The Helium abundance in the solar envelope is one of the most important seismic observables. We investigate the accuracy of its determination taking into account uncertainties in the data and in the inversion procedure. Our best value for the helium abundance in the photosphere is Y = 0.248. The estimated uncertainty of 0.002 is dominated by uncertainties in the inversion. This does not account...

Algorithms for inversion of seismic prestack AVO data into lithology-fluid classes in a vertical profile are evaluated. The inversion is defined in a Bayesian setting where the prior model for the lithology-fluid classes is a Markov chain, and the likelihood model relates seismic data and elastic material properties to these classes. The likelihood model is approximated such that the posterior ...

Heavy crude oil is known as oil that is highly viscous and of a higher density than that of conventional oil. Sand reservoirs containing heavy oil generally consist of unconsolidated sediments deposited at a shallow burial depth, with high porosity and permeability. In seismic exploration, acoustic impedance inversion is a commonly used tool in reservoir prediction. However, due to the unconsol...

As part of a joint Sino-U.S. research project to study the deep structure of the Tibetan plateau, 11 broadband digital seismic recorders were deployed on the plateau for one year of passive seismic recording. In this report we use teleseimic P waveforms to study the seismic velocity structure of crust and upper mantle under three stations by receiver function inversion. The receiver function is...

We consider numerical solution methods for seismic impedance inversion problems in this paper. The inversion process is ill-posed. To tackle the ill-posedness of the problem and take the sparsity of the reflectivity function into consideration, an l1 norm regularization model is established. In computation, a nonmonotone gradient descent method based on Rayleigh quotient for solving the minimiz...

The presence of gas hydrate and associated gas in the Makran Accretionary Prism, offshore Iran, has been confirmed by various seismic indicators, including the bottom-simulating reflector (BSR), amplitude blanking, and bright spot. The pre-stack analysis and the study of amplitude-variation-with-offset (AVO) attributes are the most reliable tools for semi-quantitative study of gas hydrate and f...

seismic tomography is an imaging technique which creates maps of subsurface elastic properties such as p/s wave velocity, density and attenuation, based on observed seismograms and use of sophisticated inversion algorithms. amongst different acquisition geometries, seismic cross-hole tomography has a special position in geophysical surveys with many applications in hydrocarbons, coal and other ...

This study investigates the effects of uncertainty in rockphysics models on estimates of reservoir parameters from joint inversion of seismic AVA and CSEM data. The reservoir parameters are related to electrical resistivity using Archie’s law, and to seismic velocity and density using the Xu-White model. To account for errors in the rock-physics models, we use two methods to handle uncertainty:...

The paper outlines a probabilistic basis for the automatic estimation from observed surface wave dispersion of structural model parameters with uncertainties. Given an earth model, a wave type and pertinent parameter values, the group velocity of seismic waves can be computed from theory as a function of frequency. Such a function may also be based on the dynamic spectrum representation of an e...