3-D Salt and Overthrust Seismic Models

Keyword(s):  
1966 ◽  
Vol 10 (3) ◽  
pp. 259-270 ◽  
Author(s):  
Vlastislav Červený
Keyword(s):  

Geophysics ◽  
1997 ◽  
Vol 62 (5) ◽  
pp. 1365-1368
Author(s):  
M. Boulfoul ◽  
Doyle R. Watts

The petroleum exploration industry uses S‐wave vertical seismic profiling (VSP) to determine S‐wave velocities from downgoing direct arrivals, and S‐wave reflectivities from upgoing waves. Seismic models for quantitative calibration of amplitude variation with offset (AVO) data require S‐wave velocity profiles (Castagna et al., 1993). Vertical summations (Hardage, 1983) of the upgoing waves produce S‐wave composite traces and enable interpretation of S‐wave seismic profile sections. In the simplest application of amplitude anomalies, the coincidence of high amplitude P‐wave reflectivity and low amplitude S‐wave reflectivity is potentially a direct indicator of the presence of natural gas.


Geophysics ◽  
1990 ◽  
Vol 55 (9) ◽  
pp. 1166-1182 ◽  
Author(s):  
Irshad R. Mufti

Finite‐difference seismic models are commonly set up in 2-D space. Such models must be excited by a line source which leads to different amplitudes than those in the real data commonly generated from a point source. Moreover, there is no provision for any out‐of‐plane events. These problems can be eliminated by using 3-D finite‐difference models. The fundamental strategy in designing efficient 3-D models is to minimize computational work without sacrificing accuracy. This was accomplished by using a (4,2) differencing operator which ensures the accuracy of much larger operators but requires many fewer numerical operations as well as significantly reduced manipulation of data in the computer memory. Such a choice also simplifies the problem of evaluating the wave field near the subsurface boundaries of the model where large operators cannot be used. We also exploited the fact that, unlike the real data, the synthetic data are free from ambient noise; consequently, one can retain sufficient resolution in the results by optimizing the frequency content of the source signal. Further computational efficiency was achieved by using the concept of the exploding reflector which yields zero‐offset seismic sections without the need to evaluate the wave field for individual shot locations. These considerations opened up the possibility of carrying out a complete synthetic 3-D survey on a supercomputer to investigate the seismic response of a large‐scale structure located in Oklahoma. The analysis of results done on a geophysical workstation provides new insight regarding the role of interference and diffraction in the interpretation of seismic data.


2021 ◽  
Author(s):  
Bing Xia ◽  
Irina Artemieva ◽  
Hans Thybo

<p>We present a thermal model for the lithosphere in Tibet and adjacent regions based on the new thermal isostasy method and our compilation of the Moho depth based on published seismic models. The predicted surface heat flow is in agreement with the few available, reliable borehole measurements. Cratonic-type cold and thick lithosphere (200-240 km) with a surface heat flow of 40-50 mW/m<sup>2</sup> typifies the Tarim craton, the north-western Yangtze craton, and most of the Lhasa Block that is possibly refrigerated by underthrusting Indian lithosphere. The thick lithosphere of the Lhasa block extends further north in its western and eastern segments than in its central section. We identify a North Tibet anomaly with a thin (<80 km) lithosphere and high surface heat flow (>80-100 mW/m<sup>2</sup>), possibly associated with the removal of lithospheric mantle and asthenospheric upwelling. Other parts of Tibet have an intermediate lithosphere thickness of 120-160 km and a surface heat flow of 45-60 mW/m<sup>2</sup>, with a patchy style in eastern Tibet. In the Qaidam deep sedimentary basin the lithosphere is about 100-120 km thick. The heterogeneous thermal lithosphere beneath Tibet suggests an interplay of several mechanisms as the driver of the observed uplift.</p>


Author(s):  
O.O. Glukhov ◽  
A.I. Kompanets ◽  
A.V. Antsiferov ◽  
V.A. Antsiferov ◽  
L.A. Kamburova

Sign in / Sign up

Export Citation Format

Share Document