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301.
Geostatistical seismic inversion for non‐stationary patterns using direct sequential simulation and co‐simulation 下载免费PDF全文
Hamid Sabeti Ali Moradzadeh Faramarz Doulati Ardejani Leonardo Azevedo Amilcar Soares Pedro Pereira Ruben Nunes 《Geophysical Prospecting》2017,65(Z1):25-48
Geostatistical seismic inversion methods are routinely used in reservoir characterisation studies because of their potential to infer the spatial distribution of the petro‐elastic properties of interest (e.g., density, elastic, and acoustic impedance) along with the associated spatial uncertainty. Within the geostatistical seismic inversion framework, the retrieved inverse elastic models are conditioned by a global probability distribution function and a global spatial continuity model as estimated from the available well‐log data for the entire inversion grid. However, the spatial distribution of the real subsurface elastic properties is complex, heterogeneous, and, in many cases, non‐stationary since they directly depend on the subsurface geology, i.e., the spatial distribution of the facies of interest. In these complex geological settings, the application of a single distribution function and a spatial continuity model is not enough to properly model the natural variability of the elastic properties of interest. In this study, we propose a three‐dimensional geostatistical inversion technique that is able to incorporate the reservoir's heterogeneities. This method uses a traditional geostatistical seismic inversion conditioned by local multi‐distribution functions and spatial continuity models under non‐stationary conditions. The procedure of the proposed methodology is based on a zonation criterion along the vertical direction of the reservoir grid. Each zone can be defined by conventional seismic interpretation, with the identification of the main seismic units and significant variations of seismic amplitudes. The proposed method was applied to a highly non‐stationary synthetic seismic dataset with different levels of noise. The results of this work clearly show the advantages of the proposed method against conventional geostatistical seismic inversion procedures. It is important to highlight the impact of this technique in terms of higher convergence between real and inverted reflection seismic data and the more realistic approximation towards the real subsurface geology comparing with traditional techniques. 相似文献
302.
The hyperbolic Radon transform has a long history of applications in seismic data processing because of its ability to focus/sparsify the data in the transform domain. Recently, deconvolutive Radon transform has also been proposed with an improved time resolution which provides improved processing results. The basis functions of the (deconvolutive) Radon transform, however, are time-variant, making the classical Fourier based algorithms ineffective to carry out the required computations. A direct implementation of the associated summations in the time–space domain is also computationally expensive, thus limiting the application of the transform on large data sets. In this paper, we present a new method for fast computation of the hyperbolic (deconvolutive) Radon transform. The method is based on the recently proposed generalized Fourier slice theorem which establishes an analytic expression between the Fourier transforms associated with the data and Radon plane. This allows very fast computations of the forward and inverse transforms simply using fast Fourier transform and interpolation procedures. These canonical transforms are used within an efficient iterative method for sparse solution of (deconvolutive) Radon transform. Numerical examples from synthetic and field seismic data confirm high performance of the proposed fast algorithm for filling in the large gaps in seismic data, separating primaries from multiple reflections, and performing high-quality stretch-free stacking. 相似文献
303.
Integration of geoelectric and hydrochemical approaches for delineation of groundwater potential zones in alluvial aquifer 下载免费PDF全文
Qaisar Mehmood Muhammad Arshad Muhammad Rizwan Shanawar Hamid Waqas Mehmood Muhammad Ansir Muneer Muhammad Irfan Lubna Anjum 《地下水科学与工程》2020,8(4):366-380
Geoelectric and hydrochemical approaches are employed to delineate the ground-water potential zones in District Okara, a part of Bari Doab, Punjab, Pakistan. Sixty-seven VES surveys are conducted with the Electrical Resistivity Meter. The resultant resistivity verses depth model for each site is estimated using computer-based software IX1D. Aquifer thickness maps and interpreted resistivity maps were generated from interpreted VES results. Dar-Zarrouk parameters, transverse resistance (TR), longitudinal conductance (SL) and anisotropy (λ) were also calculated from resistivity data to delineate the potential zones of aquifer. 70% of SL value is ≤3S, 30% of SL value is > 3S. According to SL and TR values, the whole area is divided into three potential zones, high, medium and low potential zones. The spatial distribution maps show that north, south and central parts of study area are marked as good potential aquifer zones. Longitudinal conductance values are further utilized to determine aquifer protective capacity of area. The whole area is characterized by moderate to good and up to some extent very good aquifer protective area on the basis of SL values. The groundwater samples from sixty-seven installed tube wells are collected for hydro-chemical analysis. The electrical conductivity values are determined. Correlation is then developed between the EC (μS/cm) of groundwater samples vs. interpreted aquifer resistivity showing R2 value 0.90. 相似文献
304.
