What is synthetic seismic?
A synthetic seismogram is the result of forward modelling the seismic response of an input earth model, which is defined in terms of 1D, 2D or 3D variations in physical properties. Synthetic seismograms are generated using specialized geophysical software.
What is seismic well tie?
A seismic-to-well tie is the process through which seismic data wavelets are understood and compares seismic data at a well location with log data from the well.
What is the seismic interpretation?
Seismic Interpretation is the extraction of subsurface geologic information from seismic data. Reflection seismic data comprise: Continuity of reflections indicating geologic structure. Variability of reflections indicating stratigraphy, fluids and reservoir fabric.
Why is seismic inversion?
Because of its efficiency and quality, most oil and gas companies now use seismic inversion to increase the resolution and reliability of the data and to improve estimation of rock properties including porosity and net pay. There are many different techniques used in seismic inversion.
How do you convert seismic time to depth?
To convert time reflections to a depth surface we need to know the velocity. The depth is then estimated from the simple geophysical relationship that depth = velocity x time.
How do you read seismic data?
The seismogram is “read” like a book, from left to right and top to bottom (this is the direction that time increases). As with a book, the right end of any horizontal line “connects” with the left end of the line below it. Each line represents 15 minutes of data; four lines per hour.
Which seismic wave travels the fastest?
P waves
P waves travel fastest and are the first to arrive from the earthquake. In S or shear waves, rock oscillates perpendicular to the direction of wave propagation. In rock, S waves generally travel about 60% the speed of P waves, and the S wave always arrives after the P wave.
What types of information do seismograms include?
A seismogram is a graph output by a seismograph. It is a record of the ground motion at a measuring station as a function of time. Seismograms typically record motions in three cartesian axes (x, y, and z), with the z axis perpendicular to the Earth’s surface and the x- and y- axes parallel to the surface.
How do you make a synthetic seismogram?
The basic process of creating a synthetic is simple (Figure 1) and described in many geophysical text books, however it is in the details that problems occur. Input density and sonic logs are multiplied together to obtain an impedance log. This a wavelet to obtain the synthetic seismogram.
How can I recomputed a synthetic seismic trace?
To improve the match with the seismic data, the synthetic seismic trace can be recomputed using different wavelets and filters. Figure 1 shows an example of a synthetic seismogram and associated well log data used in its generation. Different wavelets have been convolved to produce two additional synthetic seismogram displays.
What is a synthetic wavelet in seismic survey?
A wavelet is chosen that has a frequency response and band width similar to that of the nearby seismic data. The synthetic wavelet is convolved with the reflection series for the entire well survey and generates a synthetic seismic trace.
Are there any synthetic seismograms of the 2005 Kashmir earthquake?
The synthetic seismograms of the October 8, 2005 Kashmir earthquake (Mw 7.6) generated at the bedrock level using stochastic finite fault approach (Motazedian and Atkinson (2005)) of the four major towns of Anantnag, Baramulla, Kupwara and Srinagar ( Sana et al., 2019) are shown as Fig. 1.4.