Agnieszka Furmann | Indiana University (original) (raw)

Papers by Agnieszka Furmann

Fuel, 2014

h i g h l i g h t s We demonstrate the applicability of micro-FTIR to quantify shale mineralogy. ... more h i g h l i g h t s We demonstrate the applicability of micro-FTIR to quantify shale mineralogy. Characteristic peaks for minerals and kerogen in shales allow fast and reliable FTIR quantifications. Micro-FTIR offers in situ quantification at high resolution of shales.

Marine and Petroleum Geology, 2021

Thermal maturity is often readily available from optical vitrinite reflectance measurements, but ... more Thermal maturity is often readily available from optical vitrinite reflectance measurements, but in marine sediments with absence of terrigenous organic material (vitrinite macerals) or formations older than the Devonian, this technique has limitations. Raman spectroscopy has been applied as an alternative measurement to infer thermal maturity in challenging formations. Organic-rich outcrop samples from the Jordanian Lajjoun and Sultani deposits and from a Far East shale were characterized for their key geochemical properties (bulk chemical and mineral composition, total organic carbon content) and thermal maturity. Bulk mineral and chemical abundances were quantified using standard X-ray diffraction and X-ray fluorescence techniques. Total organic carbon (TOC) content was calculated from programmed temperature pyrolysis. Thermal maturity was determined and compared using conventional vitrinite reflectance and a novel, rapid laser Raman spectroscopy method. The Jordanian samples are...

Raman spectroscopy has been applied in numerous sedimentary formations to infer thermal maturity ... more Raman spectroscopy has been applied in numerous sedimentary formations to infer thermal maturity of mostly Type-II kerogen in organic-rich mudrocks. Robust correlations have been established between the Raman spectroscopic signal and vitrinite reflectance equivalents (%VRE) of the organic matter. Herein, traditional evaluation methods, organic petrography and geochemistry, were applied in addition to Raman spectroscopy, to study the prolific source rocks of the Najmah and Makhul Formations in Kuwait. The elemental analysis of isolated kerogen provided insight into the kerogen type and likely classified samples from these two formations as kerogen Type II-S. The standard organic petrography maturity and geochemistry parameters were correlated to the spectroscopy derived Raman band separation (RBS) values. This allowed to further validate our previously established thermal maturity correlation (RBS vs %VRE with R2 = 0.80) and generate a new geochemistry-related correlation of RBS vs h...

Marine and Petroleum Geology

International Journal of Coal Geology

Organic Geochemistry, 2015

Organic-rich mudstones with up to 10 wt% TOC from the upper portion of the Belle Fourche Formatio... more Organic-rich mudstones with up to 10 wt% TOC from the upper portion of the Belle Fourche Formation and the lower part of the Second White Specks Formation in the Western Canada Sedimentary Basin were evaluated as source rocks. Both geochemistry and organic petrography indicate an open marine paleoenvironment with deposition of Type II kerogen based on the predominance of marine alginite and amorphous organic matter (OM), limited amounts of terrigenous vitrinite and inertinite macerals, the presence of marine fossils, and the low ratio of TOC to total sulfur (~1.26). The prevalence of short-chain n-alkanes (n-C 13 to n-C 19), a predominance of C 28-αββ(H)-20S steranes, and small concentrations of oleanane confirm the dominantly algal and planktonic origin of OM. Alternating oxic to anoxic paleoenvironmental sedimentary conditions are proposed based on common bioturbation, abundant inoceramid prisms, and good organic richness. Biomarker distributions are consistent with intermittent anoxia, without unequivocal evidence for water column stratification or hypersalinity. The thermal maturity measured in seven sediment cores by different methods consistently indicates a westward increase in maturity according to vitrinite reflectance, T max , and hopane and sterane biomarkers. Two cores are thermally immature (~0.42 %Ro), one is early mature (~0.65 %Ro), and four cores are within the oil window (~0.78 to 0.89 %Ro). All thermally mature cores retain good to very good hydrocarbon potential (248 mg HC/g rock) and are dominantly oil-prone and minor gas-prone based on their maceral compositions. The upper Belle Fourche and lower Second White Specks Formations represent potential targets for unconventional light shale oil production.

