The application of focused Gaussian beams is investigated for the seismic imaging of common-shot reflection data. The focusing of Gaussian beams away from the source and receiver surface adds flexibility to beam imaging algorithms allowing for the narrowest portions of the beams to occur at the depth of a specific target structure. This minimizes the number of beams required to form an image at...

A key to reducing the risks and costs of associated with oil and gas exploration is the fast, accurate imaging of complex geologies, such as salt domes in the Gulf of Mexico and overthrust regions in U.S. onshore regions. Prestack depth migration generally yields the most accurate images, and one approach to this is to solve the scalar wave equation using nite diierences. Current industry compu...

Dynamic imaging provides an effective way to integrate previous time-lapse data with current data in order to estimate a current model. We present two methods useful for continuous dynamic reservoir and subsurface monitoring. The first method is a stochastic method for the inversion of geophysical data. It uses the ensemble Kalman filter (EnKF) that we demonstrate using time-lapse surface seism...

Citation Zhang, Haijiang et al. " Three-dimensional passive seismic waveform imaging around the SAFOD site, California, using the generalized Radon transform. Article is made available in accordance with the publisher's policy and may be subject to US copyright law. Please refer to the publisher's site for terms of use. The MIT Faculty has made this article openly available. Please share how th...

The increased availability and fidelity of broadband seismic instruments have played a key role in bridging the gap between exploration and global seismic applications. Long gone are the days when global structure mapping and source characterization/monitoring relied on the manual digitization of WWSSN (World-Wide Standard Seismographic Network) analogue records or hours in front of microfiche ...

One way of developing a wave-equation approach to seismic imaging is based on the concept of downward continuation of the surface reflection data. Seismic imaging is typically based on the single scattering approximation, and assumes the knowledge of a, smooth, background model in which the mentioned downward continuation is carried out. The downward continued data are subjected, at each depth,...

Receiver-side water-column multiples acquired with ocean-bottom seismic sensors can be used for elastic imaging of the subsurface, which can provide additional information relative to more conventional acoustic imaging. These multiples can be separated from primaries contained in ocean-bottom seismic data using techniques such as up/down decomposition. In elastic imaging, the down-going wavefie...

Seismic interferometry is a technique that allows one to reconstruct the full response from a virtual source inside a medium, assuming a receiver is present at the virtual source location. We describe a method that creates a virtual source inside a medium from reflection data measured at the surface, without needing a receiver inside the medium and, hence, presenting an advantage over seismic i...

Numerical modelling of seismic wave propagation is central to seismic imaging and inversion. Modelling of 3D heterogeneous anisotropic media can, however, simultaneously be both costly and of low fidelity. To address some aspects of the fidelity / cost problem, we present our implementation of seismic modelling within the Rayleigh-Sommerfeld algorithmic framework and implemented in a parallel c...