Migration of seismic reflection data to common image-point gathers is an integral part of both migration velocity analysis (MVA) and amplitude (AVA) analysis. Its applicability in complex geology depends on whether these gathers will be artifact free, and is related to the formation of caustics and turning ‘rays’ due to the heterogeneity of the velocity model used. Here, we discuss an angle tra...

Real-time location of earthquakes can be achieved by using direct imaging of the recorded wave field based on a Kirchhoff reconstruction method similar to that used in the migration of seismic reflection data. The standard method of event location requires the wave arrival at each sensor to be picked and associated with an event. By using direct imaging, the event is identified once in the imag...

Stacking plays an important role in improving signal-to-noise ratio and imaging quality of seismic data. However, for low-fold-coverage seismic profiles, the result of conventional stacking is not always satisfactory. To address this problem, we have developed a method of stacking in which we use local correlation as a weight for stacking common-midpoint gathers after NMO processing or common-i...

The objective of seismic imaging is to obtain an image of the subsurface reflectors, which is very important for estimating whether a reservoir is beneficial for oil/gas exploration or not. It can also provide the relative changes or absolute values of three elastic parameters: compressional wave velocity Vp, shear wave velocity Vs , and density ρ. Two ways can achieve the objectives. In approa...

Attenuation in seismic wave propagation is a common cause for poor illumination of subsurface structures. Attempts to compensate for amplitude loss in seismic images by amplifying the wavefield may boost high-frequency components and create undesirable imaging artifacts. In this paper, rather than amplifying the wavefield directly, we develop a stable compensation operator using smooth division...

For VSP data, interferometric migration of free-surface multiples has two significant advantages over standard VSP migration: 1). a significantly larger imaging area than that of conventional migration of VSP primaries, and 2). less sensitivity to velocity and static errors than conventional migration of VSP multiples. In this report we validate these claims by applying wave-equation interferom...

Seismic migration/inversion is presently the most used method for determining the structure and properties of the sub-surface in seismic exploration for hydrocarbons. Determining the location of abrupt changes in medium’s parameters involves, in one form or another, an imaging principle which can simply be stated by equating a component, or the full value of the travel-time t, with zero. Depend...

Seismic prospecting aims at determining the structure of the earth from indirect measurements. Acoustic wave fields are generated at the surface, penetrate the earth, and are backscattered by the earth’s inhomogeneities. The data recorded at the surface are processed in a complex sequence of steps among which seismic migration plays an important role. This is a wave depropagation process that p...