Deep seismic measurements in caracas for the determination of the sedimentary thickness and seismic velocities a contribution to the seismic microzoning study

2016 ◽  
Keyword(s):  
Seismic Velocities ◽  
Seismic Microzoning ◽  
Seismic Measurements

SEISMIC VELOCITIES FROM SURFACE MEASUREMENTS

Geophysics ◽  
1955 ◽  
Vol 20 (1) ◽  
pp. 68-86 ◽  
Author(s):  
C. Hewitt Dix
Keyword(s):  
Accurate Determination ◽  
Careful Study ◽  
Seismic Velocities ◽  
Multiple Reflections ◽  
Seismic Reflection Data ◽  
Reflection Data ◽  
Surface Measurements ◽  
Secondary Objective ◽  
Interval Velocities

The purpose of this paper is to discuss field and interpretive techniques which permit, in favorable cases, the quite accurate determination of seismic interval velocities prior to drilling. A simple but accurate formula is developed for the quick calculation of interval velocities from “average velocities” determined by the known [Formula: see text] technique. To secure accuracy a careful study of multiple reflections is necessary and this is discussed. Although the principal objective in determining velocities is to allow an accurate structural interpretation to be made from seismic reflection data, an important secondary objective is to get some lithological information. This is obtained through a correlation of velocities with rock type and depth.

Determination of sub‐seismic fracturation using azimuthal variations of seismic velocities

2004 ◽  
Author(s):  
Berthet Philippe ◽  
Philippe Julien ◽  
Jean‐Pierre Dunand ◽  
Jean Arnaud
Keyword(s):  
Seismic Velocities

scholarly journals Determination of Temperature on Ice Caps by Seismic Methods

1968 ◽  
Vol 7 (50) ◽  
pp. 333-335 ◽  
Author(s):  
F. Thyssen
Keyword(s):  
Empirical Formula ◽  
Temperature Measurements ◽  
Seismic Velocities ◽  
P Waves ◽  
Ice Caps ◽  
Seismic Methods ◽  
The Mean

An empirical formula, derived by the author for the seismic velocities of P waves in glaciers and ice caps, is used to determine the temperatures which can be deduced from the maximum and the mean vertical velocities. With the aid of several examples from previous publications, these temperatures are discussed and, as far as they are available, direct temperature measurements are compared with the derived temperatures.

scholarly journals Influence of microheterogeneity on effective stress law for elastic properties of rocks

Geophysics ◽  
2008 ◽  
Vol 73 (1) ◽  
pp. E7-E14 ◽  
Author(s):  
Radim Ciz ◽  
Anthony F. Siggins ◽  
Boris Gurevich ◽  
Jack Dvorkin
Keyword(s):  
Effective Stress ◽  
Seismic Data ◽  
Elastic Moduli ◽  
Seismic Velocity ◽  
Time Lapse ◽  
Seismic Velocities ◽  
Laboratory Measurements ◽  
Hydrocarbon Production ◽  
Stress Coefficient ◽  
Seismic Measurements

Understanding the effective stress coefficient for seismic velocity is important for geophysical applications such as overpressure prediction from seismic data as well as for hydrocarbon production and monitoring using time-lapse seismic measurements. This quantity is still not completely understood. Laboratory measurements show that the seismic velocities as a function of effective stress yield effective stress coefficients less than one and usually vary between 0.5 and 1. At the same time, theoretical analysis shows that for an idealized monomineral rock, the effective stress coefficient for elastic moduli (and therefore also for seismic velocities) will always equal one. We explore whether this deviation of the effective stress coefficient from unity can be caused by the spatial microheterogeneity of the rock. The results show that only a small amount (less than 1%) of a very soft component is sufficient to cause this effect. Such soft material may be present in grain contact areas of many rocks and may explain the variation observed experimentally.

scholarly journals Determination of Temperature on Ice Caps by Seismic Methods

1968 ◽  
Vol 7 (50) ◽  
pp. 333-335
Author(s):  
F. Thyssen
Keyword(s):  
Empirical Formula ◽  
Temperature Measurements ◽  
Seismic Velocities ◽  
P Waves ◽  
Ice Caps ◽  
Seismic Methods ◽  
The Mean

An empirical formula, derived by the author for the seismic velocities of P waves in glaciers and ice caps, is used to determine the temperatures which can be deduced from the maximum and the mean vertical velocities. With the aid of several examples from previous publications, these temperatures are discussed and, as far as they are available, direct temperature measurements are compared with the derived temperatures.

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