Energy & Fuels, 2014

ABSTRACT Shale reservoirs are becoming an increasingly important source of oil and natural gas su... more ABSTRACT Shale reservoirs are becoming an increasingly important source of oil and natural gas supply and a potential candidate for CO 2 sequestration. Understanding the pore morphology in shale may provide clues to making gas extraction more efficient and cost-effective. The porosity of Cretaceous shale samples from Alberta, Canada, collected from different depths with varying mineralogical compositions, has been investigated by small-and ultrasmall-angle neutron scattering. The samples come from the Second White Specks and Belle Fourche formations, and their organic matter content ranges between 2 and 3%. The scattering length density of the shale specimens has been estimated using the chemical composition of the different mineral components. Scattering experiments reveal the presence of fractal and non-fractal pores. It has been shown that the porosity and specific surface area are dominated by the contribution from meso-and micropores. The fraction of closed porosity has been calculated by comparing the porosities estimated by He pycnometry and scattering techniques. Although there is no correlation between total porosity and mineral components, a strong correlation has been observed between closed porosity and major mineral components in the studied specimens.

Marine and Petroleum Geology, 2014

This study presents approaches for evaluating hybrid source rock/reservoirs within tight-rock pet... more This study presents approaches for evaluating hybrid source rock/reservoirs within tight-rock petroleum systems. The emerging hybrid source rock/reservoir shale play in the Upper Cretaceous Second White Specks and Belle Fourche formations in central Alberta, Canada is used as an example to evaluate organic and inorganic compositions and their relationships to pore characteristics. Nineteen samples from a 77.5 m-long core were analyzed using organic petrography, organic geochemistry, several methods of pore characterization, and X-ray powder diffraction (XRD). The lower part of the studied section includes quartzand clay-rich mudrocks of the Belle Fourche Formation with low carbonate content, whereas the upper portion contains calcareous mudrocks of the Second White Specks Formation. Strata are mineralogically composed of quartz plus albite (18e56 wt. %), carbonates (calcite, dolomite, ankerite; 1e65 wt. %), clays (illite, kaolinite, chlorite; 15e46 wt. %), and pyrite (2e12 wt. %). Petrographic examinations document that organic matter represents marine Type II kerogen partly biodegraded with limited terrestrial input. Vitrinite reflectance R o (0.74e0.87%), T max values (438e446 C) and biomarkers indicate mid-maturity within the oil window. The relatively poor remaining hydrocarbon potential, expressed as an S2 value between 2.1 and 6.5 mg HC/g rock, may result from an estimated 60e83% of the original kerogen having been converted to hydrocarbons, with the bulk having migrated to adjacent sandstone reservoirs. However, the presentday remaining total organic carbon TOC pd content remains relatively high (1.7e3.6 wt. %), compared with the estimated original TOC o of 2.4e5.0 wt. %. The calculated transformation ratio of 60e83% suggests that the remaining 17e40 wt. % of kerogen is able to generate more hydrocarbons. The studied section is a tight reservoir with an average Swanson permeability of 3.37$10 À5 mD (measured on two samples) and total porosity between 1.7 and 5.0 vol. % (3 vol. % on average). The upper part of the sandy Belle Fourche Formation, with slightly elevated porosity values (3.5e5 vol. %), likely represents the interval with the best reservoir properties in the studied core interval. Total pore volume ranges between 0.0065 and 0.0200 cm 3 / g (measured by a combination of helium pycnometry and mercury immersion). Mesopores (2e50 nm B) are the most abundant pores and occupy 34e67% of total porosity or a volume of 0.0030e0.0081 cm 3 /g. In comparison, micropores (<2 nm B) cover a wide range from 6 to 60% (volume 0.0007e0.0053 cm 3 /g), and macropores (>50 nm B) reach up to 57% with the exception of some samples failing to indicate the presence of this pore fraction (volume 0.0000e0.0107 cm 3 /g). Macroporosity is mostly responsible for variations in total porosity, as suggested by macroporosity's strongest correlation with total porosity within the section. The relatively narrow ranges of TOC and minerals contents among measured samples limit our ability to further deconvolute factors that influence changes in total porosity and pore size distribution.

