LZ
L. Zhang
38 records found
1
Authored
One of the most crucial estimates retrieved from measured seismic reflection data is the subsurface image. The image provides detailed information of the subsurface of the Earth. Seismic reflection data consists of so-called primary and multiple reflections. Primary reflections a
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We compare two data-driven internal multiple reflection elimination schemes derived from regular Marchenko equations and Inverse Scattering Series (ISS). The scheme derived from regular Marchenko equations creates a new data set without internal multiple reflections. The schem ...
Elimination of multiples from acoustic reflection data is important to reduce the effect of their presence in velocity model building and subsequent imaging. Many processing schemes assume only primary reflection events are present in the data. Free-surface multiple elimination i
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Data-driven internal multiple elimination and its consequences for imaging
A comparison of strategies
We have compared three data-driven internal multiple reflection elimination schemes derived from the Marchenko equations and inverse scattering series (ISS). The two schemes derived from Marchenko equations are similar but use different truncation operators. The first scheme crea
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We have developed a scheme that retrieves primary reflections in the two-way traveltime domain by filtering the data. The data have their own filter that removes internal multiple reflections, whereas the amplitudes of the retrieved primary reflections are compensated for two-way
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Multiple reflections are often considered as noise in seismic data. Dealing with them has attracted much attention from industry and academia. A variety of schemes have been developed for removal of free-surface multiple reflections and success has been achieved in numerical and
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The Marchenko methods can retrieve both Green's functions and focusing functions from single-sided reflection data and an initial focusing function. Recent studies also show that they can be applied to eliminating multiples directly from reflection data without requiring model in
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We have derived a scheme for retrieving the primary reflections from the acoustic surface-reflection response by eliminating the free-surface and internal multiple reflections in one step. This scheme does not require model information and adaptive subtraction. It consists only o
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We retrieve transmission compensated subsurface primary reflections from the reflection response measured at the surface. This is achieved by filtering the reflection response. The application of this scheme does not require model information. In this process, the reflection resp
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A revised Marchenko scheme that avoids the need to compute the Green’s function is presented for artefact-free image of the subsurface with single-sided reflection response as input. The initial downgoing Green’s function which can be modelled from a macro model is needed for sol
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We have derived an improved reverse time migration (RTM) scheme to image the medium without artifacts arising from internal multiple reflections. This is based on a revised implementation of Marchenko redatuming using a new time-truncation operator. Because of the new truncation
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Marchenko imaging is a methodology to image the subsurface with two important properties: (1)accurate amplitude and (2)free from free-surface and internal multiple artefacts. It requires an estimate of the first arrival of the focusing function which is commonly obtained from ...
A modified implementation of Marchenko redatuming leads to a filter that removes internal multiples from reflection data. It produces local reflectivity at two-way travel time. The method creates new primary reflections resulting from emitted events that eliminate internal multip
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Iterative substitution of the Marchenko equation has been introduced recently to integrate internal multiple reflection in the seismic and electromagnetic imaging process. In the so-called Marchenko imaging, solving the Marchenko equation at each imaging point is required to m ...
We present a three-dimensional scheme that can be used to compute a vertical radar profile from reflection and transmission data measured at two parallel surfaces of a dissipative medium. From this double-sided data set the reflection response of a fictitious medium with negative
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We present a one-dimensional lossless scheme to compute an image of a dissipative medium from two single-sided reflection responses. One reflection response is measured at or above the top reflector of a dissipative medium and the other reflection response is computed as if measu
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We present a one-dimensional lossless scheme to compute an image of a dissipative medium from two single-sided reflection responses. One reflection response is measured at or above the top reflector of a dissipative medium and the other reflection response is computed as if measu
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Contributed
Pressure and Velocity Fields Retrieval Based on a New Normalization Option and 1D Model-Free Primaries Retrieval from Marine Data
New Marchenko-type Equations with Two-Way Wavefields at the Receiver Level
The Marchenko method is being developed to compute redatuming operators from the reflection response based on a new normalization option at the data level. These operators can be used to retrieve the two-way focusing functions in terms of pressure and velocity, respectively, with
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