Global ETD Search
Search theses and dissertations gathered from participating repositories worldwide. Every result links back to the library that holds it. No account is needed.
Results
Showing 1 to 13 of 13 for “"Moveout"”.
-
Seismic reflection moveout for azimuthally anisotropic media
… In this thesis, we study the reflection moveout for Compressional and Shear waves in horizontally stratified azimuthally anisotropic media. Reflection moveout in common-midpoint (CMP) gathers is generally treated by an azimuthally-isotropic hyperbolic equation. Recently, special treatment …
-
Seismic-Style Processing of Numerical Em Data
… appropriate for inversion (EM-style), but the moveout is interpretable (seismic-style) for the presence of a reservoir layer. Plots of normalized data exhibit distinctive moveout, similar to seismic data, but with significant dispersion. The dominant moveout is shown to be linear at a given …
-
Joint migration velocity analysis of PP- and PS-waves for VTI media
… velocity models. To avoid problems caused by the moveout asymmetry of PS-waves and take advantage of efficient MVA algorithms designed for pure modes, I suggest to generate pure SS-reflections from PP and PS data using the PP+PS=SS method. Then the residual moveout in both PP and SS common-image …
-
Multi-fold TDEM Experiment Design for Near Surface Conductivity Mapping
… heterogeneities of the profile. A Zero-Crossing Moveout (ZCMO) analysis used a brute-force grid-search inversion to estimate the two-layer Earth model that best-fit the observed moveout times for a range of interface depths. By using the ZCMO result as an initial model, regularized 1D Occam …
-
Building Velocity Models for Steep-Dip Prestack Depth Migration through First Arrival Traveltime Tomography
… Poststack time migrated seismic images, normal moveout velocity analysis, well logs, and other geologic information are used to build the velocity model. In regions of interest outside of sedimentary basins, such as major strike-slip faults, seismic reflectivity is often sparse and little is …
-
Discrimination and Enhancement of Fracture Signals on Surface Seismic Data
… the fracture signals. Prior application of dip-moveout correction (DMO) did not make any difference on reflections, but included some incoherent noise to the data. The Eigenvector filter performed very well on flat or near-flat reflectors and left the fracture signals almost intact, but …
-
Seismic characterization of geothermal reservoirs by application of the common-reflection-surface stack method and attribute analysis
… as an alternative for the conventional normal moveout (NMO) or the dip moveout (DMO) stack. The advantages of the CRS stack beside an automatic determination of stacking operator parameters include an adequate imaging of arbitrarily curved geological boundaries, and a significant increase in …
-
HRVA - a velocity analysis technique for seismic data
… from gated seismic data which has been normal-moveout corrected. All calculations are performed in the frequency-space or frequency-wavenumber domain; seismic gates are transformed from the time-space domain via the Fast Fourier Transform algorithm. HRVA is not restricted to the investigation …
-
Kirchhoff Common Offset Migration Velocity Analysis via Differential Semblance
… image gather flatness by comparing the residual moveout between neighboring traces. It stands out as a more accurate and automated inversion method among a good number of existing approaches. In this thesis, two versions of differential semblance velocity analysis are introduced: NMO-based and …
-
A unified approach to complex seismic imaging problems
… the degree of non alignment, or Migration Moveout (MMO) to corrections in the velocity model along the raypaths. Finally, I develop a cell-stripping tomography (CST) algorithm which distributes velocity residuals only to the relevant cells, allowing resolution of both horizontal and …
-
Imaging a Hydraulically Fractured Bakken Shale Reservoir Using 4D-Tomography and Reverse VSP Techniques with Perforation Shot Sources
… differences with an approximates a hyperbolic moveout solution. After testing this method with synthetic data, it was applied to real data acquired in the Bakken Formation of the Williston Basin (North Dakota). Using eighty shots triggered in two producer wells and recorded by six vertical …
-
Applications of the Radon transform, Stratigraphic filtering, and Object-based stochastic reservoir modeling
… advantage over traditional summation of normal moveout corrected common midpoint gathers because it circumvents the need to perform manual and interpretive velocity analysis. The fourth study involves the detection of thin layers in periodic layerstacks. Numerical modeling of acoustic wave …
-
All-optical photoacoustic and laser-ultrasonic imaging in heterogeneous tissue
… low-amplitude PA and LUS signals using a normal-moveout processing technique. Incorporating multiple sources in this geometry allows us to apply reverse-time migration to reconstruct LUS images. We demonstrate this methodology with both a numerical model and tissue phantom experiment to image a …