Correction for Water Velocity Variations and Tidal Statics

Lacombe, C.; Schultzen, Jon; Butt, Suhail; Lecerf, D.

doi:10.3997/2214-4609.201402385

Cited by 6 publications

(4 citation statements)

References 0 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Mackey and Fried (2003) revealed further that it not only affects the event continuity of marine seismic data but also influences stack section showing inaccuracy amplitude information and wrong submarine tectonics. The similar question is put forward by Lacombe et al (2006), that seawater velocity variation can cause seismic event dislocation. Xu and Pham (2003) and Jones (2010) studied seismic imaging and achieved the conclusion that variable seawater velocity sets back seabed imaging.…”

Section: Introductionmentioning

confidence: 92%

Research into the effects of seawater velocity variation on migration imaging in deep-water geology

Sun

Han

et al. 2016

Earth sci. res. j.

View full text Add to dashboard Cite

This paper aims at the problem that the migration quality is poor in deep water. It analyzed the influence that velocity model accuracy had on migration and studied the impact that variable seawater velocity makes on movement effect. At first, variable seawater velocity affected by temperature, pressure, and salinity is defined to replace the actual seawater velocity. Then variable seawater velocity's influence on interface migration location, layer sickness and movement energy focusing degree are analyzed in theory. Moreover, finally, a deep water layered medium model containing variable seawater velocity, a syncline wedge shape model, and a complex seafloor velocity model are constructed. By changing the seawater velocity of each model and comparing migration results of constant seawater velocity model and variable seawater-velocity model, it was found the conclusion. Under the condition of deep water, variable seawater velocity's impact on the quality of seismic migration is significant, which not only can change the location of geologic body migration result but also can influence the resolution of the geologic interface in the movement section and maybe can cause migration illusion.Este artículo se enfoca en el problema de la baja calidad de la migración en aguas profundas. Se analiza la influencia que tiene el modelo de precisión de velocidad en la migración y se estudia el impacto que la variación de velocidad del agua marina tiene en el efecto de movimiento. En primera instancia, se define la variación de la velocidad del agua marina afectada por la temperatura, la presión y la salinidad para reemplazar la velocidad del agua marina actual. Luego se analiza la teoría de la influencia de la velocidad del agua marina sobre la interfaz de la ubicación de migración, el grosor de la capa y la energía de movimiento de acuerdo con la inclinación. Además, finalmente, se construyó un modelo medio por capas de aguas profundas que contiene las variaciones de velocidad del agua marina, un modelo de forma de cuña sinclinal, y un modelo de complejo de velocidades del lecho marino. Al cambiar la velocidad del agua marina en cada modelo y comparar los resultados de migración del modelo de velocidad de agua marina constante con los del modelo modelo de velocidad variable se encontró la conclusión. Bajo las condiciones de agua profunda, el impacto de la variación de la velocidad del agua es significativo en la migración sísmica, lo que no solo puede cambiar el resultado de migración en la ubicación del cuerpo geológico sino que además puede influir en la resolución de la interconexión geológica en la sección de movimiento y podría causar la ilusión de migración. How to cite item Sun, H., Sun, J., Han, F., Sun, Z., Liu, Z., Liu, M., & Huang, X. (2016 Correspondence should be addressed to Jianguo Sun, e-mail: sun_jg@jlu.edu.cn SEISMICInvestigación de los efectos de la variación en la velocidad del agua marina sobre las imágenes de migración en la geología de aguas profundas

show abstract

Section: Introductionmentioning

confidence: 92%

Research into the effects of seawater velocity variation on migration imaging in deep-water geology

Sun

Han

et al. 2016

Earth sci. res. j.