International Journal of Coal Geology, 2013

The influence of two solvents on the degree of bitumen extractability and the porosity of the ext... more The influence of two solvents on the degree of bitumen extractability and the porosity of the extracted coals was investigated using two high-volatile bituminous coals with different petrographic composition. The Springfield Coal (vitrinite-rich) and the Lower Block Coal (vitrinite-poor) from the Illinois Basin were Soxhlet-extracted with methanol (CH 3 OH) and dichloromethane (CH 2 Cl 2). The abundances of three selected groups of biomarkers extracted from both coals were compared: (1) n-alkanes plus pristane and phytane; (2) hopanes; and (3) 3-and 4-ring aromatic hydrocarbons (phenanthrene, anthracene, fluoranthene, and pyrene). Overall, the extracts of the vitrinite-poor Lower Block Coal contained greater amounts of n-alkanes and hopanes, whereas aromatic hydrocarbons were extracted in greater quantities from the vitrinite-rich Springfield Coal. Fourier Transform Infrared Spectroscopy (FTIR) and Gas Chromatography/Mass Spectrometry (GC/MS) confirmed that the average lengths of aliphatic chains were greater in CH 2 Cl 2 extracts from both coals. For the Lower Block Coal, the aromaticity of extracted organic matter was greater in the CH 2 Cl 2 extract than in the CH 3 OH extract. Both coals showed an increase in microporosity (b2 nm; measured by CO 2 adsorption) after solvent treatments. In addition, the mesopore surface area (2-50 nm, measured by N 2 adsorption) was reduced likely because of a shift in the size distribution of mesopore diameters towards those of macropores (i.e. >50 nm). Our analyses of compound classes present in the extracts and resultant porosity changes in the extracted coals provide useful insights into the structural and molecular differences in two bituminous coals of different maceral compositions.

Chemical Geology, 2013

Microbial generation of coalbed methane (CBM) occurs in numerous basins worldwide. This study ide... more Microbial generation of coalbed methane (CBM) occurs in numerous basins worldwide. This study identifies specific classes of chemical compounds in two high volatile bituminous coals from the Illinois Basin in southwestern Indiana, USA that are being degraded during methanogenesis. Springfield Coal is rich in vitrinite (92.2 vol.% vitrinite in coal) whereas Lower Block Coal contains larger contributions of liptinite and inertinite and contains only 66.2 vol.% vitrinite. Anaerobic bioreactors used in the experiments contained a mineralsalts medium, operationally-defined coal extracts, and a microbial inoculum composed of an endemic microbial consortium that was obtained from co-produced water from an active CBM well. Our experiments investigated degradation of organic matter (OM) and concurrent methanogenesis using water-soluble, methanol (CH 3 OH)-soluble, and dichloromethane (CH 2 Cl 2)-soluble fractions of extracted OM from coal as the sole carbon sources. Only methanol and dichloromethane were found to be effective solvents to extract sufficient OM from coals for biodegradation. The methane yield over time was small (1.7 to 8.7 μmol in total headspace) and less than 1% of carbon added to bioreactors in organic extracts was converted into methane. Extracts of vitrinite-rich Springfield Coal yielded relatively more methane than extracts of Lower Block Coal. The preference of methanogenic microbial consortia for extracts from vitrinite-rich Springfield Coal may be related to the fact that the organic matter in vitrinite is rich in functional groups containing organic nitrogen, sulfur and oxygen (NSO) that provide chemical sites with low activation energies to initiate biodegradation. A comparison of the molecular compositions of the initial organic extracts with their biodegraded residues after incubation of the bioreactors for 24 weeks indicated that biodegradation of n-alkanes and aromatic hydrocarbons occurred concurrently, whereas hopanes proved to be far more refractory. Our study documents significant biodegradation of n-alkanes (14 to 91% by GC/MS peak intensity) from coal extracts. It is particularly noteworthy that biodegradation also eliminated 6 to 58% of aromatic biomarkers, although the pool of n-alkanes was not exhausted. This significant early biodegradation of aromatic hydrocarbons in coal extracts contrasts starkly with the biodegradation pattern of petroleum where similar aromatic compounds are degraded only after n-alkanes have been severely depleted. This evidence may support the hypothesis that microbial communities engaged in coal biodegradation do not express a strong preference for either aliphatic or aromatic carbon sources, in contrast to biodegradation patterns typical of petroleum. CH 3 OH-extracted organic matter from coal was generally more biodegradable than CH 2 Cl 2-extracted organic matter from the same coal, probably because CH 3 OH extracts contained lower concentrations of longer straight aliphatic chains allowing faster microbial degradation.