... that, for a wide range of realistic petrophysical parameters for sandstones partially saturated with water and gas, the quality factor, Q (wave attenuation can be defined as Q -1), can be as small as 2 in the interlayer-flow model. They applied the interlayer-flow model to study the reflection coefficient, R...

... a potentially important source of information for determining subsurface properties of relevance to reservoir characterization. Series expansions of absorptive reflection coefficients about small parameter contrasts and incidence angles can be used to separately estimate variations in anelastic target...

... model (Dutta and Seriff, 1979). Moreover, the stratified layering simplified the numerical modeling. For model 1, the reservoir is consolidated sand, and the porosity and permeability are small. In the amplitude versus incident-angle domain, Figure 2a shows that the reflection magnitude decreases...

.... Model I Figure 1 shows the case of fixed porosity and varying gas saturation and Figure 2 of varying porosity and fixed gas saturation. From Figure 1 we can see that when gas saturation is sufficiently small the velocity and reflection coefficient are independent on frequency and the attenuation is weak...

... reflection coefficient arma deconvolution filter impedance reservoir characterization rms error conventional deconvolution frequency A unified framework for the deconvolution of traces of non-white reflectivity M. M. Saggaf*, Massachusetts Institute of Technology Summary The assumption of white...

... the layer in two simulated cases: (1) a dry layer with some residual water saturation and (2) a water-saturated layer with a small amount of air trapped in the material. Their layer was 7-mm thick, with porosity of around 32 % and permeability of 300 mD. They used reflection seismic acquisition geometry...

... for a gas reservoir. Although the attenuation occurs, it is very minor and thus for a real seismic dataset, would most likely be drowned by noise and/or other types of attenuation. The same applies to the frequency dependency of the normal-incidence reflection coefficient as it is too small to be seen...

... shifts to lower frequencies as the center of the timewindow shifts to later times. Using localisation theory, Sheng, White. and Nalr (1988), apply this formula to the study of sonic log data and obtain quantitative information on the attenuation in stratified lithology. When a(r is small, the transport...

... propagates gives rise to a population of multiples which have the same form and travel in the same direction as the main but which are reduced in amplitude and delayed in time and Anstey, 1971). If the reflections are too small and to closely spaced to be individually resolved then their effect is perceived...

... phase doesn t meet the steady state in the iteratively process. Since a very small change in the time-depth function can cause a huge difference of the wavelet phase. Figure 1 shows the proposed workflow used to determine the phase of wavelet in this paper. The workflow is an iteratively procedures...

... extraction methods. For example, given a small-angle small-contrast data set with a high signal-to-noise ratio (i.e., with amplitudes varying linearly with x), the intercept-gradient method results in a very small estimation error because the span of the corresponding 1 and 2 in (8) is essentially...

... as incident angle increase. In frequency domain, it is hard to tell coefficients variation when frequency increases from 1 Hz to 80 Hz, as a result of small attenuation and velocity dispersion. However, from Figure 4 and 5, the mid-consolidated sand model and unconsolidated sand model, one can easily tell...

... of corroded region there is now disk-shaped perforation. Since formation is modeled as impermeable elastic space then effects related to fluid mobility between borehole and formation are neglected and only reflection due to geometric (diameter) changes are considered. Real perforation represents a small...

..., two kinds of reflection coefficients can be distin- guished: those relating to interfaces and those relating to heterogeneities. On several neighboring mirror points, the reflection coefficients for a single interface are considered the realization of a single random variable with small vari- ance...

... (France). Figure-5 shows a two-dimensional plot of the cross correlation coefficient obtained from the GPK2 drilling signal. High correlation at (delay, angle0, 0) is the auto correlation of the directly arriving SV wave, and the relatively small maxima suggest the existence of reflected waves. References...

... The magnitude of apparent attenuation is dependent on the nature of small-scale fluctuations in the earth parameters. In principle, it may be possible to estimate statistical param- eters characterising the sedimentary layering from measured apparent attenuation. It is difficult to estimate attenuation from...

... in time and that any competent reflectivity whitening filter would have to be very long. Usually, in seismic idealized, analysis, an often zero-phase, band-pass wavelet is superposed on the deconvolved reflectivity sequence in order to average out its small-interval variability and produce a more...

... responses. Conclusions With the application of a full color scheme, the color-coded lithologic section has proven to be an invaluable tool for delineating those hydrocarbon reserves that have small reflection coefficients with respect to the background reflectors. These are classified as Class 2 AVO...

... the reflecting surface, whereas and are coefficients of anisotropy by Tomsen (1986). Notations like in (11 ,a) are used for Z and u as well; jumps a, and so on are considered small. To tie reflection coefficients (11,a) with external pressure, consider (4). Taking into account the connection between model...

... with a 4 msec sample interval. If reflection coefficient sequences were white they should have an autocorrelation function which resembles the one on Figure 1. Figure 2 shows a typical autocorrelation function of reflection coefficients. These reflection coefficients were computed from a depth-to-time...