Application of tomographic static correction technology constrained by micro logging in 3D splicing processing

2021 ◽  
Author(s):  
M. Li ◽  
F. Li ◽  
Y. Wang ◽  
L. Xu ◽  
Y. Cao
Keyword(s):  
Static Correction

First-arrival traveltime inversion of seismic diving waves observed on undulant surface

2021 ◽  
Vol 225 (2) ◽  
pp. 1020-1031
Author(s):  
Huachen Yang ◽  
Jianzhong Zhang ◽  
Kai Ren ◽  
Changbo Wang
Keyword(s):  
Turning Points ◽  
Analytical Formula ◽  
Velocity Model ◽  
Western China ◽  
Inversion Method ◽  
Mountain Area ◽  
Traveltime Inversion ◽  
Static Correction ◽  
Velocity Models ◽  
First Arrival

SUMMARY A non-iterative first-arrival traveltime inversion method (NFTI) is proposed for building smooth velocity models using seismic diving waves observed on irregular surface. The new ray and traveltime equations of diving waves propagating in smooth media with undulant observation surface are deduced. According to the proposed ray and traveltime equations, an analytical formula for determining the location of the diving-wave turning points is then derived. Taking the influence of rough topography on first-arrival traveltimes into account, the new equations for calculating the velocities at turning points are established. Based on these equations, a method is proposed to construct subsurface velocity models from the observation surface downward to the bottom using the first-arrival traveltimes in common offset gathers. Tests on smooth velocity models with rugged topography verify the validity of the established equations, and the superiority of the proposed NFTI. The limitation of the proposed method is shown by an abruptly-varying velocity model example. Finally, the NFTI is applied to solve the static correction problem of the field seismic data acquired in a mountain area in the western China. The results confirm the effectivity of the proposed NFTI.

STACKING OF REFLECTIONS FROM COMPLEX STRUCTURES

Geophysics ◽  
1974 ◽  
Vol 39 (4) ◽  
pp. 427-440 ◽  
Author(s):  
Max K. Miller
Keyword(s):  
Deep Structure ◽  
Control Model ◽  
Layer Model ◽  
Low Velocity ◽  
Seismic Reflection Data ◽  
Near Surface ◽  
Static Correction ◽  
Reflection Data ◽  
Actual Field ◽  
Interval Velocities

Common‐depth‐point seismic reflection data were generated on a computer using simple ray tracing and analyzed with processing techniques currently used on actual field recordings. Constant velocity layers with curved interfaces were used to simulate complex geologic shapes. Two models were chosen to illustrate problems caused by curved geologic interfaces, i.e., interfaces at depths which vary laterally in a nonlinear fashion and produce large spatial variations in the apparent stacking velocity. A three‐layer model with a deep structure and no weathering was used as a control model. For comparison, a low velocity weathering layer also of variable thickness was inserted near the surface of the control model. The low velocity layer was thicker than the ordinary thin weathering layers where state‐of‐the‐art static correction methods work well. Traveltime, moveout, apparent rms velocities, and interval velocities were calculated for both models. The weathering introduces errors into the rms velocities and traveltimes. A method is described to compensate for these errors. A static correction applied to the traveltimes reduced the fluctuation of apparent rms velocities. Values for the thick weathering layer model were “over corrected” so that synclines (anticlines) replaced false anticlines (synclines) for both near‐surface and deep zones. It is concluded that computer modeling is a useful tool for analyzing specific problems of processing CDP seismic data such as errors in velocity estimates produced by large lateral variations in overburden.

Contact Modeling Technique of a Flexible Piston and Cylinder Using Modal Synthesis Method

2005 ◽  
Author(s):  
W. K. Kim ◽  
S. H. Sohn ◽  
H. J. Cho ◽  
D. S. Bae ◽  
J. H. Choi
Keyword(s):  
Contact Force ◽  
Synthesis Method ◽  
Normal Modes ◽  
Modeling Technique ◽  
Mode Shapes ◽  
Dynamics Analysis ◽  
Contact Modeling ◽  
Static Correction ◽  
Modal Synthesis ◽  
Contact Surfaces

In this paper, contact modeling technique and dynamics analysis of piston and cylinder system are presented by using modal synthesis method. It is very important to select mode shapes representing a global or local behavior of a flexible body due to a specified loading condition. This paper proposes a technique to generate the static correction modes which are nicely representing a motion by a contact force between a piston and cylinder. First normal modes of piston and cylinder under a boundary condition are computed, and then static correction modes due to a contact force applied at contacted nodes are added to the normal modes. Also, this paper proposes an efficient dynamics analysis process while changing the shape of the piston and cylinder. In optimization process or design study, their geometric data can be changed a bit. The slight changes of their contact surfaces make a high variation of the magnitude of a contact force, and it can yield the different dynamic behavior of an engine system. But, since the variations of the normal and correction modes are very small, the re-computation of their normal and correction modes due to the change of contact surfaces can be useless. Until now, whenever their contact surfaces are changed at a design cycle, the modes have been recomputed. Thus, most engineers in industries have been spent many times in very tedious and inefficient design process. In this paper, the normal and correction modes from the basic geometry of the piston and cylinder are computed. If the geometry shape is changed, nodal positions of the original modal model are newly calculated from an interpolation method and changed geometry data. And then the updated nodes are used to compute a precise contact force. The proposed methods illustrated in this investigation have good agreement with results of a nodal synthesis technique and proved that it is very efficient design method.

Short-period static correction without Normal Move Out†

2012 ◽  
Vol 61 (1) ◽  
pp. 92-103
Author(s):  
Andrey V. Masjukov ◽  
Igor S. Murzov
Keyword(s):  
Static Correction ◽  
Short Period

Modeling of Flexible Bodies for Dynamic Analysis of Multi-Body Dynamic Systems Using Ritz Vectors

1991 ◽  
Author(s):  
Henry T. Wu ◽  
Neel K. Mani
Keyword(s):  
Dynamic Analysis ◽  
Mechanical Systems ◽  
Normal Modes ◽  
Flexible Bodies ◽  
Static Correction ◽  
Ritz Vectors ◽  
Regeneration Procedure ◽  
Efficient Vector ◽  
Multi Body ◽  
Body Dynamic

Abstract Vibration normal modes and static correction modes have been previously used to model flexible bodies for dynamic analysis of mechanical systems. The efficiency and accuracy of using these modes to model a system depends on both the flexibility of each body and the applied loads. This paper develops a generalized method for the generation of a set of Ritz vectors to model flexible bodies for dynamic analysis of multi-body mechanical systems. The Ritz vectors are generated using the distribution of dynamic loading on a flexible body. Therefore they form the most efficient vector basis for the spatial distribution of the loadings. The Ritz vectors can be re-generated when the system undergoes significant changes of its configuration and the regeneration procedure is inexpensive. The combinations of vibration normal modes and the proposed Ritz vectors thus form more efficient and accurate vector bases for the modeling of flexible bodies for dynamic analysis.

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