The Experts below are selected from a list of 360 Experts worldwide ranked by ideXlab platform
Michael S Zhdanov - One of the best experts on this subject based on the ideXlab platform.
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modelling the wave phenomena in acoustic and elastic media with sharp variations of physical properties using the grid characteristic method
Geophysical Prospecting, 2018Co-Authors: A V Favorskaya, Michael S Zhdanov, N I Khokhlov, I B PetrovAbstract:This paper introduces a novel method of modelling acoustic and elastic wave propagation in inhomogeneous media with sharp variations of physical properties based on the recently developed grid-characteristic method which considers different types of waves generated in inhomogeneous linear-elastic media (e.g., longitudinal, transverse, Stoneley, Rayleigh, scattered PP-, SS-waves, and converted PS- and SP-waves). In the framework of this method, the problem of solving acoustic or elastic wave equations is reduced to the interpolation of the solutions, determined at earlier time, thus avoiding a direct solution of the large systems of linear equations required by the FD or FE methods. We apply the grid-characteristic method to compare wave phenomena computed using the acoustic and elastic wave equations in geological medium containing a Hydrocarbon Reservoir or a fracture zone. The results of this study demonstrate that the developed algorithm can be used as an effective technique for modelling wave phenomena in the models containing Hydrocarbon Reservoir and/or the fracture zones, which are important targets of seismic exploration.
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3d controlled source electromagnetic modeling in anisotropic medium using edge based finite element method
Computers & Geosciences, 2014Co-Authors: Hongzhu Cai, Bin Xiong, Muran Han, Michael S ZhdanovAbstract:This paper presents a linear edge-based finite element method for numerical modeling of 3D controlled-source electromagnetic data in an anisotropic conductive medium. We use a nonuniform rectangular mesh in order to capture the rapid change of diffusive electromagnetic field within the regions of anomalous conductivity and close to the location of the source. In order to avoid the source singularity, we solve Maxwell's equation with respect to anomalous electric field. The nonuniform rectangular mesh can be transformed to hexahedral mesh in order to simulate the bathymetry effect. The sparse system of finite element equations is solved using a quasi-minimum residual method with a Jacobian preconditioner. We have applied the developed algorithm to compute a typical MCSEM response over a 3D model of a Hydrocarbon Reservoir located in both isotropic and anisotropic mediums. The modeling results are in a good agreement with the solutions obtained by the integral equation method. HighlightsThis paper develops a novel formulation of the edge-based finite element method for 3D modeling of marine CSEM data in anisotropic conductive medium.The method uses the edge-based vector basis functions, which automatically enforce the divergence free conditions for electric and magnetic fields.The developed method is effective in modeling the seafloor bathymetry using hexahedral mesh.
Paola Ronchi - One of the best experts on this subject based on the ideXlab platform.
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continental carbonates as a Hydrocarbon Reservoir an analog case study from the travertine of saturnia italy
AAPG Bulletin, 2015Co-Authors: Paola Ronchi, Francesco CrucianiAbstract:The Pleistocene Saturnia travertine (central Italy) represents a possible analog of the pre-salt continental carbonate Reservoirs discovered in the Santos and other basins in the South Atlantic margin of Brazil. Two subhorizontal travertine tabular bodies, several tens of meters thick and extending over an area of (), have been studied in two quarries. Facies variations and associated petrophysical properties were reconstructed applying a multidisciplinary approach. The Saturnia travertine, formed from a warm water spring, is composed of various stacked carbonate banks, separated by subaerial erosive phases and paleosols. The lacustrine tabular bodies, terraces, and sills are made of crystalline crust, shrub, pisoid, paper-thin raft, coated bubble, reed, and lithoclast-breccia facies. The (from +4‰ to +8‰) supports an interpreted volcanic mantle source, whereas, the (from −9‰ to −5‰) is in agreement with warm meteoric waters. The ratio isotopic signature indicates a carbonate from dissolution of deep-seated carbonates. The facies Reservoir properties were studied via porosity and permeability analysis of plugs, three-dimensional x-ray computer tomography, as well as image analysis on microscale under thin section and macroscale on large rock slabs to define various porosity indices. A strong heterogeneity of the petrophysical properties and variable connectivity were observed (porosity from 4% to 30% and permeability up to hundreds of md), but no compartmentalization of the carbonate bodies is present.
