Ultrasonic Imaging for the Seismic Model Fault Plane

1989 ◽  
pp. 715-722
Author(s):  
Yuan Yi-Quan ◽  
Yin Ging-Rui ◽  
Shi Bing-Wen ◽  
Shen Shou-Peng
Geophysics ◽  
1965 ◽  
Vol 30 (1) ◽  
pp. 72-86 ◽  
Author(s):  
Delbert Ray Harper

The ultrasonic reflection‐diffraction complexes from simple rectangular configurations are compared for various two‐dimensional seismic models. These models represent simple faults and faults with sharp folds for two‐ and three‐layer cases. In particular, the model with cavity and models with extrusions (with square corners) represent simple faults in two‐ and three‐layer cases, respectively. Similarly the model with cavity and models with recesses (with curved corners) correspond to a sharp fold in the vicinity of the fault in two‐ and three‐layer cases. Masking of the fault plane by overlapping of diffraction upon reflection events is shown to be much more prominent for the simple fault with sharp fold than for a simple fault in both the two‐ and three‐layer cases. For the three‐layer cases, models employing recesses and extrusions have vertical dimensions less than the wavelength of the transmitted pulse; hence, waveforms for these models are more complicated due to composition of wavelets from the first interface with those from the second interface. Differences between the models were explained by synthetic waveforms derived using superposition of diffraction wavelets for the two‐layer cases (cavity models), and overlapping wavelets for the three‐layer cases (models with recesses and extrusions).


Author(s):  
Muhammad Akram Qureshi ◽  
Shahid Ghazi ◽  
Muhammad Riaz ◽  
Shakeel Ahmad

AbstractSeismic as well as structural techniques were exploited to elucidate the subsurface structure of the Zamzama area that directly led to petroleum system. Zamzama gas field is located in the Kirthar Foredeep, southern Indus Basin, Pakistan. The current research is based on data scrutinized systematically through eight seismic lines (796-JH-01, 02, 03, 07, 10, GHPK-98A-32, 34 and 40) and three wells (Zamzama-02, 03 and 05) drilled in the Zamzama field. Seismic interpretation reveals that Tertiary and Cretaceous sequence is deformed by transpressive tectonics, and a reverse fault is located from 400 to 3400 ms deep on the vertical seismic section. The hanging wall moves up along the fault plane under the action of eastward directed stress as a result an extensive North–South oriented and eastward verging thrusted anticline is formed. Stratigraphically, area encompasses well-developed Mesozoic–Cenozoic sequence. The Late Cretaceous Pab Formation is well-known primary hydrocarbon reservoir capped by the shale of the Paleocene Ranikot Formation that acts as a regional seal rock. The Jurassic and Cretaceous shales of the Sember and Goru formations are substantiated as main source rocks. The execution and portrayal of seismic and subsurface geological data provide the clues that area contains appropriate petroleum play potential. Present study suggests a worthwhile regional geo-seismic model that might be significant for future exploration in the Kirther Foredeep and adjacent areas.


Author(s):  
Guangzhi Dai ◽  
Zhiyong He ◽  
Hongwei Sun

Background: This study is carried out targeting the problem of slow response time and performance degradation of imaging system caused by large data of medical ultrasonic imaging. In view of the advantages of CS, it is applied to medical ultrasonic imaging to solve the above problems. Objective: Under the condition of satisfying the speed of ultrasound imaging, the quality of imaging can be further improved to provide the basis for accurate medical diagnosis. Methods: According to CS theory and the characteristics of the array ultrasonic imaging system, block compressed sensing ultrasonic imaging algorithm is proposed based on wavelet sparse representation. Results: Three kinds of observation matrices have been designed on the basis of the proposed algorithm, which can be selected to reduce the number of the linear array channels and the complexity of the ultrasonic imaging system to some extent. Conclusion: The corresponding simulation program is designed, and the result shows that this algorithm can greatly reduce the total data amount required by imaging and the number of data channels required for linear array transducer to receive data. The imaging effect has been greatly improved compared with that of the spatial frequency domain sparse algorithm.


2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Brijesh K. Bansal ◽  
Kapil Mohan ◽  
Mithila Verma ◽  
Anup K. Sutar

AbstractDelhi region in northern India experiences frequent shaking due to both far-field and near-field earthquakes from the Himalayan and local sources, respectively. The recent M3.5 and M3.4 earthquakes of 12th April 2020 and 10th May 2020 respectively in northeast Delhi and M4.4 earthquake of 29th May 2020 near Rohtak (~ 50 km west of Delhi), followed by more than a dozen aftershocks, created panic in this densely populated habitat. The past seismic history and the current activity emphasize the need to revisit the subsurface structural setting and its association with the seismicity of the region. Fault plane solutions are determined using data collected from a dense network in Delhi region. The strain energy released in the last two decades is also estimated to understand the subsurface structural environment. Based on fault plane solutions, together with information obtained from strain energy estimates and the available geophysical and geological studies, it is inferred that the Delhi region is sitting on two contrasting structural environments: reverse faulting in the west and normal faulting in the east, separated by the NE-SW trending Delhi Hardwar Ridge/Mahendragarh-Dehradun Fault (DHR-MDF). The WNW-ESE trending Delhi Sargoda Ridge (DSR), which intersects DHR-MDF in the west, is inferred as a thrust fault. The transfer of stress from the interaction zone of DHR-MDF and DSR to nearby smaller faults could further contribute to the scattered shallow seismicity in Delhi region.


2021 ◽  
pp. 129917
Author(s):  
Yeying Wang ◽  
Yang Liu ◽  
Jing-e Zhou ◽  
Lizhou Lin ◽  
Chao Jia ◽  
...  

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