Automated interval velocity inversion

2000 ◽  
Author(s):  
Weijian Mao ◽  
Robin Fletcher ◽  
Swavek Deregowski
Keyword(s):  
Velocity Inversion ◽  
Interval Velocity

Residual stereotomographic inversion

Geophysics ◽  
2006 ◽  
Vol 71 (4) ◽  
pp. E35-E39 ◽  
Author(s):  
Dmitry Neckludov ◽  
Reda Baina ◽  
Evgeny Landa
Keyword(s):  
Model Updating ◽  
Velocity Model ◽  
Model Estimation ◽  
Reflection Point ◽  
Velocity Inversion ◽  
Depth Migration ◽  
Interval Velocity ◽  
Step Procedure ◽  
Tomographic Method ◽  
First Ray

Depth migration requires highly accurate knowledge of the subsurface velocity field. Different traveltime tomographic methods are used for this purpose. Stereotomography is a tomographic method that uses local dip estimates in addition to traveltimes for velocity model estimation. We present a new methodology for velocity model updating. It combines poststack stereotomography and residual moveout velocity inversion. The former is used for initial model construction and the latter for updating the velocity model. Residual inversion is a kind of stereotomographic inversion applied to common reflection point (CRP) gathers after model-based moveout correction. Velocity analysis can be made more efficient by preselecting the traces that contribute to a series of CRP gathers and using only these traces for inversion. The algorithm is defined in a two-step procedure. First, ray tracing from the reflection point for nonzero reflection offsets defines the source and receiver locations of the data traces in the CRS gather. Then these traces are moveout corrected according to the calculated traveltimes and residual moveout is estimated. The interval velocity model is updated by fitting the velocity that minimizes estimated residuals. Application of the proposed technique demonstrates its robustness and reliability for fast and automatic velocity model estimation.

New Method for Imaging and Inversion of Interval Velocity

2013 ◽  
Vol 785-786 ◽  
pp. 1324-1328
Author(s):  
Yuan Yuan Huo ◽  
Guang Xun Chen ◽  
Deng Ke Hu ◽  
Lei Zhang
Keyword(s):  
Gas Hydrate ◽  
Specific Area ◽  
Geological Structure ◽  
Combination Method ◽  
Velocity Inversion ◽  
Interval Velocity ◽  
Wave Ray ◽  
Tracing Algorithm ◽  
And Inversion

In order to obtain accuracy interval velocity and improve the quality of imaging of velocity volume, so as to better describe the geological structure and reservoir of gas hydrate in specific area, a new interval velocity inversion combination method is proposed in this paper. By introducing wave ray tracing algorithm and velocity field structuring and smoothing algorithm, this new inversion solution can deduce more accuracy and reasonable interval velocity than other normal inversion methods. Empirical results shows that velocity profile has higher resolution and can finely reflect the occurrence status and spatial distribution of gas hydrate.

scholarly journals HYBRID INVERSION OF INTERVAL VELOCITIES IN MULTISCALE APPROACH

2017 ◽  
Vol 35 (4) ◽  
pp. 237
Author(s):  
Rodrigo de S. Santos ◽  
Milton J. Porsani
Keyword(s):  
Simulated Annealing ◽  
Hybrid Algorithm ◽  
Seismic Waves ◽  
Optimization Method ◽  
Multiscale Approach ◽  
Velocity Inversion ◽  
Interval Velocity ◽  
The Earth ◽  
Very Fast Simulated Annealing ◽  
Interval Velocities

