Hinderer M.,TU Darmstadt |
Kastowski M.,TU Darmstadt |
Kamelger A.,OMV Austria Exploration and Production GmbH |
Bartolini C.,University of Florence |
Schlunegger F.,University of Bern
Earth-Science Reviews | Year: 2013
This paper presents the first comprehensive analysis of sediment and dissolved load across an entire mountain range. We investigate patterns and rates of modern denudation of the European Alps based on a compilation of data about river loads and reservoir sedimentation from 202 drainage basins that are between ca. 1 to 10,000km2 large. The study basins cover about 50% of the total area of the Alps. Modern glaciated basins have the highest sediment yields of up to 7000tkm-2a-1, which are on average 5 to 10 times higher than in non-glaciated basins. Likewise sediment yield and glacial cover are positively correlated. Instead, relief is a relatively weak predictor of sediment yield. The strong glacial impact in the correlations is due to glacier recession since the 19th century as well as due to glacial conditioning during repeated Quaternary glaciations which have produced the strong transient state of the Alpine landscape. We suggest that this is the major cause for ca. 3 fold enhanced denudation of the western compared to the eastern Alps. Chemical denudation rates are highest in the external Alps dominated by carbonate sedimentary rocks, where they make up about one third of total denudation. The high rates cannot be explained without anhydrite dissolution. We estimated that only 45% of the sediments mobilized in headwaters are exported out off the Alps, most sediments being trapped in artificial reservoirs. The total amount of sediment annually trapped within the Alps equates to 43Mt. When corrected for sediment storage, we obtain an area-weighted mean total denudation rate for the Alps of about 0.32mma-1. The pre-dam rate might be as high as 0.42mma-1. In total, ca. 35 plus 23Mt of mass are exported each year out of the Alps as solids and solutes, respectively. These rates are not enough to out pace modern rock uplift. Nevertheless, pattern of sediment yield across the Alps coincides roughly with the intensity of glacial conditioning and modern rock uplift, supporting the hypothesis of an erosion-driven uplift of the Alps. © 2013 Elsevier B.V.
Dellmour R.,OMV Austria Exploration and Production GmbH |
Harzhauser M.,Natural History Museum Vienna
Marine and Petroleum Geology | Year: 2012
During the latest Early Miocene a large drainage system developed in the Alpine-Carpathian Foreland transporting sediments through a prominent submarine canyon along the narrow corridor between the south-eastern Bohemian Massif and the Waschberg-Ždánice Unit. The canyon followed the Alpine-Carpathian Foredeep from Lower Austria towards the north and northeast into the Czech Republic. 3-D seismic data allow the mapping of this 600 m deep structure over a distance of 25 km and a width of 5 km. Despite its dimension, making it the largest submarine erosive and sedimentary structure of the Neogene Alpine-Carpathian Foredeep, this canyon has not been previously recognised. Herein, it is interpreted as shelf-indenting canyon that formed due to a combination of isostatic rebound along a terminating thrust front and sea-level change during the terminal Early Miocene. The canyon fill comprises reworked littoral deposits with a typical Early Miocene, tropical micro- and macrofauna. The exact timing of this refilling remains unclear. Smaller channel structures in surface outcrops, representing potential tributaries of the canyon, suggest a more or less synsedimentary filling soon after indention. Finally, the top part of the canyon was eroded around the Early/Middle Miocene boundary, probably related to a global 3rd order sea level drop, and caped by marine marls during the subsequent early Middle Miocene transgression. With the sudden onset of the subsidence of the Northern Vienna Basin during that time, the drainage system abruptly moved southward shedding its sediments into the newly opening Vienna Basin. This explains the rather abrupt abandonment of the huge canyon feature, whose fan deposits are unknown so far. © 2012 Elsevier Ltd.
