Deliverable 1.3: Accounting for Stress History and Lithology through Forward Geomechanical Modelling

Abstract

A core theme of the SHARP project is integrating the stress history of the North Sea basins into stress characterisation and experimental testing procedures, and by extension developing an appreciation for how this might influence assessment of risk and monitoring requirements for storage operations. The link here is geomechanical modelling, which facilitates predictions of subsurface deformation as a function of evolving stress conditions and the experimentally constrained constitutive properties. This report documents a suite of geomechanical models applied to the Horda platform area of northern North Sea. Evolutionary models of the Troll area are presented, with specific focus on well 31/6-1, which examine the significance of burial history, chemical compaction and uplift/glaciation on stress and pore pressure in the area. When explicitly representing these processes and leveraging understanding of mineralogical significance developed in earlier tasks it is found that these support log-based workflows presented in Deliverable 1.2. Conclusions regarding the probable causes for elevated shallow stresses and pore pressures at these sites are made. Preliminary efforts to direct the procedures and techniques to the Smeaheia alpha well 32/4-1 are shown.

The key findings of the modelling work are summarised and implications for risk and monitoring are presented. Concepts for extending the work within 3D geomechanical models are provided and will be tackled in subsequent project tasks.