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Abdolrahim Javaherian 《地震学报(英文版)》1994,7(3):397-407
Ｇｒｉｄｄｉｓｐｅｒｓｉｏｎｉｎｇｅｎｅｒａｔｉｎｇｆｉｎｉｔｅ－ｄｉｆｆｅｒｅｎｃｅｓｓｙｎｔｈｅｔｉｃｓｅｉｓｍｏｇｒａｍｓＡｂｄｏｌｒａｈｉｍＪａｖａｈｅｒｉａｎ（ＩｎｓｔｉｔｕｔｅｏｆＧｅｏｐｈｙｓｉｃｓ，ｔｈｅＵｎｉｖｅｒｓｉｔｙｏｆＴｅｈ... 相似文献
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Abdolrahim JAVAHERIAN 《地震学报(英文版)》1994,7(1):23-31
Ｔｈｅｏｐｔｉｍｕｍｓｏｕｒｃｅ－ｔｉｍｅｆｕｎｃｔｉｏｎｆｏｒｇｅｎｅｒａｔｉｎｇｆｉｎｉｔｅ－ｄｉｆｆｅｒｅｎｃｅｓｙｎｔｈｅｔｉｃｓｅｉｓｍｏｇｒａｍｓＡｂｄｏｌｒａｈｉｍＪＡＶＡＨＥＲＩＡＮ（ＩｎｓｔｉｔｕｔｅｏｆＧｅｏｐｈｙｓｉｃｓ，ｔｈｅ... 相似文献
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Abdi-Dehkordi Mehri Bozorg-Haddad Omid Salavitabar Abdolrahim Mohammad-Azari Sahar Goharian Erfan 《Natural Hazards》2021,108(3):2543-2567
Natural Hazards - Decreasing flood damages in a basin and achieving sustainable development reveal the necessity of integrated management of flood. Integrated flood management requires the... 相似文献
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Seyyed Ali Fa’al Rastegar Abdolrahim Javaherian Naser Keshavarz Farajkhah Mehrdad Soleimani Monfared Abbas Zarei 《应用地球物理》2016,13(2):353-363
We modified the common-offset–common-reflection-surface (COCRS) method to attenuate ground roll, the coherent noise typically generated by a low-velocity, low-frequency, and high-amplitude Rayleigh wave. The COCRS operator is based on hyperbolas, thus it fits events with hyperbolic traveltimes such as reflection events in prestack data. Conversely, ground roll is linear in the common-midpoint (CMP) and common-shot gathers and can be distinguished and attenuated by the COCRS operator. Thus, we search for the dip and curvature of the reflections in the common-shot gathers prior to the common-offset section. Because it is desirable to minimize the damage to the reflection amplitudes, we only stack the multicoverage data in the ground-roll areas. Searching the CS gathers before the CO section is another modification of the conventional COCRS stacking. We tested the proposed method using synthetic and real data sets from western Iran. The results of the ground-roll attenuation with the proposed method were compared with results of the f–k filtering and conventional COCRS stacking after f–k filtering. The results show that the proposed method attenuates the aliased and nonaliased ground roll better than the f–k filtering and conventional CRS stacking. However, the computation time was higher than other common methods such as f–k filtering. 相似文献
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Seismic channel edge detection using 3D shearlets—a study on synthetic and real channelised 3D seismic data 
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下载免费PDF全文 Haleh Karbalaali Abdolrahim Javaherian Stephan Dahlke Rafael Reisenhofer Siyavash Torabi 《Geophysical Prospecting》2018,66(7):1272-1289
Automatic feature detection from seismic data is a demanding task in today's interpretation workstations. Channels are among important stratigraphic features in seismic data both due to their reservoir capability or drilling hazard potential. Shearlet transform as a multi‐scale and multi‐directional transformation is capable of detecting anisotropic singularities in two and higher dimensional data. Channels occur as edges in seismic data, which can be detected based on maximizing the shearlet coefficients through all sub‐volumes at the finest scale of decomposition. The detected edges may require further refinement through the application of a thinning methodology. In this study, a three‐dimensional, pyramid‐adapted, compactly supported shearlet transform was applied to synthetic and real channelised, three‐dimensional post‐stack seismic data in order to decompose the data into different scales and directions for the purpose of channel boundary detection. In order to be able to compare the edge detection results based on three‐dimensional shearlet transform with some famous gradient‐based edge detectors, such as Sobel and Canny, a thresholding scheme is necessary. In both synthetic and real data examples, the three‐dimensional shearlet edge detection algorithm outperformed Sobel and Canny operators even in the presence of Gaussian random noise. 相似文献