Beidinger A.,University of Vienna |
Beidinger A.,OMV Austria Exploration and Production GmbH |
Decker K.,University of Vienna
Tectonics | Year: 2014
A detailed reconstruction of late Oligocene and Early Miocene thrusting at the leading edge of the East Alpine fold-thrust belt is achieved from well data, seismic, and interpretative cross sections. Data are used for constraining the paleogeographic positions of the Alpine thrusts, quantifying in-sequence/out-of-sequence thrust distances, assessing the timing of thrust propagation from structurally higher units into more external ones, and estimating thrust velocities. Results are depicted in five palinspastic maps for time slices between ∼26 Ma and ∼16 Ma. The termination of foreland-propagating thrusting at the Alpine front is apparently controlled by the subcrop topography of the European basement, which includes a major recess in the east leading to a diachronic along-strike termination of foreland-propagating thrusting with younger thrust ages and higher in-sequence thrust distances in the east. Early locking of foreland-propagating thrusting in the west causes prominent out-of-sequence thrusts which add to the in-sequence thrust distances there. Continuing consecutive detachment of foreland units in the east occurs at rather fast propagation velocities with time intervals between foreland-thrust-propagations ranging between 0.1 and 0.7 Ma. The resulting increase of in-sequence thrust distances from west to east is balanced by out-of-sequence thrusts in the west. The total amount of late Oligocene to Early Miocene thrusting is quantified with a minimum of 51 km. Average thrust velocities range between 4.6 and 5.2 mm/yr. This rate refers to the movement of the basal thrust at the leading edge of the fold-thrust belt, which occurs contemporaneous with the eastward lateral extrusion of the Eastern Alps in the hinterland. ©2014. American Geophysical Union. All Rights Reserved.
Vengudusamy B.,Ac2t Research Gmbh |
Grafl A.,Ac2t Research Gmbh |
Novotny-Farkas F.,OMV Austria Exploration and Production GmbH |
Schofmann W.,Magna Powertrain AG and Co KG
Tribology International | Year: 2013
The friction responses of five fully formulated gear oils including mineral and synthetic oils were studied. This article examines the impact of contact motion types (rolling-sliding and pure sliding) and contact pressure on boundary and mixed friction properties of the selected gear oils in MTM (minitraction machine) and SRV (Schwing-Reib-Verschleiss tribometer). Mineral oils are found to be less affected by contact pressure compared to synthetic oils. Gear oils that show adsorption appear to be less sensitive to contact motion type in mixed lubrication while behave much more sensitive in boundary lubrication regimes. The ranking of gear oils for mixed friction was similar regardless of contact motion types at low contact pressures while differ at high contact pressures. © 2013 Elsevier Ltd.
Stotter C.,OMV Austria Exploration and Production GmbH |
Angerer E.,OMV Austria Exploration and Production GmbH
Geophysics | Year: 2011
A 2D vibroseis line was acquired in the Vienna Basin (Austria) for the purpose of comparing the data of digital multicomponent single sensors based on microelectromechanical system (MEMS) sensors alongside conventional vertical-component geophone arrays. For efficient removal of coherent noise during processing, all source points were recorded in single-sweep mode, i.e., no vertical stacking was performed in the field. On this densely sampled data set, several noise-reduction techniques, such as digital array forming, frequency-wavenumber (f-k) filtering in shot and receiver domains, and polarization filters, proved to be valuable in reducing source-generated noise. The results showed that, with the use of single-sweep recording and polarization filter techniques, it is possible to produce seismic sections for a single-receiver three-component (3C) MEMS line that are comparable to a conventional geophone array line in signal-to-noise ratio. However, the higher number of single geophones and hence the stronger attenuation of random noise in the conventional array resulted in an advantage for the analog geophone data set. The second goal for this survey was to evaluate additional information contained in the horizontal components of the MEMS data. The multicomponent data allowed for the processing of mode-converted shear-wave data, performed for the first time in the Vienna Basin. Azimuthal anisotropy related to horizontal stresses was observed in the Neogene section of the shear-wave data set. A PP-PS event correlation allowed the identification of major shallow horizons. Interpretation of the final sections confirmed that the PS data are useful to distinguish between gas reservoirs and high-porosity water sands, which can cause similar P-wave amplitude variation with offset (AVO) effects. © 2011 Society of Exploration Geophysicists.
Gasparik M.,RWTH Aachen |
Ghanizadeh A.,RWTH Aachen |
Bertier P.,RWTH Aachen |
Gensterblum Y.,RWTH Aachen |
And 2 more authors.