ABSTRACT. The understanding of the interior of the planet by using the seismic method of reflection requires knowledge of the velocities with which the seismic waves propagate in the subsurface of the Earth. This work presents strategies to obtain the velocity intervals using RMS velocity inversion. Using a hybrid algorithm that combines the Very Fast Simulated Annealing (VFSA) global optimization method and the Fletcher-Reeves local search method, we have sought to reduce the dependence between the accuracy of the results and the model by which the optimization process begins. The main innovative contribution of this study was the development and presentation of the named inversion strategy of multiscale parameters. This technique allows the use of the VFSA method in inversion problems in which the number of variables is significantly large. The hybrid algorithm with multiscale approach was used to solve 1D and 2D problems, estimating models with high degrees of accuracy, which allowed to confirm the efficiency of the proposed method.Keywords: inversion, parameter multiscale, interval velocity, Very Fast Simulated Annealing, Fletcher-Reeves, hybrid.RESUMO. O entendimento do interior do planeta por meio do método sísmico de reflexão requer o conhecimento das velocidades com que as ondas sísmicas se propagam na subsuperfície da Terra. Este trabalho apresenta estratégias para a obtenção das velocidade intervalares por uso inversão de velocidades RMS. Utilizando um algoritmo híbrido, que combina o método de otimização global Very Fast Simulated Annealing (VFSA), e o método de busca local Fletcher-Reeves, buscou-se reduzir a dependência entre a acurácia dos resultados e o modelo pelo qual o processo de otimização se inicia. A principal contribuição inovadora deste estudo foi o desenvolvimento e apresentação da estratégia de inversão nomeada de multiescala de parâmetros. Esta técnica possibilita o uso do método VFSA em problemas de inversão em que o número de variáveis é significativamente grande. O algoritmo híbrido com abordagem multiescala foi usado para solucionar problemas 1D e 2D, estimando modelos com elevado grau de acurácia, o que permitiu confirmar a eficiência do método proposto.Palavras-chave: inversão, multiescala de parâmetros, velocidade intervalar, Very Fast Simulated Annealing, Fletcher-Reeves, híbrido.

HYBRID INVERSION OF INTERVAL VELOCITIES IN MULTISCALE APPROACH

2018 ◽  
Vol 35 (4) ◽  
pp. 237
Author(s):  
Rodrigo De Santana Santos ◽  
Milton José Porsani
Keyword(s):  
Simulated Annealing ◽  
Hybrid Algorithm ◽  
Seismic Waves ◽  
Optimization Method ◽  
Multiscale Approach ◽  
Velocity Inversion ◽  
Interval Velocity ◽  
The Earth ◽  
Very Fast Simulated Annealing ◽  
Interval Velocities

RESUMO. O entendimento do interior do planeta por meio do método sísmico de reflexão, requer o conhecimento das velocidades com que as ondas sísmicas se propagam na subsuperfície da terra. Este trabalho apresenta estratégias para a obtenção das velocidades intervalares por uso inversão de velocidades RMS. Utilizando um algoritmo híbrido, que combina o poderoso método de otimização global Very Fast Simulated Annealing, e o método de busca local Fletcher-Revees, nós buscamos reduzir a dependência entre a acuracia dos resultados e o modelo pelo qual o processo de otimização se inicia. A principal contribuição inovadora deste estudo foi o desenvolvimento e apresentação da estratégia de inversão nomeada de multiescala de parâmetros. Esta técnica possibilita o uso do método VFSA em problemas de inversão em que o número de variáveis e signicativamente grande. O algoritmo hbrido com abordagem multiescala, foi usado para solucionar problemas 1D e 2D, estimando modelos com elevado grau de acurácia, o que permitiu confirmar a eci^encia do método proposto. Palavras-chave: inversão, multiescala de parâmetros, velocidade intervalar, Very Fast Simulated Annealing, Fletcher-Revees, híbrido. ABSTRACT. The understanding of the interior of the planet by using the seismic method of reflection requires knowledge of the velocities with which the seismic waves propagate in the subsurface of the earth. This work presents strategies to obtain the velocity intervals using RMS velocity inversion. Using a hybrid algorithm that combines the powerful Very Fast Simulated Annealing global optimization method and the Fletcher-Revees local search method, we have sought to reduce the dependence between the accuracy of the results and the model by which the optimization process begins. The main innovative contribution of this study was the development and presentation of the named inversion strategy of multiscale parameters. This technique allows the use of the VFSA method in inversion problems in which the number of variables is significantly large. The hybrid algorithm with multiscale approach was used to solve 1D and 2D problems, estimating models with high degrees of accuracy, which allowed to confirm the efficiency of the proposed method Keywords: inversion, parameter multiscale, interval velocity, Very Fast Simulated Annealing, Fletcher-Revees, hybrid.