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The propagation of seismic waves through a saturated reservoir compresses the fluid in the pore spaces. During this transition, parts of seismic energy would be attenuated because of intrinsic absorption. Rock physics models make the bridge between the seismic properties and petrophysical reality in the earth. Attenuation is one of the significant seismic attributes used to describe the fluid behaviour in the reservoirs. We examined the core samples using ultrasonic experiments at the reservoir conditions. Given the rock properties of the carbonate reservoir and experiment results, the patchy saturation mechanism was solved for substituted fluid using the theory of modulus frequency. The extracted relationship between the seismic attenuation and water saturation was used in time–frequency analysis. We performed the peak frequency method to estimate the Q factor in the Gabor domain and determined the water saturation based on the computed rock physics model. The results showed how the probable fault in the reservoir has stopped the fluid movement in the reservoir and caused touching the water‐bearing zone through drilling. 相似文献
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Maryam Sadat Mirkamali Abdolrahim Javaherian Hossein Hassani Mohammad Reza Saberi Seyed Abolfazl Hosseini 《Geophysical Prospecting》2020,68(7):2195-2216
Quality, availability and consistency of the measured and interpreted well log data are essential in the seismic reservoir characterization methods, and seismic petrophysics is the recommended workflow to achieve data consistency between logs and seismic domains. This paper uses seismic petrophysics workflow to improve well logs and pore geometry interpretations for an oil carbonate reservoir in the Fahliyan Formation in the southwest of Iran. The petrophysical interpreted well logs, rock physics and well-to-seismic tie analysis are integrated into the proposed workflow. Our implementation incorporates revising petrophysical well log interpretations and updating pore geometry characteristics to obtain a better well-tie quality. We first propose an improved pore-type characterization approach based on both P- and S-wave velocities for quantifying pore geometry. Then, seismic logs are estimated accordingly, and the results are used in the well-to-seismic analysis. The quality of the well-tie is improved, furthermore, by iterating on the petrophysical interpreted well logs as well as the calculated pore geometries. For the intervals with high-quality data, our workflow improves the consistency between the results of measured and modelled seismic logs. For the intervals with problematic well logs, the application of our proposed workflow results in the successful replacement of the poor data and subsequently leads to an improved wavelet estimation and well-tie results. In both cases, a higher quantification of pore geometries is achieved, which in turn is confirmed by the core images and formation micro-imager analysis. 相似文献
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Abdolrahim Jalali Donatello Cardone Peyman Narjabadifam 《Bulletin of Earthquake Engineering》2011,9(2):657-673
A modern base isolation system is proposed for the aseismic control of structures. It is composed of steel-Teflon Flat Sliding
Bearings, to support the gravity loads while allowing large horizontal displacements, and simply connected Shape Memory Alloy
(SMA) truss elements, to provide the necessary horizontal stiffness as well as a proper restoring capability. The system is
referred to as Smart Restorable Sliding Base Isolation System (SRSBIS). Depending on the arrangement of the auxiliary SMA
elements, SRSBIS can exhibit a geometric nonlinearity in addition to the nonlinearity of materials. In this paper, the dynamic
characteristics of SRSBIS are first examined in terms of the force-displacement behavior, effective period of vibration, and
equivalent damping. After that, the earthquake response of buildings equipped with SRSBIS, designed in accordance with a direct
displacement-based approach, is evaluated through extensive nonlinear time-history analyses. The effects of the design parameters
on the system behavior are then investigated within a comprehensive parametric study and the seismic performances of SRSBIS
are finally compared to those of similar practical isolation systems. Based on the results, it is shown that SRSBIS can be
suitably used for the seismic protection of structures. 相似文献
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