Energy and Fuels | Year: 2012
High-pressure methane sorption isotherms were measured on one Paleozoic and five Mesozoic shales, considered as targets for shale gas exploration in The Netherlands. The samples varied in mineralogy, organic richness, and thermal maturity. Four of the samples were clay-rich (total clay content 60-71 wt %), one contained equal amounts of clays and quartz (36 wt % and 33 wt %, respectively) and one was a marl sample (clays 34 wt %, carbonates 49 wt %). The total organic carbon contents (TOC) ranged from <1 wt % to 10.5 wt %, and the thermal maturity, as inferred from Rock-Eval analysis, from immature to overmature. Excess (Gibbs) sorption isotherms for methane were measured at 65 °C on dry samples up to 25 MPa. The maximum excess sorption capacities within this pressure range varied from 0.05 to 0.3 mmol/g (1.1-6.8 m 3 STP/t). No correlation of excess sorption capacity with TOC was found. Low-TOC, clay-rich shales had comparable or even higher methane sorption capacities per unit rock mass (mmol/g) than organic-rich shales, and a positive correlation was found between the maximum Langmuir capacity (n L) and the clay content. This observation supports the notion that clay minerals can contribute significantly to the sorption capacity of shales. Furthermore, we demonstrate that significant errors in TOC-normalized sorption capacities may result from the uncertainties in TOC contents, especially at low TOC values. A comparison between the immature and the overmature sample (both organic-rich with equal clay contents) did not show any enhancement of the sorption capacity with thermal maturity. However, the excess sorption isotherm of the overmature sample had a distinct maximum, while no maximum was observed for the immature sample in the experimental pressure range. A Langmuir-type absolute sorption function, with a term taking the volume of the adsorbed phase explicitly into account, gave a good representation of the measured excess sorption isotherms. The three-parameter fit yielded the Langmuir parameters (n L and p L) and a nominal density value for the adsorbed phase (ρ ads). Two-parameter fits of n L and p L using different fixed values of ρ ads are discussed. © 2012 American Chemical Society.
Yonze Y.,OMV Austria Exploration and Production GmbH |
Clemens T.,OMV Austria Exploration and Production GmbH
SPE Reservoir Evaluation and Engineering | Year: 2012
The Schonkirchen Tief oil field is located in the Vienna basin in Austria. It is a pervasively fractured dolomite reservoir that has been produced for more than 50 years. The field is at the tail end of production, the wells are perforated close to the top of the reservoir, and water is injected downdip. Because of the location of the field close to one of the main gas pipelines in Austria, it is planned to convert the field into high-performance underground gas storage (UGS). The field is characterized by a highly permeable fracture system and a less-permeable matrix system. It is expected that some incremental oil can be recovered because of gas/oil gravity drainage from the matrix. In addition to gas/oil gravity drainage, diffusion will have an effect on the oil recovery. The injected gas is leaner than the equilibrium gas in the reservoir. Hence, gas components diffuse from the fracture system into the matrix and components of the oil diffuse toward the fracture system. This results in a modification of the properties of the oil affected by diffusion. This type of gas injection results in a zone of decreased oil viscosity fur gases such as CO2 and CH4 at the interface of the gas and the oil in the matrix. This zone of lower oil viscosity increases the gas/oil gravity-drainage rates. The results show that the effect of diffusion can increase cumulative oil production up to 25% compared with a case neglecting the effect of diffusion. The effect of diffusion could be determined for various parameters such as permeability, porosity, fracture spacing, and matrix-block height. While for some of the parameters the effect of diffusion scales with the square root of time (e.g., permeability), for others an exponential relationship has been determined (fracture spacing). The results derived for the example reservoir can be used more generally to screen whether the effect of diffusion should be incorporated into reservoir studies concerning nonequilibrium-gas injection and to determine how large the error could be in the case where diffusion is neglected. Copyright © 2012 Society ot Petroleum Engineers.
Hinsch R.,Rohöl Aufsuchungs |
Hinsch R.,OMV Austria Exploration and Production GmbH
AAPG Bulletin | Year: 2013
The Molasse deposits of the Central Eastern Alps are partly incorporated into a fold and thrust belt that recently has come into exploration focus. The structural style and timing of deformation varies significantly alongstrike. Regional three-dimensional seismic and well data interpretation indicate three different structural segments from east to west: (1) The Sierning imbricates have a decollement close to the base of the Molasse sequence and consist of varying numbers of thrust sheets alongstrike. Early Miocene shortening of the Molasse is at least 6.2 km (3.9 mi). Overthrusting of the internal Penninic and Helvetic wedge since the Oligocene accommodated at least 25 km (15.5 mi) of additional shortening. (2) The Regau segment is dominated by one to two small thrust sheets above a shallow detachment. This segment is dominated by over-thrusting of the Alpine wedge. (3) The Perwang imbricates consist of an Oligocene wedge with complex deformed thrust sheets above a detachment horizon in Upper Cretaceous marls. Minimum shortening in the imbricates is 18.5 km (11.5 mi) with overthrusting 33.3 km (20.7 mi). All shortening estimates have an uncertainty of approximately 20% to 35%. The laterally varying thrust-belt architecture results from predeformational conditions (e.g., sediment thickness, mechanical stratigraphy, and basement dip). In the Sierning imbricates, hydrocarbon trap definition and charge issues are exploration risks. In the Regau segment, exploration is focused on the subthrust play. The Perwang imbricates have hydrocarbon shows but no economic discoveries. Charge and seal issues are the main risks. The petroleum systems in the context of the structural evolution are not yet fully understood. Copyright © 2013, The American Association of Petroleum Geologists. All rights reserved.
