MERID - Microstructural Influence on Reservoir Integrity Under Variable Hydromechanical Pressure Conditions

Porous reservoir rocks are explored as hydrocarbon reservoirs and used as geothermal or gas storage facilities. They contain sedimentary and structural interfaces (bounding surfaces, faults, deformation bands) and structures caused by compaction during pressure reduction within the reservoir (pressure solution, deformation bands), which influence the reservoir integrity as permeability anisotropies during hydromechanical pressure changes. At the same time, the rocks are flowed through by a two-phase flow (injected fluid vs. formation water, oil vs. formation water), whereby the relative permeabilities depend on the wetting properties of the mineralogical microstructures.
The aim of this interdisciplinary project is to model the microstructural influence on the two-phase flow and reservoir integrity.

The vertical and horizontal permeabilities in porous reservoirs, which vary during fluid pressure changes, are analysed and modelled experimentally and numerically. Coupled geomechanical and hydrodynamic models are used to calculate the three-dimensional hydrodynamics of the multiphase flow taking into account the wetting properties on the grain scale and to derive the representative volume for the reservoir scale. The results are validated using existing reservoir data and the knowledge gained on reservoir integrity is quantified. In the integrated interdisciplinary approach, grain-scale processes are applied to reservoir processes for the first time and digital rock models are created. The results will be applied to the more efficient use of deep reservoirs for exploration and as energy storage.

The project is funded by the German Federal Ministry of Education and Research (grant no. 03G0868).

The project was successfully completed. The publication of the DGMK research report is in progress.

Abstracts

Monsees A, Busch B, Subhedar A, Nestler B, Hilgers C. 2019 Integrating Geology and Petrophysics into Numerical Models - A Step Towards the Digitalization of Rocks. In DGMK/ÖGEW Spring Conference, Celle.

Monsees A, Busch B, Schöner N, Hilgers C. 2019. reservoir quality controls in deeply buried Rotliegend sandstones and their outcrop analogues. In Annual Conference of the German Geological Society, Münster.

Monsees A, Busch B, Hilgers C. 2018 The impact of pore-occluding cementation and chemical compaction on the reservoir quality of deeply buried sandstones. In 6th Geothermal Workshop, Strasbourg.

Technical Committee Earth Sciences Geo-Energy Systems and Subsurface Technologies