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hydrothermal dolomitization in platform and basin carbonate successions during thrusting a Hydrocarbon Reservoir analogue mesozoic of venetian southern alps italy
Marine and Petroleum Geology, 2012Co-Authors: Paola Ronchi, Daniele Masetti, Stefano Tassan, Davide CamocinoAbstract:Abstract The Early Jurassic dolomitized carbonates in the Venetian Alp, represent a surface analogue of the Hydrocarbon exploration targets in Adriatic offshore and Po Plain, Italy. Dolomitization affected the carbonate platform of Monte Zugna Formation (Lower Jurassic) and the Neptunian dikes breccia in the pelagic Maiolica Formation (Uppermost Jurassic–Lower Cretaceous) improving the poro-perm characteristics. Petrography, stable isotope, strontium isotope ratio, trace element and fluid inclusion analyses were carried out on samples from the Monte Grappa Anticline, which is the direct analogue for subsurface. The petrographic analyses showed a first pervasive, replacement dolomitization phase (D1) followed by volumetrically less important dolomite cement precipitation phases (D2, D3, DS). The same, quite wide range of oxygen isotope (−9 to −2‰ V-PDB) is observed in all dolomite types. The δ 13 C range is in the positive field of marine derived carbonate (from +0.5 to +3.2‰ PDB). The trace element analysis showed a slight enrichment in Fe and Mn contents in the Monte Zugna dolostones with respect the original limestone. The same dolomite precipitation temperature (up to 105 °C Th) was observed in the replacement and cement dolomites, suggesting a unique dolomitization event. This temperature, largely higher than the maximum burial temperature (about 50 °C), supports a hydrothermal origin of the dolomitizing fluids, which had a seawater to brackish composition. The data collected suggest a hydrothermal dolomitization occurring during to the South Alpine thrusting according to the “squeegee model”. The interpretation is consistent with the dolomitization model proposed for similar Jurassic successions in the Central Southern Alps. This study indicates that the deformed foreland and thrust fold belts carbonates in Po Plain and Adriatic offshore are suitable to be dolomitized, and therefore reflect an efficient Hydrocarbon exploration play.
Aliyuda Ali - One of the best experts on this subject based on the ideXlab platform.
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data driven based investigation of pressure dynamics in underground Hydrocarbon Reservoirs
Energy Reports, 2021Co-Authors: Aliyuda Ali, Lingzhong GuoAbstract:Abstract The process of storing natural gas in geological formations involves applying pressure to force the gas into and out of the porous and permeable Reservoir. In response to gas extraction/withdrawal and storage/injection, the Reservoir compresses and expands as a major consequences of fluid pore pressure variations. The major challenge associated with this type of energy systems is learning the pore pressure variations within the grid as fluid is being injected and/or withdrawn. As such, it is essential to identify a realistic model that accounts for the pore pressure variations at any point in time. In this paper, we present a data-driven technique called Dynamic Mode Decomposition (DMD) to investigate the pressure dynamics of an underground Hydrocarbon Reservoir model in relation to natural gas injection/storage. For demonstration purpose, we first implement a Hydrocarbon Reservoir model using a benchmark data of the first Society of Petroleum Engineers (SPE1) Comparative Solution Project. Applying DMD to a pressure field data of the simulated Reservoir model, we show that DMD is capable of approximating the average Reservoir pressure change and pore pressure variations within the Reservoir grid over time with up to 99% accuracy. Given that depleted Reservoirs are already developed Hydrocarbon Reservoirs, we conclude that DMD could serve as a reliable tool for fast evaluation of pressure dynamics of underground natural gas storage given its low complexity and insignificant loss of prediction accuracy.
Amir H Mohammadi - One of the best experts on this subject based on the ideXlab platform.
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toward an intelligent approach for determination of saturation pressure of crude oil
Fuel Processing Technology, 2013Co-Authors: Amir Farasat, Farhad Gharagheizi, Milad Arabloo, Amin Shokrollahi, Amir H MohammadiAbstract:Abstract Bubble point pressure is a crucial PVT parameter of Reservoir fluids, which has a significant effect on oil field development strategies, Reservoir evaluation and production calculations. This communication presents a new mathematical model to calculate the saturation pressures of crude oils as a function of temperature, Hydrocarbon and non-Hydrocarbon Reservoir fluid compositions, and characteristics of the heptane-plus fraction. The model was developed and tested using a total set of 130 experimentally measured compositions and saturation pressures of crude oil samples from different geographical locations covering wide ranges of crude oil properties and Reservoir temperatures. In-depth comparative studies have been carried out between this new model and five well known predictive models for estimation of saturation pressure of crude oils. The results show that the developed model is more accurate and reliable with the average absolute relative deviation of 4.7% and correlation coefficient of 0.992. In addition, it is shown that the proposed model correctly captures the physical trend of changing the saturation pressure as a function of the input variables. Finally, the applicability domains of the proposed model and quality of the existing experimental data were examined by outlier diagnostics.
Xiangyang Li - One of the best experts on this subject based on the ideXlab platform.
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water saturation effects on elastic wave attenuation in porous rocks with aligned fractures
Geophysical Journal International, 2014Co-Authors: Kelvin Amalokwu, Angus I Best, Jeremy Sothcott, M G Chapman, T A Minshull, Xiangyang LiAbstract:SUMMARY Elastic wave attenuation anisotropy in porous rocks with aligned fractures is of interest to seismic remote sensing of the Earth’s structure and to Hydrocarbon Reservoir characterization in particular. We investigated the effect of partial water saturation on attenuation in fractured rocks in the laboratory by conducting ultrasonic pulse-echo measurements on synthetic, silicacemented, sandstones with aligned penny-shaped voids (fracture density of 0.0298 ± 0.0077), chosen to simulate the effect of natural fractures in the Earth according to theoretical models. Our results show, for the first time, contrasting variations in the attenuation (Q −1 )o fP and S