The migration of common midpoint slant stacks

Geophysics ◽  
1984 ◽  
Vol 49 (3) ◽  
pp. 237-249 ◽  
Author(s):  
Richard Ottolini ◽  
Jon F. Claerbout
Keyword(s):  
Seismic Data ◽  
Lateral Velocity ◽  
Velocity Inversion ◽  
Interval Velocity ◽  
Reflection Seismic ◽  
Straightforward Method ◽  
Velocity Surface ◽  
Velocity Variations ◽  
Migration Equation ◽  
Ray Parameter

Reflection seismic data can be imaged by migrating common midpoint slant stacks. The basic method is to assemble slant stack sections from the slant stack of each common midpoint gather at the same ray parameter. Earlier investigators have described migration methods for slant stacked shot profiles or common receiver gathers instead of common midpoint gathers. However, common midpoint slant stacks enjoy the practical advantages of midpoint coordinates. In addition, the migration equation makes no approximation for steep dips, wide offsets, or vertical velocity variations. A theoretical disadvantage is that there is no exact treatment of lateral velocity variations. Slant stack migration is a method of “migration before stack.” It solves the dip selectivity problem of conventional stacking, particularly when horizontal reflectors intersect steep dipping reflectors. The correct handling of all dips also improves lateral resolution in the image. Slant stack migration provides a straightforward method of measuring interval velocity after migration has improved the seismic data. The kinematics (traveltime treatment) of slant stack migration is also accurate for postcritical reflections and refractions. These events transform into a p-τ surface with the additional dimension of midpoint. The slant stack migration equation converts the p-τ surface into a depth‐midpoint velocity surface. As with migration in general, the effects of dip are automatically accounted for during velocity inversion.

Implementation Of Interval Velocity Data In The Analysis Of Vertical Fluid Migration Routes And Charging Offshore Qatar

2014 ◽  
Author(s):  
K. J. Andresen ◽  
A. Uldall ◽  
M. Hertle ◽  
L. Madsen ◽  
C. Perrin ◽  
...  
Keyword(s):  
Fluid Migration ◽  
Velocity Data ◽  
Migration Routes ◽  
Interval Velocity

The relationship between Vs, Vp, density and depth based on PS-logging data at K-NET and KiK-net sites

2021 ◽  
Author(s):  
Fumiaki Nagashima ◽  
Hiroshi Kawase
Keyword(s):  
Standard Deviation ◽  
Seismic Velocity ◽  
Saturated Soil ◽  
P Wave ◽  
Soil Types ◽  
Depth Range ◽  
Velocity Inversion ◽  
Velocity Models ◽  
Regression Curves ◽  
Ps Logging

Summary P-wave velocity (Vp) is an important parameter for constructing seismic velocity models of the subsurface structures by using microtremors and earthquake ground motions or any other geophysical exploration data. In order to reflect the ground survey information in Japan to the Vp structure, we investigated the relationships among Vs, Vp, and depth by using PS-logging data at all K-NET and KiK-net sites. Vp values are concentrated at around 500 m/s and 1,500 m/s when Vs is lower than 1,000 m/s, where these concentrated areas show two distinctive characteristics of unsaturated and saturated soil, respectively. Many Vp values in the layer shallower than 4 m are around 500 m/s, which suggests the dominance of unsaturated soil, while many Vp values in the layer deeper than 4 m are larger than 1,500 m/s, which suggests the dominance of saturated soil there. We also investigated those relationships for different soil types at K-NET sites. Although each soil type has its own depth range, all soil types show similar relationships among Vs, Vp, and depth. Then, considering the depth profile of Vp, we divided the dataset into two by the depth, which is shallower or deeper than 4 m, and calculated the geometrical mean of Vp and the geometrical standard deviation in every Vs bins of 200 m/s. Finally, we obtained the regression curves for the average and standard deviation of Vp estimated from Vs to get the Vp conversion functions from Vs, which can be applied to a wide Vs range. We also obtained the regression curves for two datasets with Vp lower and higher than 1,200 m/s. These regression curves can be applied when the groundwater level is known. In addition, we obtained the regression curves for density from Vs or Vp. An example of the application for those relationships in the velocity inversion is shown.

Sign in / Sign up

Export Citation Format

Share Document