Basalt | Properties, Formation, Composition, Uses
Basalt is a type of volcanic rock that is formed from the solidification of molten lava. It is an igneous rock, meaning it is formed through the cooling and solidification of magma or lava. Basalt is one of the most common rock types on Earth, and it can be found in various locations around the world, both on land and under the ocean floor.
Sub-basalt imaging problems and the application of …
We vary basalt layer thickness and source frequency to generate a synthetic model that produces seismic that is similar to real sub-basalt seismic, i.e. high amplitude top basalt reflector and the absence of base basalt and sub-basalt events. ... In this situation, standard seismic processing is often unable to resolve the structure beneath ...
Imaging of intrabasalt and subbasalt structure with full wavefield
Basalt layers are found along the entire transect with a total thickness of up to 4 km. ..., the complex geology of the thrust belt limits the ability of conventional seismic processing to yield ...
The Influence of Basalt Layers on Seismic Wave Propagation
The thin layers in the basalt act as a low-pass filter to the seismic wave. For the real-data acquisition, even the topbasalt reflection is a low frequency event.
Preservation of low frequencies in wide-angle data processing …
Sub-basalt imaging continues to provide a challenge along the northwest European Atlantic Margin. Successful imaging is being achieved on 2D seismic, acquired with conventional source array and ...
(PDF) Advanced processing of long-offset seismic data for sub-basalt
Imaging below the basalt for hydrocarbon exploration is a global problem because of poor penetration of seismic energy. There is significant loss of energy due to scattering, attenuation, absorption and mode-conversions when the seismic waves encounter a highly heterogeneous and rugose basalt layer.
Seismic structure of basalt flows from surface seismic data, …
The intersec- tion of a new seismic reflection profile recorded in 2002 with a seismic profile recorded in 1998 allows a direct comparison of advances in sub-basalt imaging over this period and an ...
Numerical modelling of seismic reflection in basalt terrains
Near-Surface Basalt Models The noise generated in near-surface basalt depends on the attenuation properties of the basalt. Figure 2 shows the synthetic obtained when a near-surface high-velocity basalt layer (VP = 3750 m/s, VS = 2170 m/s, ρ = 2.5 g/cc, thickness = 50 m, depth = 4 m) is added to the reference model.
Breakthroughs in seismic and borehole …
This success supports seismic potential for subsurface basalt characterization and a path forward for developing seismic and wireline monitoring …
(PDF) Sub-basalt Imaging of Hydrocarbon-Bearing Mesozoic …
Imaging below the basalt for hydrocarbon exploration is a global problem because of poor penetration of seismic energy. There is significant loss of energy due to scattering, attenuation, absorption and mode-conversions when the seismic waves encounter a highly heterogeneous and rugose basalt layer.
Breakthroughs in seismic and borehole characterization of Basalt …
In this paper we summarize the acquisition and processing o f the multi-component seismic swath, and present observations on the integration of P- and S- waveform sonic logs with information from resistivity-based image logs to determine regional and local stress tensors and to improve identification of subsurface basalt lithofacies. 2. Seismic ...
Seismic characteristics of basalt extrusive and intrusive rocks
The layer-cake geometry of flood basalt constructions ... The time-depth conversion process is a significant task in seismic interpretation to establish the link between geophysical information in ...
Improved signal processing for sub-basalt imaging
base of basalt layer. SIGNAL PROCESSING FOR SUB-BASALT IMAGING 165. ... Recent advances in processing seismic data [e.g., Gallagher and Dromgoole, 2007;Soubaras and Dowle, 2010; ...
Imaging and regional distribution of basalt flows in …
A map of basalt and sub-basalt sedimentary layer thickness beneath the Faroe Islands and surrounding area, compiled from published wideangle seismic data, indicates that basalt thickness is ...
Seismic wave propagation through surface basalts
A model with a uniform basalt layer 40 m thick and a line of receivers at 180 m depth. The top of the basalt layer is at 40 m depth. ... Conventional seismic acquisition and processing of a 2D ...
