Sandstone petrography and diagenesis
Diagenesis studies of sandstones, coupled with porosity and permeability measurements, contribute to the understanding of reservoir properties. Prediction of reservoir quality may be possible when diagenesis can be related to provenance, depositional environment, sequence stratigraphy, burial history and fault activity.
The experience of the researchers covers multiple subjects, e.g. diagenetic effects on the porosity and permeability of sandstones, clay mineral diagenesis in sandstones, stable isotopes in carbonate and quartz cement in sandstones, alteration of heavy minerals, provenance of sandstones based on zircon age dating and heavy mineral analysis.
In hydrocarbon exploration, as well as geothermal exploration, diagenetic investigations is mandatory to predict reservoir properties on both a regional scale and a prospect scale and to improve assessment of the prospectivity in areas of interest. A recent initiative includes recognition of experimental induced changes in sandstones from experiments with CO2 and different fluid flow rates.
The major methods applied are transmitted and reflected light microscopy of polished thin sections, and scanning electron microscopy of carbon coated thin sections and gold coated rock chips. Quantification is performed by point counting of thin sections assisted by extern Qemscan analysis.
Research and consultancy
The research covers a variety of sandstone types, e.g. quartz arenites, red beds, glauconitic and volcaniclastic sandstones, both from outcrops and well cores, in particular Greenland, Denmark, North Sea Basin, Norwegian-Danish Basin, North German Basin, Vietnamese basins and elsewhere. The Diagenesis Group is involved in several major industry-sponsored projects at GEUS such as the Northeast Greenland Petroleum studies, the North Sea Jurassic Petroleum System study, a number of geothermal consultancy projects as well research projects funded by the Danish National Research Foundation.
Areas of expertise
Petrography and diagenesis studies
- Clay mineral formation in sandstone
- Quartz and carbonate diagenesis in sandstone
- Diagenetic influence on porosity and permeability (analyses by Core lab at GEUS)
- Experimentally caused changes in sandstone (analyses by Core lab at GEUS)
- General petrography and diagenesis description of sandstone
The studies include e.g.:
- Light microscopy
- Scanning electron microscopy
- Point countings of thin sections
- Qemscan analysis
- X-ray diffraction, bulk or clay
- Porosity-permeability measurements
- Stable isotope analyses
- Chemostratigraphy of clastic sediments
- Zircon age source area interpretation (analyses by LA-ICP-MS lab at GEUS)
- Heavy mineral source area interpretation (analyses by SEM lab at GEUS)