In-situ investigation of fluid-fluid-solid contacts in oil-brine filled reservoir sandstone

The combination of broad-ion-beam slope-cutting with scanning electron microscopy and energy dispersive X-ray analysis under cryogenic conditions (cryo-BIB-SEM) enables the nano-scale imaging of pore-scale fluid-fluid-solid contacts in porous, wet materials like reservoir rocks: backscattered electron image with segmented phase overlay showing kaolinite-cemented pore in sandstone filled with brine and oil (see legend for color code). Oil droplets adhere to kaolinite facets and quartz asperities. Image modified from Schmatz J., J. L. Urai, S. Berg, H. Ott (2015) Nano-scale Imaging of Pore-scale Fluid-Fluid-Solid Contacts in Sandstone, Geophysical Research Letters, doi: 10.1002/2015GL063354.

Carbonic inclusions in natural rock salt and their role in devlopment of microstructure

It has been shown that dilatant deformation promotes the incorporation of hydrocarbons (HC) into typically low permeable rock salt (Popp et al., 2001; Schoenherr et. al., 2007). However, there is not much knowledge on the mechanisms of HC migration through the salt body and of the enclosure of HC into salt grains.
HC inclusions, trapped in an Ara Salt anhydrite stringer sequence (3300 m) in recrystallized rock salt occur in networks along grain boundaries. We observe morphologies ranging from films and interconnected channel systems to arrays of isolated inclusions. The morphology indicates that fluid films shrink and neck down to isolated inclusions. Fluids are connected in a triple junction network. Enclosed fragments of fine-grained anhydrite contain HC in larger proportions inside large, patchy multi-phase fluid inclusion. The adjacent recrystallized salt grains are clear and do not contain HC inside grains. Mobile grain boundaries change and redistribute HC during grain boundary migration recrystallization.

Anhydrite layers are fractured. Dilatant fractures are filled with halite. Vein halite is recrystallized with numerous solid and liquid/vapor inclusions along grain boundaries and inside grains.

Multiphase inclusion trapped in halite grain boundary containing solid bitumen, gas, and liquid hydrocarbons.

Grain Boundary - Fluid Inclusion Interaction in Rocks and Analogues. Schmatz, J. 2010. PhD-thesis, RWTH Aachen University. pdf

Collaborative Research Project together with 10 mineral and science partners from academia and national research institutes, funded by the European Science Foundation (ESF) and the German Science Foundation (DFG).

Research on grain boundary structure and fluid inclusion mobility using natural samples, analogue and numerical models, running and developing a high-pressure, high temperature see-through deformation apparatus for rock analogues.

Abstract

This thesis deals with the interaction of moving grain boundaries with fluid inclusions in metamorphic rocks and rock analogues. The grain scale distribution of fluids, the fluid inclusion morphology and kinetics have important implications for the preserved microstructure and therefore for interpretations on thermobarometry and rheology. In order to better understand the kinetics involved and finally to enhance the reliability of fluid inclusions used as a tool in geosciences, this thesis is built as a combination of investigations on i) natural samples, ii) analogue experiments that allow in-situ observations on fluid inclusion – grain boundary interaction with carefully selected variations of boundary conditions, and iii) numerical simulations. See our toolbox for further information on see-through experiments.

Experimental Study on Clay Gouge Evolution in Mechanically Stratified Sequences. Schmatz, J. 2006. Diplom Thesis, RWTH Aachen University. pdf

Abstract

This study focuses on clay smear processes during fault gouge evolution in sand-clay sequences. A clay-rich gouge can dramatically lower the fault's permeability, and prediction of this process is therefore relevant in groundwater modeling and hydrocarbon geology. We constructed an 'underwater' sandbox to deform layered sand-clay models of 20/40/20 cm (h/w/d) above a 70° dipping rigid basement fault. The experiments are run completely water-saturated to allow deformation of wet clay and cohesionless sand. See our toolbox and clay smear project page for further information.

Analogue sandbox model used to model clay smear in normal faults. Experiment is set up with a 30 mm thick, soft clay layer in the center of the model. The setup is water-saturated to deform cohesionless sand and wet clay together in one model. PIV overlay on the same experiment is shown in movie to the right.

Geology of Moss Beach, San Mateo County, CA, Schmatz, J., 2004. Unpublished Diplom Mapping Project, RWTH Aachen University

BMWi EXIST Forschungstransfer Phase II, with Jop Klaver, Moritz Süß, Mingze Jiang and Janos Urai, Aachen, Germany, 2016.

RWTH Innovation Fond 2015, with Jop Klaver, Moritz Süß and Janos Urai

BMWi EXIST Forschungstransfer Phase I, with Jop Klaver, Aachen, Germany, 2014.

RWTH ETS (Exploratory Teaching Space) Project 'Virtual Microscopy in the Geosciences', with Janos Urai and Thomas Berlage (Fraunhofer FIT), Aachen, Germany, 2012.

Award of the Prof. Dr. Karl-Heinrich Heitfeld Stiftung for outstanding PhD Thesis, Aachen, Germany, 2011.

Award of the Prof. Dr. Karl-Heinrich Heitfeld Stiftung for outstanding Diplom Thesis, Aachen, Germany, 2007.

Grant for participation at Marie Curie Summer School: Knowledge Based Materials, Alvdalen, Sweden, 2006.

Award for outstanding student poster presentation, TSK 11, Göttingen, Germany, 2006.