Uncertainties in Ray-Tracing Tomography Models Used for Sub-Basalt
Down to top basalt the models are fairly consistent while there are deviations of up to 1 km s-1 in basalt velocities and sub-basalt sediment velocities, 2 km in basalt thickness, 3.2 km in depth ...
Improved signal processing for sub-basalt imaging
base of basalt layer. SIGNAL PROCESSING FOR SUB-BASALT IMAGING 165 ... Example processing flow used to reprocess 2D seismic data in the West of Shetland region. The flow chart
Sub-basalt seismic imaging using optical-to-acoustic
Request PDF | Sub-basalt seismic imaging using optical-to-acoustic model building and wave equation datuming processing | The presence of highly heterogeneous basalt layers has a detrimental ...
Advances in seismic imaging through basalts: a case study …
The top boundary of the basalt sequence is defined by a strong reflection with a steep velocity increase from 3.5 km s −1 to 4.5 km s −1 in the c. 200 m thick layer above it. The basalt sequence here is c. 2.5 km thick. Beneath the base of the basalt there is a velocity decrease from 5.8 km s −1 to 5.2 km s −1.
Sub-basalt Imaging of Hydrocarbon-Bearing …
Imaging below the basalt for hydrocarbon exploration is a global problem because of poor penetration and significant loss of seismic energy due to scattering, …
Experience with the issue of seismic surveying …
Basalts usually have very high seismic velocities compared to surrounding rocks and high density in comparison to most sediments. As a consequence, wave propagation through basalt layers is very complex and conventional reflection seismic surveying is less …
Sub-Basalt Imaging with Joint Inversion of …
In the inversion process, a priori information from seismic reflection data shown in figure 2 have been used fix model parameters down to top of basalt layer. Joint inversion results of MT and ...
Can seismic wide-aperture data image beneath basalt?
The high-velocity basalt layer above the imaging target separates a purely compressional wide-angle wavefield with an asymptotic move-out determined by the basalt P-wave velocity (Haugen & Yu 1998 ...
basalt layer seismic processing
Data acquisition and processing Stacked basalt flows typically exhibit a low-pass character to seismic waves ... Velocities in the basalt layer are consistent with those seen in the Lopra borehole (Christie et al., 2005). ... and White, R. S. 2001. Seismic structure of basalt flows from surface seismic data, borehole measurements, and synthetic ...
Advanced processing of long-offset seismic data for …
Seismic imaging in the Faeroe-Shetland basin faces the common sub-basalt imaging difficulties. Strong reflectivity caused by the significant velocity contrast between the top basalt and the young ...
Seismic structure of basalt flows from surface seismic data, …
Imaging sub-basalt layers by conventional seismic reflection methods can be a difficult problem in many areas (e.g., Moritz and White, 2001). Seismic surveys in the Paraná Basin in the 1980's ...
(PDF) Prospect hunting below Deccan basalt: …
The conventional (short offset) seismic data acquisition, processing and modeling techniques adopted by the oil industry generally fails to image hydrocarbon-bearing sub-trappean Mesozoic sediments hidden below …
Sub-basalt imaging problems and the application of …
In this situation, standard seismic processing is often unable to resolve the structure beneath such basalt layers. For this reason, alternative techniques are sought …
Improved signal processing for sub-basalt imaging
Maximum offset=10 km. Green dashed lines indicate top and base of basalt layer. Fig. 5. Example stack image after several key pre-migration processing stages: (a) after SRME multiple attenuation; ... Example processing flow used to reprocess 2D seismic data in the West of Shetland region. The flow chart indicates the position of the noise ...
SEISMIC DATA PROCESSING WITH THE WAVE …
FIGURE 11-1. The relationships among sound source coordinate s, geophone sound receiver coordinate g, offset coordinate f = g - s, and midpoint coordinate y = (g + s)/2. Theoreticians generally use s and g as coordinates of the wave-pressure field, but interpreters generally use f and y.