View full text Add to dashboard Cite

show abstract

“…It should be noted that water velocity variation might not be the only source of travel time shifts. Tidal variations can also cause travel time variations (Lacombe et al 2006). All the results presented in the paper have been shown after tidal static correction applied using tide tables.…”

Section: Introductionmentioning

confidence: 94%

“…Generally one or two iterations are sufficient when the initial water velocity model is a close representation of the true water velocity. Once the water velocity has been derived, the correction for water velocity variation is implemented using a water layer replacement method (Lacombe et al 2006). The goal is to replace the estimated water velocity with a "reference velocity".…”

Section: Velocity Estimation Of Sea Layermentioning

confidence: 99%

A New Way of Compensating for Water Column Variation by Velocity Estimation of Sea Layer

Kumar¹,

Jangelme²,

Barnes³

2015

Proceedings

View full text Add to dashboard Cite

Compensating for water velocity variations remains a key challenge in seismic data processing, where the water velocity varies over time. In a 3D seismic survey, adjacent sail lines are recorded at different times, and subsequently the recorded wave-field will be different. To take this effect into account at the seismic processing stage, it is necessary to estimate the water velocity. This paper proposes a new method of estimating the water velocity that can be used to compensate for the effect of water velocity variation using a novel water layer replacement method. When the water bottom becomes more complex, the established techniques underperform as they rely upon accurate water bottom model. In this paper it is demonstrated that the correct approach is to estimate the water layer velocity in migrated space. The method is also desirable for 4D processing and projects requiring merging of multiple datasets from many different vintages.

show abstract

“…Variation in sound speed within ocean water can cause problems in sub-seabed seismic reflection imaging (Wombell 1997;Barley 1999;Bertrand & Macbeth 2003;Mackay et al 2003;Xu & Pham 2003;Lacombe et al 2006Lacombe et al , 2009. Water layer sound speed variations arise from natural variations in temperature and salinity associated with oceanic currents.…”

mentioning

confidence: 99%

Seismic imaging of variable water layer sound speed in Rockall Trough, NE Atlantic and implications for seismic surveying in deep water

Jones

Sutton

Hardy

et al. 2010

PGC

View full text Add to dashboard Cite

Natural variation in sound speed within ocean water can degrade sub-seabed images from 2D, 3D and 4D seismic reflection datasets. Degrading effects include vertical offset of reflections between adjacent or intersecting sail lines and difficulties in suppressing multiples from water layer reverberations. Here we investigate water layer variability in Rockall Trough, offshore Ireland, in water depths ranging from 200 m to 3.5 km. A compilation of vertical sound speed profiles, calculated from temperature and salinity profiles obtained by probes lowered from ships, shows that the mean sound speed in the water layer mostly varies between 1490 and 1500 m s 21 . Vertical offsets of up to about 15 ms two-way travel time are predicted at seismic line intersections. A significant amount of the total observed sound speed variability can occur along a single seismic sail line. These effects result mainly from spatial and temporal fluctuations in the thicknesses of, and vertical sound speed gradients within, an upper layer of North Atlantic Central Water and a mid-depth layer of Mediterranean Outflow Water. Seismic sections across Rockall Trough commonly show lateral variability in reflectivity within these same two water layers. Some reflective packages contain lens-shaped structures consisting of reflective rims and transparent cores and with diameters between 10 and 50 km. Other reflective packages have abrupt, almost vertical boundaries and no distinct transparent core. We infer that the lateral boundaries of the reflective packages are likely to be associated with significant variations in average water layer sound speed. When processing 2D, 3D and 4D seismic surveys of regions of high oceanic variability, such as Rockall Trough, it is necessary to employ techniques that can solve for and then remove the effect of significant fluctuations in water layer sound speed over time periods as short as a few hours and distances as short as a kilometre.

show abstract

Correction for Water Velocity Variations and Tidal Statics

Cited by 6 publications

References 0 publications

Research into the effects of seawater velocity variation on migration imaging in deep-water geology

Research into the effects of seawater velocity variation on migration imaging in deep-water geology

A New Way of Compensating for Water Column Variation by Velocity Estimation of Sea Layer

Seismic imaging of variable water layer sound speed in Rockall Trough, NE Atlantic and implications for seismic surveying in deep water

Contact Info

Product

Resources

About