Markus Peltz

Bayerisches Landesamt für Umwelt | LFU

Diagenetic illite growth in porous sandstones leads to significant modifications of the initial pore system which result in tight reservoirs. Understanding and quantifying these changes provides insight into the porosity-permeability history of the reservoir and improves predictions on petrophysical behavior. To characterize the various stages of d...

Transmission electron microscopy-energy dispersive X-ray analysis (TEM-EDX) represents an effective tool for determining the stoichiometric composition of clay minerals, but the methodology is often hampered by analytical difficulties. Studies of beam-sensitive minerals, such as smectites, are associated with low count intensities and dynamic loss...

Rationale: Clumped isotope (Δ47) analysis of bioapatite-derived CO2 is a powerful tool to determine body temperatures of extinct vertebrates. The common acid bath technique in combination with dual-inlet-based mass spectrometric measurements has been the preferred method of choice for this purpose, but the large amount of material necessary and the...

There is a current need for developing improved synthetic porous materials for better constraining the dynamic and coupled processes relevant to the geotechnical use of underground reservoirs. In this study, a low temperature preparation method for making synthetic rocks is presented that uses a geopolymer binder cured at 80 °C based on alkali-acti...

At the Illinois Basin–Decatur Project, a large-scale CO2 capture and geologic storage demonstration project in the saline Mount Simon Sandstone in central Illinois, three overlying and laterally continuous shale formations (the Eau Claire, Maquoketa, and New Albany) are considered confining units overlying the sandstone reservoir. The Mount Simon r...

Bentonite is currently proposed as a potential backfill material for sealing high-level radioactive waste in underground repositories due to its low hydraulic conductivity, self-sealing ability and high adsorption capability. However, saline pore waters, high temperatures and the influence of microbes may cause mineralogical changes and affect the...

Computer X-ray microtomography (µXCT) represents a powerful tool for investigating the physical properties of porous rocks. While calculated porosities determined by this method typically match experimental measurements, computed permeabilities are often overestimated by more than 1 order of magnitude. This effect increases towards smaller pore siz...

There is a current need to develop buoyant and biocompatible nanoclays for removing oil pollution from the surface waters of rivers, lakes and oceans. Application of clay-based amendments should either aid dispersion, adsorption or biodegradation of hydrocarbons without introducing additional toxicity. Ultrathin (< 15 μm thick) nanoclay films of lo...

Computer microtomography (µXCT) represents a powerful tool for investigating the physical properties of porous rocks. While calculated porosities determined by this method typically match experimental measurements, computed permeabilities are often overestimated by more than one order of magnitude. This effect increases towards smaller pore sizes,...

Carbonated hydroxy-apatite (Ca10-b(NH4,K,Na)2b(PO4)6-y[(CO3)2x+(3/2)y(OH)2–2x]; CHAP) was synthesized in batch-type experiments by mixing of calcium (Ca)- and phosphate-bearing aqueous solutions and the transformation of calcite powder in aqueous solution between 11° and 65 °C. Compositional changes of the mother solution and solid phase products w...

Heterogeneity of geological materials poses various problems when evaluating reservoir quality and storage potential. We analysed samples of different sedimentary facies of a Rotliegend sandstone from the Flechtingen High (Northern Germany) to determine the influence of depositional environment and diagenetic history on mineralogical composition an...

The goal of this study is to better understand the porosity and permeability in shales to improve modelling fluid and gas flow related to shale diagenesis. Two samples (WIC and HAD) were investigated, both mid-Jurassic organic-rich Posidonia shales from Hils area, central Germany of different maturity (WIC R0 0.53 % and HAD R0 1.45 %). The method f...

The integrity of the caprock plays a major role for the long-term safety of CCS projects. Salt-induced anticline structures in NE Germany that are capped by Toarcian claystones could store up to 1,5 Gt CO2. This study focused on the interaction between Lower Jurassic claystones and CO2-charged brine in an attempt to identify pathways within the cap...

MX80 bentonite, composed mainly of Na-montmorillonite, is one of the prime candidates as a buffer for the Swedish spent fuel repository in Forsmark. In the repository the buffer is expected to come into contact with groundwater from surrounding rock and with cement-altered solutions derived from areas that use concrete. This study aimed to characte...