Wave‐field separation in two‐dimensional anisotropic media

Geophysics ◽  
1990 ◽  
Vol 55 (7) ◽  
pp. 914-919 ◽  
Author(s):  
J. Dellinger ◽  
J. Etgen
Keyword(s):  
Wave Field ◽  
Inversion Method ◽  
Two Dimensional ◽  
Wave Separation ◽  
Inversion Methods ◽  
Vsp Data ◽  
Wave Field Separation ◽  
Curl Operators ◽  
And Inversion ◽  
Field Separation

Until recently, the term “elastic” usually implied two‐dimensional (2-D) and isotropic. In this limited context, the divergence and curl operators have found wide use as wave separation operators. For example, Mora (1987) used them in his inversion method to allow separate correlation of P and S arrivals, although the separation is buried in the math and not obvious. Clayton (1981) used them explicitly in several modeling and inversion methods. Devaney and Oristaglio (1986) used closely related operators to separate P and S arrivals in elastic VSP data.

A new method of wave field separation in VSP data processing

1984 ◽  
Author(s):  
A. Carswell ◽  
R. Tang ◽  
C. Dillistone ◽  
W. Moon
Keyword(s):  
Data Processing ◽  
Wave Field ◽  
New Method ◽  
Vsp Data ◽  
Wave Field Separation ◽  
Field Separation

Refined karst feature and fault identification through integrated wave field separation and imaging of Diffraction energy

2021 ◽  
Author(s):  
R. Alay
Keyword(s):  
Wave Field ◽  
Water Environment ◽  
Fault Identification ◽  
Small Scale ◽  
Advantages And Disadvantages ◽  
Specular Reflections ◽  
Total Wave ◽  
Karst Feature ◽  
Wave Field Separation ◽  
Field Separation

In this abstract, a case study from offshore Indonesia is showcased with examples emphasizing integrated wave field separation methods with the objective of diffraction imaging towards refined karst feature and fault identification. For imaging optimally all diffraction energy, pre-migration and post-migration methods have been integrated. The dataset and examples in this abstract are in a complex geological setting in a very shallow water environment, with a subsurface that is characterized by large carbonate pinnacles containing large amount of karst features with thinning and thickening carbonate layers. For the purpose of refined imaging of diffraction energy only, the total wave field has been separated into specular reflections and diffractions prior to migration and these have been integrated with existing post-migration wave field separation methods. Both the pre-migration and post-migration wave field separation methods have their advantages and disadvantages and is discussed later in this abstract. Diffraction energy, in general is much lower in amplitude than the specular reflections and separately imaging these, unveils higher resolution small scale geological features such as karst features and faults complementing the total wave field PSDM data. With existing industry available methods applying wave field separation in either pre-migration or post-migration stage, limitations have been observed, and therefore we propose in this abstract to integrate both methods and take advantage of the improvements showcased with examples throughout the abstract.

Processing of a nine‐component near‐offset VSP for seismic anisotropy

Geophysics ◽  
1997 ◽  
Vol 62 (2) ◽  
pp. 676-689 ◽  
Author(s):  
Colin MacBeth ◽  
Xiang‐Yang Li ◽  
Xinwu Zeng ◽  
Dale Cox ◽  
John Queen
Keyword(s):  
Wave Field ◽  
Seismic Anisotropy ◽  
Similarity Transformation ◽  
Seismic Profile ◽  
Test Facility ◽  
Near Surface ◽  
Common Reference ◽  
Wave Field Separation ◽  
Matrix Operators ◽  
Field Separation

A convolutional sequence of matrix operators is offered as a convenient deterministic scheme for processing a multicomponent vertical seismic profile (VSP). This sequence is applied to a nine‐component near‐offset VSP recorded at the Conoco borehole test facility, Kay County, Oklahoma. These data are corrected for tool spin and near‐surface anisotropy together with source coupling or imbalance. After wave‐field separation using a standard f‐k filter, each source and receiver pair for the upgoing waves is adjusted to a common reference depth using a matrix operator based on the downgoing wave‐field. The up‐ and downgoing waves are then processed for anisotropy by a similarity transformation, to separate the [Formula: see text] and [Formula: see text] waves, from which the anisotropic properties are estimated. These estimates reveal a strong (apparent) vertical birefringence in the near‐surface, but weak or moderate values for the majority of the subsurface. The target zone consists of a thin sandstone and deeper shale layer, both of which possess a strong vertical birefringence. The sandstone corresponds to a zone of known fluid flow. An observed [Formula: see text] attenuation and polarization change in the shale suggest it contains large fractures.

Flexible Provenance Tracing

2013 ◽  
pp. 157-175
Author(s):  
Liwei Wang ◽  
Henning Koehler ◽  
Ke Deng ◽  
Xiaofang Zhou ◽  
Shazia Sadiq
Keyword(s):  
Inversion Method ◽  
Data Provenance ◽  
Time Requirement ◽  
Provenance Information ◽  
Inversion Methods ◽  
Provenance Data ◽  
Source Data ◽  
History Of ◽  
And Inversion ◽  
Derivation Process

The description of the origins of a piece of data and the transformations by which it arrived in a database is termed the data provenance. The importance of data provenance has already been widely recognized in database community. The two major approaches to representing provenance information use annotations and inversion. While annotation is metadata pre-computed to include the derivation history of a data product, the inversion method finds the source data based on the situation that some derivation process can be inverted. Annotations are flexible to represent diverse provenance metadata but the complete provenance data may outsize data itself. Inversion method is concise by using a single inverse query or function but the provenance needs to be computed on-the-fly. This paper proposes a new provenance representation which is a hybrid of annotation and inversion methods in order to achieve combined advantage. This representation is adaptive to the storage constraint and the response time requirement of provenance inversion on-the-fly.

scholarly journals A modified design of pulse sequence and inversion method for D-T2 two-dimensional NMR

2015 ◽  
Vol 64 (9) ◽  
pp. 099301
Author(s):  
Fan Yi-Ren ◽  
Wu Fei ◽  
Li Hu ◽  
Huo Ning-Ning ◽  
Wang Yao-Sen ◽  
...  
Keyword(s):  
Pulse Sequence ◽  
Inversion Method ◽  
Two Dimensional ◽  
And Inversion
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