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Collaborating Authors
- Geophysics > Seismic Surveying > Surface Seismic Acquisition (0.94)
- Geophysics > Seismic Surveying > Seismic Processing (0.91)
All based on 2D techniques The primary objective of collecting 3-I) data is to obtain Conventionally, all interpretation of 3-D seismic data is time structure and attribute (e.g.
Horizon-based curvature attributes have been used in seismic data interpretation for predicting fractures since 1994 when Lisle demonstrated the correlation of curvature values to fractures measured on an outcrop. Different measures of curvature (such as Gaussian, strike, and dip) have been shown by different workers to be highly correlated with fractures, and many more applications are also possible. By definition, all such applications need the interpretation of a seismic horizon, which may be simple if data quality is good and the horizon of interest corresponds to a prominent impedance contrast.
- Geophysics > Seismic Surveying > Surface Seismic Acquisition (1.00)
- Geophysics > Seismic Surveying > Seismic Interpretation (1.00)
Summary: It is difficult to identify minor fault using conventional seismic section interpretation technique, but the seismic attributions analysis technique is a valid method to resolve the problem. Only using one seismic attribution can not comprehensive image the geologic information, but we can find the minor faults by using the multivariate seismic attributions analysis technique. By the application of the technique in the coal seismic survey ,we interpret the minor fault with a fault throw within 2-3 meters, and result of the coal mining is shown the minor faults that we interpret by the technique is absolutely correct, so it is proved the technique is a valid method to interpret the minor fault. Introduction: Minor fault is very important in the coal mining, because the exist of the minor faults can make flooding accident, and the faults can make the coalbed broken, the fissures added , and then there will be the gas accumulate, all these factors will increase the seam mining risk. Faults also affect the design of roadway, and so on. One coal seismic survey in east of china has conducted two-dimensional three-dimensional seismic exploration and drilling job, the underground geological structure distribution and the faults with a fault throw greater than 5 meters have been clearly known on the whole, but minor faults with a fault throw less than 5 meter are not clearly. For comprehensive mechanization of mining and the need for safe production, the coal mine carried out highprecision seismic exploration test and research work to further identify the distribution of minor faults. Forward modeling Through high-precision seismic acquisition and processing, we obtained the high-density seismic data , and its sampling interval is 1ms, the surface element mesh are 5m * 5m. Through spectrum analysis of seismic data, we know the main reflective layer frequency is in around 50-60 hertz, figure 1. The depth of coal seam ranges from 630-1000 m and the scope of reflection time are approximately around 650-950ms. For this kind of seismic data and coal situation, we must first understand how the minor faults with a fault throw about 2 meter are reflected in the seismic section. Therefore, we applied the forward modeling techniques. We build up a geological model which has a minor fault. Separately, we use ray tracing and wave equation for forward modeling. The purpose of forward modeling is the focus of analysis the ability to distinguish minor faults by use of different frequency bands of the seismic reflection, which can guide minor fault identification in the actual seismic data interpretation. In figure 2, we use the technique of wave equation for forward modeling, the result show, the eye is almost impossible to identify the minor fault when the frequency is 25Hz, when the frequency is 50 hertz, there is only a weak deflection in the seismic reflection in the minor fault’s place. The deflection are more obvious when the frequency increased to 100 hertz, and we can more clearly identify the minor fault when the frequency up to 200 hertz.
- Geology > Structural Geology > Fault (1.00)
- Geology > Rock Type > Sedimentary Rock > Organic-Rich Rock > Coal (1.00)
- Geophysics > Seismic Surveying > Surface Seismic Acquisition (0.72)
- Geophysics > Seismic Surveying > Seismic Processing (0.59)
One application of this non-interpretive process Seismic data are traditionally acquired and processed results in a 3-D data volume, or "cube", of coherence for the purpose of imaging seismic reflections. This coefficients, within which faults are revealed as paper describes a method of processing seismic data numerically separated surfaces. Figures la and 1 b for the purpose of imaging seismic discontinuities compare a traditional 3-D reflection amplitude (U.S. and foreign patents pending, Bahorich and time-slice with the results obtained by applying the Farmer). Discontinuities include faults and stratigraphic new method to it.
- Geophysics > Seismic Surveying > Surface Seismic Acquisition (1.00)
- Geophysics > Seismic Surveying > Seismic Processing (1.00)
- Geophysics > Seismic Surveying > Seismic Interpretation (1.00)