair (5 min)
Al Moghadam, TNO
|Nicolaine Agofack, SINTEF
Nicolaine holds a PhD in Geomechanics from Université Paris-Est, France. He moved to Norway in 2015 for 4 years Postdoc at the Norwegian University of Science and Technology (NTNU), and he recently joined SINTEF as a Research Scientist. His main areas of expertise include geomechanics of CO2 storage, oilwell cement characterization and well integrity, micromechanics, and homogenization upscaling methods. He is well-established in Laboratory experiments, theoretical modelling as well as numerical simulation.
This webinar will be recorded. A link to the recording will be available after the event.