Saleh Yousefi Hamid Reza Moradi Saskia Keesstra Hamid Reza Pourghasemi Oldrich Navratil Janet Hooke 《国际地球制图》2019,34(3):276-292
In the present study, we investigate the effects of urbanization growth on river morphology in the downstream part of Talar River, east of Mazandaran Province, Iran. Morphological and morphometric parameters in 10 equal sub-reaches were defined along a 11.5 km reach of the Talar River after land cover maps were produced for 1955, 1968, 1994, 2005 and 2013. Land cover types changed extremely during the study period. Residential lands were found to have increased in area by about 1631%, while forest land and riparian vegetation decreased in by approximately 99.9 and 96.2%, respectively. The results of morphometric and morphological factors showed that average channel width (W) for all 11.5 km of the study river decreased by 84% during the study period, while the flow length increased by about 2.14%. 相似文献
305.
Roshanravan Bijan Aghajani Hamid Yousefi Mahyar Kreuzer Oliver 《Natural Resources Research》2019,28(2):309-325
Natural Resources Research - Classification of spatial exploration data for exploration targeting using neuro-fuzzy models means that the many spatial values have to be simplified and assigned to a... 相似文献
306.
Roshanravan Bijan Aghajani Hamid Yousefi Mahyar Kreuzer Oliver 《Natural Resources Research》2019,28(3):1089-1105
Natural Resources Research - In this paper an improved prediction-area plot has been developed. This type of plot includes performance measures similar to other existing methods (receiver operating... 相似文献
307.
A new method for modeling wave propagation is described here, its application is discussed, and its results are compared with those obtained using the conventional correlation and unit impulse response methods. The method uses spectral analysis by minimizing the mean square values of the system input and output when subjected to a constraint, and is effective in detecting arrival times of incident and reflected waves and in revealing their relative amplitudes as well. The method is applied to simple models and to the strong motion records obtained at the TTRL (Koto-ku, Minamisuna) and Chiba vertical arrays during three earthquakes in Japan. The travel times evaluated by the NIOM method agree with the results obtained by the geophysical measurements of S-wave velocity at the sites. The method is also effective in showing the amplification property of shallow layers at the TTRL and Chiba sites. 相似文献
308.
Abbasi Hamid Delavar Majid Bigdeli Nalbandan Roya Hashemy Shahdany Mehdy 《Stochastic Environmental Research and Risk Assessment (SERRA)》2020,34(6):755-774
Stochastic Environmental Research and Risk Assessment - Adaptive planning in climate change condition is a significant challenge for effective management of water resources and agricultural... 相似文献
309.
310.
A late Pleistocene long pollen record from Lake Urmia, NW Iran 总被引:4,自引:0,他引:4
Morteza Djamali Jacques-Louis de Beaulieu Madjid Shah-hosseini Valrie Andrieu-Ponel Philippe Ponel Abdolhossein Amini Hossein Akhani Suzanne A.G. Leroy Lora Stevens Hamid Lahijani Simon Brewer 《Quaternary Research》2008,69(3):413-420
A palynological study based on two 100-m long cores from Lake Urmia in northwestern Iran provides a vegetation record spanning 200 ka, the longest pollen record for the continental interior of the Near East. During both penultimate and last glaciations, a steppe of Artemisia and Poaceae dominated the upland vegetation with a high proportion of Chenopodiaceae in both upland and lowland saline ecosystems. While Juniperus and deciduous Quercus trees were extremely rare and restricted to some refugia, Hippophaë rhamnoides constituted an important phanerophyte, particularly during the late last glacial period. A pronounced expansion in Ephedra shrub-steppe occurred at the end of the penultimate late-glacial period but was followed by extreme aridity that favoured an Artemisia steppe. Very high lake levels, registered by both pollen and sedimentary markers, occurred during the middle of the last glaciation and late part of the penultimate glaciation. The late-glacial to early Holocene transition is represented by a succession of Hippophaë, Ephedra, Betula, Pistacia and finally Juniperus and Quercus. The last interglacial period (Eemian), slightly warmer and moister than the Holocene, was followed by two interstadial phases similar in pattern to those recorded in the marine isotope record and southern European pollen sequences. 相似文献