Buchgraber M.,University of Leoben |
Clemens T.,OMV Austria Exploration and Production GmbH |
Castanier L.M.,Stanford University |
Kovscek A.R.,Stanford University
SPE Reservoir Evaluation and Engineering | Year: 2011
Of the various enhanced-oil-recovery (EOR) polymer formulations, newly developed associative polymers show special promise. We investigate pore and pore-network scales because polymer solutions ultimately flow through the pore space of rock to displace oil. We conduct and monitor optically water/oil and polymer-solution/oil displacements in a 2D etched-silicon micromodel. The micromodel has the geometrical and topological characteristics of sandstone. Conventional hydrolyzed-polyacrylamide solutions and newly developed associative-polymer solutions with concentrations ranging from 500 to 2,500 ppm were tested. The crude oil had a viscosity of 450 cp at test conditions. Our results provide new insight regarding the ability of polymer to stabilize multiphase flow. At zero and low polymer concentrations, relatively long and wide fingers of injectant developed, leading to early water breakthrough and low recoveries. At increased polymer concentration, a much greater number of relatively fine fingers formed. The width-to-length ratio of these fingers was quite small, and the absolute length of fingers decreased. At a larger scale of observation, the displacement front appears to be stabilized; hence, recovery efficiency improved remarkably. Above a concentration of 1,500 ppm, plugging of the micromodel by polymer and lower oil recovery was observed for both polymer types. For tertiary polymer injection that begins at breakthrough of water, the severe fingers resulting from water injection are modified significantly. Fingers become wider and grow in the direction normal to flow as polymer solution replaces water. Apparently, improved sweep efficiency of viscous oils is possible (at this scale of investigation) even after waterflooding. The associative- and conventional-polymer solutions improved oil recovery by approximately the same amount. The associative polymers, however, showed more-stable displacement fronts in comparison to conventional-polymer solutions. © 2011 Society of Petroleum Engineers.
Behm M.,OMV Austria Exploration and Production GmbH
Geophysical Prospecting | Year: 2016
The analysis of seismic ambient noise acquired during temporary or permanent microseismic monitoring campaigns (e.g., improved/enhanced oil recovery monitoring, surveillance of induced seismicity) is potentially well suited for time-lapse studies based on seismic interferometry. No additional data acquisition required, ambient noise processing can be automatized to a high degree, and seismic interferometry is very sensitive to small medium changes. Thus there is an opportunity for detection and monitoring of velocity variations in a reservoir at negligible additional cost and effort. Data and results are presented from an ambient noise interferometry study applied to two wells in a producing oil field in Romania. Borehole microseismic monitoring on three component geophones was performed for four weeks, concurrent with a water-flooding phase for improved oil recovery from a reservoir in ca. 1 km depth. Both low-frequency (2 Hz-50 Hz) P- and S-waves propagating through the vertical borehole arrays were reconstructed from ambient noise by the virtual source method. The obtained interferograms clearly indicate an origin of the ambient seismic energy from above the arrays, thus suggesting surface activities as sources. It is shown that ambient noise from time periods as short as 30 seconds is sufficient to obtain robust interferograms. Sonic log data confirm that the vertical and horizontal components comprise first arrivals of P-wave and S-waves, respectively. The consistency and high quality of the interferograms throughout the entire observation period further indicate that the high-frequency part (up to 100 Hz) represents the scattered wave field. The temporal variation of apparent velocities based on first-arrival times partly correlates with the water injection rate and occurrence of microseismic events. It is concluded that borehole ambient noise interferometry in production settings is a potentially useful method for permanent reservoir monitoring due to its high sensitivity and robustness. © 2016 European Association of Geoscientists & Engineers.